|Year : 2001 | Volume
| Issue : 1 | Page : 25-30
Profile of glaucoma in a major eye hospital in North India
Jayachandra Das1, Sharad Bhomaj2, Zia Chaudhuri2, Pankaj Sharma3, Arun Negi3, Abhrajit Dasgupta3
1 MD. Guru Nanak Eye Centre, Maulana Azad Medical College, University of Delhi, New Delhi, India
2 MS, DNB. Guru Nanak Eye Centre, Maulana Azad Medical College, University of Delhi, New Delhi, India
3 MBBS. Guru Nanak Eye Centre, Maulana Azad Medical College, University of Delhi, New Delhi, India
E-310 Purvasha, Anand Lok Society, Mayur Vihar Phase-I, Delhi - 110 091
Source of Support: None, Conflict of Interest: None
Purpose: To study the clinical profile and distribution of various subtypes of glaucoma in a referral practice in North India.
Method: A retrospective analysis was done of 2425 patients who attended the glaucoma clinic in a tertiary eye-care centre for five years from Januaryl995 to December 1999. A detailed history was obtained and a thorough examination was performed, including gonioscopy, disc assessment, applanation tonometry and automated perimetry. Diurnal variation of IOP and provocative tests for glaucoma were done where applicable.
Result: Primary angle closure glaucoma (PACG) was the most common glaucoma subtype. The primary open angle glaucoma (POAG) to the PACG ratio was 37:63. Chronic angle closure glaucoma (CACG) was the most common PACG subtype. The majority of CACG cases were relatively asymptomatic. Male dominance was seen for POAG, juvenile open angle glaucoma (JOAG), CACG, normal tension glaucoma (NTG) and secondary glaucomas. Female dominance was seen for ocular hypertension (OHT), acute or intermittent ACG and developmental glaucomas. The mean age in years at presentation was POAG: 60.54 years (males 61.54 years, females 59.01 years) and PACG: 55.13 years (males 57.25 years, females 53.60). The three common secondary glaucomas were: glaucoma secondary to adherent leucoma, aphakic and pseudophakic glaucomas and traumatic glaucomas. Advanced glaucoma was detected in 42 to 53% of patients and bilateral blindness in 8 to 14% of patients in various subtypes.
Conclusion: Compared to Caucasians, glaucoma patients in North India seem to present nearly a decade earlier and the disease is more advanced at presentation. While PACG is the most commonly encountered glaucoma, NTG and exfoliative glaucoma are relatively rare.
Keywords: Glaucoma, North India, blindness
|How to cite this article:|
Das J, Bhomaj S, Chaudhuri Z, Sharma P, Negi A, Dasgupta A. Profile of glaucoma in a major eye hospital in North India. Indian J Ophthalmol 2001;49:25-30
Glaucoma, the second leading cause of world blindness accounts for 15% of global blindness. The regional burden of blindness (RBB) is highest for India (23.5% of global blindness), with at least 5.8 million blind due to glaucoma. India accounts for a minimum of 12.9% of Primary open angle glaucoma (POAG) blindness and 12.7% of Primary angle closure glaucoma (PACG) blindness in the world. These blindness figures are expected to double by 2020 AD. However, India still lacks epidemiologically valid data on various subtypes of glaucoma. Given the large geography and ethnic diversity, the pattern of glaucoma is bound to vary in different regions of India.
We present a 5-year analysis of glaucoma clinic referrals at our hospital. It is likely that these observations reflect the pattern of glaucoma in North India, thus providing useful background information to plan epidemiological surveys on glaucoma in this region.
| Materials and Methods|| |
A five-year retrospective analysis (January 1995- December 1999) was done of the records of 2425 patients attending the glaucoma clinic of Guru Nanak Eye Centre, Maulana Azad Medical College, New Delhi. The criteria for referrals included: intraocular pressure (IOP) more than 22 mmHg on two or more separate occasions and/or optic nerve head changes suggestive of glaucoma (focal notching of the disc, deepening of the cup, thinning of the neuroretinal rim, laminar dot sign, overpass cupping, saucerization of the cup, asymmetrical cupping in two eyes, etc.).
