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Appendix E. Literature Review: Glare Testing
Appendix E. Literature Review: Glare Testing Purpose In the evaluation of cataracts, glare testing attempts to quantify the degree of visual impairment caused by glare that results from the presence of opacities in the ocular media. The purpose of this literature review was to determine if glare testing provides valid and reliable information over and above the history and clinical examination regarding the patient's need for cataract surgery. The questions specified by the panel to be addressed in this review are detailed in the Results section.
Method The National Library of Medicine conducted a literature search for abstracts of articles published from January 1, 1975, through December 31, 1990, on three topics (glare, contrast sensitivity, and potential vision testing). (Chapter 2 and Appendix A give a detailed description of the search strategy.) A printout of potentially relevant references was produced. Additional articles were identified by reviewers and other interested parties. After the abstracts and additional articles listed on the printout were screened, 204 were selected for further review because they appeared relevant to the topics covered. A review of the 204 articles for ophthalmologic content was conducted by a group of eight individuals selected by Denis M. O'Day, MD, FACS, Arlo C. Terry, MD, and Anthony J. Adams, OD, PhD, for their known expertise in the areas under consideration. Because of the number of articles, the eight reviewers were grouped into three teams. The first team consisted of Arlo C. Terry, MD, Michael F. Marmor, MD, and Raymond A. Applegate, OD. The second team consisted of Anthony J. Adams, OD, and Douglas D. Koch, MD. The third team consisted of Gary S. Rubin, PhD, Ian L. Bailey, OD, and an ophthalmologist. Each team reviewed articles relating to contrast sensitivity, glare testing, and tests of potential vision. Prepared by Arlo C. Terry, MD; Martha S. Gerrity, MD, MPH; Denis M. O'Day, MD, FACS, Panel Chair; Kay Dickersin, PhD; Oliver D. Schein, MD, MPH; Gordon H. DeFriese, PhD; and Earl P. Steinberg, MD, MPP. Dr. Steinberg was methodology consultant to the panel, and the other authors comprised the literature review group.
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After masking each paper as to author, institution, journal, and date, Lea Gamble at the American Academy of Ophthalmology sent the papers to each member of the three teams so that one-third of the articles were reviewed independently by two reviewers and two-thirds were reviewed independently by three reviewers. Each of the reviewers received approximately equal numbers of studies on each of the three topics under consideration. A separate content evaluation form was developed by Oliver D. Schein, MD, MPH, Earl P. Steinberg, MD, MPP, and Neil R. Powe, MD, MPH, MBA, with input from Denis M. O'Day, MD, FACS, Arlo C. Terry, MD, and Gary S. Rubin, PhD, and used in the review of each article (Attachment E-1). Of the 204 articles reviewed, 16 did not address glare, contrast sensitivity, or potential acuity testing and were rejected. Of the remaining 188 articles, 37 dealt with glare testing and the other 151 were rejected. Nineteen of the 37 studies reviewed for content were rejected because they failed to meet the inclusion criteria set forth by the panel (Chapter 2). The total number of included articles was 18. Attachment E-2 at the end of this appendix summarizes the process used for selecting articles that were reviewed in detail. One additional article (Elliot, Hurst, and Weatherill, 1990) was added as a result of the peer review process, bringing the total number of included articles to 19. Each of the 19 papers that met the inclusion criteria was reviewed by two methodologists, Gordon H. DeFriese, PhD, and Martha S. Gerrity, MD, MPH, and any differences were reconciled through discussion. Methodologic evaluation was performed as suggested by Woolf (1990), and evidence tables were developed. (See Evidence Table E-1 at the end of this appendix.) The information abstracted for the table included the following categories: • Study identification. • Study design. • Number of patients. • Type of glare test. • Severity and type of cataract. • Type of comorbid ocular pathology. • Visual acuity without glare. • Data used as a "gold standard" for comparison with glare measurement (e.g., postoperative visual acuity).
Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults • Findings. • Comments.
occur across several studies are described in the Discussion section (below).
Methodologic Criteria
Results
The criteria listed below were then applied to each of the 19 papers. These criteria are based on widely accepted guidelines (or rules of evidence) for critically assessing studies that evaluate diagnostic tests (Cooper, Chalmers, McCally et al., 1988; Department of Clinical Epidemiology and Biostatistics, 1981; Fletcher, Fletcher, and Wagner, 1988; Griner, Panzer, and Greenland, 1986; Nierenberg and Feinstein, 1988; Sackett, Haynes, and Tugwell, 1991; White, McGahn, Daschbach et al., 1989). 1. Was the study design described clearly (e.g., comparisons that were made, selection of subjects, performance of the test)? 2. Was the test compared with an appropriate gold standard or outcome? 3. Were individuals interpreting the test and gold standard masked with regard to c}inical history or other test results? 4. Did the test correctly identify patients with and without the disease or outcome? In other words, were the following characteristics assessed appropriately? (If not, were the data presented in a manner that would allow these calculations?) • Sensitivity. • Specificity. • Positive and negative predictive values. • False positive and false negative rates. • Accuracy. 5. Was there an appropriate spectrum of disease among the patients tested (e.g., severity and type of cataract)? 6. Was the test reproducible (was intraobserver/interobserver variability measured)? 7. Was the contribution of the test to the overall diagnosis or prediction or an outcome assessed? Because few studies met criteria 3-6 and none met criterion 7, separate categories for these criteria were not added to Evidence Table E-1. Thus, of the preceding seven methodologic criteria, the only one addressed in Evidence Table E-1 is criterion 2 (i.e., what measure was used as the gold standard in evaluating patient outcomes). The Findings entry lists pertinent results from the study. When possible, the test characteristics, sensitivity (Se), specificity (Sp ), false positive rate (1-Sp ), and false negative rate ( 1-Se) are listed. The Comments entry provides specific methodologic comments regarding the validity of the results. Methodologic problems that
Thirty-seven studies on glare testing were reviewed by the content literature review team. Nineteen of these papers were excluded because they did not meet the inclusion/exclusion criteria set forth by the guideline panel. Most of the rejected articles were editorial or review articles or dealt only with the methodology of testing or the use of glare testing for other disease entities (e.g., corneal edema, radial keratotomy, opacified posterior capsule). The remaining 18 articles were reviewed for content and methodologic quality. It was realized during the review for methodologic quality that Maltzman, Horan, and Rengel (1988a) and Maltzman, Horan, and Rengel (1988b) reported identical data; therefore, Maltzman, Horan, and Rengel (1988b) was excluded. Also, Smith, Pratzer, Webster et al. (1987) and LeClaire, Nadler, Weiss et al. (1982) were excluded because they did not include preoperative or postoperative visual acuity data. Therefore, 15 articles were included in the panel's review. The results of the review of these articles are summarized in Evidence Table E-1. For the 15 studies reviewed, there was, in general, excellent agreement among content reviewers for items on the content evaluation form. In the few cases where there was disagreement, one of the reviewers changed his or her mind upon reevaluating the study in question, or a third content reviewer was asked to review the article and cast the deciding vote. The content evaluation forms contained several questions regarding methodology, such as type of study, sensitivity, and specificity. There was very poor agreement among content reviewers about the type of study population, and these questions were therefore referred to the methodology reviewers, with no attempt made to achieve consensus among content reviewers. With the one article added as a result of peer review, 16 was the new total of articles included in the panel's review. Neither glare tests nor testing procedures were standardized across studies. Three articles compared two or more glare tests against the same gold standard, either outdoor acuity (Neumann, McCarty, Locke et al., 1988; Prager, Urso, Holladay et al., 1989) or patients' glare complaints (Koch, 1989). In all three studies, results varied depending on which glare test was used, and there were substantial discrepancies between the results of the glare tests and the assessment based on the gold standard.
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None of the studies reported postoperative evaluations of functional visual impairment (e.g., whether the patients' complaints of glare resolved), which is considered the gold standard in this review for assessing visual impairment amenable to surgical correction. Three studies (Levin, 1989; Masket, 1989; Weiss, 1990) compared the results of glare testing with postoperative visual acuity. Two studies (Elliot, Hurst, and Weatherill, 1990; Koch, 1989) used preoperative glare complaints, and six (Hirsch, Nadler, and Miller, 1984; Holladay, Prager, Trujillo et al., 1987; Neumann, McCarty, Locke et al., 1988; Neumann, McCarty, Steedle et al., 1988a and 1988b; Prager, Urso, Holladay et al., 1989) used outdoor Snellen acuity as the gold standard. Five studies used indoor visual acuity or contrast sensitivity as the gold standard (Abrahamsson and Sjostrand, 1986; Elliot, Gilchrist, and Whitaker, 1989; Hard, Abrahamsson, and Sjostrand; 1990; Maltzman, Horan, and Rengel, 1988; Neumann, McCarty, Steedle et al., 1988a).
Question 1: Is there a correlation between the results of the test and the patient's level of functional impairment? One study (Elliott, Hurst, and Weatherill, 1990) examined whether there was a correlation between the results of glare testing and the patient's level of functional disability. This article described a case series of 33 patients with cataract in at least one eye and correlated glare scores with patient-reported functional disability. Glare disability was measured using a Mentor brightness acuity tester (BAT), which measured reduction in visual acuity due to glare (GDvA) and reduction in letter contrast sensitivity due to glare (GDc5). The BAT can take only monocular measurements, so all testing was done on the eye with the worse visual acuity. Functional disability was measured with a patient questionnaire of 20 questions. The questions were grouped into mutually exclusive categories pertaining to mobility, near vision, or discrimination. The correlation between the worse eye's GDvA and mobility was "not significant," although no correlation coefficient was provided. The correlations between the worse eye's GDvA and near vision and discrimination were 0.61 and 0.51, respectively. Only the correlation between the worse eye's GDcs and discrimination was provided (r=0.45) because the corresponding values for mobility and near vision were "not significant." The correlation between patient-reported functional disability related to near vision and discrimination was higher for worse eye glare disability than for visual acuity. One study (Koch, 1989) examined the correlation between the results of glare testing and patients'
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glare complaints. The correlations between the results of the Baylor visual function tester and glare complaints were 0.36 and 0.61, at low and high levels of glare, respectively. The correlation between the Stereo Optical Glare Tester and glare complaints was 0.68. The article did not specify the effect of glare on the patients' everyday activities and did not indicate how the glare complaints were measured. Six studies examined the association between the results of glare testing and outdoor visual acuity (Hirsch, Nadler, and Miller, 1984a; Holladay, Prager, Trujillo et al., 1987; Neumann, McCarty, Locke et al., 1988; Neumann, McCarty, Steedle et al., 1988a and 1988b; Prager, Urso, Holladay et al., 1989). The BAT was used in three of these studies (Holladay, Prager, Trujillo et al., 1987; Neumann, McCarty, Locke et al., 1988; Prager, Urso, Holladay et al., 1989). In one study (Holladay, Prager, Trujillo et al., 1987), normals showed no decrease in visual acuity caused by either the BAT or outdoor testing. For patients with cataract, the correlation between outdoor visual acuity and BAT was r=0.84. The BAT predicted outdoor acuity to within one line in 73 percent of the subjects in a second study (Neumann, McCarty, Locke et al., 1988) and overpredicted glare disability in 81 percent of subjects at the high setting and 42 percent at the medium setting in a third study (Prager, Urso, Holladay et al., 1989). In one article (Hirsch, Nadler, and Miller, 1984a), the correlation between the results of glare testing (using author's device) and outdoor acuity was better for those facing the sun than those not facing the sun, both for subjects with and without cataracts. In another (Neumann, McCarty, Steedle et al., 1988a), Snellen visual acuity was decreased by two lines in 70 percent of subjects when they faced the sun. A third study (Neumann, McCarty, Steedle et al., 1988b) found that the Miller-Nadler glare tester predicted outdoor acuity within one line for 47 percent of all eyes in the study. Two other studies relate to this question. One study (Maltzman, Horan, and Rengel, 1988a) compared visual acuity with and without penlight glare in 114 cataract patients. All patients with nonglare visual acuities of 20/40 or worse also saw 20/40 or worse with penlight glare. Forty-five percent of patients with nonglare visual acuities of 20/40 or better (sic) had an acuity of 20/40 or worse with penlight glare. Another study (Hard, Abrahamsson, and Sjostrand, 1990) found decreased visual acuity and contrast sensitivity in the presence of glare. The decreased contrast sensitivity was independent of visual acuity. Three studies (Neumann, McCarty, Locke et al., 1988; Neumann, McCarty, Steedle et al., 1988b;
Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults Prager, Urso, Holladay et al., 1989) examined the correlation between the results of glare testing and visual acuity by the type of glare test used. One study (Neumann, McCarty, Locke et al., 1988) found that the correlation varied depending on the glare test used. Outdoor visual acuity was predicted to within one line in 73 percent of the eyes for BAT, 69 percent for True Vision Analyzer (TV A), 56 percent for VisTech, 47 percent for Miller-Nadler, and 15 percent for EyeCon tests, where all tested eyes had been diagnosed with cataract. The same results were reported in a second article (Neumann, McCarty, Steedle et al., 1988b), perhaps on the same patients, for the Miller-Nadler test alone. (It predicted outdoor visual acuity to within one line in 47 percent of the eyes.) The authors also provided information regarding the cataract type and the ability to predict outdoor acuity (see below); however, a third study (Prager, Urso, Holladay et al., 1989) found that in eyes with cataract, accuracy to within one line occurred in 36 percent of eyes for Miller-Nadler, 17 percent of eyes for high luminance BAT, and 45 percent for medium luminance BAT. The MillerNadler test tended to underestimate glare disability (as measured by outdoor visual acuity) in 62 percent of the eyes, and the BAT overpredicted in 81 percent of eyes at high settings and 42 percent at medium settings. This study also found significant interobserver variability in glare test results. In terms of correlation between glare test and visual acuity for specific types of cataract, one study (Elliott, Gilchrist, and Whitaker, 1989) showed high correlations for cortical (r=l.O) and nuclear (r=0.77) cataract but not for posterior subcapsular (PSC) (r=0.12). A second study (Neumann, McCarty, Steedle et al., 1988b) demonstrated that the MillerNadler test predicted outdoor acuity to within one line in 50 percent of eyes with nuclear cataract, 40 percent with nuclear plus PSC, and 52 percent with other cataracts. A third study (Abrahamsson and Sjostrand, 1986) found a weak correlation between glare score and visual acuity in subjects with PSC cataracts or normal eyes. Thus, glare scores have the lowest correlation with visual acuity in patients with PSC cataract. Therefore, the test may be of greatest value in these patients.
