- Email: [email protected]
Chronic angle-closure with glaucomatous damage
Chronic Angle-closure with Glaucomatous Damage Long-term Clinical Course in a North American Population and Comparison with an Asian Population Mohamad Rosman, MRCSEd (Ophth), MMed (Ophth),1,2 Tin Aung, FRCS (Ed), FRCOphth,1 Leonard P. K. Ang, FRCS (Ed),1 Paul T. K. Chew, FRCS (Ed), FRCOphth,1,3 Jeffrey M. Liebmann, MD, FACS,4,5 Robert Ritch, FACS, FRCOphth4,5 Purpose: To study the long-term clinical course of North American chronic angle-closure glaucoma (CACG) patients with optic disc damage and visual field loss in the presence of an angle closed at least partially by peripheral anterior synechiae and to compare it with a similar group of Singaporean patients. Design: A retrospective, interventional case-control study series. Participants: Fifty-one patients (80 eyes) diagnosed with CACG with glaucomatous optic nerve head and visual field damage at a New York hospital from January 1990 through December 1994. All study eyes underwent laser peripheral iridotomy (LPI). Methods: The presenting features, management, and subsequent long-term intraocular pressure (IOP) outcome were analyzed and compared with 65 Asian patients (83 eyes) from a Singapore hospital who were similarly diagnosed during the same period. Main Outcome Measures: The long-term outcome after LPI was assessed in terms of IOP and the requirement for additional therapy. Results: The mean presenting IOP was higher in the Singapore eyes (40 ⫾ 15 mmHg) compared with the New York eyes (31 ⫾ 12.5 mmHg). All 80 New York eyes (100%) and 78 of 83 Singapore eyes (94%) required further treatment to control IOP during follow-up. Of the eyes with a subsequent rise in IOP, 33 of 80 eyes (41.3%) compared with 34 of 83 eyes (41.0%) of the Singapore patients were controlled with additional topical medication. Of the New York eyes, 25 of 80 (31.3%) eventually underwent filtering surgery, compared with 44 of 83 (53.0%) in the Singapore study. The other 22 eyes (27.5%) in the New York group went on to additional laser procedures, peripheral iridoplasty, laser trabeculoplasty, or a combination thereof, after which IOPs were controlled and no surgery was required. There was no similar comparison for the Singapore group, because these eyes went directly on to surgery. Conclusions: Despite the presence of a patent LPI, most eyes with CACG presenting with elevated IOP and having both optic disc and visual field damage in both populations required further treatment to control IOP. Results in the American population are similar to that reported in Asian patients. Ophthalmology 2002;109: 2227–2231 © 2002 by the American Academy of Ophthalmology.
Laser peripheral iridotomy (LPI) is the definitive treatment to relieve pupillary block in primary angle-closure glauco-
Originally received: September 5, 2001. Accepted: May 3, 2002. Manuscript no. 210758. 1 Singapore National Eye Centre, Singapore, Republic of Singapore. 2 Singapore Armed Forces, Singapore, Republic of Singapore. 3 National University of Singapore, Singapore, Republic of Singapore. 4 New York Eye and Ear Infirmary, New York, New York. 5 New York Medical College, Valhalla, New York. Presented at the annual meeting of the Association for Research in Vision and Ophthalmology, Fort Lauderdale, Florida, April 2001; and the Nineteenth Singapore-Malaysia Ophthalmological Conference, Penang, Malaysia, June 2001. © 2002 by the American Academy of Ophthalmology. Published by Elsevier Science Inc.
ma.1– 6 Any persistent or subsequent intraocular pressure (IOP) elevation is treated in a stepwise fashion, first medically or with laser trabeculoplasty, and then surgically if necessary. Argon laser peripheral iridoplasty (ALPI) is in-
Supported in part by the Martin Lewis and Diane Brandt Research Fund of the New York Glaucoma Research Institute, New York, New York; and the Department of Ophthalmology, National University Hospital, Singapore, Republic of Singapore. The authors have no commercial interest in the products or devices mentioned herein. Correspondence and reprint requests to Paul T. K. Chew, FRCS (Ed), FRCOphth, Department of Ophthalmology, National University Hospital. 5, Lower Kent Ridge Road, Main Building, Level 3, S119074, Singapore, Republic of Singapore. E-mail: [email protected]. ISSN 0161-6420/02/$–see front matter PII S0161-6420(02)01275-7
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Ophthalmology Volume 109, Number 12, December 2002 dicated for persistent appositional angle closure. Published studies in white populations using this approach found it to be effective and safe, with a low incidence of eventual trabeculectomy.2– 4 However, these studies defined angleclosure glaucoma based on the presence of a closed angle and did not use a definition parallel to that for open-angle glaucoma, that is, the presence of optic disc and visual field damage. For example, fellow eyes of acute angle-closure glaucoma attacks,2–3,5 eyes with narrow angles,3,5 and eyes with closed angles but without glaucomatous disc cupping2– 6 were included. A recent report from Singapore found that LPI alone did not prevent most eyes with chronic angle-closure glaucoma (CACG) and glaucomatous damage from developing a clinically significant rise in IOP during extended follow-up.7 Chronic angle-closure glaucoma was defined as presence of glaucomatous optic neuropathy and compatible visual field loss, in association with an angle in which at least 180° of trabecular meshwork was not visible on gonioscopy and with evidence of peripheral anterior synechiae (PAS) in any part of the angle. Most of those in whom a rise in IOP developed after LPI experienced the rise within the first 6 months. Most eyes (53%) eventually required filtering surgery. A study in South Africa on a mixed-race population produced similar results.6 The question remains as to whether there may be racial differences in outcomes between whites and nonwhites in the long-term clinical course of eyes with CACG. We investigated this by reviewing the outcome of similar patients in New York City and comparing the results with the findings of the Singapore study.
