Risk Factors for Pterygium in Korea

Abstract

The aim of this study is to report general and age-specific risk factors for pterygium prevalence in the Korean population.This in an observational case series study.Data from total 24,812 participants (age 40 years or older) from the Korean National Health and Nutrition Examination Surveys conducted from 2010 to 2012 were retrieved. After applying exclusion criteria, data from 13,204 participants (821 with pterygium and 12,383 without) were used for univariate and multivariate analyses. General risk factors were identified and participants were grouped by decade: 40 s, 50 s, 60 s, 70 s, and 80+. Age-specific risk factors were investigated for each group.After univariate analysis, 2 multiple regression models were constructed. Model 1: age + sex + spherical equivalent (SE) + sun exposure hours + occupation (indoor vs outdoor) + residency area (rural vs urban) + education level; model 2: age + sex + SE + sun exposure hours. In model 1, older age (odds ratio [OR]: 1.05 95% confidence interval [CI]: 1.05–1.06), male gender (OR: 1.28, 95% CI: 1.01–1.61), and longer sun exposure hours (OR: 1.47, 95% CI: 1.11–1.94) were significant risk factors for pterygium prevalence whereas higher level of education (elementary school vs college, OR: 3.98, 95% CI: 2.24–7.06) and urban residency (vs rural residency, OR: 0.56, 95% CI: 0.45–0.70) were protective factors. Higher SE (OR 1.11, 95% CI: 1.03–1.19) refractive error was considered a risk factor when using model 2 for the analysis. Age-specific risk factors were different in each age group. Male gender was associated with higher pterygium prevalence in younger age groups while longer sun exposure (5+ hours/day) increased pterygium prevalence in older age groups.Previously characterized risk factors were also found in this large population study. However, we found that risk factors may vary according to the age group. Myopic eyes were found to have lower prevalence than hyperopic eyes.

Outdoor Air Pollution and Pterygium in Korea

“…Our study presented that aging, male sex, and greater sun exposure, lower education level, and myopia were associated with pterygium. These results are consistent with previous studies (791014). Myopia was negatively associated with both pterygium and its recurrence.…”

“…This study presented the prevalence and recurrence rate of pterygium were 5.3 and 10.3% in the Korean population respectively. The prevalence can be lower than those in previous studies because overall population was included in the study (710). Recurrence was reported 1%–40% according to surgical methods (22).…”

“…The pterygium prevalence has been reported 6.2%–6.7% (710), however the recurrence rate of pterygium was not reported in the Korean population. This study presented the prevalence and recurrence rate of pterygium were 5.3 and 10.3% in the Korean population respectively.…”

“…Based on literature review of various epidemiological studies on pterygium (678910), we considered their common risk factors as covariates including sociodemographic and clinical factors. Sociodemographic factors included age, sex, region of residence (urban or rural), education level (high school or less or and university or higher), income level (high [1st or 2nd quartile] or low [3rd or 4th quartile]).…”

“…Sociodemographic factors included age, sex, region of residence (urban or rural), education level (high school or less or and university or higher), income level (high [1st or 2nd quartile] or low [3rd or 4th quartile]). Also, we considered sun exposure (< vs. ≥ 5 hours per a day and myopia [+/−]) as covariates, because previous studies using KNHANES data suggested that pterygium was associated with sun exposure and myopia (710). …”