Prevalence and causes of blindness, visual impairment, and cataract surgery in Timor-Leste

Abstract

Purpose: To estimate the prevalence and causes of blindness and visual impairment, cataract surgical coverage (CSC), visual outcome of cataract surgery, and barriers to uptake cataract surgery in Timor-Leste. Method: In a nationwide rapid assessment of avoidable blindness (RAAB), the latest population (1,066,409) and household data were used to create a sampling frame which consists of 2,227 population units (study clusters) from all 13 districts, with populations of 450-900 per unit. The sample size of 3,350 was calculated with the assumed prevalence of blindness at 4.5% among people aged ≥50 years with a 20% tolerable error, 95% CI, and a 90% response rate. The team was trained in the survey methodology, and inter-observer variation was measured. Door-to-door visits, led by an ophthalmologist, were made in preselected study clusters, and data were collected in line with the RAAB5 survey protocol. An Android smart phone installed with mRAAB software was used for data collection. Result: The age-gender standardized prevalence of blindness, severe visual impairment, and visual impairment were 2.8%, (1.8-3.8), 1.7% (1.7-2.3), and 8.1% (6.6-9.6), respectively. Cataract was the leading cause of blindness (79.4%). Blindness was more prevalent in the older age group and in women. CSC was 41.5% in cataract blind eyes and 48.6% in cataract blind people. Good visual outcome in the cataract-operated eyes was 62% (presenting) and 75.2% (best corrected). Two important barriers to not using available cataract surgical services were accessibility (45.5%) and lack of attendants to accompany (24.8%). Conclusion: The prevalence of blindness and visual impairment in Timor-Leste remains high. CSC is unacceptably low; gender inequity in blindness and CSC exists. Lack of access is the prominent barrier to cataract surgery.