Higher-Order Aberrations After Automated Customized Ray-Tracing Based Lasik Vs. Wavefront Optimized Lasik In Myopia And Myopic Astigmatism: A Randomized Fellow-Eye Study

In contrast to the wavefront optimized (WFO) femtosecond laser-assisted in situ keratomileusis (LASIK) (WaveLight, Alcon) which requires manifest refraction for treatment planning, the ablation profile in the automated customized femtosecond LASIK procedure wavelight plus (Alcon) is calculated by a ray-tracing algorithm using preoperative ocular wavefront, biometry and corneal tomography, without the use of manifest refraction. The aim of the study is to compare higher-order aberrations (HOA) after the automated customized LASIK vs. WFO LASIK treatments.

Department of Ophthalmology, University of Heidelberg, Heidelberg, Germany

In this ongoing prospective, double-blinded, randomized study (30 patients, 60 eyes), 24 eyes of 12 patients were treated so far: one eye per patient with wavelight plus, the fellow eye with WFO LASIK. Preoperatively, the wavelight plus Sightmap (Alcon) measurements of corneal tomography, biometry and ocular wavefront were performed. Preoperatively and one month post-surgery, we performed ocular wavefront measurement using the Pentacam AXL Wave (Oculus). We compared the spherical aberration, coma, and root-mean-square (RMS) of total HOA between the eyes treated with wavelight plus and WFO LASIK in patients who completed the one-month follow up using the Wilcoxon test for paired variables, with p<0.05 considered statistically significant.

Preoperatively, the mean (±standard deviation) spherical aberration at 6mm was 0.12±0.09µm and 0.13±0.12µm, coma (6mm) 0.19±0.11µm and 0.22±0.13µm, RMS HOA (6mm) 0.33±0.06 and 0.36±0.09 µm, RMS HOA (4.5mm) 0.15±0.03µm and 0.17±0.04µm in wavelight plus and WFO LASIK groups, respectively. One month postoperatively, spherical aberration at 6mm was -0.03±0.10µm and 0.15±0.13µm (p=0.01), coma 0.27±0.10µm and 0.28±0.16µm (p=0.78), RMS HOA 0.40±0.09µm and 0.43±0.15µm (p=0.58) after wavelight plus and WFO LASIK, respectively. At 4.5-mm zone, spherical aberration was -0.04±0.06µm and 0.03±0.05µm (p=0.02), coma 0.13±0.04µm and 0.10±0.07µm (p=0.21), RMS HOA 0.19±0.05µm and 0.17±0.06µm (p=0.23) after wavelight plus and WFO LASIK, respectively.

The automated customized ray-tracing based LASIK resulted in a lower spherical aberration, while coma and total HOA were comparable after both treatments. At ESCRS, the three months data of the entire cohort will be presented.