Pterygium in Tibetans: a population-based study in China

• Published in: Clinical & experimental ophthalmology Vol. 35; no. 9; pp. 828 - 833
• Main Authors: Lu, Peng, Chen, Xiaoming, Kang, Ying, Ke, Lang, Wei, Xiaoyan, Zhang, Wenfang
• Format: Journal Article
• Language: English
• Published: Melbourne, Australia Blackwell Publishing Asia 01.12.2007
• Subjects: Adult; Age Distribution; Aged; Aged, 80 and over; Educational Status; Eyeglasses - utilization; Female; high altitude; Humans; Male; Middle Aged; Prevalence; Prospective Studies; Protective Clothing - utilization; pterygium; Pterygium - epidemiology; Pterygium - etiology; Radiation Protection - methods; Risk Factors; Sex Distribution; Social Class; Sunlight; Tibet - epidemiology; Tibetan; Tibet
• ISSN: 1442-6404; 1442-9071
• DOI: 10.1111/j.1442-9071.2007.01630.x

Purpose:  To describe the prevalence and to identify associated risk factors for pterygium in a Tibetan population at high altitude in Zeku County, China. Methods:  A prospective population‐based survey was conducted from October to December 2006. A stratified, clustered, randomized sampling procedure was used to select 2632 Tibetan people aged 40 years and older. Pterygium was diagnosed and graded clinically as grade 1 (transparent), 2 (intermediate) and 3 (opaque). Risks factors associated with pterygium were evaluated with logistic regression models. Results:  From a total of 2632 eligible subjects, 2229 (84.69%) were examined. There were 323 people with pterygium, equivalent to an overall prevalence of 14.49% (95% confidence interval [CI] 13.03–15.95). Pterygium was independently associated with increasing age for persons aged 70–79 years, compared with those aged 40–49 years (odds ratio [OR] 2.0; 95% CI 1.4–2.8), female gender (OR 1.6; 95% CI 1.2–2.0), dry eye symptoms (OR 1.3; 95% CI 1.0–1.7), seldom use of sunglasses/crystal spectacles (OR 4.6; 95% CI 1.9–11.3) or hats (OR 3.6: 95% CI 2.4–5.4), lower education level (<3 years) (OR 1.6; 95% CI 1.1–2.4) and low socioeconomic status (OR 1.9; 95% CI 1.5–2.4). Conclusions:  The prevalence of pterygium in a Tibetan population at high altitude is significantly high, particularly in certain at‐risk groups. The primary causative factors are related to ocular sun exposure, which are easily preventable. Public health schemes to address this serious health issue are urgently needed.