purpose: to evaluate the correlation between corneal power and corneal horizontal white to white diameter in myopic patients scheduled for lasik surgery. methods: overall, in 840 eyes of 420 myopic subjects scheduled for lasik, horizontal white to white diameter and mean corneal power were obtained using orbscan ii. pearson correlation test and regression analysis were used to detect any correl...

the porcine eye is often used as an ex vivo animal model in ophthalmological research. it is well-suited for investigations concerning refractive surgery; however, corneal topography data are scarce. this study investigated the corneal topography and pachymetry of the porcine eye to provide further reproducible data. we evaluated freshly enucleated porcine eyes (n = 16) by performing computeriz...

NOVEMBER/DECEMBER 2012 CATARACT & REFRACTIVE SURGERY TODAY EUROPE 1 A ccuracy of biometric calculations and, more important, of refractive results depends on three main factors: preoperative biometric data including axial length, anterior chamber depth, lens thickness, and corneal curvature power variables; power calculation formulas; and quality and accuracy of the IOL. In the past 15 years, s...

purpose : to evaluate the accuracy of the two methods the clinical history method (chm), and the contact lens method (clm), in refractive corneal power determination and comparing the accuracy of srk ii, srk t and holladay ii (h ii) formulas for intraocular lens (iol) power calculation in patients who had laser in situ keratomileusis (lasik) surgery for myopia with or without astigmatism method...

Current Opinion in Ophthalmology 2008, 19:357–362 Purpose of review Corneal refractive procedures have become increasingly popular over the past decade allowing patients to have excellent uncorrected visual acuity and spectacle independence. As these individuals mature, many will eventually undergo cataract surgery. With the advances in modern cataract surgery and lens implant technology, parti...

PURPOSE To compare the relative advantages and disadvantages of four different representations of corneal power--identified as instantaneous, axial, position, and refractive--based on curvature, slope, coordinate position, and focal properties, respectively. METHOD The four types of corneal power were evaluated by examining their interrelationship for 12 hypothetical corneal shapes chosen to ...

PURPOSE To evaluate the performance of corneal topographic astigmatism (CorT) based on total corneal power measurements. METHODS Anterior, posterior, and total corneal power measurements of 526 virgin eyes obtained using the CSO Sirius tomographer (Costuzione Strumenti Oftalmici, Scandicci, Florence, Italy) were analyzed. Individual CorTs were created from each set of data. These CorTs were a...

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...

PURPOSE To determine the accuracy of Pentacam Scheimpflug system Holladay equivalent keratometry (K) readings (EKRs) in calculating intraocular lens (IOL) power after corneal refractive surgery, including laser in situ keratomileusis (LASIK), photorefractive keratectomy (PRK), and radial keratotomy (RK). SETTING Jules Stein Eye Institute, David Geffen School of Medicine at University of Calif...