Table 1. Demographic Features of the New York Study Population No. of Patients Gender Male Female Age (mean ⫾ standard deviation, years) Race White Black Hispanic
%
22 29 68.2 ⫾ 9.4
43.1% 56.9%
15 15 21
29.5% 29.5% 41.0%
study, a rise in IOP during follow-up was defined as IOP of more than 21 mmHg requiring treatment by medication or surgery (as deemed necessary by the clinician involved). This was not standardized but was dependent on the observer. The data collected from the New York patients was then compared with a similar Singaporean population treated during the same period.7 The inclusion and exclusion criteria and data extraction methods used were similar. Statistical analysis was carried out using the Statistical Package for Social Sciences version 8.0 (SPSS Inc., Chicago, IL). Parametric and nonparametric tests of significance were carried out where appropriate. Comparisons between groups were performed with Mann–Whitney U tests for continuous variables that are not distributed normally. Chi-square analysis was used for comparison of proportions. All statistical tests were conducted at a 5% level of significance.
Results Materials and Methods We reviewed the charts of patients who underwent LPI for CACG at the New York Eye and Ear Infirmary between January 1990 and December 1994. The term chronic angle-closure glaucoma has been by convention used to describe an eye in which portions of the anterior chamber angle are permanently closed by PAS, regardless of the presence or absence of glaucomatous damage and even elevated IOP. Variable and sometimes conflicting terminology has been used to describe somewhat differently appearing forms. For purposes of the present study, CACG was defined as the presence of a gonioscopically occludable angle accompanied by glaucomatous optic neuropathy and compatible reproducible visual field loss. An occludable angle was defined as the presence of at least 180° of angle in which the trabecular meshwork was not visible on gonioscopy and with evidence of PAS in any part of the angle. Thus, CACG as used here equals a restricted definition of chronic angle-closure glaucoma, that is, those eyes with actual glaucomatous damage. Patients with closed angles who had an acute symptomatic episode of raised IOP (acute angle closure) were included only if they also had optic nerve damage with visual field loss. Patients with less than 9 months of follow-up were excluded, as were those with secondary angle closure resulting from iris neovascularization, uveitis, trauma, lens intumescence, or lens subluxation. Demographic and ophthalmic data recorded in each case included age, gender, race, dates of presentation and onset of symptoms, presenting IOP, gonioscopic findings, and the treatment instituted. The long-term outcome after LPI was assessed in terms of IOP and the requirement for additional therapy. For the purposes of this
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A total of 51 patients (80 eyes) with CACG had LPI performed at the New York Eye and Ear Infirmary between January 1990 and December 1994 and had least 9 months of follow-up. The demographic features are listed in Table 1. There were 22 men (43.1%) and 29 women (56.9%). The mean age of the patients was 68.2 ⫾ 9.4 years. Subjects were white, black, or Hispanic. The mean follow-up was 56 ⫾ 34 months. Of the 51 patients, 11 patients (12 eyes) had a past documented history of an episode of symptomatic acute angle closure. In all 80 eyes, a rise in IOP developed that required medical treatment despite the presence of a patent LPI. Thirty-three eyes (41.3%) were controlled with LPI and medication alone, and 25 eyes (31.3%) eventually required filtering surgery to control IOP. Of the 25 patients, 24 eyes underwent trabeculectomy, whereas 1 eye had Baerveldt implant surgery. The treatment outcome is summarized in Table 2. The rise in IOP was detected in the first 6 months after LPI in 65 eyes (81.3%). The time interval for the subsequent rise in IOP is shown in Table 3.
Comparison with Singaporean Population We compared the long-term outcome of LPI in our study population with that of 65 Singaporean patients (83 eyes) who underwent LPI during the same time period. The presenting clinical features are summarized in Table 4. The mean follow-up period for the New York and the Singapore group were 56 ⫾ 34 months and 60 ⫾ 29 months, respectively (P ⫽ 0.23). The mean presenting IOP was higher in the Singapore group (40 ⫾ 15 mmHg) compared with the New York group (31 ⫾ 12.5 mmHg; P ⬍ 0.001). The presenting vertical cup-to-disc ratio was similar: 0.7 ⫾ 0.2 in the
Rosman et al 䡠 Chronic Angle-closure with Glaucomatous Damage Table 2. Long-term Treatment Required for New York Eyes with Primary Angle-closure Glaucoma No. of Eyes
Outcome Eyes with no increase in IOP after LPI Eyes Requiring medication with or without other procedures Eyes controlled only with LPI and medications Eyes requiring medication and iridoplasty or laser trabeculoplasty Eyes requiring filtering surgery Total
0 80 (100.0%) 33 (41.3%) 22 (27.5%) 25 (31.3%) 80
IOP ⫽ intraocular pressure; LPI ⫽ laser peripheral iridectomy.
