Abstract
Abstract: :
Purpose: To compare the efficacy of wavefront–guided epipolis laser in situ keratomileusis (Epi–LASIK) versus wavefront–guided conventional LASIK in reducing high order aberrations (HOA) of the cornea. Methods: Using the wavefront–guided CustomCornea LadarWave system (Alcon Laboratories Inc, Fort Worth, TX), eighteen eyes underwent Epi–LASIK using the Moria Epi–K microkeratome (Moria Inc., Antony, France) and twelve eyes underwent conventional LASIK. Wavefront analysis preoperatively, at 3 months, 4 months, and 6 months postoperatively was performed with the iTrace Aberrometer (Tracey Inc., Houston, TX). Results: Wavefront analysis showed the preoperative root mean squared (RMS) HOA for patients undergoing LASIK to be 0.171 in the 3 month group, 1.137 in the 4 month group, and 0.192 in the 6 month group. In the Epi–LASIK group, the preoperative RMS HOA was 0.272 in the 3 month group, 0.359 in the 4 month group, and 0.184 in the 6 month group. Overall, the preoperative RMS HOA was 0.499 in the LASIK group and 0.322 in the Epi–LASIK group. Postoperatively, the RMS change in high order aberrations (ΔHOA) for the LASIK group was 0.079 at 3 months, –0.596 at 4 months, and 0.026 at 6 months. Postoperatively for the Epi–LASIK group, the RMS ΔHOA was 0.139 at 3 months, 0.128 at 4 months, and 0.087 at 6 months. Overall, the postoperative RMS ΔHOA was –0.188 for the LASIK group and 0.124 for the Epi–LASIK group. Thus, LASIK had a significantly higher decrease in HOA than Epi–LASIK(P<.05, independent t–test). However, there was less follow up at 6 months with the Epi–LASIK group in contrast to the LASIK group. Plotting ΔHOA versus time, it was found that the LASIK group had a trendline with a positive slope (y = 0.029x – 0.2052) in contrast to a negative slope (y = –0.0284x + 0.2335) of the Epi–LASIK group. Conclusions:In this preliminary study with limited follow–up, CustomCornea LASIK on average induced fewer higher order aberrations than Epi–LASIK. However, a consistent trend towards decreasing HOA over the 6 month follow–up was seen with Epi–LASIK and not LASIK. Longer follow–up is needed to determine if this advantage of Epi–LASIK will continue.
Keywords: refractive surgery: LASIK • cornea: clinical science • myopia