Comparison of Myopic LASIK Centered on the Coaxially Sighted Corneal Light Reflex or Line of Sight

Abstract

To compare refractive outcomes of myopic LASIK with centration on the coaxially sighted corneal light reflex (CSCLR) to centration on the center of the pupil (line of sight [LOS]). The NIDEK CXIII excimer laser was used to treat 268 eyes with centration on the CSCLR (CSCLR group) and 288 eyes with centration on the LOS (LOS group). For the CSCLR group, the laser ablation was delivered 80% closer to the visual axis. One-month postoperative outcomes were compared. Preoperative manifest refraction spherical equivalent (MRSE) was -4.88+/-1.55 diopters (D) (range: -8.50 to -1.25 D) in the CSCLR group and -5.05+/-1.63 D (range: -9.75 to -1.50 D) in the LOS group. The postoperative MRSE was 0.17+/-0.39 D (range: -1.38 to -1.25 D) in the CSCLR group and 0.19+/-0.48 D (range: -1.63 to +1.88 D) in the LOS group. Safety (1.18) and efficacy (1.047) indices were statistically significantly higher in the CSCLR group compared to the LOS group (1.138 and 0.997, respectively) (P<.05). This trend was accentuated in a subgroup analysis of patients with >0.25-mm difference between the CSCLR and LOS, favoring the CSCLR group. A statistically significantly greater induction of higher order aberrations (P=.04) and coma (P<.01) was noted in the LOS group postoperatively. Myopic LASIK centered on the CSCLR was significantly safer and more effective than LASIK centered on the pupil (LOS), with significantly lower induction of coma and total higher order aberrations.