- Email: [email protected]
Functional outcome and satisfaction after photorefractive keratectomy
Functional Outcome and Satisfaction after Photorefractive Keratectomy Part 2: Survey of 690 Patients Isabelle Brunette, MD, FRCPC,1,2,3 Jacques Gresset, OD, PhD,2,4 Jean-Franc¸ois Boivin, MD, ScD,5 Mihai Pop, MD, FRCPC,2,6 Paul Thompson, MD, FRCPC,1,7 Gilles P. Lafond, MD, FRCPC,8,9 He´la Makni, MD,2,5 The Canadian Refractive Surgery Research Group Purpose: To document patient satisfaction and self-perceived quality of vision after bilateral photorefractive keratectomy (PRK). Design: Noncomparative, interventional case series. Participants: Consecutive patients who underwent bilateral PRK from May 1994 through May 1997 by the 12 surgeons of four collaborating centers with a minimum of 4 months since the last surgery and up to 30 months since the first surgery. Methods: A questionnaire with known psychometric properties was self-administered by the patients. Main Outcome Measures: Responses to individual questions and scale scores. Results: A total of 929 questionnaires were sent, of which 690 were answered and returned (74.3% response rate). The preoperative spherical equivalent ranged from ⫺0.38 diopters [D] to ⫺27.75 D (mean, ⫺5.32 D; standard deviation, 2.85 D). Although 91.8% of the patients were satisfied or very satisfied with their surgery, 96.3% considered that their main goal had been reached, and 95.7% would still choose to have surgery if they had it to do over. The degree of satisfaction was proportional to the postoperative uncorrected visual acuity in the best eye expressed in LogMAR (r ⫽ ⫺0.18, P ⫽ 0.0001) and was negatively correlated with the importance of the corneal haze (r ⫽ ⫺0.23, P ⫽ 0.0001). Daytime glare was reported to be greater than before surgery by 55.1% of patients. A decrease in night vision was reported by 31.7% of patients, and 31.1% of patients reported increased difficulty driving at night because of their vision. Conclusions: Overall satisfaction after PRK for low to severe myopia appears to be very good. Glare and night vision disturbance, particularly bothersome for night driving, seem to constitute significant secondary effects that deserve further investigation and should be kept in mind for future improvements in the technique. Ophthalmology 2000;107:1790 –1796 © 2000 by the American Academy of Ophthalmology. The concept of patient satisfaction is gradually beginning to be examined by the international community of refractive surgeons. In general, a relatively high level of satisfaction is reported after photorefractive keratectomy (PRK) and laser in situ keratomileusis.1–15 However, as indicated by War-
ing, (page 214)16 “such positive conclusions are often punctuated by a patient adding: But, I wish I saw as sharply as I did with my glasses . . . I wish I didn’t see halos and lines and ghost images.” Glare, halos, and night vision disturbance seem to constitute the principal causes of discomfort
Originally received: August 13, 1999. Accepted: April 21, 2000.
8
Manuscript no. 99557.
1
Department of Ophthalmology, University of Montreal, Montreal, Quebec, Canada. 2
Maisonneuve-Rosemont Hospital Research Centre, Montreal, Quebec, Canada. 3
Le Laser Excimer de l’Hoˆpital Maisonneuve-Rosemont, Montreal, Quebec, Canada. 4
School of Optometry, University of Montreal, Montreal, Quebec, Canada. 5
Department of Epidemiology and Biostatistics, McGill University, Montreal, Quebec, Canada. 6
Cliniques Michel Pop, Montreal, Quebec, Canada.
7
La Clinique du Laser Visuel, Montreal, Quebec, Canada.
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© 2000 by the American Academy of Ophthalmology Published by Elsevier Science Inc.
Le Laser Visuel de Que´bec, Quebec City, Quebec, Canada. Department of Ophthalmology, University of Laval, Quebec City, Quebec, Canada. Presented in part at the Association for Research in Vision and Ophthalmology annual meeting, Fort Lauderdale, Florida, May 1998. Supported in part by the Quebec Research in Vision Network (Fonds de la Recherche en Sante´ du Que´bec), Montreal, Quebec, Canada; the Medical Research Council of Canada (grant no.: 13385), Ottawa, Ontario, Canada; and the Quebec Eye Bank Foundation, Inc., Montreal, Quebec, Canada. Statistical analyses were supported by a grant from the Fonds de la Recherche en Sante´ du Que´bec to the Maisonneuve-Rosemont Hospital Research Centre, Montreal, Quebec, Canada. The authors have no proprietary interest in any aspect of this study. Reprint requests to Isabelle Brunette, MD, Ophthalmology Research Unit, Lavoisier Building, 3rd Floor, Maisonneuve-Rosemont Hospital, 5689 Rosemont Boulevard, Montreal, Quebec, Canada, H1T 2H1. 9
ISSN 0161-6420/00/$–see front matter PII S0161-6420(00)00267-0
Brunette et al 䡠 Functional Outcome and Satisfaction after PRK and dissatisfaction after PRK.1,2,5–7,9 –11,14 –18 The goal of this study was to evaluate patient satisfaction, self-perceived outcome, and subjective visual impairment after bilateral PRK for myopia, with or without astigmatism.
Methods The questionnaire we used was tested for acceptability, reliability, validity, and interpretability. The development of this instrument, administration conditions, and methods of results analysis are described elsewhere.19 Twelve surgeons from four refractive surgery centers participated in the study. In one clinic, the laser used was a VISX 20/20 (VISX, Inc., Santa Clara, CA); in two clinics it was a Technolas 116 (Chiron Technolas, Munich, Germany); and in the fourth clinic, a Technolas 116, was replaced by a Nidek-EC 5000 (Nidek, Tokyo, Japan) in the middle of the study period. We reviewed the charts of all consecutive patients who underwent bilateral PRK for myopia, with or without astigmatism, by one of the 12 surgeons from May 1994 through May 1997. We only included patients for whom, at the time of the mailing, a minimum of 4 months since the last surgery and a maximum of 30 months since the first surgery had elapsed. When, for a single surgeon, more than 250 patients fulfilled the above criteria, patients were randomly selected within this group of eligible patients, up to a total of 250. Reoperation was not an exclusion criterion, but patients with preexisting ocular pathologic conditions or previous ocular surgery other than PRK were excluded. Returned questionnaires were accepted up to December 1997. Informed consent was obtained, and the ethics committee of the Maisonneuve-Rosemont Hospital approved the study. For analysis purposes, items of this questionnaire were grouped in seven distinct scales.19 Each of these scales represented a concept. These included global satisfaction, quality of vision without correction, quality of vision with correction, glare problems, quality of night vision, as well as day and night driving impairments. Scale scores increased with satisfaction, ranging from 1 to 5 (1 ⫽ very dissatisfied, 5 ⫽ very satisfied). Because no clinical examination was usually performed on the day of the questionnaire, clinical information was taken from the last visit or the closest subsequent visit for stable patients. Because no binocular visual acuity measurement was usually available, visual acuity of the best eye was used. For statistical analyses, visual acuities in LogMAR were used, which means the lower the value, the better the vision. Pearson r coefficient of correlation, Kruskal-Wallis one-way analysis of variance, and chi-square tests were used to assess relationships between variables. The strength of the correlation between two variables was defined as strong (r ⱖ 0.60), moderate (0.30 ⱕ r ⬍ 0.60), or weak (0.10 ⱕ r ⬍ 0.30).
