The Corneal Topography of Epikeratophakia

Epikeratophakia is a surgical technique initially developed for the correction of aphakia, and later adapted for the correction of keratoconus and myopia. The concurrent development of colorcoded computerized corneal topography has greatly assisted in the evolution of epikeratophakia. Corneal topography has demonstrated the importance of both accurate centration of the epikeratophakia lenticle over the visual axis and the size of the optical zone on the final refractive results. Corneal topographic changes associated with correction of aphakia are primarily the result of steepening of the anterior radius of curvature of the cornea, in contrast to myopic correction which results in flattening of the anterior cornea. Correction of keratoconus results from a physical compression of the cone thereby flattening both the anterior and posterior radii of curvature. Preoperative topography in patients with keratoconus permits the precise position and extent of both regular and irregular astigmatism mation may assist in designing the optimal lenticle size and amount of graft decentration necessary to achieve the maximal surgical effect. Corneal topographic mapping has also been helpful in the management of postoperative astigmatism following epikeratophakia. Topography identifies the location and extent of both regular and irregular astigmatism which assists in planning of both surgical and nonsurgical intervention. Corneal topographic mapping has also been extremely helpful in the management of postoperative astigmatism following epikeratophakia. Topography identifies the location and extent of both regular and irregular astigmatism which assists in planning of both surgical and nonsurgical intervention [Refractive and Corneal Surgery 1990; 6:26-31]