Wavefront-optimised vs topography-guided ablation in LASIK: a contralateral eye study for myopia

Session Details

Session Title: LASIK I

Session Date/Time: Sunday 06/09/2015 | 08:00-10:00

Paper Time: 08:12

Venue: Room 11

First Author: : A.Pasari INDIA

Co Author(s): :    A. Jain   C. Malhotra   P. Chakma              

Abstract Details

Purpose:

To study and compare the outcomes of wavefront-optimized and topography-guided ablation in contralateral eyes of patients undergoing laser in situ keratomileusis (LASIK) for myopia.

Setting:

Cornea and Refractive Surgery Clinic,Advanced Eye Centre,PGIMER,Chandigarh,India

Methods:

Pre-operative mean spherical equivalent refraction was -4.22±1.22D and -4.38±1.30D in wavefront-optimised and topograpthy-guided groups, respectively. 94.29%of eyes in the wavefront-optimised group and 100% in the topography-guided group had UCVA of 20/20 or better; the UCVA of 20/16 was better for the topography-guided group. The mean ablation depth was significantly lower(p<0.001) in the topography-guided group for similar indended correction in both groups. Mean higher order aberrations (RMS) increased from 0.74±0.25μm and 0.75±0.29μm to 1.17±0.45μm and 1.07±0.38μm in the wavefront-optimized and topography-guided groups, respectively. Mesopic contrast sensitivity in topography-guided group was statistically better than that in wavefront-optimised group at high spatial frequencies.

Results:

Pre-operative mean spherical equivalent refraction was -4.22±1.22D and -4.38±1.30D in wavefront-optimised and topograpthy-guided groups, respectively. 94.29%of eyes in the wavefront-optimised group and 100% in the topography-guided group had UCVA of 20/20 or better; the UCVA of 20/16 was better for the topography-guided group. The mean ablation depth was significantly lower(p<0.001) in the topography-guided group for similar indended correction in both groups. Mean higher order aberrations (RMS) increased from 0.74±0.25μm and 0.75±0.29μm to 1.17±0.45μm and 1.07±0.38μm in the wavefront-optimized and topography-guided groups, respectively. Mesopic contrast sensitivity in topography-guided group was statistically better than that in wavefront-optimised group at high spatial frequencies.

Conclusions:

The visual outcomes of both wavefront-optimised and topography-guided ablation in LASIK for myopia using the using Carl Zeiss Meditec platform and the femtosecond laser are excellent. However, topography-guided ablation provides better refractive outcomes as compared wavefront-optimised ablation while ablating significantly lesser amount of corneal tissue for similar correction. Topography-guided ablation also induces significantly lesser higher order aberrations as well as provided better contrast sensitivity outcomes. Topography-guided ablation can be considered as an effective alternative to other existing ablation profiles in LASIK for primary treatment of virgin myopic eyes.

Financial Interest:

NONE