To the question of the geographic distribution of pterygium.
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D000368:Aged; D002648:Child; D005260:Female; D005843:Geography; D006801:Humans; D008297:Male; D008875:Middle Aged; D011625:Pterygium / Q000453:epidemiology*; D012737:Sex Factors; D014416:Tunisia