800x600 in order to determine the effect of intracorneal rings (intacs sk), when implanted in keratoconic patients, on corneal curvature, uncorrected visual acuity (ucva), best corrected visual acuity (bcva) and on the progression of the cone through three years follow-up period. in this prospective nonrandomized study 114 eyes of 71 keratoconic patients (38 females and 33 males) were implanted...

PURPOSE To develop a criterion for determining the topographic progression of keratoconus and to analyze the prognostic factors of progression. METHODS Medical records of 211 eyes of 128 patients who had been followed up for more than 2 years on three or more occasions were retrospectively reviewed. Topographic parameters, including simulated K, corneal astigmatism, irregular astigmatism at 3...

Purpose. To assess and compare the anterior and posterior corneal surface parameters, keratoconus indices, thickness profile data, and data from enhanced elevation maps of keratoconic and normal corneas with the Pentacam Scheimpflug corneal tomography and to determine the sensitivity and specificity of these parameters in discriminating keratoconus from normal eyes. Methods. The study included ...

GOAL This study aimed to investigate the differences in values of K1 and K2 readings, the central corneal thickness (PAH) before the collagen crosslinking procedure (CXL) and 3, 6, 12 months later. METHODS 64 eyes were evaluated in retrospective cross sectional study. The corneal biomechanical parameters were taken with WaveLight Allegro Oculyzer produced by Alcon before the CXL, 3,6, 12 mont...

PURPOSE Customized laser surgery attempts to correct higher order aberrations, as well as defocus and astigmatism. The success of such a procedure depends on using a laser beam that is small enough to produce fine ablation profiles needed to correct higher order aberrations. METHODS Wave aberrations were obtained from a population of 109 normal eyes and 4 keratoconic eyes using a Shack-Hartma...

Purpose. To thoroughly analyze corneal deformation responses curves obtained by Ocular Response Analyzer (ORA) testing in order to improve subclinical keratoconus detection. Methods. Observational case series of 87 control and 73 subclinical keratoconus eyes. Examination included corneal topography, tomography, and biomechanical testing with ORA. Factor analysis, logistic regression, and receiv...

PURPOSE The objective of this study is to describe the authors' results with intrastromal corneal ring segments (Intacs) and a new variation of lamellar keratoplasty, termed intralamellar keratoplasty (ILK), for the treatment of keratoconus (KCN) and post-laser-assisted in situ keratomileusis (LASIK) ectasia. METHODS A retrospective review of contact lens-intolerant KCN and post-LASIK ectasia...

s t o T b d g t C PURPOSE: To report the results of intrastromal corn ing segment [ICRS] (KeraRing; Mediphacos, Belo H onte, Brazil) implantation using a femtosecond la IntraLase Corp, Irvine, California, USA) in keratoco atients. DESIGN: Retrospective, noncomparative, interventional tudy. METHODS: Thirty-two keratoconic patients (50 eye ho underwent ICRS insertion using a femtosec aser for cha...

There is currently considerable debate concerning the visual impact of correcting the higher order aberrations of the eye. We describe new measurements of a large population of human eyes and compute the visual benefit of correcting higher order aberrations. We also describe the increase in contrast sensitivity when higher order aberrations are corrected with an adaptive optics system. All thes...