Epithelial Map Changes In Highly Aberrated Corneas After Transepithelial Prk

In a prospective study, transepithelial PRKs were performed in highly aberrated corneas to reduce corneal irregularities. The epithelial thickness map determined by anterior chamber OCT was included in the calculation of the ablation profile. The aim of this study is to show changes in the epithelial map compared to preoperative.

Medical University of Vienna

Transepithelial PRK was performed on 35 highly aberrated corneas with a Root Mean Square Higher Order Aberration (RMS-HOA) error of 1.0 – 4.0 μm. The anterior chamber OCT MS-39® (Schwind) was used to determine the epithelial map. The ablation profile was created taking into account the mean epithelial thickness for the central area of 3 mm. Changes in the epithelial map were evaluated based on the deviations compared to the standard epithelial map. The central epithelial thickness, epithelial thickness in a diameter of 2.8 mm and 6.0 mm, epithelial thickness and standard deviation of epithelial thickness along concentric circular arcs were evaluated. Changes in epithelial thickness distributions within the epithelial map were also examined.

The analysis showed a significant reduction in the central epithelial thickness as well as the epithelial thickness in a diameter of 2.8 mm and 6.0 mm. Furthermore, there was a significant improvement in the correlation of the epithelial map after treatment with the norm values compared to preoperatively. The standard deviation of epithelial thickness along circulare arcs was significantly reduced compared to preoperative values.

Transepithelial PRK in highly aberrated corneas leads to a marked decrease in central epithelial thickness and regularization of the epithelial map.