Epidemiological Insights into Childhood Vernal Keratoconjunctivitis in India: Unravelling Clinical Presentation and Environmental Influences - the EPIC VKC Study - Fourth report of the ICMR EYE SEE study group

Purpose: To study the epidemiology and clinical presentation of allergic eye diseases (AEDs) and Vernal Keratoconjunctivitis (VKC) METHODS: A cross-sectional- cum-cohort study was conducted in rural and urban areas in different geographical locations (plains, hilly, high-altitude and coastal) in India. Children (5-15 years) were included, information on exposure to environmental factors gathered, participants screened for AED and VKC on torch light, followed by a comprehensive eye examination. Cases were compared with controls. Physical environmental parameters (ultraviolet A/UVA flux) were also measured.

Results: In all, 8231 participants were screened, 410 had AED (56% males, mean age 13.7±4.5 years) and 92 had VKC (66.3% males, mean age 14.5±4.4 years). The likelihood of AED was higher for ages 11-16 years (OR 1.51, p<0.03, urban areas (OR 1.44, p=0.049), poor socioeconomic status (OR 1.5, p=0.007), exposure to smoke of incense sticks (OR 1.88, p=0.001), bright sunlight (OR 3.56, p<0.0001), dust/pollution exposure (OR 2.49, p=0.001) and winter season (OR 2.73, p=0.003). AEDs were less likely in coastal areas (OR 0.14, p<0.001). Exacerbating influences for VKC were windy weather (OR 4.35, p=0.01) and spring season (OR 13.45, p=0.001). VKC prevalence was higher in rural (69.6%) than urban areas (30.4%) (p=0.03); with 11.9% visual impairment. Palpebral VKC was the commonest type (82.6%). Maximum UVA mean flux was noted in plains.

Conclusion: The prevalence of AEDs and VKC in the community is 4.98 (95%CI: 4.51-5.45)% and 1.11 (95%CI: 0.89-1.34)%, respectively. AEDs have association with pollution or dust exposure and winter season. Palpebral VKC is the commonest clinical form of VKC.