Search results for "Conus"

Evaluation of intraocular pressure and other biomechanical parameters to distinguish between subclinical keratoconus and healthy corneas

2021

(1) Purpose: To assess the main corneal response differences between normal and subclinical keratoconus (SCKC) with a Corvis® ST device. (2) Material and Methods: We selected 183 eyes of normal patients, of a mean age of 33 ± 9 years and 16 eyes of patients with SCKC of a similar mean age. We measured best corrected visual acuity (BCVA) and corneal topography with a Pentacam HD device to select the SCKC group. Biomechanical measurements were performed using the Corvis® ST device. We carried out a non-parametric analysis of the data with SPSS software (Wilcoxon signed rank-test). (3) Results: We found statistically significant differences between the control and SCKC groups in some corneal b…

Keratoconus stage impact on visual acuity and contrast sensitivity.

2020

Contrast sensitivity decreases in keratoconus subjects even before the decrease is presented at high contrast visual acuity. The aim of our study was to estimate the subject’s contrast sensitivity and visual acuity in different keratoconus stages. In our study, there were included 45 keratoconus subjects (77 eyes) with the first, second and third keratoconus stages. Visual acuity and contrast sensitivity were measured at 3 m with the best possible spectacle correction and without vision correction using FrACT program 3.9.3. In the study, contrast sensitivity was measured at following spatial frequencies – 1, 3, 5, 7, 9, 11, 13 and 15 cpd. Contrast sensitivity analyse showed that there was a…

Entwicklung der Hornhautdicke während der UV-Vernetzungstherapie unter Anwendung verschiedener Kompositionen von Riboflavin-Augentropfen

2011

Background During the UVA-cross-linking treatment in keratoconus patients, the UVA rays are partially absorbed in the stroma of the riboflavin-loaded cornea. This effect protects the corneal endothelium from UVA irradiation damage. The intensity of UVA light reaching the endothelium is inversely correlated with corneal thickness. The common composition of riboflavin eye drops may lead to a marked reduction in corneal thickness increasing the risk of endothelial damage. Patients and methods In a retrospective analysis of 23 UVA-cross-linking procedures on 23 patients we collected data about the pre-, intra- and postoperative corneal thickness (measured with ultrasound). Among these patients …

Collagenolytic proteinases in keratoconus.

2006

To study the proteolytic phenomena contributing to the pathogenesis of keratoconus, corneal enzymes with potential to cleave fibrillar collagen were studied.Immunohistochemical labeling was undertaken of conventional and novel mammalian collagenases (MMP-1, -2, -8, -13, and -14) of the matrix metalloproteinase (MMP) family and other collagenolytic proteinases of the serine (human trypsin-2) and cysteine (cathepsin K) endoproteinase families. The results were analyzed using a semiquantitative scoring system.Labeling of MMP-8 was moderate in healthy controls, but weak in keratoconus. Moderate MMP-2 and weak MMP-14 expressions were similar in controls and keratoconus. MMP-1 was slightly overex…

Nonsurgical Procedures for Keratoconus Management

2017

Objectives. To describe the past 20 years’ correction modalities for keratoconus and their visual outcomes and possible complications.Methods. A review of the published literature related to the visual outcomes and possible complications in the context of keratoconus management using nonsurgical procedures for the last 20 years (glasses and contact lenses) was performed. Original articles that reported the outcome of any correction modalities of keratoconus management were reviewed.Results. The most nonsurgical procedure used on keratoconus management is the contact lens fitting. Soft contact lenses and soft toric contact lenses, rigid gas-permeable contact lenses, piggyback contact lens sy…

2019

Aims To report corneal topometric and aberrometric values in mucopolysaccharidosis (MPS) and to investigate their correlation with biomechanical corneal parameters. Methods One randomly chosen eye of 20 MPS patients with no to moderate corneal clouding and one eye of 23 healthy controls with comparable age were prospectively included into this study. Corneal surface regularity was assessed by index of surface variance (ISV), -vertical asymmetry (IVA), -height asymmetry (IHA), -height decentration (IHD); keratoconus index (KI), central keratoconus index (CKI) and Zernike indices of anterior and posterior corneal surface using Scheimpflug imaging (Pentacam). Corneal resistance factor (CRF) an…

Visual quality with corneo-scleral contact lenses for keratoconus management

2018

Purpose: To assess the visual quality achieved by fitting corneo-scleral contact lenses (CScL) for keratoconus management. Methods: Thirty patients with keratoconus presented to have CScL fitted because of the unsatisfactory visual quality they experienced with their contact lenses or spectacles. The eye examination included visual acuity assessment, anterior eye biomicroscopy, ocular fundus examination, corneal topographic analysis, endothelialcell count, contrast sensitivity and aberrometry. The fitting process was performed using a diagnostic trial set. Subjective visual quality and comfort, and contact lens wear time were also reported. Patients were monitored for one year. Results: Thr…

Are Ocular Response Analyzer useful to measure corneal hysteresis in patients with intracorneal rings?

2008

Purpose Corneal hysteresis is a viscoelastic property characterized by the difference in behavior under loading and unloading. The aim of the study was to determine corneal hysteresis in different eyes: healthy eyes, keratoconic eyes and keratoconic eyes after intracorneal ring implants. Methods This study comprised 95 eyes of 59 patients. The study population was divided into 3 groups. We analyze 30 healthy human eyes, 35 keratoconic eyes (Amsler grade II-III) and 30 keratoconic eyes after intracorneal rings implantation. Corneal biomechanical properties of these eyes were measured with the Ocular Response Analyser (ORA-Reichert) according to two parameters: corneal hysteresis (CH) and cor…

IC3D Classification of Corneal Dystrophies—Edition 2

2015

To update the 2008 International Classification of Corneal Dystrophies (IC3D) incorporating new clinical, histopathologic, and genetic information.The IC3D reviewed worldwide peer-reviewed articles for new information on corneal dystrophies published between 2008 and 2014. Using this information, corneal dystrophy templates and anatomic classification were updated. New clinical, histopathologic, and confocal photographs were added.On the basis of revisiting the cellular origin of corneal dystrophy, a modified anatomic classification is proposed consisting of (1) epithelial and subepithelial dystrophies, (2) epithelial-stromal TGFBI dystrophies, (3) stromal dystrophies, and (4) endothelial d…

Visual quality with corneo-scleral contact lenses after intracorneal ring segment (ICRS) implantation for keratoconus management

2019

Purpose: To evaluate the visual quality results when fitting a corneo-scleral contact lens (CScL) after intracorneal ring segment (ICRS) implantation for keratoconus management. Methods: Twenty-seven eyes of 27 patients with keratoconus underwent ICRS implantation and had CScL fitted as their visual quality was unsatisfactory with their spectacles or contact lenses. Patients received a complete eye examination, refraction and visual acuity assessment, anterior eye biomicroscopy, ocular fundus examination, corneal topographic analysis, endothelial-cell count, and visual quality assessment using contrast sensitivity and aberrometry tests. A diagnostic trial set was used in the fitting process…