Rapid assessment of avoidable blindness and diabetic retinopathy in Taif, Saudi Arabia

Background/aims To estimate the prevalence of blindness, diabetes and diabetic retinopathy (DR) in Taif, Saudi Arabia using the Rapid Assessment of Avoidable Blindness (RAAB) framework. Methods 66 clusters of 50 people aged >= 50 years were randomly selected. Participants underwent visual acuity measurement and examination by an ophthalmologist. DR among diabetic participants (previous diagnosis and/or random blood glucose > 200 mg/dl) was assessed through dilated fundus examination by an ophthalmologist using a direct and indirect ophthalmoscope ('clinical examination') and dilated digital fundus photographs graded by a retinal specialist following the Scottish DR grading system ('reference standard'). Results 3052 (93%) out of 3300 eligible people were examined. The prevalence of blindness was 2.6% (95% CI 2.0% to 3.2%). Posterior segment diseases (44%) and cataract (41%) were the leading causes of blindness. The estimated prevalence of diabetes was 29.7% (28.1% to 31.4%), among whom the prevalence of DR was 36.8% (33.3% to 40.2%) and sight-threatening DR (STDR) was 17.5% (CI 15.1% to 20.0%). Agreement was good (kappa> 0.6) between the clinical examination and reference standard for any DR and STDR. Conclusions There was a high prevalence of diabetes, DR and STDR. It was possible to assess diabetes and DR within RAAB but it increased the survey duration, cost and complexity.