Corneal blindness in a southern Indian population: need for health promotion strategies

Abstract

Aim: To assess the distribution and causes of corneal blindness in a population in southern India.

Methods: A total of 11 786 people of all ages from 94 clusters representative of the population of the Indian state of Andhra Pradesh were sampled using a stratified, random, cluster, systematic sampling strategy. These participants underwent a detailed interview and eye examination including measurement of visual acuity with logMAR charts, refraction, slit lamp biomicroscopy, applanation tonometry, gonioscopy, and stereoscopic dilated fundus evaluation. An eye was considered to have corneal blindness if the visual acuity was <20/200 due to a corneal disease.

Results: Of those sampled, 10 293 (87.3%) people participated in the study. Corneal blindness in at least one eye was present in 86 participants, an age, sex, and urban-rural distribution adjusted prevalence of 0.66% (95% confidence interval 0.49 to 0.86), which included 0.10% prevalence of corneal blindness in both eyes and 0.56% in one eye. The most frequent causes of corneal blindness in at least one eye included keratitis during childhood (36.7%), trauma (28.6%), and keratitis during adulthood (17.7%). Nearly 95% of all corneal blindness was avoidable. Multivariate analysis showed that the prevalence of corneal blindness was significantly higher with decreasing socioeconomic status and with increasing age. Of the 99 eyes with corneal blindness, 51 (51.5%) had visual acuity of inaccurate projection of light or no perception of light.

Conclusions: There is a significant burden of corneal blindness in this population, the majority of which is avoidable. Eye health promotion strategies are warranted to raise awareness about the causes and prevention of corneal blindness.

Figure 1

Prevalence of corneal blindness in both eyes, one eye, and at least one eye for the four areas of APEDS. Prevalence for all the study areas combined adjusted for age, sex, urban-rural distribution of population of India in 2000, and for the rest adjusted for age and sex distribution of population of India in 2000.

Figure 2

Causes of corneal blindness in at least one eye for the four areas of APEDS. Hyderabad is the urban area and the rest are rural areas of APEDS. Prevalence adjusted for age and sex distribution of population of India in 2000.

Figure 3

Prevalence of causes of corneal blindness in at least one eye for different age groups for the four areas of APEDS combined. Prevalence adjusted for sex and urban-rural distribution of population of India in 2000.

Figure 4

Prevalence of causes of corneal blindness in at least one eye for the two sexes for the four areas of APEDS combined. Prevalence adjusted for age and urban-rural distribution of population of India in 2000.

Figure 5

Distribution of visual acuity in 99 eyes of 86 participants with corneal blindness based on the cause of blindness. Total represents all eyes blind due to corneal disease (<20/200), and PL negative includes eyes with inaccurate projection of light and no perception of light.