New York group compared with 0.6 ⫾ 0.2 in the Singapore group (P ⫽ 0.013). The vast majority of eyes in both populations required further treatment to control IOP despite the presence of a patent LPI. All the eyes in New York group experienced a rise in IOP requiring further treatment after LPI, whereas only 5 of 83 eyes (6.0%) in the Singapore group did not require further treatment (P ⫽ 0.59). Of the eyes with subsequent rise in IOP, 33 of 80 eyes (41.3%) compared with 34 of 83 eyes (41.0%) in the Singapore group were controlled with additional topical medication (P ⫽ 0.269). Twenty-five of 80 eyes (31.3%) in the New York group eventually underwent filtering surgery, as compared with 44 of 83 eyes (53.0%) in the Singapore study (P ⫽ 0.005). The other 22 eyes in the New York group went on to additional laser procedures, such as ALPI, argon laser trabeculoplasty, or both, after which IOPs were controlled and surgery was not required. There was no similar subgroup in the Singapore study, because patients went directly on to filtering surgery. The comparisons between the two groups are summarized in Table 5.
Discussion The terminology for angle closure is used inconsistently throughout the literature. The term acute angle-closure glaucoma has been used to describe eyes with normal optic discs and visual fields, whereas chronic angle-closure glaucoma has been used to describe eyes with PAS despite normal IOP, discs, and fields. In this study, we delineated a subset of CACG to eyes with actual glaucomatous damage,8 defining the term glaucoma the way it is used in eyes with open angles. The disparity in our results compared with previous studies on laser or surgical iridectomy in white patients4,9 –12 may actually be explained by this variation in Table 3. Time Interval for Rise in Intraocular Pressure after Successful Laser Peripheral Iridectomy (in Months after Laser Peripheral Iridectomy) in New York Eyes Duration (mos) ⬍1 ⬎1–6 ⬎6–12 ⬎12 Total
Table 4. Presenting Features of the New York and Singaporean Study Population
No. of Eyes 54 (67.5%) 11 (13.8%) 4 (5.0%) 11 (13.8%) 80
New York Singapore
P Value
Age (mean ⫾ SD, yrs) 68.2 ⫾ 9.2 60.8 ⫾ 9.0 Follow-up period (mean ⫾ SD, mos) 56 ⫾ 34 63 ⫾ 29 Presenting IOP (mmHg) 31 ⫾ 12.5 40 ⫾ 15 Presenting vertical cup-to-disc ratio 0.7 ⫾ 0.2 0.6 ⫾ 0.2
⬍0.001 0.230 ⬍0.001 0.013
IOP ⫽ intraocular pressure; SD ⫽ standard deviation.
definition. Previous studies included a variety of diagnoses such as narrow angles,4,11 fellow eyes,3,4,9 –11 and acute angle closure2,3,9 –11 with or without detectable glaucomatous damage. In these eyes, LPI alone often may be successful in controlling IOP. In contrast, because our patients had glaucomatous optic neuropathy and visual field loss, they are likely to have more longstanding or advanced disease and may be less amenable to treatment by LPI alone. Some earlier studies in white populations also found limitations of iridectomy in controlling IOP in patients with CACG. In patients with chronic angle closure and visual field loss, surgical peripheral iridectomy was able to control IOP in only 21% of eyes.13 Laser iridotomy did not eliminate the need for antiglaucoma therapy in patients with CACG.10 In 19 eyes with uncontrolled CACG, 13 required medications after LPI and 6 were uncontrollable even with medications.4 Although this study found that patients with CACG almost always require additional medical or laser treatment beyond LPI, LPI to eliminate any element of pupillary block remains the appropriate initial therapy for CACG when glaucomatous optic disc and visual field damage is present. Approximately two thirds of CACG patients (68.7%) actually were managed by LPI plus medication or further laser, avoiding the need for filtering surgery with its potential complications. This is actually a respectable record for eyes with fairly advanced disease and may even rival long-term success rates of trabeculectomy. Adopting such an approach, however, requires patients to be monitored closely during follow-up to detect progression of glaucomatous damage and intervening with further treatment when necessary. Surgery may be a reasonable alternative for some patients whose IOP remains elevated and who have moderate Table 5. Comparison of Long-term Outcomes of the New York and Singapore Study Populations Outcome Eyes needing further treatment Eyes medically controlled Eyes needing laser or surgical intervention Eyes requiring filtering surgery Total
New York
Singapore
P Value
80 (100%)
78 (94.0%)
0.590
33 (41.3%)
34 (41.0%)
0.269
47 (58.8%)
44 (53.0%)
0.891
25 (31.3%)
44 (53.0%)
0.005
80
83
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Ophthalmology Volume 109, Number 12, December 2002 or severe glaucomatous damage after LPI for CACG. If the angle remains appositionally closed after LPI, ALPI should be performed to open the angle to the greatest extent possible (i.e., that portion not closed by PAS). If sufficient open angle is present to allow argon laser trabeculoplasty, this may be performed also before surgical intervention. The optimum timing of surgery is not established. Early surgery in CACG has been advocated in certain groups of patients, such as those with severe glaucomatous optic nerve damage and visual field loss at presentation,13,14 and those with more than 50% to 75% of the angle closed by PAS on indentation gonioscopy.13,15,16 There is a lack of consensus on the best approach to the surgical management of CACG, as well as scarcity of information on the long-term results of surgery in this condition. The surgical options are diverse, including filtering surgery,17 lens extraction,18 –20 combined lens extraction and filtering surgery, angle-widening procedures such as goniosynechialysis,21 and angle-widening procedures combined with lens extraction.22 The number of options is complicated further by the method of lens extraction, be it phacoemulsification or extracapsular cataract extraction, the use of antimetabolites, and the number and choice of surgical sites in combined surgery. Clinical trials