The work up of history and ophthalmic examination included the best corrected visual acuity (BCVA), slitlamp examination, Goldmann single mirror gonioscopy, Goldmann applanation tonometry, optic disc and posterior fundus examination (90-D lens), and Humphrey visual field analysis. Diurnal variation of IOP was performed in patients with open angles, and either high IOP recorded on two separate occasions or presence of disc changes suspicious of glaucoma. An absolute value of more than 30 mmHg or a difference of more than 8 mmHg between the maximum and minimum values of IOP was taken as significant. Prone provocative tests were done in asymptomatic patients with narrow angles. A difference of more than 8 mmHg at 60 minutes was considered significant. Cases -with developmental glaucoma underwent examination under general anaesthesia.
Standard definitions for various glaucoma subtypes were used for diagnosis. The diagnosis was made by a senior consultant (JCD) in all cases. An intraocular pressure (IOP) of 22 mmHg or more was considered abnormal. The anterior chamber angle was classified using Shaffer's grading;. Grade 2 or less was considered occludable, and grade 3 or more as open. Eyes with occludable angles and no glaucoma were classified as latent ACG. Field defects considered suggestive of glaucoma included isolated paracentral scotomas in presence of optic nerve head cupping, arcuate scotomas. Ronne's nasal step, Siedel's scotoma and advanced constriction of fields. Disc changes suggestive of glaucoma included focal notching of the disc, deepening of the cup, thinning of the neuroretinal rim, laminar dot sign, overpass cupping, saucerization of the cup and asymmetrical cupping in two eyes.
The criteria used for diagnoses of different subtypes of glaucoma are listed below:
1. Congenital glaucoma referred to two categories of glaucoma: (a) glaucoma associated with developmental anomalies of the eye present at birth (b) glaucoma related to an isolated maldevelopment of the trabecular meshwork not associated with other developmental anomalies or ocular diseases that can cause raised IOP.
2. Open angle glaucoma was defined as a condition in a subset of patients with open angles, raised IOP associated with either glaucomatous cupping of the optic nerve head or visual field changes suggestive of glaucoma.
3. Patients less than 40 years of age with clinical picture similar to POAG were labelled as juvenile open angle glaucoma (JOAG).
4. Primary angle closure glaucoma was classified into acute, intermittent and chronic types after Clemmensen. Patients with either a functional block between the pupillary part of the iris and anterior lens surface with shallow anterior chamber depth or a subset of patients with a zipper-like closure of the angles (creeping angle closure glaucoma) and relatively normal anterior chamber depth both comprised this group.
5. Ocular hypertensives were defined as a subset of patients with open angles, raised IOP but neither optic nerve head nor visual field changes.
6. Latent ACG comprised asymptomatic patients with occludable angles.
7. Normal tension glaucoma patients were classified as having open angles, and progressive optic nerve head changes or visual field loss suggestive of glaucoma in absence of elevated IOP.
8. Glaucoma suspects included (a) ocular hypertensive (defined above); (b) latent ACG (defined above); (c) subset of patients with open angles, IOP less than 22 mmHg, absence of field changes but with optic nerve head changes; and (d) patients with strong family history of glaucoma in absence of optic nerve head changes or high IOP.
9. Secondary glaucoma in a patient was defined as increased IOP or changes suggestive of glaucomatous nerve head cupping in a patient with any ocular or systemic problems predisposing to glaucoma.
Cases with cup and asymmetry of more than 0.30 were classified as asymmetric glaucoma; eyes with advanced field damage and /or cup to disc ratio of more than 0.80 and/or BCVA less than 3/60 due to glaucomatous disc damage were classified as advanced glaucoma. Criteria for blindness was BCVA less than 3/60 in the better eye in patients with bilateral blindness and in the worse eye for unilateral blindness. POAG suspects, JOAG suspects, ocular hypertensives (OHT) and latent ACG cases were grouped under a common heading as glaucoma suspects. JOAG was considered as a separate group and was excluded from developmental glaucomas.
| Results|| |
Based on the abovementioned criteria of definition, the distribution of different glaucoma subtypes are elucidated in [Table - 1]. Primary ACG was the most common subtype with the POAG to PACG ratio being 37:63. The details of age and gender distribution in different subtypes of glaucoma are shown in [Table - 2]. The details of the different subtypes follow.
| Glaucoma suspects/at risk cases|| |
This group [Table - 1] constituted the second largest group of referrals after PACG. Of 726 patients, there were 424 POAG suspects, 143 JOAG suspects, 58 cases of ocular hypertension and 101 cases of latent PACG.
| Primary angle closure glaucoma (PACG)|| |
PACG comprised the largest group (888/2425; 36.62%) of referrals. The peak age at presentation was the sixth decade (281/888, 31.64% cases), the mean age at presentation was 55.13 years (males 57.25 years, females 53.60) and females were marginally more than males [475/888 (53.48%)] [Table - 2].
