OCT evaluation of the morphology of FS-LASIK flaps obtained with two different femtolaser platforms: Victus® vs IntraLase®

Session Details

Session Title: LASIK

Session Date/Time: Monday 12/09/2016 | 08:00-10:30

Paper Time: 08:00

Venue: Hall C3

First Author: : M.Teus SPAIN

Co Author(s): :    C. Bouza   C. Villa   A. Rodero   M. Garcia-Gonzalez           

Abstract Details

Purpose:

To compare the morphology of FS-LASIK flaps obtained with two different femto lasers using spectral domain OCT.

Setting:

Clínica Novovisión, Madrid, Spain. Universidad Europea de Madrid, Spain, Universidad de Alcalá, Alcalá de Henares, Madrid, Spain

Methods:

This is a prospective, observational study. Consecutive eyes undergoing FS-LASIK (using either the Victus® or the Intralase®), and the same Allegretto® excimer laser to correct myopia, were analyzed. In addition to the usual visual and refraction evaluations, an AS-OCT was performed three months after surgery, in the horizontal meridian of the cornea, using the Spectralis®, by an experienced, masked observer. The flap thickness was measured in the central and also in several paracentral points in each case, in the same fashion, and by the same examiner, in order to evaluate the degree of “homogeneity” of the flap thickness.

Results:

The central flap thickness was 117.3±13.3 vs 122.4±9.2 microns in the Victus (V) and the Intralase (I) groups (20 and 40 eyes) respectively (p=0.08). The difference in flap thickness at 2mm nasal and 2mm temporal from the central point was 12.6±12.3 microns (range from 1 to 53) and 5.16±3.9 microns (range from 0 to 14), in the V and I groups respectively (p= 0.0007). The UCDVA and residual sphere at the three month post-op visit were 0.77±0.3 vs 1.12±0.1 and -0.59±0.6 vs -0.01±0.08 in the V and I groups respectively (p= 0.0001 for both comparisons).

Conclusions:

Although Femtosecond laser flaps are believed to be planar and highly reproducible in thickness, this may not be the case for every FS-device. Differences in the patient interface shape (flat or curved) and/or the level of the IOP at which each laser device works may make a difference in terms of flap thickness homogeneity (FTH). In addition, differences in FTH may have an effect on the refractive correction accuracy of myopic FS-LASIK.

Financial Disclosure:

NONE