Results A total of 973 patients were eligible. Of these, 44 were excluded because of an incorrect address (n ⫽ 43) or death (n ⫽ 1). A total of 929 questionnaires were sent. Because 239 patients either declined to participate (n ⫽ 71) or did not return the questionnaire (n ⫽ 168), we report on the remaining 690 patients who answered and returned the questionnaire. Population characteristics are listed in Tables 1 and 2. Nonrespondents were studied separately. They were slightly younger (mean age, 34.4 years; range, 17.6 – 61.3 years) than respondents (mean age, 38.0 years; range, 18.0 – 61.4 years). No other differences were found between respondents and nonrespondents.
Patient Satisfaction and Self-perceived Outcome Motivation for Surgery. The patients’ main motivations for wanting surgical correction of their myopia were: to be less dependent on glasses (18.6%), to have better vision after the operation than before the operation with glasses or contact lenses (16.9%), hated wearing glasses (16.2%), did not tolerate contact lenses (14.7%), and for professional reasons (8.9%). Although patients of both genders estimated that refractive surgery had improved their physical appearance, improvement of aesthetic appearance and self-confidence was a slightly more significant issue for women (main issue for 10.3% of women) than for men (main issue for 5.8% of men), who tended to be more concerned about comfort without glasses or contact lenses and performance in sports (main issue for 31.8% of men vs. 24.1% of women; P ⫽ 0.026). Overall Satisfaction. The distribution of the scores for the seven satisfaction scales is illustrated in Figures 1 through 7. The level of overall satisfaction was very high, with a mean score of 4.42 of a maximum of 5; 96.3% of patients reported that their main goal had been achieved, 91.8% considered themselves to be satisfied or very satisfied with the result of their operation, 96.2% thought that the operation had been a good choice for them, and 95.7% declared that if they had it to do over, they would still choose to have the operation performed. The operation allowed an improvement in the quality of life at work in 78.9% of patients, their social life in 78.1% of patients, and their family life in 66.6% of patients, when applicable. Quality of Daytime Vision without Correction. The quality of daytime vision without correction was evaluated for all patients. The mean score was 3.33 ⫾ 0.77; 55.3% of the patients characterized their uncorrected vision for distance as slightly or much better than their preoperative corrected vision, 18.1% of patients as slightly or much worse, and 26.4% of patients thought it was the same. More specifically, 41.4% of patients estimated that without glasses or contact lenses, their postoperative vision was better than it was before surgery with glasses or contact lenses for reading street names, driving during the day, watching television, and finding goods at the grocery store; 10.6% of patients estimated it was slightly or much worse. Symptoms reported to be more frequent than before surgery included a double outline of images (13.1%), ghost images (5.4%), blurred vision (19.8%), and distortion of fine details (18.2%). Uncorrected near vision was characterized as slightly or much better than the preoperative corrected vision by 18% of patients, slightly or much worse by 29.4% of patients, and the same by 52.4% of patients. Twenty-three percent of patients estimated they were better able after surgery without correction to read newspaper headlines, newspaper articles, the telephone book, a computer screen, or to thread a needle than they were before surgery with correction. However, 18.6% estimated they were slightly or much worse able to do so. Satisfaction about the quality of uncorrected vision decreased with age (r ⫽ ⫺0.211; P ⫽ 0.0001; Table 3). Quality of Daytime Vision with Correction. Nineteen patients (2.8%) reported regularly wearing glasses for distance vision, and 94 patients (13.6%) reported doing so for near vision. Only 0.6% of patients went back to contact lenses after surgery. The mean score for patients wearing glasses for distance vision was 2.97 ⫾ 0.60. For patients not wearing any type of correction, it was 3.40 ⫾ 0.75 (P ⫽ 0.234). Quality of Night Vision. In 66.1% of patients, night vision was perceived as not being as good as daytime vision, and in 20.2% of patients it was thought to be poor or very poor. Night vision was considered to be the same or better than before surgery by 68.3% of patients. However, 31.7% of patients reported that it
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Ophthalmology Volume 107, Number 9, September 2000 Table 1. Population Characteristics Mean ⴞ SD or % Patients
Characteristics (n ⴝ 690) Age (yrs) Female Time between first and last surgeries (mos) Time between questionnaire and most recent visit (mos)* Patients with repeated surgery Before surgery (n ⴝ 690) Mean SE (diopters [D]) BCVA 20/20 or better BCVA between 20/20 and 20/40 BCVA 20/40 or worse Mean pupil diameter (mm; n ⫽ 266 patients) At the time of the questionnaire Visual acuity in the best eye (n ⴝ 676 patients) UCVA 20/20 or better UCVA between 20/20 and 20/40 UCVA 20/40 or worse Loss of 1 line of BCVA Loss of 2 lines of BCVA Refraction (n ⴝ 489 patients) Mean SE (D) Mean SE within 1.00 D of emmetropia Difference in SE between eyes (D) Monovision (patients)† Grade of corneal haze (n ⴝ 604 patients) Maximum of both eyes Minimum of both eyes Mean of both eyes
38.0 ⫾ 10.2 59.1% 3.3 ⫾ 4.8 ⫺6.0 ⫾ 6.4 9.3% ⫺5.32 ⫾ 2.85 89.2% 10.7% 0.15% 6.8 ⫾ 1.5
Median
Range
38.1
18.0 to 61.4
1.4 ⫺4.4
0 to 29.7 ⫺24.2 to 4.1
⫺4.75
⫺0.38 to ⫺27.75
7.0
2.5 to 9.0
79.7% 18.2% 2.1% 4.7% 0.3% ⫺0.3 ⫾ 0.7 92% 0.5 ⫾ 0.7 42
⫺0.2
0.1 ⫾ 0.3 0.1 ⫾ 0.2 0.1 ⫾ 0.3
⫺6.6 to ⫹1.8
0.2
0 to 4.9
0 0 0
0 to 3 0 to 3 0 to 3
BCVA ⫽ best-corrected visual acuity; SE ⫽ spherical equivalent; UCVA ⫽ uncorrected visual acuity. *The time between the questionnaire and the most recent visit is negative when this visit preceded the questionnaire, and positive when it succeeded the questionnaire. †
The definition for monovision was: age 45 or more at the time of the questionnaire, emmetropia in one eye (⫺0.50 ⱕ SE ⬍ 0.50 D) and mild myopia in the other eye (⫺2.50 ⱕ SE ⬍ ⫺0.50 D).
was worse or much worse. Thirty percent of patients declared not being satisfied with their night vision. Night vision complaints included perception of stars around lights (34.3%), halos, fog, or haze around street lights (52.4%), double outline of images (11.6%), ghost images (6.1%), and distortion of details (23.1%). Patients recalled experiencing such symptoms at night before surgery in 15.4% of the cases.
Glare. Only three patients (0.5%) showed a score of 5 for the glare scale (totally satisfied; Fig 5). Patients reported experiencing glare or light sensitivity on sunny days (66.4%), when there is snow (57.9%), when it is foggy (14.2%), or when going from dim to bright lighting (50%). Daytime glare sensitivity was thought to be more bothersome than before surgery by 55% of patients. At night, glare from lights was also believed to be more important
Table 2. Distribution of Preoperative Ametropia According to the Importance of Myopia and Astigmatism* Astigmatism Degree of Myopia (N ⴝ 1380 eyes)
Low: 0 ⱕ Cylinder ⬍ 1
Moderate: 1 ⱕ Cylinder ⬍ 3
Severe: Cylinder ⱖ 3
Low: ⫺6.00 ⱕ SE ⬍ 0 Moderate: ⫺8.00 ⱕ SE ⬍ ⫺6.00 High: ⫺12.00 ⱕ SE ⬍ ⫺8.00 Severe: ⬍ ⫺12.00
604 (43.8%) 136 (9.9%) 65 (4.7%) 7 (0.5%)
290 (21%) 103 (7.5%) 82 (5.9%) 18 (1.3%)
42 (3%) 16 (1.2%) 14 (1%) 3 (0.2%)
SE ⫽ spherical equivalent. *Refractions at the spectacle plane are reported.
