BACKGROUND Recently, instruments for the measurement of wavefront aberration in the living human eye have been widely available for clinical applications. Despite the extensive background experience on wavefront sensing for research purposes, the information derived from such instrumentation in a clinical setting should not be considered a priori precise. We report on the variability of such an...

Zernike polynomials (ZPs) form a complete orthogonal basis on a circle of unit radius. This is useful in optics, since a great majority of lenses and optical instruments have circular shape and/or circular pupil. The ZP expansion is typically used to describe either optical surfaces or distances between surfaces, such as optical path differences (OPD), wavefront phase or wave aberration. Theref...

PURPOSE To compare the higher-order aberrations (HOAs) in 70 eyes (38 patients) that had wavefront-guided laser in situ keratomileusis (LASIK) with those in 70 eyes (40 patients) that had wavefront-guided laser-assisted subepithelial keratectomy (LASEK) for the treatment of myopia. SETTING Department of Ophthalmology, Yonsei University College of Medicine, Myongdong Bal-geun sesang Eye Clinic...

The in vivo spherical aberration of the lenses of 26 subjects was estimated from the measured total aberration of the eye and that predicted from the measured shape of the anterior corneal surface. Since it was only possible to estimate the aberration contribution from the posterior corneal surface, its value led to an uncertainty in the final aberration level of the lens. For all the subjects ...

PURPOSE To investigate corneal spherical aberration and corneal asphericity after small incision lenticule extraction (SMILE) and femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). METHODS This study enrolled 70 patients having SMILE and 64 subjects receiving FS-LASIK. The preoperative spherical equivalent (SE) was -5.83 ± 1.23 diopters (D) and -6.20 ± 1.52 D, respectively. T...

BACKGROUND Wavefront-guided Laser-assisted in situ keratomileusis (LASIK) is a widespread and effective surgical treatment for myopia and astigmatic correction but whether it induces higher-order aberrations remains controversial. The study was designed to evaluate the changes in higher-order aberrations after wavefront-guided ablation with IntraLase femtosecond laser in moderate to high astigm...

PURPOSE To measure the longitudinal chromatic aberration in vivo using psychophysical and wavefront-sensing methods in patients with bilateral implantation of monofocal intraocular lenses (IOLs) of similar aspheric design but different materials (hydrophobic Podeye and hydrophilic Poday). SETTING Instituto de Optica, Consejo Superior de Investigaciones Cientificas, Madrid, Spain. DESIGN Pro...

Refractive surgery is evolving rapidly. A recent development uses wavefront aberration information to improve the surgical outcome. Before the wavefront information can be used effectively a number of problems must first be resolved. One of the main concerns is the presence of halos during night driving conditions. It seems clear that this problem occurs when the pupil is large enough to overla...

ne of the exciting new research areas in laser refractive surgery is the development of sophisticated devices to measure the wave-front of the optical system of the entire eye, the various implementations of which are described in this proceedings. The ability to objectively measure performance of the eye, as opposed to simple corneal shape, is critical to " customizing " ablation algorithms an...

AIMS To examine prospectively the recovery of various parameters after discontinuation of overnight orthokeratology. METHODS Seventeen subjects undergoing orthokeratology for 12 months were examined. Refraction, corneal topography, wavefront aberrometry, a visual acuity test and a contrast sensitivity test were performed at baseline, 12 months after commencement of the procedure, and 1 week a...