eparate effect of the microkeratome inciion and laer ablation on the eye’ wave aberration

Purpoe To tudy the optical change induced by the microkeratome cut, the ubequent laer ablation, and the biomechanical healing repone of the cornea in normal laer in itu keratomileui (LAIK) eye. Deign Propective randomized clinical trial. Method A Hanatome microkeratome wa ued to cut a corneal flap in one eye (tudy eye) of 17 normal myopic patient and a ubequent laer ablation wa performed 2 month after thi initial microkeratome inciion. Control eye received conventional LAIK treatment at the latter time point. The wave aberration of both the tudy and contralateral control eye were meaured over a 6-mm pupil with a hack–Hartmann wavefront enor for all preoperative, potflap cut, and potablation viit. Reult The eye’ higher order aberration had a mall, but ignificant increae (P = .03) of approximately 30% 2 month after cutting a flap. No ytematic change were oberved in nearly all Zernike coefficient from their preoperative level at 2 month potflap cut. A ignificant difference between the tudy and control eye wa oberved for one trefoil mode, Z33 (P = .04). Concluion There wa a wide variation in the repone of individual Zernike mode acro patient after cutting a flap. The majority of pherical aberration induced by the LAIK procedure eem to be due to the laer ablation and not the microkeratome cut. In addition, the total and higher order root mean quare of wavefront error were nearly identical for both the tudy and control eye 3-month after the laer ablation, indicating that a procedure in which the inciion and the ablation are eparated in time to better control aberration doe not compromie the outcome of a conventional LAIK treatment