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Brunette et al 䡠 Functional Outcome and Satisfaction after PRK
Figure 1. Distribution of the overall satisfaction scale scores.
than before surgery by 54.1%. Glare from oncoming car headlights was reported by 61.5% and was believed to be more bothersome for night driving than before surgery by 55.6%. Night Driving. A total of 645 patients reported driving a car. Of these, 31.1% reported having more difficulty driving at night or during the evening than before surgery because of their vision, and 30.1% reported that since the operation, they preferred to drive more slowly at night because of their vision. Only one patient (0.1%) showed a night driving score of 5 (totally satisfied). Daytime Driving. However, 89.1% of patients reported a daytime driving score of 5. Only 4.5% of patients reported having some difficulty, and 5.5% reported having more difficulty driving during the day than before the operation because of their vision. Ocular Discomfort. A feeling of sand in the eyes, excessive tearing, and sensitivity to smoke were thought to be experienced more often than before the operation by 25.8%, 12.1%, and 36.7% of patients, respectively.
Figure 3. Distribution of the quality of daytime vision with correction scale scores.
Time. Satisfaction was not influenced by the duration of the postoperative follow-up. Weak but statistically significant negative correlations were found between overall patient satisfaction, night vision and night driving scales, and the delay separating the first and last surgeries (Table 3). The longer the delay to the last surgery, the less satisfied was the patient. This was true regardless of whether patients had undergone reoperation (n ⫽ 64) and remained true when only patients with 20/20 postoperative uncorrected vision were considered. Visual Acuity. Uncorrected visual acuity in the best eye at the time of the questionnaire was correlated with all scales, the strongest correlation being observed with night driving problems (Table 3): the lower the vision, the more important the handicap for driving at night. A difference in uncorrected visual acuity between the two eyes was also a source of dissatisfaction. Dissatisfaction increased significantly
when the postoperative uncorrected visual acuity was not as good as the preoperative best-corrected visual acuity. Best-corrected visual acuity and the difference between pre- and postoperative best-corrected visual acuities had no or very little influence on satisfaction scores. Refraction. The global satisfaction score was not affected by the degree of preoperative myopia, preoperative astigmatism, or by the interaction between these two variables. However, the mean spherical equivalent at the time of the questionnaire was positively correlated with all satisfaction scores (Table 3). The surgery was aimed at correction of myopia. Thus overall, the closer to zero the postoperative spherical equivalent, the happier the patient. Patients for whom surgery resulted in hyperopia were not numerous enough to reverse this tendency (the mean spherical equivalent was superior to 0.50 D for 27 patients only, and in no case was it superior to 1.75 D). After surgery, patients did not tolerate large differences in spherical equivalent between their two eyes. Corneal Haze. The grade of the haze at the time of the questionnaire was significantly correlated with all satisfaction scales, especially overall satisfaction and quality of night vision (Table 3). Three measures of haze were shown to have an influence: the grade of the most severe haze of the two eyes, the grade of the least severe, and the mean grade of both eyes. Total Number of Surgeries. The total number of surgeries for both eyes was negatively correlated with satisfaction scores. Patients who had only one successful surgery per eye were more satisfied than patients who needed one or more enhancements. In addition, the global satisfaction score for patients expecting enhancement at the time of the questionnaire (3.68 ⫾ 0.99; n ⫽ 48 patients [7.3%]) was significantly lower than the score for those for whom no enhancement was planned (4.50 ⫾ 0.54; P ⫽ 0.0001). Surgeon. No significant variation in the degree of satisfaction was found between the 12 surgeons for any of the scales. Laser Type. To compare laser types, only patients who underwent surgery with the same laser in both eyes were considered. No
Figure 2. Distribution of the quality of daytime vision without correction scale scores.
Figure 4. Distribution of the quality of night vision scale scores.
Correlations between Satisfaction Scales and Clinical Parameters
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Ophthalmology Volume 107, Number 9, September 2000
Figure 5. Distribution of the glare scale scores.
differences in satisfaction scores were found between the three types of lasers: Technolas 116 (n ⫽ 350), VISX 20/20 (n ⫽ 167), and Nidek (n ⫽ 158).
Discussion We analyzed patient satisfaction and perceived quality of vision after PRK using a self-administered questionnaire with known psychometric properties. Overall satisfaction after excimer laser PRK for low to severe myopia was very good. However, glare and night vision disturbance, especially bothersome for night driving, constituted significant secondary effects that deserve further investigation. These results confirm observations previously reported in the literature.1,2,5–7,9 –11,14 –18 Best-corrected visual acuity at the time of the questionnaire was not correlated with patient satisfaction, probably because most of the patients did not wear glasses since surgery. It is worth noting that even if best-corrected visual acuity is routinely reported in the refractive surgery literature, this parameter is not an indicator of patient satisfaction. It represents more an index of potential improvement of the vision if glasses were to be prescribed. Uncorrected visual acuity results after PRK are traditionally classified as better or worse than 20/20 or 20/40. This classification is useful because 20/40 corresponds to the vision needed for driving. However, it is arbitrary. The relationship between uncorrected visual acuity and satisfaction was found to be linear, indicating that the better the vision, the more satisfied the patient. Evaluation of satisfaction among patients with unilateral refractive surgery has been performed in early reports. This was understandable because excimer laser technology was
Figure 6. Distribution of the daytime driving scale scores.
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Figure 7. Distribution of the night driving scale scores.
