Search results for "Refractive error"
showing 10 items of 125 documents
Genetic variants associated with human eye size are distinct from those conferring susceptibility to myopia
2021
Purpose: Emmetropization requires coordinated scaling of the major ocular components, corneal curvature and axial length. This coordination is achieved in part through a shared set of genetic variants that regulate eye size. Poorly coordinated scaling of corneal curvature and axial length results in refractive error. We tested the hypothesis that genetic variants regulating eye size in emmetropic eyes are distinct from those conferring susceptibility to refractive error.Methods: A genome-wide association study (GWAS) for corneal curvature in 22,180 adult emmetropic individuals was performed as a proxy for a GWAS for eye size. A polygenic score created using lead GWAS variants was tested for…
Relative Peripheral Myopia Induced by Fractal Contact Lenses
2018
[EN] Purpose: To assess the peripheral refraction induced by Fractal Contact Lenses (FCLs) in myopic eyes by means of a two-dimensional Relative Peripheral Refractive Error (RPRE) map. Materials and Methods: This study involved 26 myopic subjects ranging from -0.50 D to -7.00 D. FCLs prototypes were custom-manufactured and characterized. Corneal topographies were taken in order to assess correlations between corneal asphericity and lens decentration. Two-dimensional RPREs were measured with an open-field autorefractor at 67 points, covering the central 60 x 30 degrees of the visual field. The bidimensional RPRE vector components: M, J(0) and J(45) of the difference between the values obtain…
Working-Age Cataract Patients: Visual Results, Reading Performance, and Quality of Life with Three Diffractive Multifocal Intraocular Lenses
2013
Purpose To compare the visual outcomes, reading performance, and quality of life (QoL) of working-age cataractous patients bilaterally implanted with 3 different diffractive multifocal intraocular lenses (MIOLs). Design Two-center, randomized, prospective, double-masked study. Participants Sixty-three consecutive patients (126 eyes) seen at Ophthalmology Section, Palermo and Florence University, Italy, randomized to receive the ReSTOR SN6AD3 (Alcon Laboratories, Inc, Irvine, CA) (20 patients, group A), ReSTOR SN6AD1 (Alcon Laboratories, Inc) (21 patients, group B), or TECNIS ZMA00 (Abbott Medical Optics, Santa Ana, CA) (22 patients, group C) MIOL. Intervention Phacoemulsification. Main Outc…
Visual and Refractive Outcomes in Hyperopic Pseudophakic Patients Implanted with the Acri.LISA 366D Multifocal Intraocular Lens
2009
Our purpose was to assess the visual quality after bilateral implantation of the Acri.LISA 366D intraocular lens (IOL; Carl Zeiss Meditec, Jena, Germany) in patients with hyperopia. We did a prospective and nonrandomized study. One hundred and seventy eyes of 85 patients had bilateral implantation of the Acri.LISA 366D IOL. The patients were divided into 2 groups: low to moderate hyperopia (IOL power, 21 to 24.5 diopters [D]) and high hyperopia (IOL power, 25 to 36 D). Monocular and binocular best spectacle-corrected visual acuity (BSCVA), best distance-corrected near visual acuity (BCNVA), binocular best distance-corrected intermediate visual acuity (VA), and distance contrast sensitivity …
Visual acuity tolerance to residual refractive errors in patients with an apodized diffractive intraocular lens.
2007
To assess visual acuity tolerance to defocus caused by residual refractive errors after clear lens extraction (CLE) with apodized diffractive intraocular lens (IOL) implantation.Fernández-Vega Ophthalmological Institute, Oviedo, Spain.In this prospective study, 150 eyes of 75 consecutive patients who had bilateral CLE with implantation of an AcrySof ReSTOR Natural IOL (Alcon) were evaluated. The eyes were divided into 2 groups: myopia and hyperopia. Residual refractive errors were analyzed using vector analysis. Monocular and binocular uncorrected distance visual acuity, best corrected distance visual acuity, uncorrected distance near visual acuity, and best distance-corrected near visual a…
Foldable toric intraocular lens for astigmatism correction in cataract patients.
2007
PURPOSE: To evaluate the results of AcrySof toric intraocular lens (IOL) (Alcon) implantation to correct preexisting astigmatism in patients having cataract surgery. SETTING: Ophthalmology Service, Donostia Hospital, San Sebastian, Spain. METHODS: This prospective observational study included 30 eyes of 15 consecutive patients with more than 1.00 diopter (D) of preexisting corneal astigmatism having cataract surgery. Bilateral implantation of the AcrySof toric IOL was performed after phacoemulsification. The uncorrected visual acuity (UCVA), best corrected visual acuity (BCVA), residual refractive sphere, residual keratometric and refractive cylinders, and toric IOL axis were measured. RESU…
Disability-related-distress in primary school learners with vision impairment due to uncorrected refractive error in KwaZulu-Natal Province, South Af…
2020
Background Uncorrected refractive error (URE) is a major cause of vision impairment among children that impacts negatively on their lives including distresses. We aim to understand the disability-related distress among vision-impaired children due to URE in rural and semi-rural South Africa using qualitative techniques. Methods Structured focus groups of children (aged 5-12 years old) with normal vision and vision impairment due to URE from four schools in Pinetown, KwaZulu Natal, South Africa, were performed (four mixed-gender group discussions and eight single gender group discussions). We recruited the study participants after the children underwent standardised vision screening. Criteri…
Is Ranibizumab effective in stopping the loss of vision for Choroidal Neovascularization in Pathologic Myopia? A Long Term Follow-up Study
2010
Aim To assess the efficacy and safety of ranibizumab in the treatment of choroidal neovascularisation (CNV) caused by pathologic myopia (PM). Design Prospective, multicentre, interventional case series. Methods 40 eyes of 39 consecutive patients with PM and CNV were treated with ‘on demand’ intravitreal injection of ranibizumab 0.5 mg. Final best corrected visual acuity (BCVA) and its change from baseline were the main outcome measures. Changes in optical coherence tomography (OCT) central retinal thickness (CRT) were a secondary outcome. Results Mean age was 53±13 years and mean refractive error –13.5±6.5 D. Median follow-up was 13.3±2 (range 12–18) months. Fifteen eyes (37.5%) had previou…
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…
Effects of multipurpose contact lens solutions on the protein composition of the tear film
2005
Abstract Objectives: To analyze the influence of multipurpose contact lens cleaning solutions on tear proteins. Changes in tear film protein profiles of contact lens wearers who used several marketed brands of multipurpose contact lens care solutions, were assessed by ProteinChip analysis. Methods: Three studies were conducted. Study I was a comparison of Complete and OptiFree multipurpose solutions. Study II was a study with Complete Moisture Plus solution, Study II was a comparison of Renu and Solocare contact lens solutions. Wearers of soft contact lenses were assigned to use the contact lens care solutions for 4 weeks. Non-contact lens wearing patients were used as controls. Tear sample…