Hospital-Based Assessment of the New Visual Acuity Level inRapid Assessment of Avoidable Blindness

Abstract

Background: There are currently two versions of rapid assessment of avoidable blindness (RAAB) method in use: RAAB5 and RAAB6. WhileRAAB5 uses visual acuity (VA) of 6/18 as cutoff for visual impairment (VI), RAAB6 uses VA of 6/12. Aim: The aim of the study was to determinethe average additional time it will take to test from 6/18 to 6/12 VA levels and to compare the causes of VI across these VA cutoffs. Methods: It wasa cross-sectional study of patients aged 50 years and above attending a tertiary hospital in Jos between April and September 2016 (6 months).RAAB6 methodology was used to test presenting VA of all participants. The time taken to obtain a VA of 6/18 and to test from 6/18 to 6/12 wasrecorded separately for each eye. Those with VA worse than 6/12 in one or both eyes had their eyes examined to determine the cause of VI. The datacollected were analyzed using the Statistical Package for Social Sciences for windows software, version 20. Results: The average additional timetaken to test VA from 6/18 to 6/12 was 42.11 seconds (95% confidence interval: 32.86–51.35). Cataract was the major cause of VI with both VAcutoffs with no significant difference in its proportion (P = 0.924). Uncorrected refractive error and glaucoma were the next important causes of VIwith 6/12 (P = 0.041) and 6/18 (P = 0.041) cutoffs, respectively. Conclusion: The spectrum of disease causing VI may not differ significantlybetween the two RAAB versions, but survey duration will likely be prolonged with RAAB6