Abstract

Measurements obtained from computer-based videokeratographic instruments have focussed on accurate representations of corneal power, in diopters or equivalent radii lengths. Zones of power arranged in discrete (annular) widths correspond to hemi-chord lengths of the familiar bulls-eye reflected corneal ring pattern. Often these zones are color-coded for dioptric equivalence and yield quick assessment of corneal power change as a function of distance from the apex. Whether the final image is of the former sort or even configured into a "3-D chicken wire" frame, the information provided is still only about discrete power boundaries -- a sort of corneal power profile. While the sense of corneal topography may be implied in such profiles accurate representation of the true corneal surface is clearly missing. Using data derived from a clinical videokeratography unit we have been able to computer-generate an image (in X,Y,Z coordinates) which we believe to be isomorphic to the actual corneal surface.

© 1992 Optical Society of America