Open-angle glaucoma in an urban population in southern India - The Andhra Pradesh Eye Disease Study

Objective: To assess the prevalence and features of open-angle glaucoma in an urban population in southern India. Design: A population-based cross-sectional study. Participants: A total of 2522 persons (85.4% of those eligible) of all ages , including 1399 persons 30 years of age or older, from 24 clusters represe ntative of the population of Hyderabad city, Testing: The participants underwent an interview and detailed eye examinati on that included logarithm of minimum angle of resolution visual acuity, re fraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, dilat ation, cataract grading, and stereoscopic fundus evaluation. Automated Hump hrey threshold 24-2 visual fields (Humphrey Instruments Inc., San Leandro, CA) and optic disc photography were performed when indicated by standardize d criteria for disc damage or if intraocular pressure (IOP) was 22 mmHg or more. Main Outcome Measures: Definite primary open-angle glaucoma (POAG) was defi ned as obvious glaucomatous optic disc damage and visual field loss in the presence of an open-angle, and suspected POAG was defined as suspected glau comatous optic disc damage without definite visual field loss. Ocular hyper tension (OHT) was defined as IOP of 22 mmHg or move without glaucomatous op tic disc damage or visual field loss in the presence of an open-angle. Glau comatous optic disc damage or IOP of 22 mmHg or more secondary to an obviou s cause and with an open-angle was defined as secondary open-angle glaucoma . Results: Definite POAG, suspected POAG, and OHT were present in 27, 14, and 7 participants, respectively, with age- and gender-adjusted prevalence (95 % confidence interval) of 1.62% (0.77%-2.48%), 0.79% (0.39%-1.41%), and 0.3 2% (0.10%-0.78%) in those 30 years of age or older, and 2.56% (1.22%-3.91%) , 1.11% (0.43%-1.78%), and 0.42% (0.11%-1.12%) in those 40 years of age or older, respectively. The prevalence of POAG increased significantly with ag e using multivariate analysis (P < 0.001). Only two of 27 participants (7.4 %) with definite POAG had been previously diagnosed and treated, and 66.7% of the previously undiagnosed had IOP less than 22 mmHg. fourteen of 27 par ticipants (51.9%) with definite POAG had severe glaucomatous damage based o n optic disc and visual field criteria, of which five participants (18.5%) had at least one blind eye as a result of POAG tall with best-corrected dis tance visual acuity less than 20/400 or central visual field less than 10 d egrees); the other 13 participants (48.1%) had moderate glaucomatous damage . Because visual fields and optic disc photography weve not performed on al l participants, the prevalence of POAG may have been underestimated. Second ary open-angle glaucoma was present in one participant as a result of angle recession. Conclusions: The prevalence of open-angle glaucoma in this urban population in southern India is at least as much as that reported recently from white populations in developed countries. However, the vast majority of persons with glaucoma were undiagnosed in this population, and a large proportion o f those having definite POAG already had severe glaucomatous damage. Ophtha lmology 2000;107:1702-1709 (C) 2000 by the American Academy of Ophthalmolog y.