scholarly journals Visualization and assessment of the anterior surface of the cornea by corneal topography (Part II)

The Eye ◽  
2020 ◽  
Vol 22 (3(131)) ◽  
pp. 43-51
Author(s):  
G. V. Andrienko
Keyword(s):  
Contact Lenses ◽  
Corneal Topography ◽  
Corneal Surface ◽  
High Quality ◽  
Main Method ◽  
Quality Of Vision ◽  
Detailed Assessment ◽  
Slit Scanning ◽  
Surface Regularity

Goal. To introduce ophthalmologists and optometrists to the basics of corneal topography. Corneal topography is the main method for assessing corneal surface regularity, the violation of which leads to a deterioration in its refractive properties and a decrease in the quality of vision. The first part of the workshop (The EYE GLAZ. 2020 (22), № 2) presented the main types of topography maps and keratometry data. In the second part, considerations are made regarding mastering the skills of capturing high-quality images and choice of color maps for analysis. Topography patterns as well as topographic signs of keratoconus are also discussed. Conclusion. Placido-based corneal topographers are a useful tool for evaluating the anterior corneal surface, fitting contact lenses and diagnosing keratoconus. Slit-scanning topographers, additionally, are capable of corneal pachymetry and analyzing the posterior surface of the cornea, which allows for carrying out a more detailed assessment and diagnosing keratoconus at preclinical stage.

The visualization and assessment of the anterior surface of the cornea using video keratotopography

The Eye ◽  
2020 ◽  
Vol 22 (130) ◽  
pp. 36-43
Author(s):  
Gulnara Andrienko
Keyword(s):  
Contact Lenses ◽  
Corneal Topography ◽  
Topographic Maps ◽  
Specific Situation ◽  
Main Method ◽  
Pathological Conditions ◽  
Quality Of Vision ◽  
Corneal Shape ◽  
Color Map

Corneal topography is the main method for assessing the regularity of the surface of the cornea. Corneal irregularity leads to a deterioration in its refractive properties and a decrease in the quality of vision. Learning the basics of corneal topography will help determine the choice of a color map for a specific situation, as well as understand and analyze the data associated with these maps. This article describes the main types of topographic maps, various patterns of corneal shape in normal and pathological conditions and how to use the data obtained to design and fit contact lenses. Despite the fact that images may vary depending on topographers used, the information presented in this article is universal.

The visualization and assessment of the anterior surface of the cornea using video keratotopography

The Eye ◽  
2020 ◽  
Vol 22 (130) ◽  
pp. 36-42
Author(s):  
Gulnara Andrienko
Keyword(s):  
Contact Lenses ◽  
Corneal Topography ◽  
Topographic Maps ◽  
Specific Situation ◽  
Main Method ◽  
Pathological Conditions ◽  
Quality Of Vision ◽  
Corneal Shape ◽  
Color Map

Corneal topography is the main method for assessing the regularity of the surface of the cornea. Corneal irregularity leads to a deterioration in its refractive properties and a decrease in the quality of vision. Learning the basics of corneal topography will help determine the choice of a color map for a specific situation, as well as understand and analyze the data associated with these maps. This article describes the main types of topographic maps, various patterns of corneal shape in normal and pathological conditions and how to use the data obtained to design and fit contact lenses. Despite the fact that images may vary depending on topographers used, the information presented in this article is universal.

scholarly journals Postkeratoplasty Anterior and Posterior Corneal Surface Wavefront Analysis: Descemet’s Stripping Automated Endothelial Keratoplasty versus Penetrating Keratoplasty

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Maria L. Salvetat ◽  
Marco Zeppieri ◽  
Flavia Miani ◽  
Paolo Brusini
Keyword(s):  
Penetrating Keratoplasty ◽  
Imaging System ◽  
Case Series ◽  
Optical Quality ◽  
Endothelial Keratoplasty ◽  
Corneal Surface ◽  
Scheimpflug Imaging ◽  
Quality Of Vision ◽  
Range Test

