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 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.

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.

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.

scholarly journals Scleral gas permeable contact lenses as a possible way of visual rehabilitation of patients with age-related macular degeneration

The Eye ◽  
2019 ◽  
Vol 125 (2019-1) ◽  
pp. 33-40
Author(s):  
Alexander Myagkov ◽  
Maria Kovalevskaya ◽  
Oksana Pererva
Keyword(s):  
Macular Degeneration ◽  
Contact Lenses ◽  
Gas Permeability ◽  
Age Related Macular Degeneration ◽  
Central Visual Field ◽  
Optimal Method ◽  
Visual Rehabilitation ◽  
Age Related ◽  
Quality Of Vision

Low visual acuity, loss of the central visual field, metamorphopsia, distortion of lines and decreased contrast sensitivity cause reduced quality of vision in patients with age-related macular degeneration (AMD). Currently existing methods of visual rehabilitation for patients with AMD, such as telescopic intraocular and scleral lenses, are functionally and cosmetically unacceptable. The use of intraocular telescopic lenses is limited by the high risk of postoperative complications, low functional parameters, as well as by difficult ophthalmoscopy and lasting adaptation of patients. Telescopic scleral lenses have а low resolution, contain impermeable to oxygen parts and require wearing special switching glasses. However, scleral lenses have potential in developing an optimal method for vision correction in patients with AMD due to the presence of following advantages: wide optical zone, gas permeability, correction of refractive astigmatism in presbyopic patients and alleviation of dry eye symptoms. In conclusion, further clinical researches are required to develop a method for improving the quality of vision in patients with AMD by using scleral lenses with an objective test for evaluating the effectiveness of correction – the 3D computer-automated threshold Amsler grid test (3D-CTAG).

scholarly journals Hybrid contact lenses for the correction of primary and induced ametropias

2020 ◽  
Vol 13 (1) ◽  
pp. 102-107 ◽  
Author(s):  
V. V. Neroev ◽  
A. V. Myagkov ◽  
O. V. Guryanova ◽  
A. T. Khandzhyan ◽  
A. I. Yakunina
Keyword(s):  
Contact Lenses ◽  
Modern Method ◽  
Permeable Material ◽  
Soft Contact ◽  
Soft Contact Lenses ◽  
Quality Of Vision ◽  
Corneal Lens ◽  
Hydrophilic Material ◽  
Optical Zone

The review presents the data on the use of hybrid contact lenses (HCL), a modern method of contact correction of ametropias of diverse origins. A HCL has a central rigid optical zone made of highly gas-permeable material and a flexible peripheral part made of hydrophilic material. These lenses combine the optical effect of gas-permeable corneal lens with the comfort and stable fitting of soft contact lenses. Compared with the corneal (RGP) lenses, HCLs are more comfortable, often are better centrated and more stably fit on the eye. HCLs are successfully used in various refractive disorders: ametropias (with regular cornea), irregular astigmatism, presbyopia, including that combined with astigmatism. This type of lens is a good option of contact correction for patients who have high requirements to the quality of vision.

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