Question 2: Is there information on the type or degree of functional impairment detected by the test that is not detected by history and routine physical examination alone? No article provided information on the type or degree of functional impairment detected by glare testing that was not detected by history and physical examination alone.
Question 3: Is there evidence to support the value of the test in detecting cases that are not suitable for surgery? No article provided information supporting the value of glare testing in detecting cases suitable for surgery. See the discussion of Koch (1989) under question 1 and the preceding paragraphs in the Results section discussing the importance of the gold standard in the description of the table. Question 4: Is there evidence to identify a relationship between the use of the test and the timing of surgery? Question 5: Is there evidence to identify a relationship between the use of the test and the volume of surgery performed annually by the ophthalmologist ordering the test? Question 6: Is there information on costs and/or cost-benefit issues? No articles were found addressing these questions. Question 7: What is the relationship between preoperative test results and postoperative test results in patients in whom no intraoperative or postoperative complication occurred? Three studies addressed the relationship between preoperative and postoperative glare test results (Levin, 1989; Masket, 1989; Weiss, 1990), and all three showed an improvement between preoperative and postoperative scores related to cataract surgery. In one study (Weiss, 1990), mean decimal acuity in conditions of glare improved from 0.06 preoperatively to 0.22 postoperatively. Mean MillerNadler glare scores improved from 55.2 percent preoperatively to 7.6 percent postoperatively in a second study (Masket, 1989), and from 15 percent preoperatively to 10 percent postoperatively, using TVA, in a third study (Levin, 1989). None of these studies examined the correlation between glare scores and functional impairment. Although the studies demonstrated that subjects' scores on the glare test improved after surgery, they do not provide evidence that the patients' complaints of glare or their functional impairment also improved. Thus, no study demonstrated that patients' complaints of impairment due to glare were accurately detected by the glare tester and that both the complaints and glare scores improved after surgery. Two studies (Hard, Abrahamsson, and Sjostrand, 1990; Hirsch, Nadler, and Miller, 1984b) examined the test-retest reliability of glare testing. One (Hirsch, Nadler, and Miller, 1984b) showed an excellent correlation between first and subsequent glare tests when the test was performed on patients with cataract (r=0.95), but the correlation was not as good when patients were aphakic (r=0.54) or had normal 1375
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vision (r=0.06). A second study (Hard, Abrahamsson, and Sjostrand, 1990) examined test-retest reliability for letter contrast sensitivity with and without glare in patients with cataract and found the reliability to be very good (r=0.83 without glare; r=0.92 with glare).
Discussion The studies reviewed were very heterogeneous. The number of studies with comparable study designs, definitions of the research problem, and presentation of results was extremely small. Few of the studies gave adequate information about the instruments used, the manner in which they were employed, or the characteristics of patients tested. A variety of instruments were used, and there was inadequate attention to control of background lighting, glare source, and target configurations, all of which could affect the measurement of the criterion indicators. In general, the reviewers had difficulty extracting information from the papers because the study designs and results were not clearly described. In particular, it was often difficult to know exactly how the patients were selected and which patients were included and excluded in the tables and statistical analyses. The characteristics of the patients in the study, and in the individual analyses, may significantly bias the results (Ransohoff and Feinstein, 1978). A study design with inclusion and exclusion criteria applied to consecutive subjects would make it easier to determine if there are biases and how the biases might affect the validity and applicability of the results. The use of a standard study design and format for presenting the results (Department of Clinical Epidemiology and Biostatistics, 1981; Fletcher, Fletcher, and Wagner, 1988; Sackett, Haynes, and Tugwell, 1991) would also make it easier to determine if there are biases and how they might affect the validity and applicability of results. Most of the studies set out to establish the validity of glare testing as a test of visual function. Typically, Snellen visual acuity test results with and without a source of glare were compared. Some tests refined this further by comparing the correlation between glare test results and Snellen visual acuity for different types of testing devices or specific types of cataract. Preoperative comparisons between glare tests and the conventional Snellen tests by themselves are not sufficient to evaluate the clinical utility of glare testing, primarily because a comparison between the two does not allow a valid assessment of the new test. To determine the utility of glare testing in
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deciding whether or not to perform cataract surgery, the best approach is to compare the patients' preoperative vs. postoperative visual acuity and visual complaints (impairment in everyday activities due to vision) to their preoperative vs. postoperative glare test results. The measurements needed for all patients in a single study include ( 1) preoperative and postoperative glare test results and (2) preoperative and postoperative visual acuity and visual complaints. Few of these studies had adequate control or comparison groups. None of the studies masked the individuals interpreting the glare test result and gold standard (e.g., outdoor Snellen acuity) or postoperative outcome (e.g., glare test score). Knowledge of the glare test result could bias the interpretation of the gold standard, and vice versa (Department of Clinical Epidemiology and Biostatistics, 1981; Fletcher, Fletcher, and Wagner, 1988; Ransohoff and Feinstein, 1978; Sackett, Haynes, and Tugwell, 1991). Individuals performing the glare test should not know the results of the gold standard test, and vice versa. In the test-retest reliability studies (Hard, Abrahamsson, and Sjostrand, 1990; Hirsch, Nadler, and Miller, 1984b), this is particularly important. In neither study were the individuals performing the test masked to prior test results. Without masking, these correlations may be artificially inflated because knowledge of a prior test result might influence the interpretation of a test. Often the reader could not determine the spectrum of disease (type and severity of cataracts) among patients enrolled in a study. This limitation makes it diffictllt to assess the external validity (i.e., generalizability) of the study results. In addition, in some studies it is difficult to assess what criteria or factors determined whether a particular patient was or was not enrolled in the study, making it difficult to evaluate the internal validity of the study conclusions. One study (Koch, 1989) found a moderate correlation between the results of glare testing and patients' visual complaints. The article did not specify the impact of glare on the patients' everyday activities and did not indicate how the glare complaints were measured. In addition, the method used to select patients for enrollment in the study may have led to compromise of the internal validity of (i.e., bias in) the study results. Even so, there was a high (20-50 percent) false positive rate in the glare test results, thus limiting the clinical value of the test. One study (Elliott, Hurst, and Weatherill, 1990) reported a moderate correlation between GDvA and
Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults GDcs and discrimination in the worse eye, and GDvA and near vision in the worse eye. These data are the only information currently available with regard to the association between glare disability scores and patient-reported functional disability. The authors suggested that glare disability test scores provide information about cataract beyond that provided by visual acuity alone. This study has several limitations, however. First, no confidence intervals around the correlation coefficients were provided, nor were statistical tests performed to determine whether the differences in magnitude of correlations (e.g., those for glare vs. those for visual acuity) were statistically significant. Second, one cannot determine from the data whether the differences in the correlation coefficients are "clinically significant," even if they are statistically significant. Specifically, it is not possible to determine from the data whether the glare test is abnormal in patients with visionrelated dysfunction who do not have abnormal visual acuity. Thus, one cannot determine from these data whether the glare test is detecting patients with vision-related functional disability who are not detected by abnormal visual acuity. Third, there are no postoperative data. One study (Hirsch, Nadler, and Miller, 1984b) assessed the reproducibility (test-retest reliability) of glare measurements and found that they varied widely: r=0.06 for normal eyes, r=0.95 for cataract eyes, and r=0.54 for aphakic eyes. A second study (Hard, Abrahamsson, and Sjostrand, 1990) found very good test reliability in patients with cataract (r=0.92). Usually, test reliabilities were in the 0.8 to 0.9 range. On the basis of these two studies, testretest reliability appears to be very good for patients with cataract. The situations in which glare testing would be recommended or required are not clear. No studies assessed whether glare testing provided information over and above the usual clinical evaluation (history, Snellen acuity, examination of the eye) or determined how the glare test contributed to the overall diagnosis or prediction of a surgical outcome. For patients with PSC, however, there are some data that glare testing may provide additional clinically relevant information, even when Snellen visual acuity is good. Sixteen studies provided useful information for researchers in this field and used methods appropriate for exploratory or basic science research. However, they did not meet the methodologic criteria necessary for establishing the clinical utility of glare testing in the preoperative evaluation of the cataract patient.
Only 5 of the 16 studies (Elliott, Hurst, and Weatherill, 1990; Koch, 1989; Levin, 1989; Masket, 1989; Weiss, 1990) provided information pertinent to the clinical questions posed for this literature review. These studies found either a fair correlation between glare score and patient complaint of glare (Koch, 1989) or functional disability (Elliott, Hurst, and Weatherill, 1990) or an improvement in glare scores postoperatively (Levin, 1989; Masket, 1989; Weiss, 1990). Although one study (Elliott, Hurst, and Weatherill, 1990) found a higher correlation between glare test results and certain types of functional disability than between visual acuity and the same functional disabilities, it is not clear that the correlations with glare test results in the study were significantly different, clinically or statistically, from the correlations with visual acuity. Thus, although these studies are pertinent, they do not resolve the issue of the clinical utility of glare testing. In addition, the studies have a variety of methodologic flaws, as described above and as noted in Evidence Table E-1, which limit the conclusions that can be drawn from them.
Conclusions Glare test results have a high rate of reproducibility in patients with cataract. One study (Elliott, Hurst, and Weatherill, 1990) reported a higher correlation between the results of glare testing and near vision and discrimination in the worse eye than between visual acuity and the same functional disabilities. However, because of limitations of this study, it is not possible to determine the clinical significance of this difference. In addition, no data were reported regarding the impact of cataract surgery on patient-reported functional disability and what, if any, changes occurred concomitantly in the glare disability test results. The correlation between glare test results and patient complaints of glare may depend on the type of test used and may vary with the type of cataract. The high correlation of glare scores with visual acuity for patients with cortical and nuclear cataracts suggests that glare testing likely provides little information beyond what is obtained by performing Snellen visual acuity. For patients with PSC, however, the correlation is low, indicating that glare testing may be providing more useful information. Studies have shown an improvement in glare scores after cataract surgery but have not provided any data regarding corresponding improvement in functional impairment.
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References In addition to the articles on the literature review lists for glare testing, the following references are cited in this appendix: Cooper LS, Chalmers TC, McCally M, Berrier J, Sacks HS. The poor quality of early evaluations of magnetic resonance imaging. JAMA 1988 Jun 10;259(22):3277-80. Department of Clinical Epidemiology and Biostatistics (McMaster University). How to read clinical journals: II. To learn about a diagnostic test. Can Med Assoc J 1981 Mar 15; 124(6):703-10. Fletcher RH, Fletcher SW, Wagner EH. Clinical epidemiology: the essentials. 2d ed. Baltimore: Williams & Wilkins; 1988. Griner PF, Panzer RJ, Greenland P. Clinical diagnosis and the laboratory: logical strategies for common medical problems. Chicago: Year Book Medical Publishers; 1986. Nierenberg AA, Feinstein AR. How to evaluate a diagnostic marker test. Lessons from the rise and fall of dexamethasone suppression test. JAMA 1988 Mar 18;259(11): 1699-702. Ransohoff DF, Feinstein AR. Problems of spectrum and bias in evaluating the efficacy of diagnostic tests. N Engl J Med 1978 Oct 26;299(17):926-30. Sackett DL, Haynes RB, Tugwell P. Clinical epidemiology: a basic science for clinical medicine. 2d ed. Boston: Little, Brown; 1991. White RH, McGahan JP, Daschbach MM, Hartling RP. Diagnosis of deep-vein thrombosis using duplex ultrasound. Ann Intern Med 1989 Aug 15; 111(4):297-304. Comment. In: Ann Intern Med 1990 Feb 15;112(4):307-8. Woolf SH. Interim manual on clinical practice guideline development. Rockville (MD): Agency for Health Care Policy and Research; 1990.
