Purpose. To compare the change of anterior corneal higher-order aberrations (HOAs) after laser in situ keratomileusis (LASIK), wavefront-guided LASIK with iris registration (WF-LASIK), femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK), and small incision lenticule extraction (SMILE). Methods. In a prospective study, 82 eyes underwent LASIK, 119 eyes underwent WF-LASIK, 88 eyes ...

We read with interest the article by Kung and Manche in the April 2016 issue.1 In the first part of the article, they explained that most studies seemed to suggest that the wavefront-guided excimer laser procedures were slightly superior than wavefront-optimized approaches, particularly in patients with preoperative root mean square (RMS) of higher order aberrations (HOAs) less than 0.3 μm. How...

PURPOSE To describe the treatment of highly aberrated eyes due to previous excimer laser surgery or trauma. METHODS Three eyes (three patients) with reduced visual quality due to previous decentration or corneal laceration (one eye) underwent topography-guided ablation using the CXIII excimer laser (NIDEK Co Ltd) to correct residual refractive error and/or wavefront aberrations. RESULTS Pos...

standing of the eye’s refractive characteristics to a new level. It has changed our concepts for examining refraction in the same way that computerized corneal topography changed corneal surface measurement, which previously had been limited to the yardstick of keratometry. We now possess two, highly sensitive tools for the objective measurement of the eye—corneal topography and wavefront asses...

MyOPiC LASer COrreCtiOn The most popular type of laser correction for myopia is LASIK. Myopic laser correction is achieved by central corneal ablation, which reduces the refractive power of the anterior corneal surface. Myopic LASIK has been shown to be effective in correcting low to moderate myopia.1,2 LASIK correction of high myopia has been fraught with quality issues until recently. Factors...

AIM To analyze the correlations between ocular biomechanical and biometric data of the eye, measured by Scheimpflug-based devices on healthy subjects. METHODS Three consecutive measurements were carried out using the corneal visualization Scheimpflug technology (CorVis ST) device on healthy eyes and the 10 device-specific parameters were recorded. Pentacam HR-derived parameters (corneal curva...

Abstract The geometrical aberration of an optical system is usually measured through wavefront aberration. We propose a very direct experimental ray-tracing measurement method in this paper. Two fiber point-light-sources are used to simulate arbitrary incident ray space, the diffracting wavefronts two fibers pass lens under test and interfere on photographic planes. outgoing intersects planes a...

This paper presents active surface control techniques for space mirrors. These techniques use adaptive optics concepts for correcting aberration in images due to air turbulence. Due to mirror surface error, a reference beam can be distorted and this error is measured by a wavefront sensor. A control system is used to provide input to the actuators based on the wavefront errors. This paper discu...