are necessary to evaluate the best method and optimum timing of surgical treatment in CACG. Argon laser peripheral iridoplasty is a simple and effective means of opening an appositionally closed angle in situations in which laser iridotomy does not physically eliminate appositional angle-closure because mechanisms other than pupillary block are present.23,24 The procedure consists of placing contraction burns (long duration, low power, and large spot size) in the extreme iris periphery to compact at the site of the burn and contract the iris stroma between the site of the burn and the angle, physically pulling open the angle. Seven eyes in the New York group underwent ALPI, after which IOPs were controlled and surgery was not required. There was no similar subgroup in the Singapore study, because patients went directly on to filtering surgery. It is possible that the lower eventual rate of surgery in the New York series was the result of the effectiveness of ALPI. However, in one series, iridoplasty was not found to be effective in lowering the IOP in some eyes with CACG in which medical therapy had already failed,24 although it is observed that the laser settings used in this study differed from the standard.23 The optimum timing for iridoplasty may be earlier in the course of the disease in patients who have mild damage, had successful LPI and yet show residual appositional closure. This study was limited by being retrospective with variable follow-up of subjects. Because there were several ophthalmologists involved in the care of the patients, standardized documentation was not available in all cases. The review was conducted in a New York hospital, and the study population consisted of whites, blacks, and Hispanics. This may not necessarily be representative of populations in other parts of the North America. Nevertheless, this study provides us with important information regarding the longterm clinical course of CACG after LPI in American eyes. The study also was unique because it used similar methods
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to an analogous study in Singapore, allowing comparisons to be made between the two populations. In conclusion, the results of this study suggest that LPI alone is not adequate as long-term therapy in North American eyes with CACG, and patients almost always require additional medical or laser treatment. The similar results found in the New York and Singapore patients make it unlikely that there is any racial or ethnic difference in the severity of the clinical course. The challenge for clinicians managing such patients is to identify the subgroup of patients who will be treated adequately with LPI alone versus those in whom the disease goes on developing despite LPI. Our inability to prognosticate this difference in behavior makes it difficult for us to follow-up patients appropriately and to advise prompt and optimum treatment in those at risk of further visual loss. There is a pressing need for further research into this major cause of world blindness.
References 1. Ritch R. The treatment of chronic angle-closure glaucoma. Ann Ophthalmol 1981;13:21–3. 2. Robin AL, Pollack IP. Argon laser peripheral iridotomies in the treatment of primary angle closure glaucoma: long-term follow-up. Arch Ophthalmol 1982;100:919 –23. 3. Quigley HA. Long-term follow-up of laser iridotomy. Ophthalmology 1981;88:218 –24. 4. Gieser DK, Wilensky JT. Laser iridectomy in the management of chronic angle-closure glaucoma. Am J Ophthalmol 1984; 98:446 –50. 5. Schwartz LW, Moster MR, Spaeth GL, et al. NeodymiumYAG laser iridectomies in glaucoma associated with closed or occludable angles. Am J Ophthalmol 1986;102:41– 4. 6. Salmon JF. Long-term intraocular pressure control after NdYAG laser iridotomy in chronic angle-closure glaucoma. J Glaucoma 1993;2:291– 6. 7. Alsagoff Z, Aung T, Ang LPK, Chew PTK. Long-term clinical course of primary angle-closure glaucoma in an Asian population. Ophthalmology 2000;107:2300 – 4. 8. Foster PJ, Johnson GJ. Primary angle-closure: classification and clinical features. In: Hitchings RA, ed. Glaucoma. London: BMJ, 2000;145–52. Fundamentals of Clinical Ophthalmology Series. 9. Krupin T, Mitchell KB, Johnson MF, Becker B. The long-term effects of iridectomy for primary acute angle-closure glaucoma. Am J Ophthalmol 1978;86:506 –9. 10. Yassur Y, Melamed S, Cohen S, Ben-Sira I. Laser iridotomy in closed-angle glaucoma. Arch Ophthalmol 1979;97:1920 –1. 11. Murphy MB, Spaeth GL. Iridectomy in primary angle-closure glaucoma. Classification and differential diagnosis of glaucoma associated with narrowness of the angle. Arch Ophthalmol 1974;91:114 –22. 12. Fleck BW, Wright E, Fairley EA. A randomised prospective comparison of operative peripheral iridectomy and Nd:YAG laser iridotomy treatment of acute angle closure glaucoma: 3 year visual acuity and intraocular pressure control outcome. Br J Ophthalmol 1997;81:884 – 8. 13. Playfair TJ, Watson PG. Management of chronic or intermittent primary angle-closure glaucoma: a long-term follow-up of the results of peripheral iridectomy used as an initial procedure. Br J Ophthalmol 1979;63:23– 8. 14. Gelber EC, Anderson DR. Surgical decisions in chronic angleclosure glaucoma. Arch Ophthalmol 1976;94:1481– 4.
Rosman et al 䡠 Chronic Angle-closure with Glaucomatous Damage 15. Hoskins HD Jr, Kass MA. Becker-Shaffer’s Diagnosis and Therapy of the Glaucomas. St Loius: CV Mosby, 1989;208 –37. 16. Shields MB. Textbook of Glaucoma, 3rd ed. Baltimore: Williams & Wilkins, 1992;198 –219. 17. Aung T, Tow SLC, Yap EY, et al. Trabeculectomy for acute primary angle closure. Ophthalmology 2000;107: 1298 –302. 18. Wishart PK, Atkinson PL. Extracapsular cataract extraction and posterior chamber lens implantation in patients with primary chronic angle-closure glaucoma: effect on intraocular pressure control. Eye 1989;3:706 –12. 19. Acton J, Salmon JF, Scholtz R. Extracapsular cataract extraction with posterior chamber lens implantation in primary angle-closure glaucoma. J Cataract Refract Surg 1997;23: 930 – 4.
