Corneal contour mapping: an isomorphic approach.

Computer-assisted videokeratography holds great promise for the contact lens fitter as well as the refractive surgeon. However, conventional methods of corneal mapping, which present color-coded representations of corneal refractive power, do not provide information about corneal surface contour. We introduce a three-dimensional isomorphic corneal modeling technique that produces a freely rotatable wire-frame image that is infinitely rescalable and open to manipulation such as digital subtraction. As an illustration of this technique, we provide isomorphic representations of corneas with astigmatism induced by large pterygia.