Cox proportional hazards model of myopic regression for LASEK, LASIK flap creation with mechanical microkeratome and femtosecond laser in low and moderate myopia

Session Details

Session Title: LASIK: Flap Morphology and Ablation Profile

Session Date/Time: Monday 09/10/2017 | 08:30-10:20

Paper Time: 08:36

Venue: Room 3.6

First Author: : Z.Jihong CHINA

Co Author(s): :    G. Yan                    

Abstract Details

Purpose:

To compare predictive factors for postoperative myopic regression among LASEK(laser-assisted subepithelial keratomileusis), LASIK flap creation with a mechanical microkeratome(MM-LASIK) and with a femtosecond laser(FS-LASIK)

Setting:

Beijing AierIntech Eye Hospital China

Methods:

Retrospective comparative study. Refractive outcomes were recorded in 1, 3, 6, 12 months after surgery. A Cox proportional hazards model was used to evaluate the impact of the three kind of surgeries and other covariates on postoperative myopic regression. Myopic regression was defined as 0.50 D and a greater than o.50 D shift toward myopia during the follow-ups

Results:

The LASEK group comprised 236 eyes, the FS-LASIK group 1333 eyes and MM-LASIK group, 1178 eyes. Survival rates (not regression) were 63.36%, 77.00% and 74.00% respectively for MM-LASIK, FS-LASIK and LASEK in 12 months. Hazard for myopic regression included: central corneal thickness (RR=1.01, P=0.02), female (RR=1.28, P=0.00) increased with age (RR=1.02, P=0.08), customized ablation (RR=1.27, P=0.01) and border region (RR=1.45, P=0.00). FS-LASIK and MM-LASIK had a higher probability of postoperative myopic regression than LASEK (RR=1.33, 2.05; P=0.23, 0.00). The year vision lost (RR=0.98, P=0.03)，corneal curvature (RR=0.85, P=0.00) and optical region (RR=0.63, P=0.00) were protective factors.

Conclusions:

MM-LASIK was the highest risk for myopic regression, fellow by FS-LASIK and LASEK through 12 months posteroperative. Corneal thickness, female , age, customized ablation , and ablation of border region were risk factors; time of visual acuity decreased, corneal curvature and ablation of optical region were protective elements. Formula of Cox proportional hazards model was made to predict postoperative myopic regression in low and moderate myopia

Financial Disclosure:

NONE