The prevalence of glaucoma in Bangladesh: a population based survey in Dhaka division.

BACKGROUND/AIM Few studies have reported on the epidemiology and clinical characteristics of glaucoma in south Asia. This project aimed to determine the prevalence of glaucoma of Dhaka, Bangladesh. METHOD A multistage, stratified, clustered sample was drawn from Dhaka Division, Bangladesh, using systematic sampling to identify individual subjects aged 35 years and older. Examination of all subjects included Snellen visual acuity, slit lamp examination (including gonioscopy and applanation tonometry) and a stereoscopic assessment of the vertical cup:disc ratio (CDR). In selected subjects, a threshold visual field examination was performed. Glaucoma was diagnosed on the basis of statistical abnormality of the vertical CDR combined with an abnormal visual field test, or in subjects with advanced glaucoma who could not complete field testing, a grossly abnormal CDR. If it was not possible to examine the optic discs and the subject was blind, glaucoma was diagnosed on the basis of a raised intraocular pressure. RESULTS Of 3562 eligible subjects, 2347 were examined (66%). Among people aged 40 years and older, the prevalence of definite glaucoma was 2.1% (95% confidence interval: 1.5 to 2.9; 39 people). The prevalence of definite and probable glaucoma was 3.1% (95% CI: 2.4 to 4.0; 58 people) in subjects of the same age. Primary open angle glaucoma was the most common form of glaucoma, accounting for 75% of the total. Among cases of blindness not attributable to refractive error, 5% were caused by glaucoma. Glaucoma prevalence was higher in men than women, but did not show the typical increase with age. CONCLUSION Glaucoma prevalence is relatively high in Bangladesh, although it accounts for only a small proportion of blindness in the community. It is estimated that there are approximately 586 000 people 40 years and older with definite or probable glaucoma in Bangladesh.