Literature Review Lists Literature Included This list comprises the 16 included articles that were found to be relevant and were further reviewed for content and methodologic rigor. Abrahamsson M, Sjostrand J. Impairment of contrast sensitivity function (CSF) as a measure of disability glare. Invest Ophthalmol Vis Sci 1986 Jul;27(7):1131-6. Elliott DB, Gilchrist J, Whitaker D. Contrast sensitivity and glare sensitivity changes with three types of cataract morphology: are these techniques necessary in a clinical evaluation of cataract? Ophthalmic Physiol Opt 1989 Jan;9(1):25-30. Elliott DB, Hurst MA, Weatherill J. Comparing clinical tests of visual function in cataract with the patient's perceived visual disability. Eye 1990;4(Pt 5):712-7. Hard AL, Abrahamsson M, Sjostrand J. A new glare test based on low contrast letters--evaluation in cataract
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patients. Acta Ophthalmol (Copenh) 1990 Apr;68(2): 14550. Hirsch RP, Nadler MP, Miller D. Glare measurement as a predictor of outdoor vision among cataract patients. Ann Ophthalmol 1984a Oct;16(10):965-8. Hirsch RP, Nadler MP, Miller D. Clinical performance of a disability glare tester. Arch Ophthalmol 1984b Nov; 102(11): 1633-6. Holladay JT, Prager TC, Trujillo J, Ruiz RS. Brightness acuity test and outdoor visual acuity in cataract patients. J Cataract Refract Surg 1987 Jan;13(1):67-9. Koch DD. Glare and contrast sensitivity testing in cataract patients. J Cataract Refract Surg 1989 Mar;15(2):158-64. Levin ML. Opalescent nuclear cataract. J Cataract Refract Surg 1989 Sep;15(5):576-9. Maltzman BA, Horan C, Rengel A. Penlight test for glare disability of cataracts. Ophthalmic Surg 1988a May; 19(5):356-8. Masket S. Reversal of glare disability after cataract surgery. J Cataract Refract Surg 1989 Mar;15:165-8. Neumann AC, McCarty GR, Locke J, Cobb B. Glare disability devices for cataractous eyes: a consumer's guide. J Cataract Refract Surg 1988 Mar;14(2):212-6. Neumann AC, McCarty GR, Steedle TO, Sanders DR, Raanan MG. The relationship between indoor and outdoor Snellen visual acuity in cataract patients. J Cataract Refract Surg 1988a Jan;l4(1):35-9. Neumann AC, McCarty GR, Steedle TO, Sanders DR, Raanan MG. The relationship between cataract type and glare disability as measured by the Miller-Nadler glare tester. J Cataract Refract Surg 1988b Jan;14(1):40-5. Prager TC, Urso RG, Holladay IT, Stewart RH. Glare testing in cataract patients: instrument evaluation and identification of sources of methodological error. J Cataract Refract Surg 1989 Mar;15(2):149-57. Weiss JF. Glare and mesopic vision before and after cataract surgery. J Cataract Refract Surg 1990 Jan;l6(1):88-91.
Literature Excluded This list comprises the 22 excluded articles rejected because they did not meet the inclusion criteria or provided duplicate data. American Academy of Ophthalmology. Ophthalmic Procedures Assessment. Contrast sensitivity and glare testing in the evaluation of anterior segment disease. Ophthalmology 1990 Sep;97(9): 1233-7. Applegate RA, Trick LR, Meade DL, Hartstein J. Radial keratotomy increases the effects of disability glare: initial results. Ann Ophthalmol 1987 Aug;19(8):293-7. Hoffer KJ. Preoperative evaluation of the cataractous patient. Surv Ophthalmol 1984 Jul-Aug;29(1):55-69. Jaffe NS. Glare and contrast: indications for cataract surgery. J Cataract Refract Surg 1986 Jul;12(4):372-5.
Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults Knighton RW, Slomovic AR, Parrish RK 2d. Glare measurements before and after neodymium-YAG laser posterior capsulotomy. Am J Ophthalmol 1985 Nov 15; 100(5):708-13. Koch DD. The role of glare testing in managing the cataract patient. Focal points 1988: clinical modules for ophthalmologists. Vol. 6, Module 4, American Academy of Ophthalmology; 1988. LeClaire J, Nadler MP, Weiss S, Miller D. A new glare tester for clinical testing. Results comparing normal subjects and variously corrected aphakic patients. Arch Ophthalmol1982 Jan;100(1):153-8. Lin S, Reiter K, Dreher AW, Frucht-Pery J, Feldman ST. The effect of pterygia on contrast sensitivity and glare disability. Am J Ophthalmol 1989 Apr 15;107(4):407-10. Maltzman BA, Horan C, Rengel A. Penlight test for glare disability of cataracts. J Ophthalmic Nurs Technol 1988b Jul-Aug;7(4):137-9. Markow SA. Penlight glare test [letter]. Ophthalmic Surg 1988 Sep;19(9):678. Marron JA, Bailey IL. Visual factors and orientationmobility performance. Am J Optom Physiol Opt 1982 May;59(5):413-26. Miller D, Jernigan ME, Molnar S, WolfE, Newman J. Laboratory evaluation of a clinical glare tester. Arch Ophthalmol 1972 Mar;87(3):324-32. Nadler DJ, Jaffe NS, Clayman HM, Jaffe MS, Luscombe SM. Glare disability in eyes with intraocular lenses. Am J Ophthalmol 1984 Jan;97(1):43-7.
Paulsson LE, Sjostrand J. Contrast sensitivity in the presence of a glare light. Theoretical concepts and preliminary clinical studies. Invest Ophthalmol Vis Sci 1980 Apr;19(4):40l-6. Prager TC, Urso RG, Lewis JW, Ruiz RS. Methodological considerations in glare testing in patients with cataract [letter]. Arch Ophthalmol 1988 Nov;106(l1):1501-2. Pulling NH, WolfE, Sturgis SP, Vaillancourt DR, Dolliver JJ. Headlight glare resistance and driver age. Hum Factors 1980 Feb;22(l):103-12. Roper-Hall MJ. Rayner lecture 1984. Sophistication in intraocular lens surgery. Trans Ophthalmol Soc U K 1985; 104(Pt 5):500-6. Sjostrand J, Abrahamsson M, Hard AL. Glare disability as a cause of deterioration of vision in cataract patients. Acta Ophthalmol Suppl (Copenh) 1987;182:103-6. Smith PW, Pratzer KA, Webster N, Fenton J, Bonham RD. A clinical comparison of two methods of glare testing. Ophthalmic Surg 1987 Sep; 18(9):680-2. Soper JW. Autobiographical pictorial study of a cataract in progress. J Cataract Refract Surg 1986 May;12(3):303-5. Terry CM, Brown PK. Clinical measurement of glare effect in cataract patients. Ann Ophthalmol 1989 May;21(5):183-7. Wolf E. Glare and age. Arch Ophthalmol 1960 Oct;64(4):502-14.
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Evidence Table E-1. Literature Review Evidence: Glare Testing Reference: Holladay, Prager, Trujillo et al., 1987. Study Design: Case series. Patients: 64 patients (14 normal, 50 cataract). Type of Glare Test: Brightness acuity tester. Severity and Type of Cataract: Not given. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: Not given. Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor VA (5,358 to 13,198 ft. candles). Findings: No decrease in VA with the BAT or outdoor testing in normals. For cataract subjects, correlation between BAT and outdoor VA was r=0.84. Cataract patients had a 1- to 10-line reduction in VA. Comments: No information regarding type/severity of cataract, complaints of glare, or sensitivity/specificity. No test-retest data given although abstract claims BAT reliable. Reference: Hirsch, Nadler, and Miller, 1984a. Study Design: Consecutive case series. Patients: 52 cataract patients (84 eyes), 48 normal patients (81 eyes). Type of Glare Test: Author's device. Severity and Type of Cataract: Not given. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: Mean = 20/48; range = 20/20 to 20/60. Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor VA (~2,000 ft. candles). Findings: For cataract patients, correlation between glare scores and outdoor VA better for individuals facing sun (r2=0.64) than those not facing sun (r=0.36). For normals, glare scores were "highly predictive" of outdoor acuity (r2 not given). Comments: Data difficult to decipher. Methods not standardized. Sun glare not standardized for glare test measurement. Reference: Hirsch, Nadler, and Miller, 1984b. Study Design: Case series. Patients: 3 studies: N=46 (test-retest); N=5 (effect of refractive error on glare); N=126 (effect of contrast on glare). Type of Glare Test: Described. Severity and Type of Cataract: N=46 (13 normal eyes, 23 cataract eyes, 27 aphakic eyes). N=126 (35 normal; 94 cataract; 57 aphakic eyes). Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: N/A. Postoperative Visual Acuity or "Gold Standard": Gold standard: N/A. Findings: Test-retest reliability varies with eye status: r=0.06, normal; r=0.95, cataract; r=0.54, aphakic. Glare scores change up to 5% with refractive error, and contrast sensitivity accounts for 10% of the variance in glare scores. Comments: Reliability is highest in patients with cataract. Reference: Hard, Abrahamsson, and Sjostrand, 1990. Study Design: Case series. Patients: N=16; 10 cataract patients who had glare problems, 3 normal, 3 others. Type of Glare Test: Described. Severity and Type of Cataract: • Severity: not given. • Type: nuclear, cortical, and PSC. Type of Comorbid Ocular Pathology: None in cataract subjects. Visual Acuity Without Glare: Better than 20/70. Postoperative Visual Acuity or "Gold Standard": Gold standard: letter CS (without glare). Findings: Test-retest reliability for: letter CS r=0.83, letter CS with glare r=0.92, VA r=0.89. With glare, cataract patients had a decreased letter CS independent of VA. Comments: Tables and graphs difficult to interpret. Test-retest reliability good under conditions specified. However, study design would be stronger if individuals performing the test were masked. Reference: Elliott, Gilchrist, and Whitaker, 1989. Study Design: Case series. Patients: 18 subjects (39 eyes) with cataracts, 16 subjects (16 eyes) normal. Type of Glare Test: • Contrast sensitivity described, not named. • Glare described, not named. Severity and Type of Cataract: • Severity: graded 1-5 scale (Oxford cataract classification and grading system). • Type: nuclear, cortical, subcapsular. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: LogMar VA: 0.12 to 0.50. Postoperative Visual Acuity or "Gold Standard": Gold standard: LogMar VA. Findings: 1) High correlations between glare sensitivity and Log Mar VA for cortical (r=1.0) and nuclear (r=0.77), but not PSC (r=0.12) cataracts. 2) Moderate to high (r=0.44 to 1.0) correlations between CS and LogMar VA at ~2 c/deg (r=0.44 to 1.0). Comments: Correlation coefficients may not be precise because of small numbers in each subgroup. Study results vary considerably with the type of cataract.
