Prevalence and associated factors for pterygium and pinguecula in a South Indian population

Purpose: To describe the prevalence and factors associated with pterygium and pinguecula in a south Indian population.

Methods: The Chennai Glaucoma Study examined 7774 (Urban 3850, Rural 3924) subjects aged above 40 years. All subjects underwent a comprehensive ophthalmic evaluation. Personal history, occupation and lifetime ultraviolet exposure were documented. The presence of pterygium and pinguecula on slit-lamp examination was recorded. The prevalence of pterygium and pinguecula, differences in the rural and urban populations and their association with age, gender, residence, nature of occupation, lifetime ultraviolet radiation exposure, tobacco use (smoking/smokeless), alcohol use, diabetes mellitus and hypertension were analyzed.

Results: The mean age of the subjects was 54.6 (SD: 10.6) years. Pterygium was present in either eye of 740 subjects (9.5%, 95% CI: 8.6-10.4%), of which 329 subjects were male and 411 subjects were female. The prevalence of pterygium differed significantly (OR: 4.60 95% CI: 3.82-5.56, p < 0.0001) between the urban (144, 3.7%, 95% CI: 3.1-4.3%) and the rural population (596, 15.2%, 95% CI: 14.1-16.3%). Pinguecula was present in either eye of 875 subjects (11.3%, 95% CI: 10.5-12.0%), of which 368 subjects were male and 507 subjects were female. The prevalence of pinguecula differed significantly (OR: 2.94, 95% CI: 2.51-3.43, p < 0.0001) between the urban (238, 6.2%, 95% CI: 5.4-6.9%) and the rural population (637, 16.2%, 95% CI: 15.1-17.4%). Pinguecula and pterygium were significantly associated with rural residence (p < 0.0001). We found rural residence and exposure to higher lifetime UV exposure to be significantly associated with the presence of pterygium (p < 0.0001). Non-use of spectacles was found to be associated with both pterygium (OR: 1.41, 95% CI: 1.12-1.79) and pinguecula (OR: 1.69, 95% CI: 1.38-2.08). The presence of pterygium and pinguecula was not associated with smoking, use of alcohol, nature of work, diabetes and hypertension.

Conclusion: The prevalence of pterygium and pinguecula a South Indian population were 9.5% and 11.3% respectively. Rural residence were associated with presence of both pterygium and pinguecula. Higher lifetime UV exposure was associated with the presence of pterygia.