new, and careful evaluation of the first eye was required before performing surgery on the second eye. However, PRK is now typically a surgery performed on both eyes. Consequently, except for a very limited category of patients for whom monocular surgery is the final goal (monovision or anisometropia), the success of PRK from the patient’s point of view should be evaluated after bilateral surgery. Otherwise, the outcome of this intervention is masked by the impact of anisometropia, disturbance of dominance, and compensation for visual symptoms by the unoperated eye. How can one explain that patients were so satisfied with their surgery despite the handicaps reported? Although glare, night vision, and night driving problems were shown to influence satisfaction negatively, 96.2% of patients still believed that the operation had been a good choice for them, and 95.7% declared they would still choose to have surgery if they had it to do over. Self-conditioning to the belief in the success of this expensive and irreversible surgery was not assessed in the present study. However, if such a psychological process prevailed, one would expect patients to deny secondary effects such as glare and night vision problems. This was not the case here. Patients may simply adapt to their new condition. A progressive adaptation to a certain degree of visual impairment could possibly be documented with readministration of the questionnaire on several occasions after surgery. An increased level of tolerance could also come from the fact that often patients had glare and halos with contact lenses and glasses before surgery. Finally, as a general rule, it has been documented that when administering a questionnaire to evaluate the outcome of a treatment, general questions about patient satisfaction such as ‘Are you happy with the outcome?’ always lead most respondents to answer in the affirmative. To identify areas of dissatisfaction or areas where there is room for improvement, questions must be more specific.20 Studies of this type confirm that the dimension of the success of refractive surgery, from the patient’s point of view, extends beyond the standard criteria of success, namely refraction and Snellen chart visual acuity measured in ideal conditions of contrast and in the absence of glare. Until problems of glare, halos, and night vision disturbance can be prevented or treated, patients should be told, before surgery, about these potential side effects. Further studies are essential for future improvements in refractive surgery. Prospective studies should include preand postoperative patient self-assessment, as well as func-
Brunette et al 䡠 Functional Outcome and Satisfaction after PRK Table 3. Correlation Coefficients between Clinical Parameters and Satisfaction Scales Scales Clinical Parameters Age Delay between first and last surgery Total no. of surgeries Visual acuity in the best eye at the time of the questionnaire§ UCVA (LogMAR) Difference in UCVA between eyes Decrease in vision between preoperative BCVA and postoperative UCVA BCVA (LogMAR) Decrease in vision between preoperative and postoperative BCVA Sherical equivalent at the time of the questionnaire Mean postoperative SE Difference in SE between eyes Grade of corneal haze at the time of the questionnaire Mean of both eyes Maximum of both eyes Minimum of both eyes
Overall Satisfaction
Uncorrected Day Vision
Night Vision
Daytime Driving
Night Driving
⫺0.097* ⫺0.135† ⫺0.188‡
⫺0.211† ⫺0.076* ⫺0.159†
⫺0.047 ⫺0.120* ⫺0.101*
⫺0.041 ⫺0.077 ⫺0.113*
⫺0.090* ⫺0.134† ⫺0.144*
⫺0.177‡ ⫺0.150‡ ⫺0.216‡ ⫺0.07 ⫺0.115*
⫺0.126† ⫺0.085* ⫺0.167‡ ⫺0.084* ⫺0.137†
⫺0.133† ⫺0.168‡ ⫺0.167‡ ⫺0.059 ⫺0.092*
⫺0.217‡ ⫺0.110* ⫺0.257‡ ⫺0.053 ⫺0.088*
⫺0.243‡ ⫺0.169‡ ⫺0.238‡ ⫺0.128 ⫺0.091*
0.227‡ ⫺0.146†
0.161† ⫺0.111*
0.243‡ ⫺0.084
0.217‡ ⫺0.092
0.328‡ ⫺0.082
⫺0.229‡ ⫺0.240‡ ⫺0.174‡
⫺0.144† ⫺0.136† ⫺0.133†
⫺0.177‡ ⫺0.189‡ ⫺0.128*
⫺0.126* ⫺0.101* ⫺0.145†
⫺0.133* ⫺0.135† ⫺0.109*
BCVA ⫽ best-corrected visual acuity; UCVA ⫽ uncorrected visual acuity. * P ⬍ 0.05. P ⬍ 0.001. P ⬍ 0.0001. § Visual acuities are in LogMAR, which means the lower the value, the better the vision. When squared, r values represent the percentage of explained variance in responses. † ‡
tional evaluation. Glare, contrast sensitivity testing, objective quantification of the optical quality of the eye, including optical aberrations measurements and eventually driving simulation, may be required.
References 1. Al-Kaff AS. Patient satisfaction after photorefractive keratectomy. J Refract Surg 1997;13(Suppl):S459 – 60. 2. Ben-Sira A, Loewenstein A, Lipshitz I, et al. Patient satisfaction after 5.0-mm photorefractive keratectomy for myopia. J Refract Surg 1997;13:129 –34. 3. Fichte CM, Bell AM. Ongoing results of excimer laser photorefractive keratectomy for myopia: subjective patient impressions. J Cataract Refract Surg 1994;20(Suppl):268 –70. 4. Freitas C, Oliveiros BM, Marques E, Leite EB. Effect of photorefractive keratectomy on visual functioning and quality of life. J Refract Surg 1995;11(Suppl):S327–34. 5. Gimbel HV, van Westenbrugge JA, Johnson WH, et al. Visual, refractive, and patient satisfaction results following bilateral photorefractive keratectomy for myopia. Refract Corneal Surg 1993;9(Suppl):S5–10. 6. Halliday BL. Refractive and visual results and patient satisfaction after excimer laser photorefractive keratectomy for myopia. Br J Ophthalmol 1995;79:881–7. 7. Hamberg-Nystro¨m H, Tengroth B, Fagerholm P, et al. Patient satisfaction following photorefractive keratectomy for myopia. J Refract Surg 1995;11(Suppl):S335– 6. 8. Shah S, Perera S, Chatterjee A. Satisfaction after photorefractive keratectomy. J Refract Surg 1998;14:S226 –7. 9. Hersh PS, Stulting RD, Steinert RF, et al. Results of phase III excimer laser photorefractive keratectomy for myopia. Ophthalmology 1997;104:1535–53.
10. Kahle G, Seiler T, Wollensak J. Report on psychosocial findings and satisfaction among patients 1 year after excimer laser photorefractive keratectomy. Refract Corneal Surg 1992;8:286 –9. 11. Pallikaris I, McDonald MB, Siganos D, et al. Tracker-assisted photorefractive keratectomy for myopia of ⫺1 to ⫺6 diopters. J Refract Surg 1996;12:240 –7. 12. Piovella M, Camesasca FI, Fattori C. Excimer laser photorefractive keratectomy for high myopia: four-year experience with a multiple zone technique. Ophthalmology 1997;104:1554 – 65. 13. Rushood AA, Nassim HM, Azeemuddin T. Patient satisfaction after photorefractive keratectomy for low myopia using the visual analogue scale. J Refract Surg 1997;13(Suppl):S438 – 40. 14. Schallhorn CS, Blanton CL, Kaupp SE, et al. Preliminary results of photorefractive keratectomy in active-duty United States Navy personnel. Ophthalmology 1996;103:5–22. 15. Hersh PS, Shah SI. Corneal topography of excimer laser photorefractive keratectomy using a 6-mm beam diameter. Summit PRK Topography Study Group. Ophthalmology 1997;104:1333– 42. 16. Waring GO III. Quality of vision and freedom from optical correction after refractive surgery [editorial]. J Refract Surg 1997;13:213–5. 17. Diamond S. Excimer laser photorefractive keratectomy (PRK) for myopia present status: aerospace considerations [review]. Aviat Space Environ Med 1995;66:690 –3. 18. Quah BL, Wong EYM, Tseng PSF, et al. Analysis of photorefractive keratectomy patients who have not had PRK in their second eye. Ophthalmic Surg Lasers 1996;27(Suppl):S429 –34. 19. Brunette I, Gresset J, Boivin JF, et al. Functional outcome and satisfaction following photorefractive keratectomy. Part 1: development and validation of a survey questionnaire 2000; 107:1783–1789. 20. McGhee CNJ, Orr D, Kidd B, et al. Psychological aspects of excimer laser surgery for myopia: reasons for seeking treatment and patient satisfaction. Br J Ophthalmol 1996;80:874 –9.
