Evaluation of flap striae after laser in situ keratomileusis

Poster Details

First Author: H.Helaly EGYPT

Co Author(s):    A. Malaty   A. Gaith   A. Abdelazim        

Abstract Details

Purpose:

The aim of the present study was to evaluate the risk factors contributing to the development corneal flap striae after Laser in situ keratomileusis.

Setting:

Faculty of Medecine, Alexandria University, Egypt

Methods:

This clinical study included 148 eyes of patients undergoing LASIK. The eyes included had a refractive error of myopia up to -12D, and myopic astigmatism up to -4D. Every patient was subjected to complete ophthalmologic examination. LASIK was performed. The Microkeratome head Moria, M2 automated microkeratome ( Moria, Antony, France ) was used to create the corneal flap. VISX STAR 4 Excimer laser system ( VISX, Santa Clara,CA) was used for the ablation. Central corneal thickness was measured using DGH 555 ultrasonic Pachymeter (PACHETTE 3). Three groups of readings were taken; one before the procedure, the second after corneal flap creation, and the third after ablation. Flap thickness and actual ablation depth were calculated by subtraction method. The patients were followed up at one day, one week, one month, and three months postoperative.

Results:

The studied eyes were classified into two groups; group I included the eyes which did not develop striae, and group II included those which developed striae. After using statistical analysis, only 2 variables were statistically significant; the hinge length and blade use. Hinge length : We had 26 eyes with striae, of them 3 eyes ( 11.5% ) had a hinge length of 3 mm. These eyes had smaller hinges in comparison with the eyes that did not develop striae, where no cases had 3 mm hinge length Blade use : Out of 122 eyes that did not develop striae, thirty seven eyes ( 30.3% ) had third or fourth blade use. In contrast to 14 ( 53.8% ) out of 26 eyes had third or fourth blade use in the group of eyes that developed corneal flap microfolds.

Conclusions:

? Several interdigitated risk factors can affect the incidence of development of striae; the most important in this study were hinge length and blade use. ? Smaller hinge length may increase incidence of striae due to more flap instability. ? With multiple use of blades, the quality of the blades and the stromal bed deteriorates. Refractive surgeons should abandon the practice of using the microkeratome blade for more than one patient. ? Preoperative manifest refraction and central corneal thickness were not found significant as a risk factor for development of striae in this study FINANCIAL DISCLOSURE?: No