Astigmatism and surface phenomena in pterygium.

Examination of 39 eyes with pterygium and 17 contralateral eyes revealed increased astigmatism with the rule (greater than 0.5 D in 46%, greater than or equal to 4 D in 13%) without associated impairment of vision. Intensified vital staining was seen to be provoked over the pterygium by tetrazolium and rose bengal, whereas this was not the case with fluorescein or alcian blue. There were no signs of desiccation (Break up time normal). Stocker's line in front of the pterygium was observed in 46%. In 13% this was continuous with Hudson Stahli's line. A quantitative cytologic study disclosed keratinisation in 5%. Increased desquamation was seen in 10%. The central thickness of the cornea was the same as in normal eyes.