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Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults Reference: Abrahamsson and Sjostrand, 1986. Study Design: Case series. Patients: 18 normals, 34 subjects with PSG. Type of Glare Test: Described. Severity and Type of Cataract: • Severity: 0 to 100% opacification. • Type: PSG only. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: 20/20 to 20/200 (by figure). Postoperative Visual Acuity or "Gold Standard": Gold standard: visual acuity. Findings: Weak correlation between glare score and visual acuity, with a trend of increasing glare relating to decreasing VA (r not given). Comments: 2 methods used to calculate glare scores gave different results. The average discrepancy in threshold contrast was used because of a "high reproducibility" of results, but no test-retest data were given. Reference: Maltzman, Horan, and Rengel, 1988a. Study Design: Case series. Patients: 114 eyes cataract, 20 eyes normal. Type of Glare Test: Penlight. Severity and Type of Cataract: • Severity: VA better than 20/200. • Type: not given. Type of Comorbid Ocular Pathology: None. Visual Acuity Without Glare: Better than 20/200. Postoperative Visual Acuity or "Gold Standard": Gold standard: Snellen acuity. Findings: Out of 40 eyes with VA 20/40 or better, 22 (55%) did not change with penlight and 2 (5%) had VA of 20/200. 16 of 22 eyes with VA of 20/50 had VA of 20/200 or worse with penlight. Comments: No mention was made of patients with glare complaints. Unclear whether patients with VA of 20/200 with the penlight complained of glare. Without an assessment of patients' functional disability and/or postop outcomes, these data do not directly address the ability of the penlight test to predict who will benefit from surgery. Reference: Neumann, McCarty, Locke et al., 1988. Study Design: Case series. Patients: 48 cataract eyes. Type of Glare Test: 1) Miller-Nadler. 2) Brightness acuity tester. 3) lnnoMed true vision analyzer. 4) Vis Tech VCT8000. 5) EyeCon 5. Severity and Type of Cataract: Not given. Type of Comorbid Ocular Pathology: None. Visual Acuity Without Glare: Not given. Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor Snellen acuity. Findings: The tests predicted outdoor acuity to within 1-line accuracy in 73% for BAT, 69% for TVA, 56% for VisTech, 47% for MillerNadler, and 15% for EyeCon. False positive and negative rates provided in the article. Comments: Study highlights the problem of variability in glare tester's ability to predict outdoor acuity. Reference: Koch, 1989. Study Design: Case series. Patients: 41 cataract subjects with VA 20/60 or better and complained of glare. 10 patients without glare. Type of Glare Test: 1) Miller-Nadler glare tester; 2) Baylor visual function tester; 3) Stereo Optical glare tester; 4) Vistech vision contrast test system. Severity and Type of Cataract: • Severity: acuity 20/60 or better. • Type: PSG, nuclear. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: 20/60 or better. Postoperative Visual Acuity or "Gold Standard": Gold standard: 1) glare complaint; 2) severity and type of cataract. Findings: Correlation between the 3 glare testers and patients' complaints ranged from r=0.39 to r=0.68. False positive rates (1-Sp) were 20% to 50% and false negative rates (1-Se) were 2% to 15%. Comments: Selection of patients (only those able to compare their complaints with the glare testing formats) may bias the results and make the tests look better than they are (especially the correlations and false negative rates). With only moderate correlations with patients' complaints and a high false positive rate, these tests have questionable clinical utility. Reference: Neumann, McCarty, Steedle et al., 1988b. Study Design: Case series. Patients: 78 patients (92 eyes with cataract and glare scores between 10% and 80%). Type of Glare Test: Miller-Nadler glare tester. Severity and Type of Cataract: • Severity: VA 20/20 to 20/300. • Type: pure nuclear, nuclear PSG, and other. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: 20/20 to 20/300 (81 eyes had VA 20/20 to 20/40 indoors and 33 had VA 20/20 to 20/40 outdoors). Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor VA (8,000 to 11 ,900 ft. candles). Findings: The Miller-Nadler predicted outdoor acuity was within 1 Snellen line of actual outdoor acuity for 47% of the eyes overall. For the 3 categories of cataract type, this percent ranged from 50% (nuclear), to 40% (nuclear and PSG), to 52% (other). Comments: Predictions of outdoor acuity (within 1 line) are poor for all 3 types of cataract. No assessments of patients' complaints of glare and/or postoperative outcomes. As a result, this study does not directly address value of the test for preoperative decisionmaking.
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Reference: Neumann, McCarty, Steedle et al., 1988a. Study Design: Case series. Patients: 78 subjects (106 cataractous eyes). Type of Glare Test: Indoor Snellen acuity. Severity and Type of Cataract: • Severity: VA 20/20 to 20/300. • Type: nuclear, nuclear and PSC, other. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: 20/20 to 20/300 (81 eyes had VA 20/20 to 20/40 indoors and 33 had VA 20/20 to 20/40 outdoors). Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor VA (8,000 to 11,900 ft. candles). Findings: 74 (70%) of eyes had outdoor VA~ 2 Snellen lines worse than indoor VA and 23 (22%) had outdoor VA~ 5 lines worse. Comments: Authors compared indoor and outdoor Snellen acuity. There was no assessment of subjects' complaints of visual impairment or glare. Many of the eyes had VA of 20/40 or better indoors (76%) and outdoors (31%). Reference: Prager, Ursa, Holladay et al., 1989. Study Design: Case series. Patients: 51 normal subjects/eyes; 47 cataractous subjects/eyes. Type of Glare Test: 1) Miller-Nadler glare tester; 2) brightness acuity tester. Severity and Type of Cataract: • Severity: "minimal." • Type: not given. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: Mean for controls 20/20 (±2.11 SD); cataracts 20/43 (±18 SD). Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor VA. Findings: 1) Normal eyes had a mean VA of 20/20 indoors, outdoors, and with BAT. Miller-Nadler gave a VA mean of 20/24. 2) For cataract eyes, mean outdoor acuity was 20/45 (±17 SD). BAT overpredicted glare disability in 81% at high and 42% at medium settings. Miller-Nadler underpredicted in 62%. Comments: 1) Randomization of indoor vs. outdoor testing and order of each instrument makes this a strong study design. It decreases the bias of a "carryover" or "training" effect from one test or setting to the other. 2) Use of only one eye from each patient is also a strength of this study. 3) Study demonstrates significant variability among glare testers. Reference: Weiss, 1990. Study Design: Case series. Patients: 74 patients (118 eyes). Type of Glare Test: 1) Glare situation described. 2) Mesopic vision situation described. Severity and Type of Cataract: • Severity: VA 20/46 to 20/154. • Type: not given. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: 20/46 to 20/154. Postoperative Visual Acuity or "Gold Standard": Postop vision: 20/22 to 20/42. Findings: Statistically significant improvements occurred for all 3 acuity measures postop: standard Iandoit (0.28 preop vs. 0.69 postop), glare (0.06 vs. 0.22), and mesopic (0.11 vs. 0.34). Comments: Comparisons were not made between preop glare (or mesopic vision) and postop Snellen acuity. Patients' complaints of glare were not given for preop and postop periods. Reference: Masket, 1989. Study Design: Case series. Patients: 26 patients (30 eyes) with uncomplicated cataract surgery and postop acuity 20/20. Type of Glare Test: Miller-Nadler. Severity and Type of Cataract: • Severity: VA 20/30 to HM. • Type: nuclear, PSC, cortical. Type of Comorbid Ocular Pathology: None. Visual Acuity Without Glare: 20/30 to HM (mean 20/122). Postoperative Visual Acuity or "Gold Standard": Postoperative VA: 20/20. Findings: Mean glare score preop (55.2%, range 25% to 80%) was significantly different from postop mean (7.6%, range 2.5% to 15%). Comments: 1) Selecting patients based on good surgical outcome (VA 20/20) may have biased results and limits generalizability of findings to the typical preoperative situation. 2) Glare scores improved after cataract removal. No indication as to whether patients had glare symptoms and if these resolved postop. 3) Technician performing the glare testing was masked, making this a stronger study design. Reference: Elliott, Hurst, and Weatherill, 1990. Study Design: Case series (cross-sectional). Patients: 33 patients with cataract in at least 1 eye. Type of Glare Test: Mentor brightness acuity meter: 1) reduction in VA (GDvA); 2) reduction in CS (GDc 8 ). Severity and Type of Cataract: VA range = 6/4 to 6/36. Type of Comorbid Ocular Pathology: Exclude patients with high intraocular pressure, retinal disease, refractive error >± 6.00, amblyopia, monophakia, abnormal neural function, poor general health. Visual Acuity Without Glare: N/A. Postoperative Visual Acuity or "Gold Standard": N/A. Findings: Patients also completed questionnaire on vision-related functional disability. • Correlation (r) = 0.61 between worse eye GDvA and near vision and r = 0.57 between worse eye GDvA and discrimination. • r = 0.45 between worse eye GDcs and discrimination. These correlations were slightly higher than those between VA and the same functional disabilities (r = 0.46 and 0.41, respectively). Comments: Moderately strong association between GDvA and near vision and between GDvA and GDcs and discrimination. • No statistical test performed to determine whether the differences in magnitude of correlations are statistically significant (e.g., between glare/functional disability vs. VA/functional disability). • Cannot determine if differences in the correlation coefficients are clinically significant even if they are statistically significant. • There are no postop data. • No data (scatter plots) or confidence intervals provided, just p values; so difficult to assess validity of analysis conclusions.
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Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults Reference: Levin, 1989. Study Design: Case series. Patients: 38 patients, good VA and with other visual symptoms. Type of Glare Test: lnnomed TVA-glare mode. Severity and Type of Cataract: • Severity: VA 20/25 to 20/70. • Type: opalescent nuclear. Type of Comorbid Ocular Pathology: None. Visual Acuity Without Glare: 20/25 to 20/70. Postoperative Visual Acuity or "Gold Standard": Postop VA: 20/15 to 20/30. Findings: Preop contrast sensitivity (15%, glare mode) ranged from 20/80 to 20/2000. Postop CS (10% glare mode) ranged from 20/15 to 20/70 for all 38 patients. Comments: 1) No report of whether patients' visual symptoms resolved postop. 2) All 38 patients had mild cataracts and no other ocular pathology, making it difficult to apply the results to a broader range of patients seen in practice. Note: BAT= Brightness acuity tester. CS = Contrast sensitivity. GDcs =Glare disability as measured by reduction in contrast sensitivity. GDvA = Glare disability as measured by reduction in visual acuity. HM = Hand motion. PSG = Posterior subcapsular. SD = Standard deviation. Se = Sensitivity. 1-Se = False negative rate. Sp = Specificity. 1-Sp = False positive rate. TVA =True Vision Analyzer. VA = Visual acuity.
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Attachment E-1. Content Evaluation Form: Glare Testing Article ID #: Reviewer ID#: _ _ _ _ _ _ _ __ Review Date: N A M E (S) 0 F I N S T R U M E N T: • Nature of the study population. Check all that apply: __ Population-based sample __ Statistical sample of cataract patients __ Study limited to preop cataract patients __ Study includes patients with posterior pole disease/corneal disease Other • If study includes subjects with eye disease other than cataract, does the study address influence of noncataract disease on glare testing? Yes No • Does the study address the SENSITIVITY of the glare test for cataract? _Yes _No If yes, what is the reported sensitivity? __0/o. • Does the study address the SPECIFICITY of the glare test for cataract? _Yes _No If yes, what is the reported sensitivity? __0/o. • If article addresses sensitivity and specificity, what evaluations were used as "gold standard" (i.e., symptoms, signs, etc.) in patients without intraoperative or postoperative complications?
• Is instrument compared against actual Snellen outdoor acuity? _Yes _No If yes,% predicted within 1 and 2 Snellen lines: Within: 1 line 2 lines Instrument 1 (name) % % Instrument 2 (name) % % 0 Instrument 3 (name) /o % 0 Instrument 4 (name) % /o 0 Instrument 5 (name) /o % • Does the study contain data to support or refute an association between a measured level of glare disability loss with the instrument(s) and visual symptoms/dysfunction as reported by the subject? __Yes __No __N/A
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Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults
• Does the study show an association between increasing degrees of cataract and increasing measured glare disability? __Yes __No __N/A If yes, is there an association? __Yes No Can't tell If Yes, closest correlation is for nuclear_; cortical_; PSG_; mixed_. • Does the study compare instrument measured glare disability preoperatively and postoperatively on the same patient in whom no intraoperative or postoperative complication occurred? __Yes __ No If yes, average improvement:,_ _ _ _ _ _ _ _ _ _ _ _ __ • Does the study compare patient-reported preoperative and postoperative subjective glare disability? __Yes __No If yes, describe results: _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ • Does the article contain data to support or refute an association between performance of tests for glare disability and: 1. Volume of surgery performed annually by surgeon ordering the test? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 2. Cost effectiveness? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 3. The qualifications of the person performing the test: _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 4. The timing of cataract surgery? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 5. The detection of cases NOT suitable for surgery? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ • Does the article report a correlation between results of a particular glare test and results of other glare tests? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ • Does the article report results of tests of intertester reliability? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ • Does the article describe the technique and parameters of the test in such a way that the test can be used in clinical practice? _Yes _No • If article characteristics are not covered in this questionnaire, please indicate here:D
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Please note below references from this article that should be included in this review but are not on your list:
·--------------------------------------------------------------------•--------------------------------------------------------------------•--------------------------------------------------------------------•--------------------------------------------------------------------•--------------------------------------------------------------------A.
Does the paper define a successful outcome for cataract surgery (e.g., 20/40 or better acuity by 3 or more lines)? __Yes _ _No If yes, what is the definition?_ _ _ _ _ _ _ _ _ _ _ _ __ Percentage of patients with successful outcomes:
B.
If the answer to "A" is yes and the paper provides sufficient data, please fill in the following: _ _ _ _
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%
1. 2. 3. 4.
# of patients with # of patients with # of patients with # of patients with
positive test results who had successful outcomes. positive test results who had unsuccessful outcomes. negative test results who had successful outcomes. negative test results who had unsuccessful outcomes.
Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults
Attachment E-2. Article Selection Process: Glare Testing National Library of Medicine Search:
204 potentially pertinent articles relating to glare, contrast sensitivity, and potential vision testing
-t -t -t ~~~~~LESS~~ -t -t
~
16 articles eliminated : Did not relate to glare, contrast sensitivity, or potential visi on testing
188 potentially pertinent articles on contrast sensitivity testing
-t -t -t ~ ~ ~ ~ ~ -t -t
151 articles rejected : Did not meet inclusion criteria for glare testing
LESS ~ ~
~
37 potentially pertinent articles on glare testing
-t -t -t ~~~~~LESS~~ -t -t
19 articles excluded: Failed to meet inclusion criteria ~
18 articles met inclusion criteria and were reviewed for content and methodologic quality
-t -t -t ~ ~ ~ ~ ~ -t -t
3 articles excluded : Provided duplicate data
LESS ~ ~
~
15 articles included that used glare directly as a measure of visual function
-t -t -t f- f- f- f- f-t -t
1 article added: Included as a result of peer review PLUS
f- f-
f-
16 articles is the new included total
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Method The National Library of Medicine conducted a literature search for abstracts of articles published from January 1, 1975, through December 31, 1990, on three topics (glare, contrast sensitivity, and potential vision testing). (Chapter 2 and Appendix A give a detailed description of the search strategy.) A printout of potentially relevant references was produced. Additional articles were identified by reviewers and other interested parties. After the abstracts and additional articles listed on the printout were screened, 204 were selected for further review because they appeared relevant to the topics covered. A review of the 204 articles for ophthalmologic content was conducted by a group of eight individuals selected by Denis M. O'Day, MD, FACS, Arlo C. Terry, MD, and Anthony J. Adams, OD, PhD, for their known expertise in the areas under consideration. Because of the number of articles, the eight reviewers were grouped into three teams. The first team consisted of Arlo C. Terry, MD, Michael F. Marmor, MD, and Raymond A. Applegate, OD. The second team consisted of Anthony J. Adams, OD, and Douglas D. Koch, MD. The third team consisted of Gary S. Rubin, PhD, Ian L. Bailey, OD, and an ophthalmologist. Each team reviewed articles relating to contrast sensitivity, glare testing, and tests of potential vision. Prepared by Arlo C. Terry, MD; Martha S. Gerrity, MD, MPH; Denis M. O'Day, MD, FACS, Panel Chair; Kay Dickersin, PhD; Oliver D. Schein, MD, MPH; Gordon H. DeFriese, PhD; and Earl P. Steinberg, MD, MPP. Dr. Steinberg was methodology consultant to the panel, and the other authors comprised the literature review group.
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After masking each paper as to author, institution, journal, and date, Lea Gamble at the American Academy of Ophthalmology sent the papers to each member of the three teams so that one-third of the articles were reviewed independently by two reviewers and two-thirds were reviewed independently by three reviewers. Each of the reviewers received approximately equal numbers of studies on each of the three topics under consideration. A separate content evaluation form was developed by Oliver D. Schein, MD, MPH, Earl P. Steinberg, MD, MPP, and Neil R. Powe, MD, MPH, MBA, with input from Denis M. O'Day, MD, FACS, Arlo C. Terry, MD, and Gary S. Rubin, PhD, and used in the review of each article (Attachment E-1). Of the 204 articles reviewed, 16 did not address glare, contrast sensitivity, or potential acuity testing and were rejected. Of the remaining 188 articles, 37 dealt with glare testing and the other 151 were rejected. Nineteen of the 37 studies reviewed for content were rejected because they failed to meet the inclusion criteria set forth by the panel (Chapter 2). The total number of included articles was 18. Attachment E-2 at the end of this appendix summarizes the process used for selecting articles that were reviewed in detail. One additional article (Elliot, Hurst, and Weatherill, 1990) was added as a result of the peer review process, bringing the total number of included articles to 19. Each of the 19 papers that met the inclusion criteria was reviewed by two methodologists, Gordon H. DeFriese, PhD, and Martha S. Gerrity, MD, MPH, and any differences were reconciled through discussion. Methodologic evaluation was performed as suggested by Woolf (1990), and evidence tables were developed. (See Evidence Table E-1 at the end of this appendix.) The information abstracted for the table included the following categories: • Study identification. • Study design. • Number of patients. • Type of glare test. • Severity and type of cataract. • Type of comorbid ocular pathology. • Visual acuity without glare. • Data used as a "gold standard" for comparison with glare measurement (e.g., postoperative visual acuity).
Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults • Findings. • Comments.
occur across several studies are described in the Discussion section (below).
Methodologic Criteria
Results
The criteria listed below were then applied to each of the 19 papers. These criteria are based on widely accepted guidelines (or rules of evidence) for critically assessing studies that evaluate diagnostic tests (Cooper, Chalmers, McCally et al., 1988; Department of Clinical Epidemiology and Biostatistics, 1981; Fletcher, Fletcher, and Wagner, 1988; Griner, Panzer, and Greenland, 1986; Nierenberg and Feinstein, 1988; Sackett, Haynes, and Tugwell, 1991; White, McGahn, Daschbach et al., 1989). 1. Was the study design described clearly (e.g., comparisons that were made, selection of subjects, performance of the test)? 2. Was the test compared with an appropriate gold standard or outcome? 3. Were individuals interpreting the test and gold standard masked with regard to c}inical history or other test results? 4. Did the test correctly identify patients with and without the disease or outcome? In other words, were the following characteristics assessed appropriately? (If not, were the data presented in a manner that would allow these calculations?) • Sensitivity. • Specificity. • Positive and negative predictive values. • False positive and false negative rates. • Accuracy. 5. Was there an appropriate spectrum of disease among the patients tested (e.g., severity and type of cataract)? 6. Was the test reproducible (was intraobserver/interobserver variability measured)? 7. Was the contribution of the test to the overall diagnosis or prediction or an outcome assessed? Because few studies met criteria 3-6 and none met criterion 7, separate categories for these criteria were not added to Evidence Table E-1. Thus, of the preceding seven methodologic criteria, the only one addressed in Evidence Table E-1 is criterion 2 (i.e., what measure was used as the gold standard in evaluating patient outcomes). The Findings entry lists pertinent results from the study. When possible, the test characteristics, sensitivity (Se), specificity (Sp ), false positive rate (1-Sp ), and false negative rate ( 1-Se) are listed. The Comments entry provides specific methodologic comments regarding the validity of the results. Methodologic problems that
Thirty-seven studies on glare testing were reviewed by the content literature review team. Nineteen of these papers were excluded because they did not meet the inclusion/exclusion criteria set forth by the guideline panel. Most of the rejected articles were editorial or review articles or dealt only with the methodology of testing or the use of glare testing for other disease entities (e.g., corneal edema, radial keratotomy, opacified posterior capsule). The remaining 18 articles were reviewed for content and methodologic quality. It was realized during the review for methodologic quality that Maltzman, Horan, and Rengel (1988a) and Maltzman, Horan, and Rengel (1988b) reported identical data; therefore, Maltzman, Horan, and Rengel (1988b) was excluded. Also, Smith, Pratzer, Webster et al. (1987) and LeClaire, Nadler, Weiss et al. (1982) were excluded because they did not include preoperative or postoperative visual acuity data. Therefore, 15 articles were included in the panel's review. The results of the review of these articles are summarized in Evidence Table E-1. For the 15 studies reviewed, there was, in general, excellent agreement among content reviewers for items on the content evaluation form. In the few cases where there was disagreement, one of the reviewers changed his or her mind upon reevaluating the study in question, or a third content reviewer was asked to review the article and cast the deciding vote. The content evaluation forms contained several questions regarding methodology, such as type of study, sensitivity, and specificity. There was very poor agreement among content reviewers about the type of study population, and these questions were therefore referred to the methodology reviewers, with no attempt made to achieve consensus among content reviewers. With the one article added as a result of peer review, 16 was the new total of articles included in the panel's review. Neither glare tests nor testing procedures were standardized across studies. Three articles compared two or more glare tests against the same gold standard, either outdoor acuity (Neumann, McCarty, Locke et al., 1988; Prager, Urso, Holladay et al., 1989) or patients' glare complaints (Koch, 1989). In all three studies, results varied depending on which glare test was used, and there were substantial discrepancies between the results of the glare tests and the assessment based on the gold standard.
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None of the studies reported postoperative evaluations of functional visual impairment (e.g., whether the patients' complaints of glare resolved), which is considered the gold standard in this review for assessing visual impairment amenable to surgical correction. Three studies (Levin, 1989; Masket, 1989; Weiss, 1990) compared the results of glare testing with postoperative visual acuity. Two studies (Elliot, Hurst, and Weatherill, 1990; Koch, 1989) used preoperative glare complaints, and six (Hirsch, Nadler, and Miller, 1984; Holladay, Prager, Trujillo et al., 1987; Neumann, McCarty, Locke et al., 1988; Neumann, McCarty, Steedle et al., 1988a and 1988b; Prager, Urso, Holladay et al., 1989) used outdoor Snellen acuity as the gold standard. Five studies used indoor visual acuity or contrast sensitivity as the gold standard (Abrahamsson and Sjostrand, 1986; Elliot, Gilchrist, and Whitaker, 1989; Hard, Abrahamsson, and Sjostrand; 1990; Maltzman, Horan, and Rengel, 1988; Neumann, McCarty, Steedle et al., 1988a).
Question 1: Is there a correlation between the results of the test and the patient's level of functional impairment? One study (Elliott, Hurst, and Weatherill, 1990) examined whether there was a correlation between the results of glare testing and the patient's level of functional disability. This article described a case series of 33 patients with cataract in at least one eye and correlated glare scores with patient-reported functional disability. Glare disability was measured using a Mentor brightness acuity tester (BAT), which measured reduction in visual acuity due to glare (GDvA) and reduction in letter contrast sensitivity due to glare (GDc5). The BAT can take only monocular measurements, so all testing was done on the eye with the worse visual acuity. Functional disability was measured with a patient questionnaire of 20 questions. The questions were grouped into mutually exclusive categories pertaining to mobility, near vision, or discrimination. The correlation between the worse eye's GDvA and mobility was "not significant," although no correlation coefficient was provided. The correlations between the worse eye's GDvA and near vision and discrimination were 0.61 and 0.51, respectively. Only the correlation between the worse eye's GDcs and discrimination was provided (r=0.45) because the corresponding values for mobility and near vision were "not significant." The correlation between patient-reported functional disability related to near vision and discrimination was higher for worse eye glare disability than for visual acuity. One study (Koch, 1989) examined the correlation between the results of glare testing and patients'
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glare complaints. The correlations between the results of the Baylor visual function tester and glare complaints were 0.36 and 0.61, at low and high levels of glare, respectively. The correlation between the Stereo Optical Glare Tester and glare complaints was 0.68. The article did not specify the effect of glare on the patients' everyday activities and did not indicate how the glare complaints were measured. Six studies examined the association between the results of glare testing and outdoor visual acuity (Hirsch, Nadler, and Miller, 1984a; Holladay, Prager, Trujillo et al., 1987; Neumann, McCarty, Locke et al., 1988; Neumann, McCarty, Steedle et al., 1988a and 1988b; Prager, Urso, Holladay et al., 1989). The BAT was used in three of these studies (Holladay, Prager, Trujillo et al., 1987; Neumann, McCarty, Locke et al., 1988; Prager, Urso, Holladay et al., 1989). In one study (Holladay, Prager, Trujillo et al., 1987), normals showed no decrease in visual acuity caused by either the BAT or outdoor testing. For patients with cataract, the correlation between outdoor visual acuity and BAT was r=0.84. The BAT predicted outdoor acuity to within one line in 73 percent of the subjects in a second study (Neumann, McCarty, Locke et al., 1988) and overpredicted glare disability in 81 percent of subjects at the high setting and 42 percent at the medium setting in a third study (Prager, Urso, Holladay et al., 1989). In one article (Hirsch, Nadler, and Miller, 1984a), the correlation between the results of glare testing (using author's device) and outdoor acuity was better for those facing the sun than those not facing the sun, both for subjects with and without cataracts. In another (Neumann, McCarty, Steedle et al., 1988a), Snellen visual acuity was decreased by two lines in 70 percent of subjects when they faced the sun. A third study (Neumann, McCarty, Steedle et al., 1988b) found that the Miller-Nadler glare tester predicted outdoor acuity within one line for 47 percent of all eyes in the study. Two other studies relate to this question. One study (Maltzman, Horan, and Rengel, 1988a) compared visual acuity with and without penlight glare in 114 cataract patients. All patients with nonglare visual acuities of 20/40 or worse also saw 20/40 or worse with penlight glare. Forty-five percent of patients with nonglare visual acuities of 20/40 or better (sic) had an acuity of 20/40 or worse with penlight glare. Another study (Hard, Abrahamsson, and Sjostrand, 1990) found decreased visual acuity and contrast sensitivity in the presence of glare. The decreased contrast sensitivity was independent of visual acuity. Three studies (Neumann, McCarty, Locke et al., 1988; Neumann, McCarty, Steedle et al., 1988b;
Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults Prager, Urso, Holladay et al., 1989) examined the correlation between the results of glare testing and visual acuity by the type of glare test used. One study (Neumann, McCarty, Locke et al., 1988) found that the correlation varied depending on the glare test used. Outdoor visual acuity was predicted to within one line in 73 percent of the eyes for BAT, 69 percent for True Vision Analyzer (TV A), 56 percent for VisTech, 47 percent for Miller-Nadler, and 15 percent for EyeCon tests, where all tested eyes had been diagnosed with cataract. The same results were reported in a second article (Neumann, McCarty, Steedle et al., 1988b), perhaps on the same patients, for the Miller-Nadler test alone. (It predicted outdoor visual acuity to within one line in 47 percent of the eyes.) The authors also provided information regarding the cataract type and the ability to predict outdoor acuity (see below); however, a third study (Prager, Urso, Holladay et al., 1989) found that in eyes with cataract, accuracy to within one line occurred in 36 percent of eyes for Miller-Nadler, 17 percent of eyes for high luminance BAT, and 45 percent for medium luminance BAT. The MillerNadler test tended to underestimate glare disability (as measured by outdoor visual acuity) in 62 percent of the eyes, and the BAT overpredicted in 81 percent of eyes at high settings and 42 percent at medium settings. This study also found significant interobserver variability in glare test results. In terms of correlation between glare test and visual acuity for specific types of cataract, one study (Elliott, Gilchrist, and Whitaker, 1989) showed high correlations for cortical (r=l.O) and nuclear (r=0.77) cataract but not for posterior subcapsular (PSC) (r=0.12). A second study (Neumann, McCarty, Steedle et al., 1988b) demonstrated that the MillerNadler test predicted outdoor acuity to within one line in 50 percent of eyes with nuclear cataract, 40 percent with nuclear plus PSC, and 52 percent with other cataracts. A third study (Abrahamsson and Sjostrand, 1986) found a weak correlation between glare score and visual acuity in subjects with PSC cataracts or normal eyes. Thus, glare scores have the lowest correlation with visual acuity in patients with PSC cataract. Therefore, the test may be of greatest value in these patients.
