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

Abstract

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 (κ>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.