The Effect of Trabeculeetomy on Corneal Topography

Ahn, Seong Il; Kim, Chang Sik; Choi, Si Hwan

Abstract

We performed prospective study evaluating surgically-induced alterations in corneal curvature resulting from filtering surgery using the data obtained by corneal topographic analysis. The operation was performed on 12 eyes of 11patients by one operator with the same method. Preoperatively and 6 times postoperatively, we measured vision, axial length, and intraocular pressure and also performed refraction, keratometry and corneal topography. Keratometry showed against-the-rule astigmatic change by corneal topography, five of twelve eyes developed with-the-rule atigmatism. Three patients including two cases combined with phacoemulsification developed against-the-rule astigmatism. Quantitative descriptors of corneal topography such as SAi(surface asymmetry index), SRI(surface regularity index), and Sim K(simulated keratometry value) indicated increase in corneal stability as time went by. In conclusion, compared with keratometry, corneal topography was more valuable in evaluating corneal change following trabeculectomy in that it correctly indentified the amount of astigmatism and could provide information on peripheral corneal change.