Causes of blindness in people aged 50 years and over: community-based versus hospital-based study.

The causes of blindness in Yemen were determined in people aged 50+ years in both a community- and hospital-based study and documented using WHO/PBL criteria. In the community sample of 707 individuals in a rural area of Taiz governorate the prevalence of bilateral blindness was 7.9% and the main causes were cataract (71.4%) and age-related macular degeneration (ARMD) (14.3%). Corneal opacities and uncorrected aphakia were rare (1 case each) and there were no cases of diabetic retinopathy. Unilateral blindness was found in 8.6% of the community sample. In a case-notes review of 1320 new patients attending an eye clinic in Sana'a, bilateral blindness was documented in 26.5% and unilateral blindness in 9.0% (main causes: cataract, glaucoma, ARMD, diabetic retinopathy, corneal opacities and trauma.