Posters

Corneal densitometry changes following corneal refractive surgery measured with a Pentacam-Scheimpflug system

Poster Details

First Author: N.Garzón Jiménez SPAIN

Co Author(s):    J. Aramberri   I. Illarramendi   P. Caro   O. Janez   F. Argueso   A. Lopez     

Abstract Details

Purpose:

To establish a normal-value range for corneal densitometry in healthy subjects and to assess corneal densitometry changes resulting from corneal refractive surgery by means of a Pentacam HD system (Oculus, Inc., Wetzlar, Germany).

Setting:

Innova Ocular, Spain

Methods:

225 eyes from 225 patients were included in the study. They had no ocular pathologies, and were all eligible for corneal refractive surgery to correct their myopic refractive error. Pentacam measurements were performed during the pre-operative workup and upon surgical discharge. The device's own software was used to assess corneal optical densitometry in various ring-shaped zones (0-2 mm, 2-6 mm and 0-12 mm [total area]) for different corneal (anterior [120 microns], center layer, posterior [60 microns] and total corneal thickness). Patients were split into 3 groups according to their surgical procedure: PRK, Femto-LASIK and ReLEx smile.

Results:

Once the normal-value range was determined by measuring healthy subjects with no prior refractive surgery, the comparison of pre- and post-surgical results revealed statistically significant differences for the PRK technique for the anterior layer in all three corneal zones under consideration. Similar outcomes were obtained for those same zones when the total corneal thickness was considered. As for Femto-LASIK, statistically significant differences were found only in the central 2 mm-zone for all corneal layers (up to 120 microns, center layer and total corneal thickness). For the ReLEx smile group, statistically significant pre-vs-post-operative differences were found only when evaluating the center layer and the total corneal thickness in the 2-to-6 mm ring-shaped zone.

Conclusions:

Corneal densitometry does change as a result of the refractive surgery procedure for all laser-based techniques under analysis. The depth at which laser ablation occurs is the predictor factor affecting corneal densitometry the most, though for all three techniques densitometry values are worse when the analysis includes the cornea's full thickness.

Financial Disclosure:

NONE