Purpose. To compare the higher-order aberrations (HOAs) due to the anterior and posterior corneal surfaces in patients that underwent either Descemet-stripping-automated-endothelial-keratoplasty (DSAEK) or penetrating keratoplasty (PK) for endothelial dysfunction and age-matched controls. Methods. This retrospective, observational, case series included 28 patients after PK, 30 patients after DSAEK, and 30 healthy controls. A Scheimpflug imaging system was used to assess the HOAs due to the anterior and posterior corneal surfaces at 4 mm and 6 mm optical zones. Total, 3rd and 4th order HOAs were considered. Intra- and intergroup differences were assessed using the Friedman and the Kruskal-Wallis tests, respectively; paired comparisons were performed using Duncan's multiple range test. Results. Total, 3rd and 4th order HOAs due to both corneal surfaces at 4 mm and 6 mm optical zones were significantly higher in the PK group, intermediate in the DSAEK group, and lower in controls (). The most important HOAs components in both PK and DSAEK groups were trefoil and coma from the anterior corneal surface () and trefoil from the posterior corneal surface (). Conclusions. The optical quality of both corneal surfaces appeared significantly higher after DSAEK than after PK, which can increase the postoperative patient's quality of vision and satisfaction.

Keratoconic Bi-aspheric Contact Lenses

2016 ◽  
Vol 5 (3) ◽  
pp. 132-138
Author(s):  
Ariela Gordon-Shaag ◽  
Philip Fine ◽  
Liat Gantz ◽  
Arige Gideon-Abousaid ◽  
Gad Serero
Keyword(s):  
Visual Acuity ◽  
Contact Lenses ◽  
Case Series ◽  
Visual Stability ◽  
Wavefront Aberrations ◽  
Body Sensation ◽  
Quality Of Vision ◽  
Base Curve ◽  
Aspheric Lenses

ABSTRACT Aim This observational clinical case series examined patients with keratoconus (KC) fit with keratoconic bi-aspheric (KBA) lenses to assess visual acuity (VA), wavefront aberrations, physiological fitting, subjective comfort, and manufacturer's fitting guidelines. Materials and methods Seven adult patients (11 eyes, four females, mean age: 34.15 ± 14.12) with nipple cones from the Hadassah Academic College contact lens clinic (Jerusalem, Israel) were fit with KBA lenses by modifying the initial base curve (BC) to obtain an acceptable physiological fit. The uncorrected and corrected distance (D) and near (N) Snellen VA and the ocular wavefront measurements, and responses to a self-administered five-point scale questionnaire were compared after 2 weeks of wear using paired two-tailed t-test or Mann-Whitney U test, as appropriate. Results Visual acuity and total root mean square (RMS) improved significantly with the lenses (DVAuncorrected = 0.04 ± 0.02, DVAcorrected = 0.66 ± 0. 22, NVAuncorrected = 0.34 ± 0.30, NVAcorrected = 0.95 ± 0.12). Subjects reported an average of 7.0 ± 2.7 hours of wear daily, with good scores in visual stability, satisfaction with VA and quality of vision, improvement of mood and quality of life, and low scores in foreign body sensation, pain, red eye, and itching during wear, and difficulty with lens removal. An average of two BC modifications from the diagnostic lens were necessary (0.16 mm steeper in nine eyes, 0.27 mm flatter in two eyes). Conclusion Keratoconic bi-aspheric lenses can provide 7 hours of comfortable wear, significantly improved VA and total RMS aberrations, alongside subjective satisfaction. Base curve modifications can be reduced by fitting a diagnostic lens 0.75 mm steeper than the flattest keratometry reading. How to cite this article Gantz L, Gordon-Shaag A, Gideon-Abousaid A, Serero G, Fine P. Keratoconic Bi-aspheric Contact Lenses. Int J Kerat Ect Cor Dis 2016;5(3):132-138.

