Objectives: To estimate the prevalence and causes of blindness and other degrees of vision impairment in people aged 50 years and older in North Kordofan state, Sudan, using the Rapid Assessment for Avoidable Blindness methodology.
Design: Cross-sectional, population-based survey.
Participants: Forty-three clusters of 50 people aged 50 years and older were selected by probability proportionate to size sampling of clusters. Households within clusters were selected through compact segment sampling. A total of 2167 eligible persons were selected, of whom 2032 (93.8%) persons were examined.
Materials and Methods: Participants underwent a comprehensive ophthalmic examination in their houses by trained ophthalmic teams, including measurement of visual acuity (VA) with a tumbling-E chart and the diagnosis of the principal cause of visual impairment.
Results: The prevalence of bilateral blindness (presenting VA < 3/60) was 8.37% (95% confidence interval [CI]: ±1.60), the prevalence of severe visual impairment (VA < 6/60–3/60) was 2.71% (95% CI: ±0.59) and the prevalence of bilateral visual impairment (VA < 6/18–6/60) was 9.06% (95% CI: ±1.76) in the sample. Definite avoidable causes of blindness (i.e., cataract, refractive error, trachoma and corneal scarring) were responsible for 76.5% of bilateral blindness. Cataract was the major cause of blindness (60.6%), followed by Glaucoma (20%).
Conclusions: The prevalence of blindness in people aged 50 years and older in North Kordofan state was higher than that expected for Sudan. The main cause of blindness was Cataract, followed by Glaucoma. More than 75% of blindness was due to avoidable causes.