Refractive and high order aberration outcomes after high-definition wavefront-guided LASIK for myopic patients

Session Details

Session Title: LASIK Outcomes I

Session Date/Time: Tuesday 16/09/2014 | 14:00-16:00

Paper Time: 15:32

Venue: Boulevard B

First Author: : M.Shafik Shaheen EGYPT

Co Author(s): :    M. Khalifa   H. Ezz Eldin           

Abstract Details

Purpose:

The purpose of this evaluation was to assess the efficacy, predictability, safety and change of HOA (High Order Aberrations) RMS and Spherical Aberration RMS after CustomVue procedure using a High Definition Aberrometer (iDesign System) to design the treatment.

Setting:

HORUS Vision Correction Center (HVCC), Alexandria, Egypt

Methods:

This was a prospective, consecutive non comparative study. 40 myopic patients with up to -8:00D sphere and -6:00D cylinder but maximum spherical equivalent of -12D suitable for refractive surgery targeted for emetropia were enrolled. All eyes were treated with the Star S4IR (Abbott Medical Optics Inc) using the iDesign System to calculate the wavefront guided ablation and flaps were created with the Moria M2 microkeratome. Refractive outcomes were evaluated 3 months after surgery as well as the change in HOA RMS and primary spherical aberration. In order to compare preop to postop aberrations Zernike coefficients were converted to the same pupil diameter for both visits (5mm).

Results:

Mean age was 28±8.3 years, 62% females and 38% male. 69 eyes were followed up for 3 month. Mean preoperative spherical refraction was -2.99D±1.74 (-8.00 to -1.00D) and mean preoperative cylinder was -1.70D± 1.07 (0.0 to -5.25D). At baseline 79% of eyes had a BCVA (Best Corrected Visual Acuity) of 20/20 or better and 12% of eyes were 20/16 or better, 3 months post operatively UCVA (Uncorrected Visual Acuity) was 20/20 or better for 86% of eyes and 20/16 or better for 26% of eyes. After 3 months, 97% of eyes were within 0.25 D of MRSE (Manifest Refraction Spherical Equivalent), 59,4%found no change in lines of BCVA, 30.4% gained one line of BCVA and 10.1% gained 2 lines of BCVA. No eye lost lines of vision. 64 eyes had pupils sizes larger than 5mm at both visit, when converted to 5mm mean HOA RMS was 0.20±0.08µm (0.08 to 0.39) and 0.25±0.08µm (0.11 to 0.48) (p=0.002) preoperative and post operative respectively and mean primary spherical aberration was +0.03±0.08µm (-0.18 to +0.19) and +0.04±0.08µm (-0.18 to +0.18) (p=0.16) preoperative and post operative respectively.

Conclusions:

The LASIK procedure using a high definition aberrometer to calculate the shape of the ablation has been found to be safe and very effective, 50% more eyes were 20/16 uncorrected post operatively than corrected preoperatively. This new procedure provides very high predictability with 97% of eyes within 0.25D of the intended correction. This is the first time we see such a low induction of high order aberrations and spherical aberration after a lASIK procedure.

Financial Interest:

NONE