“OKVision® SMARTFIT™” Customizable Mini-Scleral Lenses Fitting Guide

The Eye ◽  
2021 ◽  
Vol 23 (1) ◽  
pp. 41-51
Author(s):  
N. A. Bakalova
Keyword(s):  
Basic Skills ◽  
Professional Knowledge ◽  
Visual Quality ◽  
High Quality ◽  
Basic Principles ◽  
Daily Care ◽  
Quality Of Vision ◽  
Parameters Calculation ◽  
Clinical Cases

As of today, scleral lenses are the only optical rehabilitation method that provides high visual quality of vision for patients with irregular cornea. This fitting guide is aimed at helping ophthalmologists acquire professional knowledge in the field of fitting scleral lenses and suggest tactics for managing patients with irregular corneas.The workshop outlines indications for prescribing scleral lenses, describes the basic principles of lens parameters calculation and fitting, taking into account the patientspecific parameters of the eyes. In addition, guidelines for acquiring skills in assessing and changing the position of scleral lenses on the patient’s eye, using customization options, daily care, manipulations for inserting on and removing lenses, and further dispensary observation are given.Mastering the basic skills of calculation and fitting customized scleral lenses helps practitioners expand their areas of practice, enhance professional competitiveness and provide patients with high quality vision, even in the most difficult clinical cases.

scholarly journals EVALUATION OF CLINICAL AND FUNCTIONAL OUTCOME OF MULTIFOCAL CORRECTION BY CONTACT LENS IN PATIENTS WITH PRESBYOPIA AND MYOPIA REFRACTION

2016 ◽  
Vol 1 (6) ◽  
pp. 103-107
Author(s):  
Рогожникова ◽  
Elena Rogozhnikova ◽  
Селиверстова ◽  
Nataliya Seliverstova ◽  
Розанова ◽  
...  
Keyword(s):  
Contact Lens ◽  
Contact Lenses ◽  
Tear Film ◽  
Functional Results ◽  
Corneal Epithelial ◽  
Interaction Field ◽  
Standard Procedures ◽  
Quality Of Vision ◽  
Selection Of

The aim of the study was to evaluate the effectiveness of multifocal contact lens correction in patients with presbyopia and myopic refractive error. The study involved 45patients with myopia ranging in age from 43 to 56years in conditions of habitual monofocal contact lens correction, a month after the selection and wearing multifocal contact lenses. Contact correction was carried out according to standard procedures taking into account the accuracy of contact lens fitting, with carrying out functional tests for the “dry eye” syndrome and evaluation of corneal epithelial thickness (Optovue, USA). The as-sessment of the following parameters of visual perception was made: far, near and middle distance (monocular and binocular) visual acuity, the spatial contrast sensitivity, stereovision (I & II Lang test), the area of binocular interaction field (binarymeter), the quality of vision (VF-14 test ). The use of multifocal contact lenses for the correction of presbyopia with the initial myopic refraction ensures high functional results at different distances. Patients with a myopic refraction, previously used contact lenses, easy pass to multifocal correction option. The greatest satisfaction by achieved vision noted in those patients who had achieved refraction (–)0.5diopters. In the selection of contact lenses in older patients the thickness of the corneal epithelium and tear film validity must be taken into account.

scholarly journals Frequently Experienced Problems in the Early Stages after Prescribing Rigid Gas Permeable Contact Lenses

2021 ◽  
Vol 20 (4) ◽  
pp. 135-139
Author(s):  
Dong Ho Lee
Keyword(s):  
Visual Acuity ◽  
Foreign Body ◽  
Contact Lenses ◽  
Foreign Body Sensation ◽  
Corneal Curvature ◽  
Slit Lamp ◽  
Body Sensation ◽  
Quality Of Vision ◽  
Slit Lamp Microscopy

Prescribing rigid gas-permeable (RGP) lenses involves a series of processes that determine the most appropriate final lens through the trial use of test lenses based on the results of slit lamp microscopy, measuring refraction and corneal curvature, and corneal topography. The final prescription is reached by judging the dynamic lens movement, adequacy of the tear layer around the lens, corrected vision, and quality of vision. Various problems are encountered soon after prescribing lenses, including foreign body sensation, tear hypersecretion, decreased visual acuity, blurring, visual acuity change, redness, dryness, sudden pain, lens centering, and lens fallout. Here, we examine these problems and how to solve them.

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