20. Gunning FP, Greve EL. Lens extraction for uncontrolled angle-closure glaucoma: long-term follow-up. J Cataract Refract Surg 1998;24:1347–56. 21. Campbell DG, Vela A. Modern goniosynechialysis for the treatment of synechial angle-closure glaucoma. Ophthalmology 1984;91:1052– 60. 22. Teekhasaenee C, Ritch R. Combined phacoemulsification and goniosynechialysis for uncontrolled chronic angle-closure glaucoma after acute angle-closure glaucoma. Ophthalmology 1999;106:669 –75. 23. Ritch R. Argon laser peripheral iridoplasty: an overview. J Glaucoma 1992;1:206 –13. 24. Chew PTK, Yeo LMW. Argon laser iridoplasty in chronic angle closure glaucoma. Int Ophthalmol 1995;19:67–70.
Answers to questions on page 2225. Answers: 1. B 2. D 3. A 4. C 5. C
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Laser peripheral iridotomy (LPI) is the definitive treatment to relieve pupillary block in primary angle-closure glauco-
Originally received: September 5, 2001. Accepted: May 3, 2002. Manuscript no. 210758. 1 Singapore National Eye Centre, Singapore, Republic of Singapore. 2 Singapore Armed Forces, Singapore, Republic of Singapore. 3 National University of Singapore, Singapore, Republic of Singapore. 4 New York Eye and Ear Infirmary, New York, New York. 5 New York Medical College, Valhalla, New York. Presented at the annual meeting of the Association for Research in Vision and Ophthalmology, Fort Lauderdale, Florida, April 2001; and the Nineteenth Singapore-Malaysia Ophthalmological Conference, Penang, Malaysia, June 2001. © 2002 by the American Academy of Ophthalmology. Published by Elsevier Science Inc.
ma.1– 6 Any persistent or subsequent intraocular pressure (IOP) elevation is treated in a stepwise fashion, first medically or with laser trabeculoplasty, and then surgically if necessary. Argon laser peripheral iridoplasty (ALPI) is in-
Supported in part by the Martin Lewis and Diane Brandt Research Fund of the New York Glaucoma Research Institute, New York, New York; and the Department of Ophthalmology, National University Hospital, Singapore, Republic of Singapore. The authors have no commercial interest in the products or devices mentioned herein. Correspondence and reprint requests to Paul T. K. Chew, FRCS (Ed), FRCOphth, Department of Ophthalmology, National University Hospital. 5, Lower Kent Ridge Road, Main Building, Level 3, S119074, Singapore, Republic of Singapore. E-mail: [email protected]. ISSN 0161-6420/02/$–see front matter PII S0161-6420(02)01275-7
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Ophthalmology Volume 109, Number 12, December 2002 dicated for persistent appositional angle closure. Published studies in white populations using this approach found it to be effective and safe, with a low incidence of eventual trabeculectomy.2– 4 However, these studies defined angleclosure glaucoma based on the presence of a closed angle and did not use a definition parallel to that for open-angle glaucoma, that is, the presence of optic disc and visual field damage. For example, fellow eyes of acute angle-closure glaucoma attacks,2–3,5 eyes with narrow angles,3,5 and eyes with closed angles but without glaucomatous disc cupping2– 6 were included. A recent report from Singapore found that LPI alone did not prevent most eyes with chronic angle-closure glaucoma (CACG) and glaucomatous damage from developing a clinically significant rise in IOP during extended follow-up.7 Chronic angle-closure glaucoma was defined as presence of glaucomatous optic neuropathy and compatible visual field loss, in association with an angle in which at least 180° of trabecular meshwork was not visible on gonioscopy and with evidence of peripheral anterior synechiae (PAS) in any part of the angle. Most of those in whom a rise in IOP developed after LPI experienced the rise within the first 6 months. Most eyes (53%) eventually required filtering surgery. A study in South Africa on a mixed-race population produced similar results.6 The question remains as to whether there may be racial differences in outcomes between whites and nonwhites in the long-term clinical course of eyes with CACG. We investigated this by reviewing the outcome of similar patients in New York City and comparing the results with the findings of the Singapore study.
Table 1. Demographic Features of the New York Study Population No. of Patients Gender Male Female Age (mean ⫾ standard deviation, years) Race White Black Hispanic
%
22 29 68.2 ⫾ 9.4
43.1% 56.9%
15 15 21
29.5% 29.5% 41.0%
study, a rise in IOP during follow-up was defined as IOP of more than 21 mmHg requiring treatment by medication or surgery (as deemed necessary by the clinician involved). This was not standardized but was dependent on the observer. The data collected from the New York patients was then compared with a similar Singaporean population treated during the same period.7 The inclusion and exclusion criteria and data extraction methods used were similar. Statistical analysis was carried out using the Statistical Package for Social Sciences version 8.0 (SPSS Inc., Chicago, IL). Parametric and nonparametric tests of significance were carried out where appropriate. Comparisons between groups were performed with Mann–Whitney U tests for continuous variables that are not distributed normally. Chi-square analysis was used for comparison of proportions. All statistical tests were conducted at a 5% level of significance.
