ABSTRACT
Objectives: to estimate the prevalence of avoidable blindness in people aged 50 years and older in Gezira state, Sudan using Rapid Assessment for Avoidable Blindness [RAAB] methodology
Design: cross-sectional population-based survey
Participants: forty three clusters of 50 people aged 50 years or older were selected by probability proportionate to size sampling of clusters. Households within clusters were selected through compact segment sampling. A total of 2150 eligible persons were selected, of whom 2103 [97.8%] were examined
Methods: participants underwent a comprehensive ophthalmic examination in their homes by specially 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 9.37% [95% confidence interval [CI], +/- 1.95], and prevalence of bilateral visual impairment [VA of <6/18-6/60] was 3.9% [95% CI, +/- 1.10] in the sample. Definite avoidable causes of blindness [i.e., cataract, refractive error, trachoma, and corneal scarring] were responsible for 74.6% of bilateral blindness. Cataract was the major cause of blindness [57.4%] followed by glaucoma [17.3%]
Conclusions: the prevalence of blindness in people aged 50 years and older in Gezira state was slightly higher than expected. The main cause of blindness is cataract, followed by glaucoma. Three quarters of blindness is due to avoidable causes
ABSTRACT
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