Question 2: Is there information on the type or degree of functional impairment detected by the test that is not detected by history and routine physical examination alone? No article provided information on the type or degree of functional impairment detected by glare testing that was not detected by history and physical examination alone.
Question 3: Is there evidence to support the value of the test in detecting cases that are not suitable for surgery? No article provided information supporting the value of glare testing in detecting cases suitable for surgery. See the discussion of Koch (1989) under question 1 and the preceding paragraphs in the Results section discussing the importance of the gold standard in the description of the table. Question 4: Is there evidence to identify a relationship between the use of the test and the timing of surgery? Question 5: Is there evidence to identify a relationship between the use of the test and the volume of surgery performed annually by the ophthalmologist ordering the test? Question 6: Is there information on costs and/or cost-benefit issues? No articles were found addressing these questions. Question 7: What is the relationship between preoperative test results and postoperative test results in patients in whom no intraoperative or postoperative complication occurred? Three studies addressed the relationship between preoperative and postoperative glare test results (Levin, 1989; Masket, 1989; Weiss, 1990), and all three showed an improvement between preoperative and postoperative scores related to cataract surgery. In one study (Weiss, 1990), mean decimal acuity in conditions of glare improved from 0.06 preoperatively to 0.22 postoperatively. Mean MillerNadler glare scores improved from 55.2 percent preoperatively to 7.6 percent postoperatively in a second study (Masket, 1989), and from 15 percent preoperatively to 10 percent postoperatively, using TVA, in a third study (Levin, 1989). None of these studies examined the correlation between glare scores and functional impairment. Although the studies demonstrated that subjects' scores on the glare test improved after surgery, they do not provide evidence that the patients' complaints of glare or their functional impairment also improved. Thus, no study demonstrated that patients' complaints of impairment due to glare were accurately detected by the glare tester and that both the complaints and glare scores improved after surgery. Two studies (Hard, Abrahamsson, and Sjostrand, 1990; Hirsch, Nadler, and Miller, 1984b) examined the test-retest reliability of glare testing. One (Hirsch, Nadler, and Miller, 1984b) showed an excellent correlation between first and subsequent glare tests when the test was performed on patients with cataract (r=0.95), but the correlation was not as good when patients were aphakic (r=0.54) or had normal 1375
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vision (r=0.06). A second study (Hard, Abrahamsson, and Sjostrand, 1990) examined test-retest reliability for letter contrast sensitivity with and without glare in patients with cataract and found the reliability to be very good (r=0.83 without glare; r=0.92 with glare).
Discussion The studies reviewed were very heterogeneous. The number of studies with comparable study designs, definitions of the research problem, and presentation of results was extremely small. Few of the studies gave adequate information about the instruments used, the manner in which they were employed, or the characteristics of patients tested. A variety of instruments were used, and there was inadequate attention to control of background lighting, glare source, and target configurations, all of which could affect the measurement of the criterion indicators. In general, the reviewers had difficulty extracting information from the papers because the study designs and results were not clearly described. In particular, it was often difficult to know exactly how the patients were selected and which patients were included and excluded in the tables and statistical analyses. The characteristics of the patients in the study, and in the individual analyses, may significantly bias the results (Ransohoff and Feinstein, 1978). A study design with inclusion and exclusion criteria applied to consecutive subjects would make it easier to determine if there are biases and how the biases might affect the validity and applicability of the results. The use of a standard study design and format for presenting the results (Department of Clinical Epidemiology and Biostatistics, 1981; Fletcher, Fletcher, and Wagner, 1988; Sackett, Haynes, and Tugwell, 1991) would also make it easier to determine if there are biases and how they might affect the validity and applicability of results. Most of the studies set out to establish the validity of glare testing as a test of visual function. Typically, Snellen visual acuity test results with and without a source of glare were compared. Some tests refined this further by comparing the correlation between glare test results and Snellen visual acuity for different types of testing devices or specific types of cataract. Preoperative comparisons between glare tests and the conventional Snellen tests by themselves are not sufficient to evaluate the clinical utility of glare testing, primarily because a comparison between the two does not allow a valid assessment of the new test. To determine the utility of glare testing in
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deciding whether or not to perform cataract surgery, the best approach is to compare the patients' preoperative vs. postoperative visual acuity and visual complaints (impairment in everyday activities due to vision) to their preoperative vs. postoperative glare test results. The measurements needed for all patients in a single study include ( 1) preoperative and postoperative glare test results and (2) preoperative and postoperative visual acuity and visual complaints. Few of these studies had adequate control or comparison groups. None of the studies masked the individuals interpreting the glare test result and gold standard (e.g., outdoor Snellen acuity) or postoperative outcome (e.g., glare test score). Knowledge of the glare test result could bias the interpretation of the gold standard, and vice versa (Department of Clinical Epidemiology and Biostatistics, 1981; Fletcher, Fletcher, and Wagner, 1988; Ransohoff and Feinstein, 1978; Sackett, Haynes, and Tugwell, 1991). Individuals performing the glare test should not know the results of the gold standard test, and vice versa. In the test-retest reliability studies (Hard, Abrahamsson, and Sjostrand, 1990; Hirsch, Nadler, and Miller, 1984b), this is particularly important. In neither study were the individuals performing the test masked to prior test results. Without masking, these correlations may be artificially inflated because knowledge of a prior test result might influence the interpretation of a test. Often the reader could not determine the spectrum of disease (type and severity of cataracts) among patients enrolled in a study. This limitation makes it diffictllt to assess the external validity (i.e., generalizability) of the study results. In addition, in some studies it is difficult to assess what criteria or factors determined whether a particular patient was or was not enrolled in the study, making it difficult to evaluate the internal validity of the study conclusions. One study (Koch, 1989) found a moderate correlation between the results of glare testing and patients' visual complaints. The article did not specify the impact of glare on the patients' everyday activities and did not indicate how the glare complaints were measured. In addition, the method used to select patients for enrollment in the study may have led to compromise of the internal validity of (i.e., bias in) the study results. Even so, there was a high (20-50 percent) false positive rate in the glare test results, thus limiting the clinical value of the test. One study (Elliott, Hurst, and Weatherill, 1990) reported a moderate correlation between GDvA and
Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults GDcs and discrimination in the worse eye, and GDvA and near vision in the worse eye. These data are the only information currently available with regard to the association between glare disability scores and patient-reported functional disability. The authors suggested that glare disability test scores provide information about cataract beyond that provided by visual acuity alone. This study has several limitations, however. First, no confidence intervals around the correlation coefficients were provided, nor were statistical tests performed to determine whether the differences in magnitude of correlations (e.g., those for glare vs. those for visual acuity) were statistically significant. Second, one cannot determine from the data whether the differences in the correlation coefficients are "clinically significant," even if they are statistically significant. Specifically, it is not possible to determine from the data whether the glare test is abnormal in patients with visionrelated dysfunction who do not have abnormal visual acuity. Thus, one cannot determine from these data whether the glare test is detecting patients with vision-related functional disability who are not detected by abnormal visual acuity. Third, there are no postoperative data. One study (Hirsch, Nadler, and Miller, 1984b) assessed the reproducibility (test-retest reliability) of glare measurements and found that they varied widely: r=0.06 for normal eyes, r=0.95 for cataract eyes, and r=0.54 for aphakic eyes. A second study (Hard, Abrahamsson, and Sjostrand, 1990) found very good test reliability in patients with cataract (r=0.92). Usually, test reliabilities were in the 0.8 to 0.9 range. On the basis of these two studies, testretest reliability appears to be very good for patients with cataract. The situations in which glare testing would be recommended or required are not clear. No studies assessed whether glare testing provided information over and above the usual clinical evaluation (history, Snellen acuity, examination of the eye) or determined how the glare test contributed to the overall diagnosis or prediction of a surgical outcome. For patients with PSC, however, there are some data that glare testing may provide additional clinically relevant information, even when Snellen visual acuity is good. Sixteen studies provided useful information for researchers in this field and used methods appropriate for exploratory or basic science research. However, they did not meet the methodologic criteria necessary for establishing the clinical utility of glare testing in the preoperative evaluation of the cataract patient.
Only 5 of the 16 studies (Elliott, Hurst, and Weatherill, 1990; Koch, 1989; Levin, 1989; Masket, 1989; Weiss, 1990) provided information pertinent to the clinical questions posed for this literature review. These studies found either a fair correlation between glare score and patient complaint of glare (Koch, 1989) or functional disability (Elliott, Hurst, and Weatherill, 1990) or an improvement in glare scores postoperatively (Levin, 1989; Masket, 1989; Weiss, 1990). Although one study (Elliott, Hurst, and Weatherill, 1990) found a higher correlation between glare test results and certain types of functional disability than between visual acuity and the same functional disabilities, it is not clear that the correlations with glare test results in the study were significantly different, clinically or statistically, from the correlations with visual acuity. Thus, although these studies are pertinent, they do not resolve the issue of the clinical utility of glare testing. In addition, the studies have a variety of methodologic flaws, as described above and as noted in Evidence Table E-1, which limit the conclusions that can be drawn from them.
Conclusions Glare test results have a high rate of reproducibility in patients with cataract. One study (Elliott, Hurst, and Weatherill, 1990) reported a higher correlation between the results of glare testing and near vision and discrimination in the worse eye than between visual acuity and the same functional disabilities. However, because of limitations of this study, it is not possible to determine the clinical significance of this difference. In addition, no data were reported regarding the impact of cataract surgery on patient-reported functional disability and what, if any, changes occurred concomitantly in the glare disability test results. The correlation between glare test results and patient complaints of glare may depend on the type of test used and may vary with the type of cataract. The high correlation of glare scores with visual acuity for patients with cortical and nuclear cataracts suggests that glare testing likely provides little information beyond what is obtained by performing Snellen visual acuity. For patients with PSC, however, the correlation is low, indicating that glare testing may be providing more useful information. Studies have shown an improvement in glare scores after cataract surgery but have not provided any data regarding corresponding improvement in functional impairment.
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References In addition to the articles on the literature review lists for glare testing, the following references are cited in this appendix: Cooper LS, Chalmers TC, McCally M, Berrier J, Sacks HS. The poor quality of early evaluations of magnetic resonance imaging. JAMA 1988 Jun 10;259(22):3277-80. Department of Clinical Epidemiology and Biostatistics (McMaster University). How to read clinical journals: II. To learn about a diagnostic test. Can Med Assoc J 1981 Mar 15; 124(6):703-10. Fletcher RH, Fletcher SW, Wagner EH. Clinical epidemiology: the essentials. 2d ed. Baltimore: Williams & Wilkins; 1988. Griner PF, Panzer RJ, Greenland P. Clinical diagnosis and the laboratory: logical strategies for common medical problems. Chicago: Year Book Medical Publishers; 1986. Nierenberg AA, Feinstein AR. How to evaluate a diagnostic marker test. Lessons from the rise and fall of dexamethasone suppression test. JAMA 1988 Mar 18;259(11): 1699-702. Ransohoff DF, Feinstein AR. Problems of spectrum and bias in evaluating the efficacy of diagnostic tests. N Engl J Med 1978 Oct 26;299(17):926-30. Sackett DL, Haynes RB, Tugwell P. Clinical epidemiology: a basic science for clinical medicine. 2d ed. Boston: Little, Brown; 1991. White RH, McGahan JP, Daschbach MM, Hartling RP. Diagnosis of deep-vein thrombosis using duplex ultrasound. Ann Intern Med 1989 Aug 15; 111(4):297-304. Comment. In: Ann Intern Med 1990 Feb 15;112(4):307-8. Woolf SH. Interim manual on clinical practice guideline development. Rockville (MD): Agency for Health Care Policy and Research; 1990.
