Rapid assessment of avoidable blindness in Kurdistan, Iran

Purpose: To determine the magnitude and causes of blindness and visual impairment (VI) in Kurdistan, using the Rapid Assessment of Avoidable Blindness methodology. Methods: In this population-based cross sectional study, 99 clusters were selected through probability proportional to size sampling. Visual acuity (VA) was measured using a standard tumbling “E” chart. Ophthalmologists examined participants with VA < 6/18 in both eyes. The cause of VI in the better eye or the most treatable cause was considered as the primary cause of VI. Results: A total of 3203 (response rate: 92.4%) individuals aged 50 years and older participated, of whom 1657 (51.7%) were female. The standardized prevalence of blindness, severe visual impairment (SVI), and moderate visual impairment (MVI) based on available correction (presenting VA) were 2.1% (1.5-2.6), 1.7% (1.2-2.2), and 9.6%(8.4-10.8), respectively. The proportion of avoidable causes of blindness, SVI, and MVI were 58.1%, 78.4%, and 83.4%, respectively. The most common cause of blindness and SVI was cataract (27.4% and 60.8% respectively), followed by age-related macular degeneration (25.8% and 13.7%, respectively). The leading causes of MVI were uncorrected refractive errors (RE) (37.2%) and cataract (33.6%). Conclusion: The prevalence of blindness in the study population seems comparable to the region. According to our results, blindness, SVI, and MVI were mostly due to avoidable causes. Cataract and refractive errors are the principal causes of blindness and VI in Kurdistan