Prevalence and types of glaucoma among an indigenous African population in southwestern Nigeria.

PURPOSE: To determine the prevalence and identify the types of glaucoma in the Akinyele district of Oyo State in southwestern Nigeria. METHODS: Residents of Akinyele district of Oyo State in southwestern Nigeria aged 40 years and older were randomly selected in a stratified manner. All participants underwent comprehensive ophthalmic examination, including visual acuity assessment, anterior segment biomicroscopy, IOP measurement, gonioscopy, optic nerve head and disc evaluation, and central visual field assessment. Glaucoma was diagnosed using the International Society of Geographical and Epidemiological Ophthalmology (ISGEO) classification scheme. RESULTS: A sample of 811 subjects (90% response rate) was examined. The crude prevalence of all forms of glaucoma was 7.3% (95% confidence interval [CI] 5.5%-9.1%) with an age and sex standardized rate of 6.9% (95% CI 6.88%-6.92%). Primary open angle glaucoma was found in 6.2% (95% CI 4.5%-7.8%) and primary angle closure glaucoma in 0.2% (95% CI 0.0%-0.6%). Secondary glaucoma accounted for 0.9% of the cases, with couching and neovascular process being the main causes (0.2% each). Prevalence of glaucoma increased significantly with increasing age (P for trend < 0.05). CONCLUSIONS: The high prevalence of glaucoma (7.3%) in the Akinyele district in southwestern Nigeria is comparable with those in predominantly black populations in the Akwapim-South district of Ghana and Barbados. Primary open angle glaucoma remains the most prevalent form of glaucoma.

Distribution pattern of lens opacity among a rural population in South Western Nigeria.

PURPOSE: To determine prevalence of the morphological types of age-related lens opacity in Southwestern Nigeria as part of need assessment survey towards planning an eye health care service. METHOD: Multistage cluster sampling was used in selecting a representative cross-sectional sample of persons 50 years of age or older among the residents of the rural wards in Akinyele Local Government Area in southwestern Nigeria. Lens opacity was graded using the World Health Organization cataract grading system. RESULTS: One thousand two-hundred persons were recruited for the survey and 1031 (85.9%) had grading of lens opacity. The mean age of the participants was 64.9 years and 51.1% were male. Five hundred and ninety persons had definite lens opacity (crude prevalence rate 57.2%; 95% Confidence interval [CI] 54.1-60.3) (standardized prevalence 47.0%; 95% confidence interval 46.7-47.3). The prevalence for participants aged 70 years and above (82.5%; 95% CI 78.2-86.3) was three times more than for participants aged 50-59 years (29.2%; 95% CI 24.2-34.6). Nuclear opacity was the most prevalent type of lens opacity (20.9%; 95% CI 18.4-23.5). Sixty percent of the grade 3 lens opacity was found among participants aged 70 years and above. CONCLUSION: This is the first population-based survey on prevalence of lens opacity subtype in this West Africa subregion. The prevalence of lens opacity in the rural Akinyele local government is high. Nuclear sclerosis was the most prevalent form among this rural population.