Assessment of avoidable blindness using the rapid assessment of avoidable blindness methodology

Abstract

BACKGROUND: More than 90% of visual impairment can either be treated or avoided. Rapid Assessment of Avoidable Blindness methodology provides valid estimates in short time to assess magnitude and causes of blindness. AIMS: To estimate the prevalence and causes of blindness in persons above 50 years in Kolar, South India, using the above methodology. MATERIALS AND METHODS: Sixty one clusters of 50 people aged above 50 years were selected by probability-proportionate to size sampling. Participants were evaluated using a standardized survey form. Persons with vision <20/60 were dilated and examined by an ophthalmologist. RESULTS: Of the 3050 people listed 2907 were examined (95.3%). Prevalence of bilateral blindness in persons was 3.9%; severe visual impairment 3.5%, and visual impairment 10.4%. Untreated cataract was the leading cause of blindness (74.6%) and severe visual impairment (73.3%). Avoidable causes of blindness accounted for 91.2% of all blindness and 95.0% of severe visual impairment. 'Waiting for maturity' and 'No one to accompany' were the most common barriers to uptake of cataract surgery. CONCLUSION: Untreated cataract continues to be the leading cause of avoidable blindness. Modified strategies need to be implemented to tackle the burden of cataract blindness.