Blindness and visual impairment due to uncorrected refractive error in sub-Saharan Africa: review of recent population-based studies.
OBJECTIVE
The authors aimed to review published data on uncorrected refractive error (URE) as a cause of blindness and visual impairment in adults aged ≥40 years in sub-Saharan Africa (SSA).


METHODS
Data were extracted from population-based prevalence surveys measuring presenting visual acuity (PVA). Results from 11 surveys performed in 10 countries in SSA, encompassing 39,458 people aged ≥40 years and older, are presented.


RESULTS
The prevalence of blindness (PVA<3/60 in better eye) ranged from 1.1% in an urban district of Cameroon to 7.9% in a rural district in Ethiopia. More than half of studies (6/11) reported no blindness due to URE. The proportion of moderate visual impairment (PVA ≤6/60 and >6/18) due to URE ranged from 12.3% to 57.1%. Excluding two studies that included uncorrected aphakia as part of URE, the highest proportion of blindness and severe visual impairment due to uncorrected aphakia was found in Gambia (15.2%) and Nigeria (15.8%), respectively.


CONCLUSIONS
Although URE is a leading cause of visual impairment, it does not represent a major cause of blindness in SSA.
Department of Public Health and Primary Care, University of Cambridge, Cambridge, UK.
Justin C
JC
Sherwin
Susan
S
Lewallen
Paul
P
Courtright
D000328:Adult; D017954:Africa South of the Sahara / Q000453:epidemiology; D001036:Aphakia, Postcataract / Q000453:epidemiology; D001766:Blindness / Q000453:epidemiology* / Q000209:etiology; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D012030:Refractive Errors / Q000150:complications / Q000453:epidemiology* / Q000628:therapy; D012424:Rural Population / Q000706:statistics & numerical data; D014505:Urban Population / Q000706:statistics & numerical data; D015354:Vision, Low / Q000453:epidemiology* / Q000209:etiology; D014792:Visual Acuity; D019987:Persons with Visual Disabilities / Q000706:statistics & numerical data*