Corneal Topographic Changes Induced by Pterygia

BACKGROUND: This study characterizes the topographic changes induced by pterygia. METHODS: Using data obtained from a videokeratoscope (TMS-1), we assessed the topographic changes of corneas from 24 consecutive eyes with pterygia. RESULTS: Each pterygium induced a localized area of flattening central to its apex of 38.00 +/- 2.80 diopter (D) which was significantly flatter (p < .0001) than the mean corneal power (43.70 +/- 1.70), minimum corneal power (MinK, 42.70 +/- 2.10), and the power of the flattest corneal meridian (42.90 +/- 1.90). CONCLUSIONS: Our topographic findings characterize an area of localized corneal flattening central to the apex of pterygia. It is not known if this pterygium-associated corneal flattening influences the centripetal growth of pterygia or their tendency not to cross the visual axis.