Search results for "corneal astigmatism"
showing 10 items of 12 documents
A genome-wide association study of corneal astigmatism: The CREAM Consortium
2018
Contains fulltext : 191261.pdf (Publisher’s version ) (Open Access) Purpose: To identify genes and genetic markers associated with corneal astigmatism. Methods: A meta-analysis of genome-wide association studies (GWASs) of corneal astigmatism undertaken for 14 European ancestry (n=22,250) and 8 Asian ancestry (n=9,120) cohorts was performed by the Consortium for Refractive Error and Myopia. Cases were defined as having >0.75 diopters of corneal astigmatism. Subsequent gene-based and gene-set analyses of the meta-analyzed results of European ancestry cohorts were performed using VEGAS2 and MAGMA software. Additionally, estimates of single nucleotide polymorphism (SNP)-based heritability for …
Anisometropia of ocular refractive and biometric measures among 66- to 79-year-old female twins
2016
Purpose To examine the prevalence of anisometropia of spherical refraction (AnisoSR), astigmatism (AnisoAST) and spherical equivalent (AnisoSE) and their associations with spherical refraction (SR), refractive astigmatism (AST), spherical equivalent (SE) and interocular differences of ocular biometric parameters among elderly female twins. Methods Refraction of 117 monozygotic (MZ) and 116 dizygotic (DZ) female twin subjects aged 66–79 years was assessed with an auto-refractor (Topcon AT) and controlled by subjective refraction. Corneal refraction, anterior chamber depth and axial length were measured with a Zeiss IOL Master. Participants with eyes operated for cataract or glaucoma were exc…
Corneal and Refractive Astigmatism in Adults: A Power Vectors Analysis
2009
Purpose. In this article, we examine the relationship between corneal and refractive astigmatism (including with the rule, against-the-rule, and oblique astigmatism) in an adult population using power vectors. Methods. Refractive and keratometric measures of astigmatism were conducted on right eyes of 105 white subjects aged 18 to 59 years. We performed a linear regression of refractive astigmatic error on corneal astigmatism, using the J0 and J45 components of the astigmatism. Results. We obtained a statistically significant regression relationship between the corneal (C) and refractive (R) astigmatism for both J0 and J45 components, namely, RJ0 = 1.07 × CJ0 − 0.28; and RJ45 = 1.46 × CJ45 …
Prevalence of corneal astigmatism before cataract surgery.
2008
To analyze the prevalence and presentation patterns of corneal astigmatism in cataract surgery candidates.University of Valencia, Valencia, Spain.Refractive and keratometric values were measured before surgery in patients having cataract extraction. Descriptive statistics of refractive and keratometric cylinder data were analyzed and correlated by age ranges.Refractive and keratometric data from 4,540 eyes of 2,415 patients (mean age 60.59 years +/- 9.87 [SD]; range 32 to 87 years) differed significantly when the patients were divided into 10-year subsets. There was a trend toward less negative corneal astigmatism values, except the steepest corneal radius and the J(45) vector component, in…
Analysis of the Corneal Anterior and Posterior Surface in Patients With Peripheral Hypertrophic Subepithelial Corneal Opacification
2019
PURPOSE To characterize the corneal changes in peripheral hypertrophic subepithelial corneal opacification (PHSCO) considering elevation of the anterior and posterior corneal surface, corneal astigmatism, tear secretion, and endothelial cell density. METHODS Thirty-eight eyes of 22 patients with PHSCO on at least 1 eye and 38 eyes of 22 age- and sex-matched healthy subjects were included in this retrospective cross-sectional study. Using the Pentacam system (Oculus, Wetzlar, Germany), measurement of the anterior and posterior corneal surface was performed. In addition, the Schirmer test was conducted, and endothelial cells were counted in the central cornea with a specular microscope (SP-30…
Genome-wide association study for refractive astigmatism reveals genetic co-determination with spherical equivalent refractive error: the CREAM conso…
2015
To identify genetic variants associated with refractive astigmatism in the general population, meta-analyses of genome-wide association studies were performed for: White Europeans aged at least 25 years (20 cohorts, N = 31,968); Asian subjects aged at least 25 years (7 cohorts, N = 9,295); White Europeans aged <25 years (4 cohorts, N = 5,640); and all independent individuals from the above three samples combined with a sample of Chinese subjects aged <25 years (N = 45,931). Participants were classified as cases with refractive astigmatism if the average cylinder power in their two eyes was at least 1.00 diopter and as controls otherwise. Genome-wide association analysis was carried out for …
Anisometropia of spherical equivalent and astigmatism among myopes: a 23-year follow-up study of prevalence and changes from childhood to adulthood.
2017
Purpose To study anisometropia of spherical equivalent and astigmatism from the onset of myopia at school age to adulthood. Methods A total of 240 myopic schoolchildren (mean age 10.9 years), with no previous spectacles, were recruited during 1983–1984 to a randomized 3-year clinical trial of bifocal treatment of myopia. Examinations with subjective cyclopedic refraction were repeated 3 years later (follow-up 1) for 238 subjects and thereafter at the mean ages of 23.2 (follow-up 2) and 33.9 years (follow-up 3) for 178 and 134 subjects. After exclusions, the 102 subjects who attended all three follow-ups were included in the analyses. Corneal refractive power and astigmatism and anterior cha…
Refractive Lens Exchange with Foldable Toric Intraocular Lens
2009
To assess visual and refractive outcomes, and rotational stability after refractive lens exchange (RLE) with toric intraocular lens (IOL) implantation to correct ametropia and preexisting astigmatism.Prospective, nonrandomized, observational case series (self-controlled).This prospective, nonrandomized, and self-controlled study included 32 eyes of 19 consecutive patients with more than 1.00 diopter (D) of preexisting corneal astigmatism having RLE with AcrySof Toric IOL implantation (Alcon Laboratories Inc, Fort Worth, Texas, USA). Uncorrected visual acuity (UCVA), best-corrected visual acuity (BCVA), refractive sphere, and keratometric and refractive cylinder were recorded preoperatively …
Astigmatism among myopics and its changes from childhood to adult age: a 23‐year follow‐up study
2014
Purpose To study the prevalence of and changes in astigmatism from the onset of myopia at school age. Methods Two hundred and forty myopic schoolchildren (mean age 10.9 years), with no previous spectacles, were recruited during 1983–1984 to a randomized 3-year clinical trial of bifocal treatment of myopia. Three annual examinations with subjective cycloplegic refraction were performed for 237–238 subjects. Subsequent examinations were performed at the mean ages of 23.2 and 33.9 years for 178 and 163 subjects, and the last examination, including data from prescriptions of different ophthalmologists, for 32 subjects. Corneal topography was studied at baseline, at the 3-year follow-up and at t…
Trifocal toric intraocular lenses in eyes with low amount of corneal astigmatism.
2020
Aim To evaluate the refractive and visual outcomes following cataract surgery and implantation of a trifocal toric intraocular lens (IOL) in eyes with low degrees of corneal astigmatism. Methods Twenty-six eyes of 22 patients who underwent implantation a trifocal toric IOL (FineVision PODFT, PhysIOL s.a., Liege, Belgium) were enrolled. Phacoemulsification with femtosecond laser, capsular tension ring insertion and intraoperative aberrometry were performed in all cases. All IOLs used showed a cylinder power of 1.00 D. Main outcome measures were refractive error and corrected-distance visual acuity (CDVA) and uncorrected-distance visual acuity (UDVA) values. Eyes were evaluated at 4mo post-su…