Purpose: To evaluate the prevalence and associated factors of keratoconus in the adult Indian population.
Design: Population-based study.
Methods: The Central India Eye and Medical Study is a population-based study performed in a rural region close to Nagpur in Central India. It included 4,711 subjects (aged 30 years and above) out of 5,885 eligible subjects (response rate, 80.1%). The participants underwent a detailed ophthalmic and medical examination. This study was focused on the prevalence of keratoconus, defined as an anterior corneal refractive power exceeding 48 diopters (D).
Results: Out of the 4,711 subjects, corneal refractive power measurements were available for 4,667 subjects (99.1%). Keratoconus was detected in 212 eyes (2.3%) of 128 subjects (prevalence rate, 2.3% +/- 0.2%). In multivariate analysis, the presence of keratoconus was significantly associated with lower body height (P < .001), lower level of education (P= .03), higher myopic refractive error (P = .004), and thinner central corneal thickness (P = .006). It was not significantly associated with alcohol consumption (P = .99) or smoking (P = .08) nor with questions relating to the psychiatric status. Defining a keratoconus as corneal refractive power of > or =49 D or of > or =50 D, a keratoconus was detected in 58 eyes (0.6%) and 10 eyes (0.1%), respectively.
Conclusions: Keratoconus defined as corneal refractive power of 48+ D has a prevalence of 2.3% +/- 0.2% among Indians aged 30 years and above and living in the rural region of Central India. The prevalence of keratoconus was associated with lower body height, lower level of education, myopic refractive error, and thinner central cornea.