Posters

Large field-of-view corneal epithelium and Bowman’s layer thickness maps in keratoconic and healthy eyes

Poster Details

First Author: N.Pircher AUSTRIA

Co Author(s):    F. Beer   S. Holzer   M. Pircher   C. Hitzenberger   G. Schmidinger   J. Lammer     

Abstract Details

Purpose:

To assess differences in epithelium thickness (ET) and Bowman’s layer thickness (BLT) maps in keratoconic eyes and healthy eyes.

Setting:

Institutional.

Methods:

Epithelium and Bowman’s layer measurements were performed with a custom-designed polarization sensitive (PS)-OCT with a conical scanning optics design. En-face corneal ET and BLT maps with a diameter of 11 mm were computed. The mean ET and BLT of 25 sectors, the thinnest (minET, minBLT) and the thickest sector (maxET, maxBLT) were assessed. Ratios between thinnest/thickest sector (R1) as well as between mean ET and BLT of the inferior temporal quadrant/the superior nasal quadrant (R2) were calculated (R1ET, R1BLT; R2ET, R2BLT). Receiver operator characteristic (ROC) curve analysis was used to assess the diagnostic power of statistically different parameters.

Results:

In healthy eyes smooth ET-maps were observed. KC eyes showed a “doughnut pattern” with central thinning above the cone. The BLT-maps of healthy eyes had a smooth appearance but a highly irregular “moth damage” like pattern could be observed in keratoconic eyes. Highest AUC values were found for the thinnest sector of the BLT-map, R1ET and the thinnest sector of the ET-map.

Conclusions:

PS-OCT imaging enables the visualisation of significant differences of the corneal epithelium and the Bowman’s’ layer in en-face maps covering almost the entire cornea. Epithelial thickness and BLT profiles could clearly show their diagnostic importance for the distinguishing of keratoconic eyes and healthy eyes.

Financial Disclosure:

None