Results Materials and Methods We reviewed the charts of patients who underwent LPI for CACG at the New York Eye and Ear Infirmary between January 1990 and December 1994. The term chronic angle-closure glaucoma has been by convention used to describe an eye in which portions of the anterior chamber angle are permanently closed by PAS, regardless of the presence or absence of glaucomatous damage and even elevated IOP. Variable and sometimes conflicting terminology has been used to describe somewhat differently appearing forms. For purposes of the present study, CACG was defined as the presence of a gonioscopically occludable angle accompanied by glaucomatous optic neuropathy and compatible reproducible visual field loss. An occludable angle was defined as the presence of at least 180° of angle in which the trabecular meshwork was not visible on gonioscopy and with evidence of PAS in any part of the angle. Thus, CACG as used here equals a restricted definition of chronic angle-closure glaucoma, that is, those eyes with actual glaucomatous damage. Patients with closed angles who had an acute symptomatic episode of raised IOP (acute angle closure) were included only if they also had optic nerve damage with visual field loss. Patients with less than 9 months of follow-up were excluded, as were those with secondary angle closure resulting from iris neovascularization, uveitis, trauma, lens intumescence, or lens subluxation. Demographic and ophthalmic data recorded in each case included age, gender, race, dates of presentation and onset of symptoms, presenting IOP, gonioscopic findings, and the treatment instituted. The long-term outcome after LPI was assessed in terms of IOP and the requirement for additional therapy. For the purposes of this
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A total of 51 patients (80 eyes) with CACG had LPI performed at the New York Eye and Ear Infirmary between January 1990 and December 1994 and had least 9 months of follow-up. The demographic features are listed in Table 1. There were 22 men (43.1%) and 29 women (56.9%). The mean age of the patients was 68.2 ⫾ 9.4 years. Subjects were white, black, or Hispanic. The mean follow-up was 56 ⫾ 34 months. Of the 51 patients, 11 patients (12 eyes) had a past documented history of an episode of symptomatic acute angle closure. In all 80 eyes, a rise in IOP developed that required medical treatment despite the presence of a patent LPI. Thirty-three eyes (41.3%) were controlled with LPI and medication alone, and 25 eyes (31.3%) eventually required filtering surgery to control IOP. Of the 25 patients, 24 eyes underwent trabeculectomy, whereas 1 eye had Baerveldt implant surgery. The treatment outcome is summarized in Table 2. The rise in IOP was detected in the first 6 months after LPI in 65 eyes (81.3%). The time interval for the subsequent rise in IOP is shown in Table 3.
Comparison with Singaporean Population We compared the long-term outcome of LPI in our study population with that of 65 Singaporean patients (83 eyes) who underwent LPI during the same time period. The presenting clinical features are summarized in Table 4. The mean follow-up period for the New York and the Singapore group were 56 ⫾ 34 months and 60 ⫾ 29 months, respectively (P ⫽ 0.23). The mean presenting IOP was higher in the Singapore group (40 ⫾ 15 mmHg) compared with the New York group (31 ⫾ 12.5 mmHg; P ⬍ 0.001). The presenting vertical cup-to-disc ratio was similar: 0.7 ⫾ 0.2 in the
Rosman et al 䡠 Chronic Angle-closure with Glaucomatous Damage Table 2. Long-term Treatment Required for New York Eyes with Primary Angle-closure Glaucoma No. of Eyes
Outcome Eyes with no increase in IOP after LPI Eyes Requiring medication with or without other procedures Eyes controlled only with LPI and medications Eyes requiring medication and iridoplasty or laser trabeculoplasty Eyes requiring filtering surgery Total
0 80 (100.0%) 33 (41.3%) 22 (27.5%) 25 (31.3%) 80
IOP ⫽ intraocular pressure; LPI ⫽ laser peripheral iridectomy.
New York group compared with 0.6 ⫾ 0.2 in the Singapore group (P ⫽ 0.013). The vast majority of eyes in both populations required further treatment to control IOP despite the presence of a patent LPI. All the eyes in New York group experienced a rise in IOP requiring further treatment after LPI, whereas only 5 of 83 eyes (6.0%) in the Singapore group did not require further treatment (P ⫽ 0.59). Of the eyes with subsequent rise in IOP, 33 of 80 eyes (41.3%) compared with 34 of 83 eyes (41.0%) in the Singapore group were controlled with additional topical medication (P ⫽ 0.269). Twenty-five of 80 eyes (31.3%) in the New York group eventually underwent filtering surgery, as compared with 44 of 83 eyes (53.0%) in the Singapore study (P ⫽ 0.005). The other 22 eyes in the New York group went on to additional laser procedures, such as ALPI, argon laser trabeculoplasty, or both, after which IOPs were controlled and surgery was not required. There was no similar subgroup in the Singapore study, because patients went directly on to filtering surgery. The comparisons between the two groups are summarized in Table 5.
