Rapid Assessment of Avoidable Blindness in India.
BACKGROUND
Rapid assessment of avoidable blindness provides valid estimates in a short period of time to assess the magnitude and causes of avoidable blindness. The study determined magnitude and causes of avoidable blindness in India in 2007 among the 50+ population.


RESULTS
Sixteen randomly selected districts where blindness surveys were undertaken 7 to 10 years earlier were identified for a follow up survey. Stratified cluster sampling was used and 25 clusters (20 rural and 5 urban) were randomly picked in each district.. After a random start, 100 individuals aged 50+ were enumerated and examined sequentially in each cluster. All those with presenting vision <6/18 were dilated and examined by an ophthalmologist. 42722 individuals aged > = 50 years were enumerated, and 94.7% examined. Based on presenting vision,, 4.4% (95% Confidence Interval[CI]: 4.1,4.8) were severely visually impaired (vision<6/60 to 3/60 in the better eye) and 3.6% (95% CI: 3.3,3.9) were blind (vision<3/60 in the better eye). Prevalence of low vision (<6/18 to 6/60 in the better eye) was 16.8% (95% CI: 16.0,17.5). Prevalence of blindness and severe visual impairment (<6/60 in the better eye) was higher among rural residents (8.2%; 95% CI: 7.9,8.6) compared to urban (7.1%; 95% CI: 5.0, 9.2), among females (9.2%; 95% CI: 8.6,9.8) compared to males (6.5%; 95% CI: 6.0,7.1) and people above 70 years (20.6%; 95% CI: 19.1,22.0) compared to people aged 50-54 years (1.3%; 95% CI: 1.1,1.6). Of all blindness, 88.2% was avoidable. of which 81.9% was due to cataract and 7.1% to uncorrected refractive errors/uncorrected aphakia.


CONCLUSIONS
Cataract and refractive errors are major causes of blindness and low vision and control strategies should prioritize them. Most blindness and low vision burden is avoidable.
Neena
John
J
Community Ophthalmology Unit, Dr RP Centre for Ophthalmic Sciences, All India Institute of Medical Sciences, New Delhi, Delhi State, India.
Rachel
Jose
J
Praveen
Vashist
V
Murthy
Gudlavalleti V S
GV
D000368:Aged; D001766:Blindness / Q000209:etiology / Q000503:physiopathology* / Q000517:prevention & control*; D002386:Cataract / Q000175:diagnosis; D004651:Employment / Q000706:statistics & numerical data; D005260:Female; D005901:Glaucoma / Q000175:diagnosis; D006306:Health Surveys; D006801:Humans; D007194:India; D008297:Male; D008875:Middle Aged; D020380:Needs Assessment; D012030:Refractive Errors / Q000175:diagnosis; D012424:Rural Population; D014505:Urban Population