Among the 888 PACG cases, acute PACG accounted for 141 (15.88%) cases, [Table - 3] intermittent PACG for 171 (19.26%) cases and chronic PACG for 576 (64.86%) cases. Females dominated amongst acute PACG (96/ 141, 68.08%) cases and intermittent ACG cases (104/171, 60.82%) cases. In chronic ACG males were slightly more than females (301/576, 52.26%) [Table - 3].
Asymmetric glaucoma was found in 170/888 (19.14%) of cases, 65/888 (7.32%) cases had unilateral glaucoma and 432/888 (48.64%) cases had advanced glaucoma at presentation. 127/888 (14.30%) cases were bilaterally blind (VA less than 3/60 in the better eye) and an additional 121/888 (13.63%) cases were unilaterally blind (VA less than 3/60 in worse eye).
Two female patients had central retinal artery occlusion (CRAO) in one eye. Both gave a history of acute ACG attack in the past in the affected eye associated with a sudden decrease in vision.
| Primary open angle glaucoma (POAG)|| |
POAG had an overall peak presentation in the seventh decade (184/523; 35.18%). The peak for males and females was in the seventh decade. Males accounted for 300/523 (57.36%) and females for 223/523 (42.64%) of POAG cases. The mean age at presentation was 60.43 years (Male 61.75 years, females 59.01 years)
Of the 523 patients, 68 (13.0%) had asymmetric glaucoma and 23/523 (4.40%) had unilateral POAG; 235/523 (44.93%) had advanced glaucoma at presentation; and 45/523 (8.60%) were bilaterally blind (VA less than 3/60 in the worse eye).
Thirteen of the 523 (2.48%) patients had preexisting venous occlusion in one eye [10 cases had branch retinal vein occlusion (BRVO) and 3 cases had non-ischemic central retinal vein occlusion (CRVO)]. 94/523 (17.97%) patients had varying degrees of myopia.
| Normal tension glaucoma (NTG)|| |
Only 15 cases of NTG were found (0.62% of all referrals). The peak presentation was in the seventh decade (7/15; 46.67%) [Table - 2]. The mean age for presentation was 60.04 years (males 62.17, females 58.00 years). Males represented 11/15 (73.33%) cases. 8/15 (53.33%) cases had advanced glaucoma at presentation [Table - 4].
| Juvenile open angle glaucoma (JOAG)|| |
Juvenile OAG constituted 82/2425 (3.38%) of glaucoma referrals. The mean age at presentation was 29.16 years (males 29.52, females 27.5) [Table - 2]. Of 82 patients, 67 were males (81.7%), thus demonstrating a striking male predominance. Myopia was seen in 60/82 (73.17%) patients. 34/82 (41.46%) patients had advanced glaucoma at presentation. 7/82 (8.54%) patients were bilaterally blind and 10/82 (12.92% patients were unilaterally blind. 15/82 (18.30%) patients had asymmetric glaucoma [Table - 4].
| Developmental glaucoma|| |
Twenty eight patients of developmental glaucomas were examined. Primary congenital glaucoma (PCG) accounted for 20 (71.43%) of these cases. Females accounted for 15/20 (75%) of PCG cases. Sturge Weber syndrome (3), Reiger's syndrome (1), aniridia (2), Peter's anomaly (1) and microspherophakia (1) were the other types of developmental glaucomas [Table - 5].
| Secondary glaucoma|| |
One hundred and sixty three patients of secondary glaucoma [Table - 6] accounted for 6.72% of all referrals; 108 of these cases (66.26%) were males and 55 (33.74%) were females. The 5 most common secondary glaucomas were glaucoma secondary to adherent leucoma, aphakic and pseudophakic glaucomas, traumatic glaucomas, neovascular glaucomas and post-uveitic glaucomas. Of these 163 cases, 120 (73.62%) were blind in the affected eye at presentation.
