The topography of normal corneas.

Previously we have analyzed photokeratographs to determine the topography of congenital, acquired, and surgically induced deformations of corneal shape. In this article, we survey the variety of corneal shapes found in both eyes of 22 individuals with normal corneas. The degree of correlation of the distribution of corneal power around the visual axis was striking for both eyes of 18 of the 22 individuals, as was the variability of the corneal topography of different individuals. The average centrally weighted corneal power determined from the photokeratographs correlated well with the average keratometric corneal power (r = .96). By defining the topographic features characteristic of normal corneas, we will be better able to diagnose corneal shape anomalies and understand the role such anomalies play in the degradation of vision.