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APPENDIX: The Canadian Refractive Surgery Research Group
Research Assistants and Students: He´la Makni, MD2,3 Yves Payette, MSc10
Project Coordinator: Isabelle Brunette, MD, FRCPC1,2
Affiliations:
Epidemiology and Public Health Consultants: He´le`ne Boisjoly, MD, FRCPC, MPH1,2 Jean-Franc¸ois Boivin, MD, ScD, FRCPC3 Jacques Gresset, OD, PhD4,2 Statistical Analysis Consultant: Marie-Claude Guertin, MSc5 Surgeons: Marcel Amyot, MD, FRCPC1,6 Ghislain A. Boudreault, MD, FRCPC7 Michel R. Brunet, MD, FRCPC1,8 Isabelle Brunette, MD, FRCPC1,2,6 Jean-Andre´ De Groot, MD,FRCPC1,2,6 Raymond Duchesne, MD, FRCPC8 Pierre Laflamme, MD, FRCPC1,8 Gilles P. Lafond, MD, FRCPC7,9 Jacques Lemire, MD, FRCPC1,8 Michel Podtetenev, MD, FRCPC1,8 Mihai Pop, MD, FRCPC10,2 Paul Thompson, MD, FRCPC1,8
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1
Department of Ophthalmology, University of Montreal, Montreal, Quebec, Canada. 2 Maisonneuve-Rosemont Hospital Research Centre, Montreal, Quebec, Canada. 3 Department of Epidemiology and Biostatistics, McGill University, Montreal, Quebec, Canada. 4 School of Optometry, University of Montreal, Montreal, Quebec, Canada. 5 Department of Mathematic and Statistics, University of Montreal, Montreal, Quebec, Canada. 6 Le Laser Excimer de l’Hoˆpital Maisonneuve-Rosemont, Montreal, Quebec, Canada. 7 Le Laser Visuel de Que´bec, Quebec City, Quebec, Canada. 8 La Clinique du Laser Visuel, Montreal, Quebec, Canada. 9 Department of Ophthalmology, University of Laval, Quebec City, Quebec, Canada. 10 Cliniques Michel Pop, Montreal, Quebec, Canada.
ing, (page 214)16 “such positive conclusions are often punctuated by a patient adding: But, I wish I saw as sharply as I did with my glasses . . . I wish I didn’t see halos and lines and ghost images.” Glare, halos, and night vision disturbance seem to constitute the principal causes of discomfort
Originally received: August 13, 1999. Accepted: April 21, 2000.
8
Manuscript no. 99557.
1
Department of Ophthalmology, University of Montreal, Montreal, Quebec, Canada. 2
Maisonneuve-Rosemont Hospital Research Centre, Montreal, Quebec, Canada. 3
Le Laser Excimer de l’Hoˆpital Maisonneuve-Rosemont, Montreal, Quebec, Canada. 4
School of Optometry, University of Montreal, Montreal, Quebec, Canada. 5
Department of Epidemiology and Biostatistics, McGill University, Montreal, Quebec, Canada. 6
Cliniques Michel Pop, Montreal, Quebec, Canada.
7
La Clinique du Laser Visuel, Montreal, Quebec, Canada.
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© 2000 by the American Academy of Ophthalmology Published by Elsevier Science Inc.
Le Laser Visuel de Que´bec, Quebec City, Quebec, Canada. Department of Ophthalmology, University of Laval, Quebec City, Quebec, Canada. Presented in part at the Association for Research in Vision and Ophthalmology annual meeting, Fort Lauderdale, Florida, May 1998. Supported in part by the Quebec Research in Vision Network (Fonds de la Recherche en Sante´ du Que´bec), Montreal, Quebec, Canada; the Medical Research Council of Canada (grant no.: 13385), Ottawa, Ontario, Canada; and the Quebec Eye Bank Foundation, Inc., Montreal, Quebec, Canada. Statistical analyses were supported by a grant from the Fonds de la Recherche en Sante´ du Que´bec to the Maisonneuve-Rosemont Hospital Research Centre, Montreal, Quebec, Canada. The authors have no proprietary interest in any aspect of this study. Reprint requests to Isabelle Brunette, MD, Ophthalmology Research Unit, Lavoisier Building, 3rd Floor, Maisonneuve-Rosemont Hospital, 5689 Rosemont Boulevard, Montreal, Quebec, Canada, H1T 2H1. 9
ISSN 0161-6420/00/$–see front matter PII S0161-6420(00)00267-0
Brunette et al 䡠 Functional Outcome and Satisfaction after PRK and dissatisfaction after PRK.1,2,5–7,9 –11,14 –18 The goal of this study was to evaluate patient satisfaction, self-perceived outcome, and subjective visual impairment after bilateral PRK for myopia, with or without astigmatism.
Methods The questionnaire we used was tested for acceptability, reliability, validity, and interpretability. The development of this instrument, administration conditions, and methods of results analysis are described elsewhere.19 Twelve surgeons from four refractive surgery centers participated in the study. In one clinic, the laser used was a VISX 20/20 (VISX, Inc., Santa Clara, CA); in two clinics it was a Technolas 116 (Chiron Technolas, Munich, Germany); and in the fourth clinic, a Technolas 116, was replaced by a Nidek-EC 5000 (Nidek, Tokyo, Japan) in the middle of the study period. We reviewed the charts of all consecutive patients who underwent bilateral PRK for myopia, with or without astigmatism, by one of the 12 surgeons from May 1994 through May 1997. We only included patients for whom, at the time of the mailing, a minimum of 4 months since the last surgery and a maximum of 30 months since the first surgery had elapsed. When, for a single surgeon, more than 250 patients fulfilled the above criteria, patients were randomly selected within this group of eligible patients, up to a total of 250. Reoperation was not an exclusion criterion, but patients with preexisting ocular pathologic conditions or previous ocular surgery other than PRK were excluded. Returned questionnaires were accepted up to December 1997. Informed consent was obtained, and the ethics committee of the Maisonneuve-Rosemont Hospital approved the study. For analysis purposes, items of this questionnaire were grouped in seven distinct scales.19 Each of these scales represented a concept. These included global satisfaction, quality of vision without correction, quality of vision with correction, glare problems, quality of night vision, as well as day and night driving impairments. Scale scores increased with satisfaction, ranging from 1 to 5 (1 ⫽ very dissatisfied, 5 ⫽ very satisfied). Because no clinical examination was usually performed on the day of the questionnaire, clinical information was taken from the last visit or the closest subsequent visit for stable patients. Because no binocular visual acuity measurement was usually available, visual acuity of the best eye was used. For statistical analyses, visual acuities in LogMAR were used, which means the lower the value, the better the vision. Pearson r coefficient of correlation, Kruskal-Wallis one-way analysis of variance, and chi-square tests were used to assess relationships between variables. The strength of the correlation between two variables was defined as strong (r ⱖ 0.60), moderate (0.30 ⱕ r ⬍ 0.60), or weak (0.10 ⱕ r ⬍ 0.30).
Results A total of 973 patients were eligible. Of these, 44 were excluded because of an incorrect address (n ⫽ 43) or death (n ⫽ 1). A total of 929 questionnaires were sent. Because 239 patients either declined to participate (n ⫽ 71) or did not return the questionnaire (n ⫽ 168), we report on the remaining 690 patients who answered and returned the questionnaire. Population characteristics are listed in Tables 1 and 2. Nonrespondents were studied separately. They were slightly younger (mean age, 34.4 years; range, 17.6 – 61.3 years) than respondents (mean age, 38.0 years; range, 18.0 – 61.4 years). No other differences were found between respondents and nonrespondents.
