Prevalence and causes of blindness and visual impairment in Limbe urban area, South West Province, Cameroon

Aim: To conduct a rapid assessment of cataract surgical services to estimate the prevalence and causes of blindness and visual impairment in members of the population aged >= 40 years in the Limbe urban area, Cameroon. Methods: Clusters of 50 people aged >= 40 years were sampled with probability proportionate to size. Compact segment sampling was used to select households within clusters. All eligible people had their visual acuity (VA) measured by an ophthalmic nurse. An ophthalmologist examined people with VA,< 6/18. Results: 2215 people were examined ( response rate=92.3%). The prevalence of bilateral blindness was 1.1% (95% CI: 0.7-1.5%), 0.3% (0.1-0.6%) for severe visual impairment and 3.0% (2.0-4.0%) for visual impairment. Posterior-segment disease was the leading cause of blindness (29%),followed by cataracts (21%) and optic atrophy (21%). Cataracts were the most common cause of severe visual impairment (43%) and visual impairment (48%). Most cases of blindness (50%), severe visual impairment ( 57%) and visual impairment (78%) were avoidable (that is, they were caused by cataracts, refractive error, corneal scar, onchocerciasis or phthisis/no globe). The cataract surgical coverage was relatively high, although 57% of eyes operated upon had a poor outcome ( presenting VA, 6/60). Conclusions: Although the prevalence of blindness was relatively low, most of the cases were avoidable. The implementation of an effective eye-care programme remains a priority in the Limbe urban area.