Wavefront Aberrations Following LASIK And Lensectomy Corrections For Hypermetropia

Purpose: To compare the magnitude of aberrations in patients having undergone elective hypermetropic LASIK (laser-in-situ keratomileusis) and hypermetropic lensectomy (clear lens replacement surgery).Methods: Subjects were 49 hypermetropic LASIK and 28 hypermetropic lensectomy patients, with 23 hypermetropic subjects acting as a control group. Aberrations and corneal topography were measured with the Nidek OPD-Scan model ARK-10000 more than 12 months after surgery. The higher-order root-mean squared (HORMS) wave aberrations for combined 3rd to 6th Zernike aberration orders and the Zernike spherical aberration co-efficient C₄⁰ at both 4.2mm and 6.0mm pupil sizes were calculated.Results: For the LASIK group, surgical refractive change correlated significantly with total, corneal and internal HORMS and spherical aberrations (except with internal spherical aberration for a 4.2mm diameter pupil). For the lensectomy group, there were no significant correlations of surgical refractive change with any of these factors. Similarly for the control group there were no significant correlations of refraction with any of these factors. For a 3D change in refraction with 6mm pupils, LASIK doubled the total HORMS aberrations. LASIK changed the sign of spherical...