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Comparison of optical quality parameters and ocular aberration after wavefront-guided LASEK

Session Details

Session Title: Surface Ablation I

Session Date/Time: Sunday 06/10/2013 | 08:00-09:30

Paper Time: 08:18

Venue: Main Lecture Hall (Ground Floor)

First Author: : T.Kim SOUTH KOREA

Co Author(s): :    K. Lee   H. Kim   E. Kim   K. Seo     

Abstract Details

Purpose:

To compare optical quality, ocular scattering and higher-order aberrations (HOAs) after laser in situ keratomileusis (LASIK) versus laser epithelial keratomileusis (LASEK).

Setting:

Department of Ophthalmology, Yonsei University College of Medicine, Seoul, KOREA,

Methods:

A total of 47 eyes from 47 participants who underwent the LASIK (Group I) or LASEK (Group II) procedure at least six months prior were enrolled. Ocular aberrations and modulation transfer function (MTF) values measured using iTrace, a ray-tracing type aberrometer, were compared to MTF cut-off values, Strehl ratio, and objective indices of scattering obtained using the Objective Quality Analysis System II (OQAS II).

Results:

There was no significant correlation between the postoperative optical quality parameters and the HOAs between both groups. In group I, the MTF cut-off value was significantly correlated with cylinder refraction (p=0.037), and the objective scattering index (OSI) was positively correlated with spherical equivalent (p=0.023). In group II, there was a statistically significant correlation between the OSI and achieved refractive correction (p=0.001). Regression analysis showed that the OSI was the most significant predictor of MTF cut-off values after refractive surgery. Additionally, MTF values measured by OQAS were significantly lower than those measured by iTrace without correlation.

Conclusions:

Optical quality after refractive surgery may be influenced by not only ocular aberration but also by scattering. Even though the accuracies of the machines used in this study to measure optical quality have yet to be proven, this study showed limited correlation among the values measured using the two different machines after refractive surgery. Therefore, for more generalized evaluation of visual function after refractive surgery, more advanced optical devices still need to be developed.

Financial Interest:

NONE