Patient Satisfaction and Self-perceived Outcome Motivation for Surgery. The patients’ main motivations for wanting surgical correction of their myopia were: to be less dependent on glasses (18.6%), to have better vision after the operation than before the operation with glasses or contact lenses (16.9%), hated wearing glasses (16.2%), did not tolerate contact lenses (14.7%), and for professional reasons (8.9%). Although patients of both genders estimated that refractive surgery had improved their physical appearance, improvement of aesthetic appearance and self-confidence was a slightly more significant issue for women (main issue for 10.3% of women) than for men (main issue for 5.8% of men), who tended to be more concerned about comfort without glasses or contact lenses and performance in sports (main issue for 31.8% of men vs. 24.1% of women; P ⫽ 0.026). Overall Satisfaction. The distribution of the scores for the seven satisfaction scales is illustrated in Figures 1 through 7. The level of overall satisfaction was very high, with a mean score of 4.42 of a maximum of 5; 96.3% of patients reported that their main goal had been achieved, 91.8% considered themselves to be satisfied or very satisfied with the result of their operation, 96.2% thought that the operation had been a good choice for them, and 95.7% declared that if they had it to do over, they would still choose to have the operation performed. The operation allowed an improvement in the quality of life at work in 78.9% of patients, their social life in 78.1% of patients, and their family life in 66.6% of patients, when applicable. Quality of Daytime Vision without Correction. The quality of daytime vision without correction was evaluated for all patients. The mean score was 3.33 ⫾ 0.77; 55.3% of the patients characterized their uncorrected vision for distance as slightly or much better than their preoperative corrected vision, 18.1% of patients as slightly or much worse, and 26.4% of patients thought it was the same. More specifically, 41.4% of patients estimated that without glasses or contact lenses, their postoperative vision was better than it was before surgery with glasses or contact lenses for reading street names, driving during the day, watching television, and finding goods at the grocery store; 10.6% of patients estimated it was slightly or much worse. Symptoms reported to be more frequent than before surgery included a double outline of images (13.1%), ghost images (5.4%), blurred vision (19.8%), and distortion of fine details (18.2%). Uncorrected near vision was characterized as slightly or much better than the preoperative corrected vision by 18% of patients, slightly or much worse by 29.4% of patients, and the same by 52.4% of patients. Twenty-three percent of patients estimated they were better able after surgery without correction to read newspaper headlines, newspaper articles, the telephone book, a computer screen, or to thread a needle than they were before surgery with correction. However, 18.6% estimated they were slightly or much worse able to do so. Satisfaction about the quality of uncorrected vision decreased with age (r ⫽ ⫺0.211; P ⫽ 0.0001; Table 3). Quality of Daytime Vision with Correction. Nineteen patients (2.8%) reported regularly wearing glasses for distance vision, and 94 patients (13.6%) reported doing so for near vision. Only 0.6% of patients went back to contact lenses after surgery. The mean score for patients wearing glasses for distance vision was 2.97 ⫾ 0.60. For patients not wearing any type of correction, it was 3.40 ⫾ 0.75 (P ⫽ 0.234). Quality of Night Vision. In 66.1% of patients, night vision was perceived as not being as good as daytime vision, and in 20.2% of patients it was thought to be poor or very poor. Night vision was considered to be the same or better than before surgery by 68.3% of patients. However, 31.7% of patients reported that it
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Ophthalmology Volume 107, Number 9, September 2000 Table 1. Population Characteristics Mean ⴞ SD or % Patients
Characteristics (n ⴝ 690) Age (yrs) Female Time between first and last surgeries (mos) Time between questionnaire and most recent visit (mos)* Patients with repeated surgery Before surgery (n ⴝ 690) Mean SE (diopters [D]) BCVA 20/20 or better BCVA between 20/20 and 20/40 BCVA 20/40 or worse Mean pupil diameter (mm; n ⫽ 266 patients) At the time of the questionnaire Visual acuity in the best eye (n ⴝ 676 patients) UCVA 20/20 or better UCVA between 20/20 and 20/40 UCVA 20/40 or worse Loss of 1 line of BCVA Loss of 2 lines of BCVA Refraction (n ⴝ 489 patients) Mean SE (D) Mean SE within 1.00 D of emmetropia Difference in SE between eyes (D) Monovision (patients)† Grade of corneal haze (n ⴝ 604 patients) Maximum of both eyes Minimum of both eyes Mean of both eyes
38.0 ⫾ 10.2 59.1% 3.3 ⫾ 4.8 ⫺6.0 ⫾ 6.4 9.3% ⫺5.32 ⫾ 2.85 89.2% 10.7% 0.15% 6.8 ⫾ 1.5
Median
Range
38.1
18.0 to 61.4
1.4 ⫺4.4
0 to 29.7 ⫺24.2 to 4.1
⫺4.75
⫺0.38 to ⫺27.75
7.0
2.5 to 9.0
79.7% 18.2% 2.1% 4.7% 0.3% ⫺0.3 ⫾ 0.7 92% 0.5 ⫾ 0.7 42
⫺0.2
0.1 ⫾ 0.3 0.1 ⫾ 0.2 0.1 ⫾ 0.3
⫺6.6 to ⫹1.8
0.2
0 to 4.9
0 0 0
0 to 3 0 to 3 0 to 3
BCVA ⫽ best-corrected visual acuity; SE ⫽ spherical equivalent; UCVA ⫽ uncorrected visual acuity. *The time between the questionnaire and the most recent visit is negative when this visit preceded the questionnaire, and positive when it succeeded the questionnaire. †
The definition for monovision was: age 45 or more at the time of the questionnaire, emmetropia in one eye (⫺0.50 ⱕ SE ⬍ 0.50 D) and mild myopia in the other eye (⫺2.50 ⱕ SE ⬍ ⫺0.50 D).
was worse or much worse. Thirty percent of patients declared not being satisfied with their night vision. Night vision complaints included perception of stars around lights (34.3%), halos, fog, or haze around street lights (52.4%), double outline of images (11.6%), ghost images (6.1%), and distortion of details (23.1%). Patients recalled experiencing such symptoms at night before surgery in 15.4% of the cases.
Glare. Only three patients (0.5%) showed a score of 5 for the glare scale (totally satisfied; Fig 5). Patients reported experiencing glare or light sensitivity on sunny days (66.4%), when there is snow (57.9%), when it is foggy (14.2%), or when going from dim to bright lighting (50%). Daytime glare sensitivity was thought to be more bothersome than before surgery by 55% of patients. At night, glare from lights was also believed to be more important
Table 2. Distribution of Preoperative Ametropia According to the Importance of Myopia and Astigmatism* Astigmatism Degree of Myopia (N ⴝ 1380 eyes)
Low: 0 ⱕ Cylinder ⬍ 1
Moderate: 1 ⱕ Cylinder ⬍ 3
Severe: Cylinder ⱖ 3
Low: ⫺6.00 ⱕ SE ⬍ 0 Moderate: ⫺8.00 ⱕ SE ⬍ ⫺6.00 High: ⫺12.00 ⱕ SE ⬍ ⫺8.00 Severe: ⬍ ⫺12.00
604 (43.8%) 136 (9.9%) 65 (4.7%) 7 (0.5%)
290 (21%) 103 (7.5%) 82 (5.9%) 18 (1.3%)
42 (3%) 16 (1.2%) 14 (1%) 3 (0.2%)
SE ⫽ spherical equivalent. *Refractions at the spectacle plane are reported.
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Brunette et al 䡠 Functional Outcome and Satisfaction after PRK
Figure 1. Distribution of the overall satisfaction scale scores.
than before surgery by 54.1%. Glare from oncoming car headlights was reported by 61.5% and was believed to be more bothersome for night driving than before surgery by 55.6%. Night Driving. A total of 645 patients reported driving a car. Of these, 31.1% reported having more difficulty driving at night or during the evening than before surgery because of their vision, and 30.1% reported that since the operation, they preferred to drive more slowly at night because of their vision. Only one patient (0.1%) showed a night driving score of 5 (totally satisfied). Daytime Driving. However, 89.1% of patients reported a daytime driving score of 5. Only 4.5% of patients reported having some difficulty, and 5.5% reported having more difficulty driving during the day than before the operation because of their vision. Ocular Discomfort. A feeling of sand in the eyes, excessive tearing, and sensitivity to smoke were thought to be experienced more often than before the operation by 25.8%, 12.1%, and 36.7% of patients, respectively.
