Comparion of corneal wavefront aberration after photorefractive keratectomy and laer in itu keratomileui Original Reearch Article

PURPOE: To compare change in the corneal wavefront aberration after photorefractive keratectomy and laer in itu keratomileui. METHOD: In a propective randomized tudy, 22 patient with bilateral myopia received photorefractive keratectomy on one eye and laer in itu keratomileui on the other eye. The procedure aigned to each eye and the equence of urgery for each patient were randomized. Corneal topography meaurement were performed preoperatively, 2 and 6 week, 3, 6, and 12 month after urgery. The data were ued to calculate the wavefront aberration of the cornea for both mall (3-mm) and large (7-mm) pupil. REULT: Both photorefractive keratectomy and laer in itu keratomileui ignificantly increaed the total wavefront aberration for 3- and 7-mm pupil, and value did not return to the preoperative level throughout the 12-month follow-up period. For a 3-mm pupil, there wa no tatitically ignificant difference between photorefractive keratectomy and laer in itu keratomileui at any potoperative point. For a 7-mm pupil, the pot–laer in itu keratomileui eye exhibited ignificantly larger total aberration than the pot–photorefractive keratectomy eye, where a ignificant intergroup difference wa oberved for pherical-like aberration, but not for coma-like aberration. Thi dicrepancy eemed to be attributable to the maller tranition zone of the laer ablation in the laer in itu keratomileui procedure. Before urgery, imulated pupillary dilation from 3 to 7 mm caued a five- to ix-fold increae in the total aberration. After urgery, the ame dilation reulted in a 25- to 32-fold increae in the photorefractive keratectomy group and a 28- to 46-fold increae in the laer in itu keratomileui group. For a 3-mm pupil, the proportion of coma-like aberration increaed after both photorefractive keratectomy and laer in itu keratomileui. For a 7-mm pupil, coma-like aberration wa dominant before urgery, but pherical-like aberration became dominant potoperatively. CONCLUION: Both photorefractive keratectomy and laer in itu keratomileui increae the wavefront aberration of the cornea and change the relative contribution of coma- and pherical-like aberration. For a large pupil, laer in itu keratomileui induce more pherical aberration than photorefractive keratectomy. Thi finding could be attributable to the maller tranition zone of the laer ablation in the laer in itu keratomileui procedure.