Prevalence of pinguecula and pterygium in a general population in Spain

To determine the prevalence of pinguecula and pterygium and to investigate their associations in a general adult population in North-Western Spain.

An age-stratified random sample of 1155 subjects ≥ 40 years was selected in O Salnés (Spain). From 937 eligible subjects, 619 (66.1%) participated (mean age (SD): 63.4 (14.5) years, range: 40-96 years, 37.0% males). An interview to collect history of systemic diseases and lifestyle details and a comprehensive ophthalmic evaluation in which pinguecula and pterygium were recorded was carried out. The prevalence of pinguecula and pterygium and their relationship with lifestyle factors and ocular and systemic diseases was investigated.

The prevalence of pinguecula was 47.9% (95% confidence interval (CI): 43.9-51.9). This prevalence increased significantly with aging (P = 0.002) and was higher in men (56.4%; 95% CI: 50.0-62.7) than in women (42.7%; 95% CI: 37.8-47.8) (P=0.001). The prevalence of pterygium was 5.9% (95% CI: 4.3-7.9). This prevalence also increased significantly with aging (P = 0.005) and was 4.8% (95% CI: 2.6-8.4) in men and 6.5% (95% CI: 4.5-9.3) in women (P = 0.346). After controlling for age and sex, pinguecula was associated with alcohol intake (adjusted odds ratio (OR(a)): 3.08; 95% CI: 1.60-5.95), pterygium with fluorescein staining (OR(a): 2.64; 95% CI: 1.08-6.46) and both disorders with outer activity (OR(a): 2.07; 95% CI: 1.36-3.15 and 2.28; 95% CI: 1.04-4.98, respectively).

Pinguecula is far more common than pterygium. Alcohol consumption is strongly associated with pinguecula. Fluorescein staining is highly prevalent in subjects with pterygium. Both disorders increase with age and are associated with outer activity.