The Prevalence of and Risk Factors Associated with Pterygium in a Rural Adult Chinese Population: The Handan Eye Study

Purpose: To describe the prevalence and risk factors for pterygium in a rural adult Chinese population. Methods: A total of 7557 people aged 30 years and over were randomly selected from 13 villages in a rural county, Yongnian, within Handan district, Hebei Province of China. All eligible subjects were invited to undergo a comprehensive eye examination. A slit-lamp was used to examine the anterior segment for evidence of pterygium. Pterygium was graded for severity (G1 to G3) by visibility of episcleral vessels. Results: Of 6685 participants (88.5% of 7557) included in this study, pterygium was present in 401 (6.0%). Using direct standardization to the 2000 China population census for rural residents, the prevalence of pterygium was 7.1% (95% confidence interval [CI], 6.5-7.8%) among subjects aged 40+ years, and 4.8% (95% CI 4.3-5.3%) when including those aged 30-39 years. Pterygium was more common in men than in women (age-adjusted odds ratio [OR] 2.0, 95% CI 1.4-2.8). Prevalence increased with age (OR 1.8, 95% CI 1.6-2.1 per decade increase in age). Current smoking appeared to be protective (OR 0.5, 95% CI 0.4-0.7). Of eyes with any pterygium, 4.6% (95% CI 1.9-7.3%) had low vision. Conclusion: Approximately one in ten adults had pterygium in this rural Chinese population. Age and male sex were positively, and current smoking negatively associated with the prevalence of pterygium.