Discussion The terminology for angle closure is used inconsistently throughout the literature. The term acute angle-closure glaucoma has been used to describe eyes with normal optic discs and visual fields, whereas chronic angle-closure glaucoma has been used to describe eyes with PAS despite normal IOP, discs, and fields. In this study, we delineated a subset of CACG to eyes with actual glaucomatous damage,8 defining the term glaucoma the way it is used in eyes with open angles. The disparity in our results compared with previous studies on laser or surgical iridectomy in white patients4,9 –12 may actually be explained by this variation in Table 3. Time Interval for Rise in Intraocular Pressure after Successful Laser Peripheral Iridectomy (in Months after Laser Peripheral Iridectomy) in New York Eyes Duration (mos) ⬍1 ⬎1–6 ⬎6–12 ⬎12 Total
Table 4. Presenting Features of the New York and Singaporean Study Population
No. of Eyes 54 (67.5%) 11 (13.8%) 4 (5.0%) 11 (13.8%) 80
New York Singapore
P Value
Age (mean ⫾ SD, yrs) 68.2 ⫾ 9.2 60.8 ⫾ 9.0 Follow-up period (mean ⫾ SD, mos) 56 ⫾ 34 63 ⫾ 29 Presenting IOP (mmHg) 31 ⫾ 12.5 40 ⫾ 15 Presenting vertical cup-to-disc ratio 0.7 ⫾ 0.2 0.6 ⫾ 0.2
⬍0.001 0.230 ⬍0.001 0.013
IOP ⫽ intraocular pressure; SD ⫽ standard deviation.
definition. Previous studies included a variety of diagnoses such as narrow angles,4,11 fellow eyes,3,4,9 –11 and acute angle closure2,3,9 –11 with or without detectable glaucomatous damage. In these eyes, LPI alone often may be successful in controlling IOP. In contrast, because our patients had glaucomatous optic neuropathy and visual field loss, they are likely to have more longstanding or advanced disease and may be less amenable to treatment by LPI alone. Some earlier studies in white populations also found limitations of iridectomy in controlling IOP in patients with CACG. In patients with chronic angle closure and visual field loss, surgical peripheral iridectomy was able to control IOP in only 21% of eyes.13 Laser iridotomy did not eliminate the need for antiglaucoma therapy in patients with CACG.10 In 19 eyes with uncontrolled CACG, 13 required medications after LPI and 6 were uncontrollable even with medications.4 Although this study found that patients with CACG almost always require additional medical or laser treatment beyond LPI, LPI to eliminate any element of pupillary block remains the appropriate initial therapy for CACG when glaucomatous optic disc and visual field damage is present. Approximately two thirds of CACG patients (68.7%) actually were managed by LPI plus medication or further laser, avoiding the need for filtering surgery with its potential complications. This is actually a respectable record for eyes with fairly advanced disease and may even rival long-term success rates of trabeculectomy. Adopting such an approach, however, requires patients to be monitored closely during follow-up to detect progression of glaucomatous damage and intervening with further treatment when necessary. Surgery may be a reasonable alternative for some patients whose IOP remains elevated and who have moderate Table 5. Comparison of Long-term Outcomes of the New York and Singapore Study Populations Outcome Eyes needing further treatment Eyes medically controlled Eyes needing laser or surgical intervention Eyes requiring filtering surgery Total
New York
Singapore
P Value
80 (100%)
78 (94.0%)
0.590
33 (41.3%)
34 (41.0%)
0.269
47 (58.8%)
44 (53.0%)
0.891
25 (31.3%)
44 (53.0%)
0.005
80
83
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Ophthalmology Volume 109, Number 12, December 2002 or severe glaucomatous damage after LPI for CACG. If the angle remains appositionally closed after LPI, ALPI should be performed to open the angle to the greatest extent possible (i.e., that portion not closed by PAS). If sufficient open angle is present to allow argon laser trabeculoplasty, this may be performed also before surgical intervention. The optimum timing of surgery is not established. Early surgery in CACG has been advocated in certain groups of patients, such as those with severe glaucomatous optic nerve damage and visual field loss at presentation,13,14 and those with more than 50% to 75% of the angle closed by PAS on indentation gonioscopy.13,15,16 There is a lack of consensus on the best approach to the surgical management of CACG, as well as scarcity of information on the long-term results of surgery in this condition. The surgical options are diverse, including filtering surgery,17 lens extraction,18 –20 combined lens extraction and filtering surgery, angle-widening procedures such as goniosynechialysis,21 and angle-widening procedures combined with lens extraction.22 The number of options is complicated further by the method of lens extraction, be it phacoemulsification or extracapsular cataract extraction, the use of antimetabolites, and the number and choice of surgical sites in combined surgery. Clinical trials are necessary to evaluate the best method and optimum timing of surgical treatment in CACG. Argon laser peripheral iridoplasty is a simple and effective means of opening an appositionally closed angle in situations in which laser iridotomy does not physically eliminate appositional angle-closure because mechanisms other than pupillary block are present.23,24 The procedure consists of placing contraction burns (long duration, low power, and large spot size) in the extreme iris periphery to compact at the site of the burn and contract the iris stroma between the site of the burn and the angle, physically pulling open the angle. Seven eyes in the New York group underwent ALPI, after which IOPs were controlled and surgery was not required. There was no similar subgroup in the Singapore study, because patients went directly on to filtering surgery. It is possible that the lower eventual rate of surgery in the New York series was the result of the effectiveness of ALPI. However, in one series, iridoplasty was not found to be effective in lowering the IOP in some eyes with CACG in which medical therapy had already failed,24 although it is observed that the laser settings used in this study differed from the standard.23 The optimum timing for iridoplasty may be earlier in the course of the disease in patients who have mild damage, had successful LPI and yet show residual appositional closure. This study was limited by being retrospective with variable follow-up of subjects. Because there were several ophthalmologists involved in the care of the patients, standardized documentation was not available in all cases. The review was conducted in a New York hospital, and the study population consisted of whites, blacks, and Hispanics. This may not necessarily be representative of populations in other parts of the North America. Nevertheless, this study provides us with important information regarding the longterm clinical course of CACG after LPI in American eyes. The study also was unique because it used similar methods
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to an analogous study in Singapore, allowing comparisons to be made between the two populations. In conclusion, the results of this study suggest that LPI alone is not adequate as long-term therapy in North American eyes with CACG, and patients almost always require additional medical or laser treatment. The similar results found in the New York and Singapore patients make it unlikely that there is any racial or ethnic difference in the severity of the clinical course. The challenge for clinicians managing such patients is to identify the subgroup of patients who will be treated adequately with LPI alone versus those in whom the disease goes on developing despite LPI. Our inability to prognosticate this difference in behavior makes it difficult for us to follow-up patients appropriately and to advise prompt and optimum treatment in those at risk of further visual loss. There is a pressing need for further research into this major cause of world blindness.
