Planning low vision services in India : a population-based perspective.
OBJECTIVE
To assess the prevalence and causes of low vision in a population in southern India for planning low vision services.


METHODS
Population-based, cross-sectional study.


METHODS
A total of 10,293 persons of all ages from 94 clusters representative of the population of the Indian state of Andhra Pradesh.


METHODS
The participants underwent a detailed eye examination, including measurement of visual acuity with logarithm of the minimum angle of resolution charts, refraction, slit-lamp biomicroscopy, applanation tonometry, gonioscopy, and stereoscopic dilated fundus evaluation. Automated threshold visual fields and slit-lamp and fundus photography were done when indicated using predefined criteria.


METHODS
Low vision was defined as permanent visual impairment that was not correctable with refractive error correction or surgical intervention. The participants with best-corrected distance visual acuity <6/18 to perception of light or central visual field <10 degrees because of an untreatable cause in both eyes were considered as having low vision.


RESULTS
Low vision was present in 144 participants, an age, gender, and urban-rural distribution adjusted prevalence of 1.05% (95% confidence interval, 0.82%-1.28%). The most frequent causes of low vision included retinal diseases (35.2%), amblyopia (25.7%), optic atrophy (14.3%), glaucoma (11.4%), and corneal diseases (8.6%). Multivariate analysis showed that the prevalence of low vision was significantly higher with increasing age, and there was a trend for higher prevalence with decreasing socioeconomic status. Extrapolating these data to the estimated 1014 million population of India in the year 2000, 10.6 (95% confidence interval, 8.4-12.8) million people would have low vision.


CONCLUSIONS
These data imply that there is a significant burden of low vision in this population, suggesting the need for low vision services.
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D018672:Community Health Planning; D003430:Cross-Sectional Studies; D003710:Demography; D005260:Female; D006296:Health Services; D006801:Humans; D007194:India / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D015995:Prevalence; D015354:Vision, Low / Q000453:epidemiology* / Q000209:etiology*