Population-based assessment of visual impairment and pattern of corneal disease: results from the CORE (Corneal Opacity Rural Epidemiological) study.

Abstract

To characterise types of corneal diseases and resulting visual impairment (VI) in a rural North Indian population. Cross-sectional, population-based study. The Corneal Opacity Rural Epidemiological study included 12 899 participants from 25 random clusters of rural Gurgaon, Haryana, India to determine the prevalence of the corneal disease in the general population. Sociodemographic details, presence and type of corneal morbidity, laterality, VI (presenting visual acuity (PVA) <6/18 in the better eye) and characteristics of corneal opacities were noted. Overall, 12 113 participants of all ages underwent detailed ophthalmic examination and prevalence of corneal opacity was found to be 3.7% (n=452) with bilateral involvement in 140 participants (31%) during the house-to-house visits. Of the total 571 eyes of 435 patients presenting with corneal opacity at the central clinic, PVA was <3/60 in 166 (29.1%), 3/60 to <6/60 in 14 (2.5%), 6/60 to <6/18 in 164 (28.7%), 6/18 to ≤6/12 in 85 (14.9%) and 6/9 to 6/6 in 142 eyes (24.9%), respectively. Further, there were a total of 115 eyes (20.1%) with nebular corneal opacity, 263 (46.1%) with macular, 162 (28.4%) with leucomatous and 31 (5.4%) with an adherent leucoma. The odds of having VI due to corneal disease were greater for the illiterate (OR:4.26; 95% CI: 2.88 to 6.31; p<0.001) and elderly (OR:11.05; 95% CI: 7.76 to 15.74; p<0.001). The data from this study give an insight into the characteristics of various corneal pathologies and resulting VI in the general population. This is a pioneer study involving all age groups on the burden of VI due to corneal diseases.