Frequency United States
Age
Mortality/Morbidity
Frequency International
Sex
Pterygium is reported to occur in males twice as frequently as in females.
A pterygium can cause a significant alteration in visual function in advanced cases. It can become inflamed, resulting in redness and ocular irritation.
It is uncommon for patients to present with pterygium prior to age 20 years. Patients older than 40 years have the highest prevalence of pterygia, while patients aged 20-40 years are reported to have the highest incidence of pterygium.
Internationally, the relationship between decreased incidence in the upper latitudes and relatively increased incidence in lower latitudes persists.
The incidence of pterygium within the United States varies with geographical location. Within the continental United States, prevalence rates vary from less than 2% above the 40th parallel to 5-15% in latitudes between 28-36°. A relationship is thought to exist between increased prevalence and elevated levels of ultraviolet light exposure in the lower latitudes.