Figure 3. Distribution of the quality of daytime vision with correction scale scores.
Time. Satisfaction was not influenced by the duration of the postoperative follow-up. Weak but statistically significant negative correlations were found between overall patient satisfaction, night vision and night driving scales, and the delay separating the first and last surgeries (Table 3). The longer the delay to the last surgery, the less satisfied was the patient. This was true regardless of whether patients had undergone reoperation (n ⫽ 64) and remained true when only patients with 20/20 postoperative uncorrected vision were considered. Visual Acuity. Uncorrected visual acuity in the best eye at the time of the questionnaire was correlated with all scales, the strongest correlation being observed with night driving problems (Table 3): the lower the vision, the more important the handicap for driving at night. A difference in uncorrected visual acuity between the two eyes was also a source of dissatisfaction. Dissatisfaction increased significantly
when the postoperative uncorrected visual acuity was not as good as the preoperative best-corrected visual acuity. Best-corrected visual acuity and the difference between pre- and postoperative best-corrected visual acuities had no or very little influence on satisfaction scores. Refraction. The global satisfaction score was not affected by the degree of preoperative myopia, preoperative astigmatism, or by the interaction between these two variables. However, the mean spherical equivalent at the time of the questionnaire was positively correlated with all satisfaction scores (Table 3). The surgery was aimed at correction of myopia. Thus overall, the closer to zero the postoperative spherical equivalent, the happier the patient. Patients for whom surgery resulted in hyperopia were not numerous enough to reverse this tendency (the mean spherical equivalent was superior to 0.50 D for 27 patients only, and in no case was it superior to 1.75 D). After surgery, patients did not tolerate large differences in spherical equivalent between their two eyes. Corneal Haze. The grade of the haze at the time of the questionnaire was significantly correlated with all satisfaction scales, especially overall satisfaction and quality of night vision (Table 3). Three measures of haze were shown to have an influence: the grade of the most severe haze of the two eyes, the grade of the least severe, and the mean grade of both eyes. Total Number of Surgeries. The total number of surgeries for both eyes was negatively correlated with satisfaction scores. Patients who had only one successful surgery per eye were more satisfied than patients who needed one or more enhancements. In addition, the global satisfaction score for patients expecting enhancement at the time of the questionnaire (3.68 ⫾ 0.99; n ⫽ 48 patients [7.3%]) was significantly lower than the score for those for whom no enhancement was planned (4.50 ⫾ 0.54; P ⫽ 0.0001). Surgeon. No significant variation in the degree of satisfaction was found between the 12 surgeons for any of the scales. Laser Type. To compare laser types, only patients who underwent surgery with the same laser in both eyes were considered. No
Figure 2. Distribution of the quality of daytime vision without correction scale scores.
Figure 4. Distribution of the quality of night vision scale scores.
Correlations between Satisfaction Scales and Clinical Parameters
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Figure 5. Distribution of the glare scale scores.
differences in satisfaction scores were found between the three types of lasers: Technolas 116 (n ⫽ 350), VISX 20/20 (n ⫽ 167), and Nidek (n ⫽ 158).
Discussion We analyzed patient satisfaction and perceived quality of vision after PRK using a self-administered questionnaire with known psychometric properties. Overall satisfaction after excimer laser PRK for low to severe myopia was very good. However, glare and night vision disturbance, especially bothersome for night driving, constituted significant secondary effects that deserve further investigation. These results confirm observations previously reported in the literature.1,2,5–7,9 –11,14 –18 Best-corrected visual acuity at the time of the questionnaire was not correlated with patient satisfaction, probably because most of the patients did not wear glasses since surgery. It is worth noting that even if best-corrected visual acuity is routinely reported in the refractive surgery literature, this parameter is not an indicator of patient satisfaction. It represents more an index of potential improvement of the vision if glasses were to be prescribed. Uncorrected visual acuity results after PRK are traditionally classified as better or worse than 20/20 or 20/40. This classification is useful because 20/40 corresponds to the vision needed for driving. However, it is arbitrary. The relationship between uncorrected visual acuity and satisfaction was found to be linear, indicating that the better the vision, the more satisfied the patient. Evaluation of satisfaction among patients with unilateral refractive surgery has been performed in early reports. This was understandable because excimer laser technology was
Figure 6. Distribution of the daytime driving scale scores.
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Figure 7. Distribution of the night driving scale scores.
new, and careful evaluation of the first eye was required before performing surgery on the second eye. However, PRK is now typically a surgery performed on both eyes. Consequently, except for a very limited category of patients for whom monocular surgery is the final goal (monovision or anisometropia), the success of PRK from the patient’s point of view should be evaluated after bilateral surgery. Otherwise, the outcome of this intervention is masked by the impact of anisometropia, disturbance of dominance, and compensation for visual symptoms by the unoperated eye. How can one explain that patients were so satisfied with their surgery despite the handicaps reported? Although glare, night vision, and night driving problems were shown to influence satisfaction negatively, 96.2% of patients still believed that the operation had been a good choice for them, and 95.7% declared they would still choose to have surgery if they had it to do over. Self-conditioning to the belief in the success of this expensive and irreversible surgery was not assessed in the present study. However, if such a psychological process prevailed, one would expect patients to deny secondary effects such as glare and night vision problems. This was not the case here. Patients may simply adapt to their new condition. A progressive adaptation to a certain degree of visual impairment could possibly be documented with readministration of the questionnaire on several occasions after surgery. An increased level of tolerance could also come from the fact that often patients had glare and halos with contact lenses and glasses before surgery. Finally, as a general rule, it has been documented that when administering a questionnaire to evaluate the outcome of a treatment, general questions about patient satisfaction such as ‘Are you happy with the outcome?’ always lead most respondents to answer in the affirmative. To identify areas of dissatisfaction or areas where there is room for improvement, questions must be more specific.20 Studies of this type confirm that the dimension of the success of refractive surgery, from the patient’s point of view, extends beyond the standard criteria of success, namely refraction and Snellen chart visual acuity measured in ideal conditions of contrast and in the absence of glare. Until problems of glare, halos, and night vision disturbance can be prevented or treated, patients should be told, before surgery, about these potential side effects. Further studies are essential for future improvements in refractive surgery. Prospective studies should include preand postoperative patient self-assessment, as well as func-
Brunette et al 䡠 Functional Outcome and Satisfaction after PRK Table 3. Correlation Coefficients between Clinical Parameters and Satisfaction Scales Scales Clinical Parameters Age Delay between first and last surgery Total no. of surgeries Visual acuity in the best eye at the time of the questionnaire§ UCVA (LogMAR) Difference in UCVA between eyes Decrease in vision between preoperative BCVA and postoperative UCVA BCVA (LogMAR) Decrease in vision between preoperative and postoperative BCVA Sherical equivalent at the time of the questionnaire Mean postoperative SE Difference in SE between eyes Grade of corneal haze at the time of the questionnaire Mean of both eyes Maximum of both eyes Minimum of both eyes
Overall Satisfaction
Uncorrected Day Vision
Night Vision
Daytime Driving
Night Driving
⫺0.097* ⫺0.135† ⫺0.188‡
⫺0.211† ⫺0.076* ⫺0.159†
⫺0.047 ⫺0.120* ⫺0.101*
⫺0.041 ⫺0.077 ⫺0.113*
⫺0.090* ⫺0.134† ⫺0.144*
⫺0.177‡ ⫺0.150‡ ⫺0.216‡ ⫺0.07 ⫺0.115*
⫺0.126† ⫺0.085* ⫺0.167‡ ⫺0.084* ⫺0.137†
⫺0.133† ⫺0.168‡ ⫺0.167‡ ⫺0.059 ⫺0.092*
⫺0.217‡ ⫺0.110* ⫺0.257‡ ⫺0.053 ⫺0.088*
⫺0.243‡ ⫺0.169‡ ⫺0.238‡ ⫺0.128 ⫺0.091*
0.227‡ ⫺0.146†
0.161† ⫺0.111*
0.243‡ ⫺0.084
0.217‡ ⫺0.092
0.328‡ ⫺0.082
⫺0.229‡ ⫺0.240‡ ⫺0.174‡
⫺0.144† ⫺0.136† ⫺0.133†
⫺0.177‡ ⫺0.189‡ ⫺0.128*
⫺0.126* ⫺0.101* ⫺0.145†
⫺0.133* ⫺0.135† ⫺0.109*
BCVA ⫽ best-corrected visual acuity; UCVA ⫽ uncorrected visual acuity. * P ⬍ 0.05. P ⬍ 0.001. P ⬍ 0.0001. § Visual acuities are in LogMAR, which means the lower the value, the better the vision. When squared, r values represent the percentage of explained variance in responses. † ‡
tional evaluation. Glare, contrast sensitivity testing, objective quantification of the optical quality of the eye, including optical aberrations measurements and eventually driving simulation, may be required.