Literature Review Lists Literature Included This list comprises the 16 included articles that were found to be relevant and were further reviewed for content and methodologic rigor. Abrahamsson M, Sjostrand J. Impairment of contrast sensitivity function (CSF) as a measure of disability glare. Invest Ophthalmol Vis Sci 1986 Jul;27(7):1131-6. Elliott DB, Gilchrist J, Whitaker D. Contrast sensitivity and glare sensitivity changes with three types of cataract morphology: are these techniques necessary in a clinical evaluation of cataract? Ophthalmic Physiol Opt 1989 Jan;9(1):25-30. Elliott DB, Hurst MA, Weatherill J. Comparing clinical tests of visual function in cataract with the patient's perceived visual disability. Eye 1990;4(Pt 5):712-7. Hard AL, Abrahamsson M, Sjostrand J. A new glare test based on low contrast letters--evaluation in cataract
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patients. Acta Ophthalmol (Copenh) 1990 Apr;68(2): 14550. Hirsch RP, Nadler MP, Miller D. Glare measurement as a predictor of outdoor vision among cataract patients. Ann Ophthalmol 1984a Oct;16(10):965-8. Hirsch RP, Nadler MP, Miller D. Clinical performance of a disability glare tester. Arch Ophthalmol 1984b Nov; 102(11): 1633-6. Holladay JT, Prager TC, Trujillo J, Ruiz RS. Brightness acuity test and outdoor visual acuity in cataract patients. J Cataract Refract Surg 1987 Jan;13(1):67-9. Koch DD. Glare and contrast sensitivity testing in cataract patients. J Cataract Refract Surg 1989 Mar;15(2):158-64. Levin ML. Opalescent nuclear cataract. J Cataract Refract Surg 1989 Sep;15(5):576-9. Maltzman BA, Horan C, Rengel A. Penlight test for glare disability of cataracts. Ophthalmic Surg 1988a May; 19(5):356-8. Masket S. Reversal of glare disability after cataract surgery. J Cataract Refract Surg 1989 Mar;15:165-8. Neumann AC, McCarty GR, Locke J, Cobb B. Glare disability devices for cataractous eyes: a consumer's guide. J Cataract Refract Surg 1988 Mar;14(2):212-6. Neumann AC, McCarty GR, Steedle TO, Sanders DR, Raanan MG. The relationship between indoor and outdoor Snellen visual acuity in cataract patients. J Cataract Refract Surg 1988a Jan;l4(1):35-9. Neumann AC, McCarty GR, Steedle TO, Sanders DR, Raanan MG. The relationship between cataract type and glare disability as measured by the Miller-Nadler glare tester. J Cataract Refract Surg 1988b Jan;14(1):40-5. Prager TC, Urso RG, Holladay IT, Stewart RH. Glare testing in cataract patients: instrument evaluation and identification of sources of methodological error. J Cataract Refract Surg 1989 Mar;15(2):149-57. Weiss JF. Glare and mesopic vision before and after cataract surgery. J Cataract Refract Surg 1990 Jan;l6(1):88-91.
Literature Excluded This list comprises the 22 excluded articles rejected because they did not meet the inclusion criteria or provided duplicate data. American Academy of Ophthalmology. Ophthalmic Procedures Assessment. Contrast sensitivity and glare testing in the evaluation of anterior segment disease. Ophthalmology 1990 Sep;97(9): 1233-7. Applegate RA, Trick LR, Meade DL, Hartstein J. Radial keratotomy increases the effects of disability glare: initial results. Ann Ophthalmol 1987 Aug;19(8):293-7. Hoffer KJ. Preoperative evaluation of the cataractous patient. Surv Ophthalmol 1984 Jul-Aug;29(1):55-69. Jaffe NS. Glare and contrast: indications for cataract surgery. J Cataract Refract Surg 1986 Jul;12(4):372-5.
Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults Knighton RW, Slomovic AR, Parrish RK 2d. Glare measurements before and after neodymium-YAG laser posterior capsulotomy. Am J Ophthalmol 1985 Nov 15; 100(5):708-13. Koch DD. The role of glare testing in managing the cataract patient. Focal points 1988: clinical modules for ophthalmologists. Vol. 6, Module 4, American Academy of Ophthalmology; 1988. LeClaire J, Nadler MP, Weiss S, Miller D. A new glare tester for clinical testing. Results comparing normal subjects and variously corrected aphakic patients. Arch Ophthalmol1982 Jan;100(1):153-8. Lin S, Reiter K, Dreher AW, Frucht-Pery J, Feldman ST. The effect of pterygia on contrast sensitivity and glare disability. Am J Ophthalmol 1989 Apr 15;107(4):407-10. Maltzman BA, Horan C, Rengel A. Penlight test for glare disability of cataracts. J Ophthalmic Nurs Technol 1988b Jul-Aug;7(4):137-9. Markow SA. Penlight glare test [letter]. Ophthalmic Surg 1988 Sep;19(9):678. Marron JA, Bailey IL. Visual factors and orientationmobility performance. Am J Optom Physiol Opt 1982 May;59(5):413-26. Miller D, Jernigan ME, Molnar S, WolfE, Newman J. Laboratory evaluation of a clinical glare tester. Arch Ophthalmol 1972 Mar;87(3):324-32. Nadler DJ, Jaffe NS, Clayman HM, Jaffe MS, Luscombe SM. Glare disability in eyes with intraocular lenses. Am J Ophthalmol 1984 Jan;97(1):43-7.
Paulsson LE, Sjostrand J. Contrast sensitivity in the presence of a glare light. Theoretical concepts and preliminary clinical studies. Invest Ophthalmol Vis Sci 1980 Apr;19(4):40l-6. Prager TC, Urso RG, Lewis JW, Ruiz RS. Methodological considerations in glare testing in patients with cataract [letter]. Arch Ophthalmol 1988 Nov;106(l1):1501-2. Pulling NH, WolfE, Sturgis SP, Vaillancourt DR, Dolliver JJ. Headlight glare resistance and driver age. Hum Factors 1980 Feb;22(l):103-12. Roper-Hall MJ. Rayner lecture 1984. Sophistication in intraocular lens surgery. Trans Ophthalmol Soc U K 1985; 104(Pt 5):500-6. Sjostrand J, Abrahamsson M, Hard AL. Glare disability as a cause of deterioration of vision in cataract patients. Acta Ophthalmol Suppl (Copenh) 1987;182:103-6. Smith PW, Pratzer KA, Webster N, Fenton J, Bonham RD. A clinical comparison of two methods of glare testing. Ophthalmic Surg 1987 Sep; 18(9):680-2. Soper JW. Autobiographical pictorial study of a cataract in progress. J Cataract Refract Surg 1986 May;12(3):303-5. Terry CM, Brown PK. Clinical measurement of glare effect in cataract patients. Ann Ophthalmol 1989 May;21(5):183-7. Wolf E. Glare and age. Arch Ophthalmol 1960 Oct;64(4):502-14.
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Evidence Table E-1. Literature Review Evidence: Glare Testing Reference: Holladay, Prager, Trujillo et al., 1987. Study Design: Case series. Patients: 64 patients (14 normal, 50 cataract). Type of Glare Test: Brightness acuity tester. Severity and Type of Cataract: Not given. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: Not given. Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor VA (5,358 to 13,198 ft. candles). Findings: No decrease in VA with the BAT or outdoor testing in normals. For cataract subjects, correlation between BAT and outdoor VA was r=0.84. Cataract patients had a 1- to 10-line reduction in VA. Comments: No information regarding type/severity of cataract, complaints of glare, or sensitivity/specificity. No test-retest data given although abstract claims BAT reliable. Reference: Hirsch, Nadler, and Miller, 1984a. Study Design: Consecutive case series. Patients: 52 cataract patients (84 eyes), 48 normal patients (81 eyes). Type of Glare Test: Author's device. Severity and Type of Cataract: Not given. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: Mean = 20/48; range = 20/20 to 20/60. Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor VA (~2,000 ft. candles). Findings: For cataract patients, correlation between glare scores and outdoor VA better for individuals facing sun (r2=0.64) than those not facing sun (r=0.36). For normals, glare scores were "highly predictive" of outdoor acuity (r2 not given). Comments: Data difficult to decipher. Methods not standardized. Sun glare not standardized for glare test measurement. Reference: Hirsch, Nadler, and Miller, 1984b. Study Design: Case series. Patients: 3 studies: N=46 (test-retest); N=5 (effect of refractive error on glare); N=126 (effect of contrast on glare). Type of Glare Test: Described. Severity and Type of Cataract: N=46 (13 normal eyes, 23 cataract eyes, 27 aphakic eyes). N=126 (35 normal; 94 cataract; 57 aphakic eyes). Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: N/A. Postoperative Visual Acuity or "Gold Standard": Gold standard: N/A. Findings: Test-retest reliability varies with eye status: r=0.06, normal; r=0.95, cataract; r=0.54, aphakic. Glare scores change up to 5% with refractive error, and contrast sensitivity accounts for 10% of the variance in glare scores. Comments: Reliability is highest in patients with cataract. Reference: Hard, Abrahamsson, and Sjostrand, 1990. Study Design: Case series. Patients: N=16; 10 cataract patients who had glare problems, 3 normal, 3 others. Type of Glare Test: Described. Severity and Type of Cataract: • Severity: not given. • Type: nuclear, cortical, and PSC. Type of Comorbid Ocular Pathology: None in cataract subjects. Visual Acuity Without Glare: Better than 20/70. Postoperative Visual Acuity or "Gold Standard": Gold standard: letter CS (without glare). Findings: Test-retest reliability for: letter CS r=0.83, letter CS with glare r=0.92, VA r=0.89. With glare, cataract patients had a decreased letter CS independent of VA. Comments: Tables and graphs difficult to interpret. Test-retest reliability good under conditions specified. However, study design would be stronger if individuals performing the test were masked. Reference: Elliott, Gilchrist, and Whitaker, 1989. Study Design: Case series. Patients: 18 subjects (39 eyes) with cataracts, 16 subjects (16 eyes) normal. Type of Glare Test: • Contrast sensitivity described, not named. • Glare described, not named. Severity and Type of Cataract: • Severity: graded 1-5 scale (Oxford cataract classification and grading system). • Type: nuclear, cortical, subcapsular. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: LogMar VA: 0.12 to 0.50. Postoperative Visual Acuity or "Gold Standard": Gold standard: LogMar VA. Findings: 1) High correlations between glare sensitivity and Log Mar VA for cortical (r=1.0) and nuclear (r=0.77), but not PSC (r=0.12) cataracts. 2) Moderate to high (r=0.44 to 1.0) correlations between CS and LogMar VA at ~2 c/deg (r=0.44 to 1.0). Comments: Correlation coefficients may not be precise because of small numbers in each subgroup. Study results vary considerably with the type of cataract.
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Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults Reference: Abrahamsson and Sjostrand, 1986. Study Design: Case series. Patients: 18 normals, 34 subjects with PSG. Type of Glare Test: Described. Severity and Type of Cataract: • Severity: 0 to 100% opacification. • Type: PSG only. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: 20/20 to 20/200 (by figure). Postoperative Visual Acuity or "Gold Standard": Gold standard: visual acuity. Findings: Weak correlation between glare score and visual acuity, with a trend of increasing glare relating to decreasing VA (r not given). Comments: 2 methods used to calculate glare scores gave different results. The average discrepancy in threshold contrast was used because of a "high reproducibility" of results, but no test-retest data were given. Reference: Maltzman, Horan, and Rengel, 1988a. Study Design: Case series. Patients: 114 eyes cataract, 20 eyes normal. Type of Glare Test: Penlight. Severity and Type of Cataract: • Severity: VA better than 20/200. • Type: not given. Type of Comorbid Ocular Pathology: None. Visual Acuity Without Glare: Better than 20/200. Postoperative Visual Acuity or "Gold Standard": Gold standard: Snellen acuity. Findings: Out of 40 eyes with VA 20/40 or better, 22 (55%) did not change with penlight and 2 (5%) had VA of 20/200. 16 of 22 eyes with VA of 20/50 had VA of 20/200 or worse with penlight. Comments: No mention was made of patients with glare complaints. Unclear whether patients with VA of 20/200 with the penlight complained of glare. Without an assessment of patients' functional disability and/or postop outcomes, these data do not directly address the ability of the penlight test to predict who will benefit from surgery. Reference: Neumann, McCarty, Locke et al., 1988. Study Design: Case series. Patients: 48 cataract eyes. Type of Glare Test: 1) Miller-Nadler. 2) Brightness acuity tester. 3) lnnoMed true vision analyzer. 4) Vis Tech VCT8000. 5) EyeCon 5. Severity and Type of Cataract: Not given. Type of Comorbid Ocular Pathology: None. Visual Acuity Without Glare: Not given. Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor Snellen acuity. Findings: The tests predicted outdoor acuity to within 1-line accuracy in 73% for BAT, 69% for TVA, 56% for VisTech, 47% for MillerNadler, and 15% for EyeCon. False positive and negative rates provided in the article. Comments: Study highlights the problem of variability in glare tester's ability to predict outdoor acuity. Reference: Koch, 1989. Study Design: Case series. Patients: 41 cataract subjects with VA 20/60 or better and complained of glare. 10 patients without glare. Type of Glare Test: 1) Miller-Nadler glare tester; 2) Baylor visual function tester; 3) Stereo Optical glare tester; 4) Vistech vision contrast test system. Severity and Type of Cataract: • Severity: acuity 20/60 or better. • Type: PSG, nuclear. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: 20/60 or better. Postoperative Visual Acuity or "Gold Standard": Gold standard: 1) glare complaint; 2) severity and type of cataract. Findings: Correlation between the 3 glare testers and patients' complaints ranged from r=0.39 to r=0.68. False positive rates (1-Sp) were 20% to 50% and false negative rates (1-Se) were 2% to 15%. Comments: Selection of patients (only those able to compare their complaints with the glare testing formats) may bias the results and make the tests look better than they are (especially the correlations and false negative rates). With only moderate correlations with patients' complaints and a high false positive rate, these tests have questionable clinical utility. Reference: Neumann, McCarty, Steedle et al., 1988b. Study Design: Case series. Patients: 78 patients (92 eyes with cataract and glare scores between 10% and 80%). Type of Glare Test: Miller-Nadler glare tester. Severity and Type of Cataract: • Severity: VA 20/20 to 20/300. • Type: pure nuclear, nuclear PSG, and other. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: 20/20 to 20/300 (81 eyes had VA 20/20 to 20/40 indoors and 33 had VA 20/20 to 20/40 outdoors). Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor VA (8,000 to 11 ,900 ft. candles). Findings: The Miller-Nadler predicted outdoor acuity was within 1 Snellen line of actual outdoor acuity for 47% of the eyes overall. For the 3 categories of cataract type, this percent ranged from 50% (nuclear), to 40% (nuclear and PSG), to 52% (other). Comments: Predictions of outdoor acuity (within 1 line) are poor for all 3 types of cataract. No assessments of patients' complaints of glare and/or postoperative outcomes. As a result, this study does not directly address value of the test for preoperative decisionmaking.