References 1. Ritch R. The treatment of chronic angle-closure glaucoma. Ann Ophthalmol 1981;13:21–3. 2. Robin AL, Pollack IP. Argon laser peripheral iridotomies in the treatment of primary angle closure glaucoma: long-term follow-up. Arch Ophthalmol 1982;100:919 –23. 3. Quigley HA. Long-term follow-up of laser iridotomy. Ophthalmology 1981;88:218 –24. 4. Gieser DK, Wilensky JT. Laser iridectomy in the management of chronic angle-closure glaucoma. Am J Ophthalmol 1984; 98:446 –50. 5. Schwartz LW, Moster MR, Spaeth GL, et al. NeodymiumYAG laser iridectomies in glaucoma associated with closed or occludable angles. Am J Ophthalmol 1986;102:41– 4. 6. Salmon JF. Long-term intraocular pressure control after NdYAG laser iridotomy in chronic angle-closure glaucoma. J Glaucoma 1993;2:291– 6. 7. Alsagoff Z, Aung T, Ang LPK, Chew PTK. Long-term clinical course of primary angle-closure glaucoma in an Asian population. Ophthalmology 2000;107:2300 – 4. 8. Foster PJ, Johnson GJ. Primary angle-closure: classification and clinical features. In: Hitchings RA, ed. Glaucoma. London: BMJ, 2000;145–52. Fundamentals of Clinical Ophthalmology Series. 9. Krupin T, Mitchell KB, Johnson MF, Becker B. The long-term effects of iridectomy for primary acute angle-closure glaucoma. Am J Ophthalmol 1978;86:506 –9. 10. Yassur Y, Melamed S, Cohen S, Ben-Sira I. Laser iridotomy in closed-angle glaucoma. Arch Ophthalmol 1979;97:1920 –1. 11. Murphy MB, Spaeth GL. Iridectomy in primary angle-closure glaucoma. Classification and differential diagnosis of glaucoma associated with narrowness of the angle. Arch Ophthalmol 1974;91:114 –22. 12. Fleck BW, Wright E, Fairley EA. A randomised prospective comparison of operative peripheral iridectomy and Nd:YAG laser iridotomy treatment of acute angle closure glaucoma: 3 year visual acuity and intraocular pressure control outcome. Br J Ophthalmol 1997;81:884 – 8. 13. Playfair TJ, Watson PG. Management of chronic or intermittent primary angle-closure glaucoma: a long-term follow-up of the results of peripheral iridectomy used as an initial procedure. Br J Ophthalmol 1979;63:23– 8. 14. Gelber EC, Anderson DR. Surgical decisions in chronic angleclosure glaucoma. Arch Ophthalmol 1976;94:1481– 4.
Rosman et al 䡠 Chronic Angle-closure with Glaucomatous Damage 15. Hoskins HD Jr, Kass MA. Becker-Shaffer’s Diagnosis and Therapy of the Glaucomas. St Loius: CV Mosby, 1989;208 –37. 16. Shields MB. Textbook of Glaucoma, 3rd ed. Baltimore: Williams & Wilkins, 1992;198 –219. 17. Aung T, Tow SLC, Yap EY, et al. Trabeculectomy for acute primary angle closure. Ophthalmology 2000;107: 1298 –302. 18. Wishart PK, Atkinson PL. Extracapsular cataract extraction and posterior chamber lens implantation in patients with primary chronic angle-closure glaucoma: effect on intraocular pressure control. Eye 1989;3:706 –12. 19. Acton J, Salmon JF, Scholtz R. Extracapsular cataract extraction with posterior chamber lens implantation in primary angle-closure glaucoma. J Cataract Refract Surg 1997;23: 930 – 4.
20. Gunning FP, Greve EL. Lens extraction for uncontrolled angle-closure glaucoma: long-term follow-up. J Cataract Refract Surg 1998;24:1347–56. 21. Campbell DG, Vela A. Modern goniosynechialysis for the treatment of synechial angle-closure glaucoma. Ophthalmology 1984;91:1052– 60. 22. Teekhasaenee C, Ritch R. Combined phacoemulsification and goniosynechialysis for uncontrolled chronic angle-closure glaucoma after acute angle-closure glaucoma. Ophthalmology 1999;106:669 –75. 23. Ritch R. Argon laser peripheral iridoplasty: an overview. J Glaucoma 1992;1:206 –13. 24. Chew PTK, Yeo LMW. Argon laser iridoplasty in chronic angle closure glaucoma. Int Ophthalmol 1995;19:67–70.
Answers to questions on page 2225. Answers: 1. B 2. D 3. A 4. C 5. C
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