PURPOSE To examine the physiological optics of photorefractive corneal surgery and to study the effect on glare production of the optical zone diameter. METHODS An optical analysis computer program was used to generate rays that define the edge of the optical zone for any given pupil size and glare-free field. RESULTS The optical zone diameter must be based on the postoperative corneal curv...

purpose: to assess alterations in parameters measured by the ocular response analyzer (ora) after photorefractive keratectomy (prk) with or without 0.02% mitomycin c (mmc) in myopic eyes. methods: in 33 right eyes of 33 patients, iop was determined using the goldmann applanation tonometry (gat) before and 3 months after prk. corneal hysteresis (ch), corneal resistance factor (crf), goldmann-cor...

PURPOSE To determine the ability of motion-corrected optical coherence tomography (OCT) to measure the corneal refractive power change due to LASIK. DESIGN Evaluation of a diagnostic test or technology in a cohort. SUBJECTS A total of 70 eyes from 37 subjects undergoing LASIK were measured preoperatively. A total of 39 eyes from 22 subjects were measured postoperatively and completed the st...

diagnosis of corneal diseases is possible by measuring and evaluation of corneal thickness in different layers. thus, the need for precise segmentation of corneal layer boundaries is inevitable. obviously, manual segmentation is time‑consuming and imprecise. in this paper, the gaussian mixture model (gmm) is used for automatic segmentation of three clinically important corneal boundaries on opt...

PURPOSE Lenticule implantation can be used to correct vision problems. However, it is significantly restrained by the sources of autologous lenticules. The aim of the present study was to investigate the feasibility and effects of femtosecond laser-assisted corneal small incision allogenic intrastromal lenticule implantation (AILI) in monkeys. METHODS Six healthy adult monkeys were included i...

The main objective of this work is to demonstrate the relation between corneal surface imperfections and retinal image imperfections. Its originality resides on the fact that specialized literature approximate the eye and the cornea as mathematical surfaces to explain simple refraction problems (myopic, hyperopic, astigmatic), whereas in the present work we have used topographic data for in viv...

PURPOSE To investigate the accuracy of a new optical biometer for intraocular lens (IOL) power calculation in eyes undergoing cataract surgery. METHODS Consecutive eyes of patients undergoing cataract surgery with the same IOL model were enrolled in a prospective cohort study. Axial length (AL) and corneal power were measured with an optical biometer based on optical low-coherence interferome...

UNLABELLED The increasing volume of patients interested in refractive surgery and the new treatment options available for keratoconus have generated a higher interest in achieving a better characterization of this pathology. The ophthalmic devices for corneal analysis and diagnosis have experienced a rapid development during the past decade with the implementation of technologies such as the Pl...