| Miscellaneous data|| |
Reduced vision, eye ache and headache were the three most common symptoms leading to ophthalmology consultations [Table - 7]. Of 576 cases, 451 (70.23%) of chronic ACG patients presented without a past history of acute or subacute attack. A shallow anterior chamber (AC) depth by oblique flashlight illumination was noted in 568/888 (63.96%) of PACG patients; the rest had normal AC depth. At our clinic, 68/888 cases (7.66%) of PACG were referred with a presumptive diagnosis of POAG due to the presence of a normal AC depth. Gonioscopy was not done in these cases before referral.
Family of glaucoma in first degree relatives was seen in 114/523 (21.80%) cases of POAG, 24/888 (2.70%) cases of PACG, 24/82 (29.27%) cases of JOAG, 7/58 (12.07%) cases of OHT, and 3/28 (10.71%) cases of primary congenital glaucoma.
| Discussion|| |
In Caucasian races, POAG accounts for 75-95% of the primary glaucomas, the disease presents later and is less severe at presentation. In other races, the disease appears to occur earlier, is more advanced at presentation and results in blindness[7-8] times more often.[9-10] We noted a POAG to PACG ratio of 37:63 a mean age of presentation for POAG of 60.54 years and a mean age of presentation for PACG as 55.13 years in our study group. Only 9 (1.72%) of 523 cases of POAG and 5 out of 888 cases (0.56%) of PACG presented after 81 years. This could reflect the lower life expectancy of Indians. At the same time, it could indicate that glaucoma probably occurs almost a decade earlier in Indians as compared to Caucasians for whom the average age of presentation of POAG is 69.1 years.
A remarkably low number of NTG (15) and exfoliative glaucoma (16) cases were noted in this study. Due to ethnic diversity, there might be marked differences in the frequency of various glaucoma subtypes, even amongst Asians. In a Japanese survey [11,12] NTG was the most common glaucoma subtype and exfoliative glaucoma accounted for nearly three-fifth of POAG. In contrast, a low prevalence of exfoliative glaucoma is reported amongst Eskimos. It is yet to be substantiated whether exfoliative glaucoma is uncommon in populations with high incidence of PACG such as Eskimos and Indians.
The gender dominance for POAG is variable.[14-16] We found a male predominance for POAG (male to female ratio of 1.35:1). Females accounted for 75% of cases (15/20) of primary congenital glaucoma, similar to the Japanese study. A strong male dominance for primary congenital glaucoma is reported from the USA and the UK.[17-18]
Asymmetric glaucoma has been reported in 10% POAG cases in the Blue Mountains Eye Study. We documented asymmetric glaucoma in 13.02% cases of POAG, 19.14% cases of PACG and 17.24% cases of JOAG.
In the Wilmer Eye Clinic (USA) study, advanced glaucoma at presentation was seen in 18.5% of Caucasian patients and 33.3% of black patients. We found advanced glaucoma in 44.39% of POAG and 48.65% of PACG cases, and along with blindness in 8.6% of POAG and 14.3% of PACG cases presentation. The high proportion of blindness due to advanced disease at presentation was disturbing and indicates an urgent need for early detection and treatment through national programs. The national policies which seem to be exclusively batting cataract blindness at the moment need urgent reorientation due to the enormity of the problem of glaucoma blindness. In England and Wales, at least 20,000 new cases of glaucoma are detected every year by optometrists alone. While such help may be a distant dream for India, the major responsibility seems to rest with the ophthalmologists.
In summary, we have attempted to define the pattern of glaucoma in North India. The main drawback is the hospital and speciality clinic-based data analysis. The data needs validation by population-based epidemiologic studies. Nevertheless, this study could provide useful background information for planning glaucoma surveys in this region.
| Acknowledgement|| |
We are thankful to Dr. V.K. Bhatia, for his invaluable help with the statistical analysis.
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[Table - 1], [Table - 2], [Table - 3], [Table - 4], [Table - 5], [Table - 6], [Table - 7]
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