Blindness and vision impairment in a rural south Indian population: the Aravind Comprehensive Eye Survey☆
Received 20 March 2002; accepted 8 March 2003.
Abstract
Objective
To determine the prevalence of blindness and vision impairment in a rural population of southern India.
Design
A population-based cross-sectional study.
Participants
A total of 17,200 subjects aged 6 years or older, including 5150 subjects aged 40 years or older from 50 clusters representative of three southern districts of Tamil Nadu in southern India.
Methods
All participants had preliminary screenings consisting of vision using a LogMAR illiterate E chart and anterior segment hand light examinations at the village level. Subjects aged 40 years or older were offered comprehensive eye examinations at the base hospital, including visual acuity using LogMAR illiterate E charts and refraction, slit-lamp biomicroscopy, gonioscopy, applanation tonometry, dilated fundus examinations, and automated Humphrey central 24-2 full threshold perimetry; subjects younger than 40 years of age who had any signs or symptoms of ocular disease were also offered comparable examinations at the base hospital.
Main outcome measures
Visual impairment was defined as best-corrected visual acuity <6/18, and blindness was defined using both Indian (<6/60) and World Health Organization (<3/60) definitions.
Results
Comprehensive examinations at the base hospital were performed on 5150 (96.5%) of 5337 persons 40 years of age or older. Among those 40 years of age and older, presenting visual acuity at the <3/60 level was present in 4.3% (95% confidence interval [CI]: 3.8, 4.9) and 11.4% (95% CI: 10.6, 12.3) at the <6/60 level. After best correction, the corresponding figures were 1.0% (95% CI: 0.79, 1.2) and 2.1% (95% CI: 1.7, 2.5). Over 70% of subjects improved their vision by at least one line, and nearly a third by three lines after refraction. Age-related cataract was the most common potentially reversible blinding disorder (72.0%) among eyes presenting with blindness.
Conclusions
Blindness and vision impairment remain major public health problems in India that need to be addressed. Cataracts and refractive errors remain the major reversible causes for the burden of vision impairment in this rural population.
1Aravind Eye Care System and Lions-Aravind Institute for Community Ophthalmology, Madurai, Tamil Nadu, India
2Department of International Health, Johns Hopkins Bloomberg School of Public Health, Baltimore, Maryland, USA
3Dana Center for Preventive Ophthalmology, Johns Hopkins University Schools of Medicine and Public Health, Baltimore, Maryland, USA
4Department of Ophthalmology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
Correspondence to Alan L. Robin, MD, 6115 Falls Road, Suite 333, Baltimore, MD 21209-2226, USA.
ABSTRACT