References 1. Al-Kaff AS. Patient satisfaction after photorefractive keratectomy. J Refract Surg 1997;13(Suppl):S459 – 60. 2. Ben-Sira A, Loewenstein A, Lipshitz I, et al. Patient satisfaction after 5.0-mm photorefractive keratectomy for myopia. J Refract Surg 1997;13:129 –34. 3. Fichte CM, Bell AM. Ongoing results of excimer laser photorefractive keratectomy for myopia: subjective patient impressions. J Cataract Refract Surg 1994;20(Suppl):268 –70. 4. Freitas C, Oliveiros BM, Marques E, Leite EB. Effect of photorefractive keratectomy on visual functioning and quality of life. J Refract Surg 1995;11(Suppl):S327–34. 5. Gimbel HV, van Westenbrugge JA, Johnson WH, et al. Visual, refractive, and patient satisfaction results following bilateral photorefractive keratectomy for myopia. Refract Corneal Surg 1993;9(Suppl):S5–10. 6. Halliday BL. Refractive and visual results and patient satisfaction after excimer laser photorefractive keratectomy for myopia. Br J Ophthalmol 1995;79:881–7. 7. Hamberg-Nystro¨m H, Tengroth B, Fagerholm P, et al. Patient satisfaction following photorefractive keratectomy for myopia. J Refract Surg 1995;11(Suppl):S335– 6. 8. Shah S, Perera S, Chatterjee A. Satisfaction after photorefractive keratectomy. J Refract Surg 1998;14:S226 –7. 9. Hersh PS, Stulting RD, Steinert RF, et al. Results of phase III excimer laser photorefractive keratectomy for myopia. Ophthalmology 1997;104:1535–53.
10. Kahle G, Seiler T, Wollensak J. Report on psychosocial findings and satisfaction among patients 1 year after excimer laser photorefractive keratectomy. Refract Corneal Surg 1992;8:286 –9. 11. Pallikaris I, McDonald MB, Siganos D, et al. Tracker-assisted photorefractive keratectomy for myopia of ⫺1 to ⫺6 diopters. J Refract Surg 1996;12:240 –7. 12. Piovella M, Camesasca FI, Fattori C. Excimer laser photorefractive keratectomy for high myopia: four-year experience with a multiple zone technique. Ophthalmology 1997;104:1554 – 65. 13. Rushood AA, Nassim HM, Azeemuddin T. Patient satisfaction after photorefractive keratectomy for low myopia using the visual analogue scale. J Refract Surg 1997;13(Suppl):S438 – 40. 14. Schallhorn CS, Blanton CL, Kaupp SE, et al. Preliminary results of photorefractive keratectomy in active-duty United States Navy personnel. Ophthalmology 1996;103:5–22. 15. Hersh PS, Shah SI. Corneal topography of excimer laser photorefractive keratectomy using a 6-mm beam diameter. Summit PRK Topography Study Group. Ophthalmology 1997;104:1333– 42. 16. Waring GO III. Quality of vision and freedom from optical correction after refractive surgery [editorial]. J Refract Surg 1997;13:213–5. 17. Diamond S. Excimer laser photorefractive keratectomy (PRK) for myopia present status: aerospace considerations [review]. Aviat Space Environ Med 1995;66:690 –3. 18. Quah BL, Wong EYM, Tseng PSF, et al. Analysis of photorefractive keratectomy patients who have not had PRK in their second eye. Ophthalmic Surg Lasers 1996;27(Suppl):S429 –34. 19. Brunette I, Gresset J, Boivin JF, et al. Functional outcome and satisfaction following photorefractive keratectomy. Part 1: development and validation of a survey questionnaire 2000; 107:1783–1789. 20. McGhee CNJ, Orr D, Kidd B, et al. Psychological aspects of excimer laser surgery for myopia: reasons for seeking treatment and patient satisfaction. Br J Ophthalmol 1996;80:874 –9.
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APPENDIX: The Canadian Refractive Surgery Research Group
Research Assistants and Students: He´la Makni, MD2,3 Yves Payette, MSc10
Project Coordinator: Isabelle Brunette, MD, FRCPC1,2
Affiliations:
Epidemiology and Public Health Consultants: He´le`ne Boisjoly, MD, FRCPC, MPH1,2 Jean-Franc¸ois Boivin, MD, ScD, FRCPC3 Jacques Gresset, OD, PhD4,2 Statistical Analysis Consultant: Marie-Claude Guertin, MSc5 Surgeons: Marcel Amyot, MD, FRCPC1,6 Ghislain A. Boudreault, MD, FRCPC7 Michel R. Brunet, MD, FRCPC1,8 Isabelle Brunette, MD, FRCPC1,2,6 Jean-Andre´ De Groot, MD,FRCPC1,2,6 Raymond Duchesne, MD, FRCPC8 Pierre Laflamme, MD, FRCPC1,8 Gilles P. Lafond, MD, FRCPC7,9 Jacques Lemire, MD, FRCPC1,8 Michel Podtetenev, MD, FRCPC1,8 Mihai Pop, MD, FRCPC10,2 Paul Thompson, MD, FRCPC1,8
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1
Department of Ophthalmology, University of Montreal, Montreal, Quebec, Canada. 2 Maisonneuve-Rosemont Hospital Research Centre, Montreal, Quebec, Canada. 3 Department of Epidemiology and Biostatistics, McGill University, Montreal, Quebec, Canada. 4 School of Optometry, University of Montreal, Montreal, Quebec, Canada. 5 Department of Mathematic and Statistics, University of Montreal, Montreal, Quebec, Canada. 6 Le Laser Excimer de l’Hoˆpital Maisonneuve-Rosemont, Montreal, Quebec, Canada. 7 Le Laser Visuel de Que´bec, Quebec City, Quebec, Canada. 8 La Clinique du Laser Visuel, Montreal, Quebec, Canada. 9 Department of Ophthalmology, University of Laval, Quebec City, Quebec, Canada. 10 Cliniques Michel Pop, Montreal, Quebec, Canada.