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Reference: Neumann, McCarty, Steedle et al., 1988a. Study Design: Case series. Patients: 78 subjects (106 cataractous eyes). Type of Glare Test: Indoor Snellen acuity. Severity and Type of Cataract: • Severity: VA 20/20 to 20/300. • Type: nuclear, nuclear and PSC, other. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: 20/20 to 20/300 (81 eyes had VA 20/20 to 20/40 indoors and 33 had VA 20/20 to 20/40 outdoors). Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor VA (8,000 to 11,900 ft. candles). Findings: 74 (70%) of eyes had outdoor VA~ 2 Snellen lines worse than indoor VA and 23 (22%) had outdoor VA~ 5 lines worse. Comments: Authors compared indoor and outdoor Snellen acuity. There was no assessment of subjects' complaints of visual impairment or glare. Many of the eyes had VA of 20/40 or better indoors (76%) and outdoors (31%). Reference: Prager, Ursa, Holladay et al., 1989. Study Design: Case series. Patients: 51 normal subjects/eyes; 47 cataractous subjects/eyes. Type of Glare Test: 1) Miller-Nadler glare tester; 2) brightness acuity tester. Severity and Type of Cataract: • Severity: "minimal." • Type: not given. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: Mean for controls 20/20 (±2.11 SD); cataracts 20/43 (±18 SD). Postoperative Visual Acuity or "Gold Standard": Gold standard: outdoor VA. Findings: 1) Normal eyes had a mean VA of 20/20 indoors, outdoors, and with BAT. Miller-Nadler gave a VA mean of 20/24. 2) For cataract eyes, mean outdoor acuity was 20/45 (±17 SD). BAT overpredicted glare disability in 81% at high and 42% at medium settings. Miller-Nadler underpredicted in 62%. Comments: 1) Randomization of indoor vs. outdoor testing and order of each instrument makes this a strong study design. It decreases the bias of a "carryover" or "training" effect from one test or setting to the other. 2) Use of only one eye from each patient is also a strength of this study. 3) Study demonstrates significant variability among glare testers. Reference: Weiss, 1990. Study Design: Case series. Patients: 74 patients (118 eyes). Type of Glare Test: 1) Glare situation described. 2) Mesopic vision situation described. Severity and Type of Cataract: • Severity: VA 20/46 to 20/154. • Type: not given. Type of Comorbid Ocular Pathology: Not given. Visual Acuity Without Glare: 20/46 to 20/154. Postoperative Visual Acuity or "Gold Standard": Postop vision: 20/22 to 20/42. Findings: Statistically significant improvements occurred for all 3 acuity measures postop: standard Iandoit (0.28 preop vs. 0.69 postop), glare (0.06 vs. 0.22), and mesopic (0.11 vs. 0.34). Comments: Comparisons were not made between preop glare (or mesopic vision) and postop Snellen acuity. Patients' complaints of glare were not given for preop and postop periods. Reference: Masket, 1989. Study Design: Case series. Patients: 26 patients (30 eyes) with uncomplicated cataract surgery and postop acuity 20/20. Type of Glare Test: Miller-Nadler. Severity and Type of Cataract: • Severity: VA 20/30 to HM. • Type: nuclear, PSC, cortical. Type of Comorbid Ocular Pathology: None. Visual Acuity Without Glare: 20/30 to HM (mean 20/122). Postoperative Visual Acuity or "Gold Standard": Postoperative VA: 20/20. Findings: Mean glare score preop (55.2%, range 25% to 80%) was significantly different from postop mean (7.6%, range 2.5% to 15%). Comments: 1) Selecting patients based on good surgical outcome (VA 20/20) may have biased results and limits generalizability of findings to the typical preoperative situation. 2) Glare scores improved after cataract removal. No indication as to whether patients had glare symptoms and if these resolved postop. 3) Technician performing the glare testing was masked, making this a stronger study design. Reference: Elliott, Hurst, and Weatherill, 1990. Study Design: Case series (cross-sectional). Patients: 33 patients with cataract in at least 1 eye. Type of Glare Test: Mentor brightness acuity meter: 1) reduction in VA (GDvA); 2) reduction in CS (GDc 8 ). Severity and Type of Cataract: VA range = 6/4 to 6/36. Type of Comorbid Ocular Pathology: Exclude patients with high intraocular pressure, retinal disease, refractive error >± 6.00, amblyopia, monophakia, abnormal neural function, poor general health. Visual Acuity Without Glare: N/A. Postoperative Visual Acuity or "Gold Standard": N/A. Findings: Patients also completed questionnaire on vision-related functional disability. • Correlation (r) = 0.61 between worse eye GDvA and near vision and r = 0.57 between worse eye GDvA and discrimination. • r = 0.45 between worse eye GDcs and discrimination. These correlations were slightly higher than those between VA and the same functional disabilities (r = 0.46 and 0.41, respectively). Comments: Moderately strong association between GDvA and near vision and between GDvA and GDcs and discrimination. • No statistical test performed to determine whether the differences in magnitude of correlations are statistically significant (e.g., between glare/functional disability vs. VA/functional disability). • Cannot determine if differences in the correlation coefficients are clinically significant even if they are statistically significant. • There are no postop data. • No data (scatter plots) or confidence intervals provided, just p values; so difficult to assess validity of analysis conclusions.
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Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults Reference: Levin, 1989. Study Design: Case series. Patients: 38 patients, good VA and with other visual symptoms. Type of Glare Test: lnnomed TVA-glare mode. Severity and Type of Cataract: • Severity: VA 20/25 to 20/70. • Type: opalescent nuclear. Type of Comorbid Ocular Pathology: None. Visual Acuity Without Glare: 20/25 to 20/70. Postoperative Visual Acuity or "Gold Standard": Postop VA: 20/15 to 20/30. Findings: Preop contrast sensitivity (15%, glare mode) ranged from 20/80 to 20/2000. Postop CS (10% glare mode) ranged from 20/15 to 20/70 for all 38 patients. Comments: 1) No report of whether patients' visual symptoms resolved postop. 2) All 38 patients had mild cataracts and no other ocular pathology, making it difficult to apply the results to a broader range of patients seen in practice. Note: BAT= Brightness acuity tester. CS = Contrast sensitivity. GDcs =Glare disability as measured by reduction in contrast sensitivity. GDvA = Glare disability as measured by reduction in visual acuity. HM = Hand motion. PSG = Posterior subcapsular. SD = Standard deviation. Se = Sensitivity. 1-Se = False negative rate. Sp = Specificity. 1-Sp = False positive rate. TVA =True Vision Analyzer. VA = Visual acuity.
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Attachment E-1. Content Evaluation Form: Glare Testing Article ID #: Reviewer ID#: _ _ _ _ _ _ _ __ Review Date: N A M E (S) 0 F I N S T R U M E N T: • Nature of the study population. Check all that apply: __ Population-based sample __ Statistical sample of cataract patients __ Study limited to preop cataract patients __ Study includes patients with posterior pole disease/corneal disease Other • If study includes subjects with eye disease other than cataract, does the study address influence of noncataract disease on glare testing? Yes No • Does the study address the SENSITIVITY of the glare test for cataract? _Yes _No If yes, what is the reported sensitivity? __0/o. • Does the study address the SPECIFICITY of the glare test for cataract? _Yes _No If yes, what is the reported sensitivity? __0/o. • If article addresses sensitivity and specificity, what evaluations were used as "gold standard" (i.e., symptoms, signs, etc.) in patients without intraoperative or postoperative complications?
• Is instrument compared against actual Snellen outdoor acuity? _Yes _No If yes,% predicted within 1 and 2 Snellen lines: Within: 1 line 2 lines Instrument 1 (name) % % Instrument 2 (name) % % 0 Instrument 3 (name) /o % 0 Instrument 4 (name) % /o 0 Instrument 5 (name) /o % • Does the study contain data to support or refute an association between a measured level of glare disability loss with the instrument(s) and visual symptoms/dysfunction as reported by the subject? __Yes __No __N/A
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• Does the study show an association between increasing degrees of cataract and increasing measured glare disability? __Yes __No __N/A If yes, is there an association? __Yes No Can't tell If Yes, closest correlation is for nuclear_; cortical_; PSG_; mixed_. • Does the study compare instrument measured glare disability preoperatively and postoperatively on the same patient in whom no intraoperative or postoperative complication occurred? __Yes __ No If yes, average improvement:,_ _ _ _ _ _ _ _ _ _ _ _ __ • Does the study compare patient-reported preoperative and postoperative subjective glare disability? __Yes __No If yes, describe results: _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ • Does the article contain data to support or refute an association between performance of tests for glare disability and: 1. Volume of surgery performed annually by surgeon ordering the test? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 2. Cost effectiveness? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 3. The qualifications of the person performing the test: _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 4. The timing of cataract surgery? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ 5. The detection of cases NOT suitable for surgery? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ • Does the article report a correlation between results of a particular glare test and results of other glare tests? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ • Does the article report results of tests of intertester reliability? _Yes _No If yes, describe: _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ __ • Does the article describe the technique and parameters of the test in such a way that the test can be used in clinical practice? _Yes _No • If article characteristics are not covered in this questionnaire, please indicate here:D
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Please note below references from this article that should be included in this review but are not on your list:
·--------------------------------------------------------------------•--------------------------------------------------------------------•--------------------------------------------------------------------•--------------------------------------------------------------------•--------------------------------------------------------------------A.
Does the paper define a successful outcome for cataract surgery (e.g., 20/40 or better acuity by 3 or more lines)? __Yes _ _No If yes, what is the definition?_ _ _ _ _ _ _ _ _ _ _ _ __ Percentage of patients with successful outcomes:
B.
If the answer to "A" is yes and the paper provides sufficient data, please fill in the following: _ _ _ _
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%
1. 2. 3. 4.
# of patients with # of patients with # of patients with # of patients with
positive test results who had successful outcomes. positive test results who had unsuccessful outcomes. negative test results who had successful outcomes. negative test results who had unsuccessful outcomes.
Cataract Management Guideline Panel • Management of Functional Impairment Due to Cataract in Adults
Attachment E-2. Article Selection Process: Glare Testing National Library of Medicine Search:
204 potentially pertinent articles relating to glare, contrast sensitivity, and potential vision testing
-t -t -t ~~~~~LESS~~ -t -t
~
16 articles eliminated : Did not relate to glare, contrast sensitivity, or potential visi on testing
188 potentially pertinent articles on contrast sensitivity testing
-t -t -t ~ ~ ~ ~ ~ -t -t
151 articles rejected : Did not meet inclusion criteria for glare testing
LESS ~ ~
~
37 potentially pertinent articles on glare testing
-t -t -t ~~~~~LESS~~ -t -t
19 articles excluded: Failed to meet inclusion criteria ~
18 articles met inclusion criteria and were reviewed for content and methodologic quality
-t -t -t ~ ~ ~ ~ ~ -t -t
3 articles excluded : Provided duplicate data
LESS ~ ~
~
15 articles included that used glare directly as a measure of visual function
-t -t -t f- f- f- f- f-t -t
1 article added: Included as a result of peer review PLUS
f- f-
f-
16 articles is the new included total
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