OBJECTIVE: This is a cross sectional ophthalmic clinic-based study to estimate the prevalence and severity of pterygium in a selected population in the Amazon Basin, Brazil. METHODS: The study included 225 subjects above 20 years age from three different places of residence of Manaus city (group 1, n=89), river based communities (group 2, n= 116) and indigenous rainforest inhabitants (group 3, n=20). Pterygia was graded 1-4 by torch examination and gender, age and occupation determined. RESULTS: were assessed to have pterygia (grades 2-4) 117 people; 52% against 108 control subjects with bilateral disease in 43% of subjects. Prevalence of grades 2-4 increased from 36% in group 1 to 62.5 % in group 2 and 75% in group 3. Of these subjects the percentage with outdoor professions increased across the groups from 31.2% to 67.1 % and 70% respectively. Also subjects of group 2 who worked largely outdoors, showed increasing pterygia severity, from grades 2 at 57% (p=0.0002), grade 3 at 93.3% (p,0.0001) to grade 4 at 100% (p=0.0004 CONCLUSION: Amazonian communities have a high prevalence of pterygia, which correlates to greater outdoor occupation and sun exposure. This study agrees with previous worldwide reports and it is the first study to compare the prevalence of pterygium in rural and urban living in Amazonian in Brazil. This study highlights the public health significance and gross need for intervention studies.
Pterygium; Prevalence; Public health; Severity of illness index; Sunlight
