Ocular morbidity patterns among children in schools for the blind in Chennai

Abstract

Purpose:To identify the morbidity patterns causing blindness in children attending schools for the blind in Chennai and comparing our data with similar studies done previously.Methods:A cross-sectional prevalence study was carried out in two schools for the blind in Chennai. Blind schools were visited by a team of ophthalmologists and optometrists. Students with best-corrected visual acuity (BCVA) worse than 3/60 in the better eye were included and relevant history was noted. Every student underwent anterior segment evaluation and detailed fundus examination. Morbidity of the better eye was taken as cause of blindness. Health records maintained by the school were referred to wherever available.Results:The anatomical causes of blindness include optic nerve disorders in 75 (24.8%) cases, retinal disorders in 55 (18.2%), corneal disorders in 47 (15.6%), lens-related disorders in 39 (12.9%), congenital anomalies in 11 (3.6%), and congenital glaucoma in 20 (6.6%) cases. The whole globe was involved in six cases (1.99%). Among conditions causing blindness, optic atrophy seen in 73 (24.17%) cases was the most common, followed by retinal dystrophy in 44 (14.56%), corneal scarring in 35 (11.59%), cataract in 22 (7.28%), and congenital glaucoma in 20 (6.6%) cases.Conclusion:It was found that avoidable causes of blindness were seen in 31% of cases and incurable causes in 45%. Optic nerve atrophy and retinal dystrophy are the emerging causes of blindness, underlining the need for genetic counseling and low vision rehabilitation centers, along with a targeted approach for avoidable causes of blindness.

Commentary: Childhood blindness in India: Regional variations

“…The proportion of the various causes of CB varies region to region and the time frame, but estimates range from 0.4/1000 to 1/1000. In the past 20 years, there are a couple of studies done in schools for the blind in India;[ 6 7 8 9 10 11 12 13 14 15 ] however, these are mostly from Southern India,[ 8 10 11 12 13 ] and there are very few studies and limited data from other parts. [ 6 7 9 15 ] Only one study was undertaken in nine states and 40% of the sample was from Southern India.…”

“…[ 6 7 9 10 12 ] There is a variation in retinal disease as the cause of blindness, and it is more common in the southern part of the country. [ 8 10 11 12 13 ] Cataract as a cause of blindness varied from 7% to 14%. While corneal infections (due to measles, vitamin A deficiency, etc.)…”

“…While corneal infections (due to measles, vitamin A deficiency, etc.) declined in the more affluent states (especially in South India),[ 10 12 13 ] it continues to be a problem in north and north-east part of the country. [ 6 7 ] One of the reasons for the decline in some of the states is good immunization coverage for measles and good nutritional programs run by the government.…”

“…Looking at the etiological causes, childhood disorders (mainly corneal infections) as a cause of blindness have declined in the southern part of the country but are still prevalent in north and north-east part of the country (especially in the rural pockets). [ 6 7 10 12 13 ] Data also show that congenital anomalies and retinal causes are increasing in certain regions of the country. [ 8 10 11 12 ] However, the etiology is still not known for a majority of causes.…”

“…These studies also show that about 30%–40% of the children suffer from easily preventable and treatable causes of blindness, mainly corneal diseases and lens-related disorders. [ 6 7 8 9 10 11 12 13 14 15 ] The remaining were due to relatively unavoidable causes such as congenital anomalies and genetic diseases. However, due to regional variations in causes and differences between urban and rural areas, strategies should be customized to each region rather than developing a generic strategy for the entire country.…”