PURPOSE To assess the anterior segment parameters of keratoconus (KC) eyes at different stages of the disease by a new Scheimpflug camera combined with Placido disk corneal topography (Sirius, CSO, Italy) in a sample of the Iranian population. METHODS A total of 225 eyes of 225 individuals comprising 41 suspect KC, 40 mild KC, 71 moderate KC, 48 severe KC and 25 normal eyes were assessed for ...

PURPOSE To compare forward shift of posterior corneal surface and higher-order aberration (HOA) changes after LASIK, LASEK, and wavefront-guided LASEK surgery in moderate myopia METHODS One hundred eighty four eyes undergoing LASIK, LASEK and wavefront-guided LASEK with VISX STAR S4 were included in this study. The posterior corneal elevation was measured with Orbscan before, 2 and 4 months a...

PURPOSE To investigate the bilateral symmetry of the global corneal topography in normal corneas with a wide range of curvature, astigmatism and thickness values. DESIGN Cross-Sectional Study. METHODS Topography images were recorded for the anterior and posterior surfaces of 342 participants using a Pentacam. Elevation data were fitted to a general quadratic model that considered both trans...

PURPOSE To compare the changes in posterior corneal curvature using scanning slit topography (Orbscan II) and Scheimpflug imaging (Pentacam) before and after Epi-laser in situ keratomileusis (LASIK) for myopia. METHODS In a prospective observational case-series study, 20 myopic patients having undergone Epi-LASIK were examined serially with two different devices, Orbscan II and Pentacam, preo...

normal 0 false false false en-us x-none ar-sa background : the aim of this study was to determine the correlation between corneal hysteresis (ch) and the corneal resistance factor (crf), which are both novel methods of analyzing ocular rigidity/elasticity, and various corneal characteristics, mainly corneal volume in normal subjects. methods : this cross-sectional study included 500 normal eyes...

AIMS To map the thickness, elevation (anterior and posterior corneal surface), and axial curvature of the cornea in normal eyes with the Orbscan corneal topography system. METHODS 94 eyes of 51 normal subjects were investigated using the Orbscan corneal topography system. The anterior and posterior corneal elevation maps were classified into regular ridge, irregular ridge, incomplete ridge, i...

PURPOSE To assess the correlation between keratoconus severity and intereye asymmetry of pachymetric data and posterior elevation values and to evaluate their combined accuracy in discriminating normal corneas from those with keratoconus. METHODS This study included 97 patients: 65 subjects with bilateral normal corneas (NC) and 32 with keratoconus (KC). Central corneal thickness (CCT), thinn...

Purpose: To compare changes in posterior corneal elevation, anterior chamber depth (ACD), anterior chamber volume (ACV) and corneal volume (CV) after laser in situ keratomileusis (LASIK ) and photorefractive keratectomy (PRK) for low to moderate myopia by pentacam imaging Methods: In this prospective comparative case series, 105 consecutive myopic eyes randomly scheduled for LASIK (n=59) or PRK...

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...

PURPOSE The aim was to evaluate the anterior and posterior corneal topographic characteristics of three patients with posterior polymorphous corneal dystrophy (PPCD) using a rotating Scheimpflug camera combined with a Placido disc system (Sirius, CSO, Italy). CASE REPORTS Two children with unilateral PPCD and a 53-year-old woman with bilateral PPCD were diagnosed by the presence of vesicles a...