Distribution Pattern of Lens Opacity Among A Rural Population in South Western Nigeria

Abstract

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. 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. 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. 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.