Abstract
Abstract: :
Purpose: To determine prevalence rates and risk factors of pterygia in adults in provincial Indonesia. Methods: A population-based prevalence survey of 1210 adults aged 21 years and above was conducted in five rural villages and one provincial town in Riau province, Sumatra, Indonesia, near to the equator. A one-stage household cluster sampling procedure was employed: 100 households were randomly selected from each village or town. Pterygia were graded for severity (T1 to T3, by visibility of episcleral vessels) and the basal and apical extent measured by an ophthalmologist (GG) with a hand-held slit lamp. Refraction was measured by handheld autorefractor (Retinomax). Face-to-face household interviews assessed outdoor activity and smoking. The participation rate was 96.7%. Results: The mean age was 36.6 years (SD +/-13.1), 612 were male. The age-adjusted prevalence rate of any pterygium was 10.0% (95% confidence intervals (CI) 8.2, 11.7) and of bilateral pterygia was 4.1% (95% CI 2.9, 5.3). There was a significant dose response relationship with age, (2.9% (CI 1.3, 4.5) for 21-30 years versus 17.3% (CI 11.7, 22.9) ≷51 years; p for trend < 0.001) and occupations with more time outdoors (p for trend = 0.02). This was true for both genders, all grades of lesion (T1 to T3) and bilateral disease. A multivariate logistic regression model showed pterygia was independently related to increasing age and outdoor activity 10 years before. The mean basal diameter = 3.3mm (SD 1.51, range 0.1-9.5) and extent from limbus = 1.4mm (SD 1.18, range 0.1-8.0). Higher grade pterygia were larger for basal and apical extent (p for trend < 0.001). Presence of pterygium was associated with astigmatism [defined as cylinder at least -0.5 Diopters (D); p < 0.001]. This association increased with increasing grade of lesion (p for trend <0.001). Median cylinder for those with pterygium (-0.50 D) was greater than for those without (-0.25D), (p < 0.001), and increased with higher grade of lesion (p for trend < 0.001). For eyes with pterygia, magnitude of astigmatism was associated with greatest extent from the limbus, (p = 0.03), but not with basal width (p = 0.99). Conclusions: The prevalence of pterygia in provincial Sumatra is higher than in other populations. The independent increase with age and past outdoor activity (a surrogate for sun exposure) is consistent with previous findings.
Keywords: 532 Pterygium • 354 clinical (human) or epidemiologic studies: prevalence/incidence