Factors influencing the changes in coma-like aberrations after myopic laser in situ keratomileusis.

PURPOSE: To assess factors affecting changes in coma-like aberrations after myopic laser in situ keratomileusis (LASIK).

METHODS

We retrospectively examined 91 eyes of 48 patients undergoing LASIK (mean patient age ± standard deviation, 29.6 ± 8.1 years; gender, 29 male and 19 female; manifest refraction, -4.76 ± 1.42 diopters). We quantitatively assessed the values of coma-like aberrations for 4-mm and 6-mm pupils using a Hartmann-Shack aberrometer before and 3 months after surgery. Multiple regression analysis was used to assess the relevant factors of the changes in coma-like aberrations.

RESULTS

The mean changes in coma-like aberrations for 4-mm and 6-mm pupils were 0.08 ± 0.09 μm and 0.31 ± 0.30 μm, respectively. Explanatory variables relevant to the changes in coma-like aberrations were, in order of influence, amount of spherical equivalent correction (partial regression coefficient B = 0.022, p <0.001 for a 4-mm pupil, B = 0.090, p <0.001 for a 6-mm pupil), and surgical technique (B = -0.062, p = 0.01 for a 4-mm pupil, B = -0.169, p = 0.03 for a 6-mm pupil). No significant correlation was seen with other clinical factors such as age, gender, astigmatism correction, mean keratometric readings, central corneal thickness, or eye tracking (with or without).

CONCLUSIONS

High myopic eyes requiring larger amounts of laser correction and eyes undergoing conventional LASIK tend to induce more coma-like aberration after surgery. Wavefront-guided LASIK may be a better surgical approach for preventing the induction of coma-like aberrations, especially in eyes with high myopia.