Results of a rapid assessment of avoidable blindness (RAAB) in Eritrea

To collect baseline data for planning of the National Blindness Prevention & Control Program and for monitoring future achievements.

Sixty six clusters of 50 people were selected from a sampling frame that included all 2,593 villages in Eritrea (population 3.56 million). Within each selected village, 50 eligible people aged 50+ years were selected. All eligible participants underwent visual acuity (VA) measurement followed by examination by an ophthalmologist if the presenting VA (PVA) was less than 6/18.

Three thousand one hundred sixty three of the 3300 eligible persons were examined (coverage 95.9%). The adjusted prevalence of blindness (PVA < 3/60 in the better eye) in the survey population was 7.5% (95% confidence interval [CI]: 6.2-8.8%), bilateral severe visual impairment (PVA < 6/60 to ≥ 3/60 in the better eye) 3.0% (95% CI: 2.3-3.7%) and of bilateral moderate visual impairment (PVA < 6/18 to ≥ 6/60 in the better eye) 10.5% (95% CI: 9.1-11.9%). Of all bilateral blindness 55% was due to cataract. The adjusted cataract surgical coverage (percentage of people requiring cataract surgery that have had surgery) was 68% for blind people and 41% for blind eyes. Cataract surgery outcome was poor (PVA < 6/60) in 39% of all eyes operated in the past.

The prevalence of blindness was high compared to recent surveys in Africa. Visual outcome after cataract surgery potentially could be improved by more detailed pre-operative examination, coaching of surgeons, and provision of adequate optical correction, including routine monitoring of visual outcome after cataract surgery. The development of intervention programs for refractive error and glaucoma should be considered.