Posters

Evaluation of corneal biomechanical properties before and after LASIK for treatment of myopia

Poster Details

First Author: H.Elsobky EGYPT

Co Author(s):    S. El Gohary   M. Zein El Din                 

Abstract Details

Purpose:

To study the correlation between corneal biomechanical properties and surgical parameters in myopic patients before and after laser in situ keratomileusis (LASIK).

Setting:

Departement of Ophthalmology - Menoufia University Hospital

Methods:

In 70 eyes with myopia and myopic astigmatism the Ocular Response Analyzer (ORA) was used to measure corneal hysteresis (CH) and corneal resistance factor (CRF). The patients undergoing LASIK with manifest refractive spherical equivalent (MRSE) from -1 to -10 diopters. postoperative Corneal hysteresis (CH) and corneal resistane factor (CRF) were recorded for each eye one and three month after surgery.

Results:

There was highly significant statistical difference between preoperative and postoperative CH and CRF. The average reduction in CH and CRF one month postoperative was (mean 2.5 1.2 and (mean 3.6 1.42) respectively and three month post-operative was (mean 2 1.2) and (mean 3.1 1.5) respectively. There is statistically significant correlation between ablation depth (AD) and both CH and CRF (r = -0.90, r = -0.83) (P <0.001). There is statistically significant correlation between preoperative MRSE and ablation depth AD and both CH and CRF (r = -0.96, r = -0.0.80, r = 0.80) (P <0.001).

Conclusions:

Ocular response analyzer can be used to detect the biomechanical changes of the cornea after refractive surgery. LASIK surgery decreases the corneal hysteresis and corneal resistance factor. The deeper the ablation depth, the higher the amount of reduction in corneal hysteresis and corneal resistance factor.

Financial Disclosure:

NONE