Results 131 to 140 of about 12,156 (169)

Influence of Posterior Corneal Astigmatism on Total Corneal Astigmatism in Eyes With Keratoconus

Cornea, 2016
To measure posterior corneal astigmatism (PCA) and investigate its influence on total corneal astigmatism (TCA) in eyes with keratoconus.Keratometric astigmatism (KA), PCA, and TCA were investigated by means of a dual Scheimpflug analyzer in patients with keratoconus.
Giacomo, Savini, Kristian, Næser, Domenico, Schiano-Lomoriello, Alessandro, Mularoni   +3 more
openaire   +2 more sources

Influence of posterior corneal astigmatism on total corneal astigmatism in eyes with moderate to high astigmatism

Journal of Cataract and Refractive Surgery, 2014
To evaluate the influence of posterior corneal astigmatism on total corneal astigmatism in patients with 1.00 diopter (D) or more of corneal astigmatism.Private practice, Bologna, Italy.Prospective case series.Corneal astigmatism was measured using a Scheimpflug camera combined with a corneal topographer (Sirius).
Giacomo, Savini, Francesco, Versaci, Gabriele, Vestri, Pietro, Ducoli, Kristian, Næser   +4 more
openaire   +2 more sources

Posterior Corneal Surface Toricity and Total Corneal Astigmatism

Optometry and Vision Science, 1991
ABSTRACT: The influence of posterior corneal surface toricity upon total corneal astigmatism was investigated in 60 young subjects (mean age 22.04 ± 3.24 years). Both surfaces were found to be flatter horizontally than vertically.
M C, Dunne, J M, Royston, D A, Barnes
openaire   +2 more sources

Quantifying Corneal Topographic Astigmatism (CorT Total) in Keratoconic Eyes

Journal of Refractive Surgery, 2023
Purpose: To determine optimal corneal regions from which to derive corneal topographic astigmatism (CorT) in kerato-conic eyes. Methods: In this retrospective study, potential measures of corneal astigmatism are calculated from raw total corneal power data (179 eyes from 124 ...
Noel, Alpins, James K Y, Ong, J Bradley, Randleman, George, Stamatelatos   +3 more
openaire   +2 more sources

Estimating Total Corneal Astigmatism From Anterior Corneal Data

Cornea, 2017
Purpose: To determine keratometric astigmatism (KA), posterior corneal astigmatism (PCA), and total corneal astigmatism (TCA) in 951 normal eyes, to establish a model for estimating TCA from anterior corneal data, and to test this method in a new group of eyes with toric intraocular lenses (TIOLs).
Kristian, Næser, Giacomo, Savini, Jesper Flethøj, Bregnhøj   +2 more
openaire   +2 more sources

Assessing Total Keratometry Astigmatism, Simulated Keratometry, and Total Corneal Topographic Astigmatism Against Manifest Refractive Cylinder

Journal of Refractive Surgery, 2021
PURPOSE: To evaluate how the Total Keratometry astigmatism measure from a swept-source optical biometer compares with simulated keratometry astigmatism from the same device, and total corneal topographic astigmatism (CorT Total) derived from a Scheimpflug tomographer. METHODS:
Noel, Alpins, James K Y, Ong, George, Stamatelatos   +2 more
openaire   +2 more sources

Corneal and Lenticular Components of Total Astigmatism in a Preschool Sample

Optometry and Vision Science, 2004
ABSTRACT: Purpose. To examine the contribution of corneal and lenticular components to total astigmatism in preschool low and high astigmats to determine whether there was any compensation for high astigmatism by the lenticular component.
Sunita, Shankar, William R, Bobier
openaire   +2 more sources

Age-Related Changes in Total Corneal Astigmatism in Eyes With High Myopia

Cornea, 2023
Purpose: The purpose of this study was to compare age-related changes in corneal astigmatism in eyes with and without high myopia. Methods: Eight-hundred eyes with high myopia (axial length ≥26.0 mm) and 800 eyes without high myopia (200 eyes each from patients in their 40s, 50s ...
Ken Hayashi, Koichi Uno, Shin-ichi Manabe, Koichi Yoshimura   +3 more
openaire   +2 more sources

The effect of posterior corneal flat meridian and astigmatism amount on the total corneal astigmatism estimated from anterior corneal measurements

Graefe's Archive for Clinical and Experimental Ophthalmology, 2014
To evaluate the effects of posterior corneal astigmatism and the absolute flat meridian difference between anterior and posterior corneal surfaces (AMDAnt-Post) on the estimation of total corneal astigmatism using anterior corneal measurements (simulated keratometry [K]).Ninety-nine eyes of 99 healthy participants were enrolled.
Youngsub, Eom, Su-Yeon, Kang, Hyo Myung, Kim, Jong Suk, Song   +3 more
openaire   +2 more sources

Distribution of the anterior, posterior, and total corneal astigmatism in healthy eyes

International Ophthalmology, 2017
To evaluate the magnitude and axis orientation of the anterior, posterior, and total corneal astigmatism in normal healthy eyes of an Iranian population.In a prospective cross-sectional study, ophthalmic and anterior segment parameters of 153 healthy eyes of 153 subjects were evaluated by Galilei dual Scheimpflug analyzer.
Sepehr Feizi, Mohammad Naderan, Vahid Ownagh, Fatemeh Sadeghpour   +3 more
openaire   +2 more sources