Prevalence and associated factors for pterygium in rural agrarian central India. The central India eye and medical study.

PURPOSE: To evaluate the prevalence of pterygia and associated factors in a rural population in a mostly undeveloped agrarian region. METHODS: The Central India Eye and Medical Study is a population-based study performed in a rural region of Central India. The study comprised 4711 subjects (aged 30+ years). A detailed ophthalmic and medical examination was performed. A pterygium was diagnosed during the slit lamp examination and confirmed on corneal photographs. It was defined as a fleshy fibrovascular growth, crossing the limbus and typically seen on the nasal, and sometimes temporal, conjunctiva. RESULTS: A pterygium was detected in 798 eyes (prevalence rate: 8.47 ± 0.29%) of 608 (12.91 ± 0.49%) subjects. Bilateral pterygia were present in 190 subjects (4.0% of study population). Pterygia prevalence increased from 6.7 ± 0.8% in the age group 30-39 years, to 13.5 ± 1.2% in the age group 50-59 years, to 25.3 ± 2.1% in the age group 70-79 years. Prevalence of pterygia was associated with older age (P<0.001; regression coefficient B: 0.02; odds ratio (OR): 1.02; 95%CI: 1.01, 1.03), male gender (P<0.001;B:-0.73;OR: .48;95%CI:0.39,0.61), lower level of education (P<0.001;B:-0.30;OR:0.74;95%CI:0.69,0.80), lower body height (P=0.001;B:-0.02;OR:0.98;95%CI:0.97,0.99), and higher cylindrical refractive error (P<0.001;B:0.23;OR:1.26;95%CI:1.18,1.34). If the education level was dropped, the number of hours spent with vigorous activity outdoors (P=0.001;B:0.001;OR:1.001;95%CI:1.000,1.0001) was significantly associated with the prevalence of pterygia, in addition to older age (P<0.001;B:0.03;OR:1.03;95%CI:1.03,1.04), male gender (P<0.001;B:-0.49;OR:0.62;95%CI:0.49,0.77), lower body height (P=0.005;B:-0.02;OR:0.98;95%CI:0.97,0.99), and higher cylindrical refractive error (P