Search results for "refractive error"
showing 10 items of 125 documents
Femtosecond laser versus mechanical keratome LASIK for myopia.
2005
To assess efficacy, safety, predictability, stability, and changes in corneal higher-order aberrations (CHOAs) and contrast sensitivity (CS) after a femtosecond laser for LASIK and standard LASIK for myopia.Prospective, randomized, comparative clinical study.Two hundred eyes of 100 consecutive patients who underwent LASIK treatment using the VISX S2 laser system. A femtosecond laser for flap creation was used in 100 eyes (50 patients; spherical equivalent [SE], -2.85+/-1.79 diopters [D]), and a mechanical microkeratome was used in 100 eyes (50 patients; SE, -2.90+/-1.63 D).Uncorrected visual acuity (UCVA), best spectacle-corrected visual acuity (BSCVA), manifest refraction, CS by means of t…
Visual quality after diffractive intraocular lens implantation in eyes with previous hyperopic laser in situ keratomileusis
2010
To evaluate distance, intermediate, and near visual quality in eyes with diffractive intraocular lens (IOL) implantation after previous hyperopic laser in situ keratomileusis (LASIK).Fernández-Vega Ophthalmological Institute, Oviedo, Spain.Cohort study.Corrected distance visual acuity (CDVA) at 12.5%, 25.0%, and 100% contrast levels under photopic and mesopic conditions; uncorrected (UNVA) and distance-corrected (DCNVA) near visual acuity, defocus curves, and corneal higher-order aberrations (HOAs) were measured in eyes that had AcrySof Restor SN60D3 spherical IOL implantation (study group) and in phakic eyes (control group) after hyperopic LASIK.Under photopic conditions at 100% contrast, …
Genetic variants linked to myopic macular degeneration in persons with high myopia: CREAM Consortium.
2019
Purpose: To evaluate the roles of known myopia-associated genetic variants for development of myopic macular degeneration (MMD) in individuals with high myopia (HM), using case-control studies from the Consortium of Refractive Error and Myopia (CREAM). Methods: A candidate gene approach tested 50 myopia-associated loci for association with HM and MMD, using meta-analyses of case-control studies comprising subjects of European and Asian ancestry aged 30 to 80 years from 10 studies. Fifty loci with the strongest associations with myopia were chosen from a previous published GWAS study. Highly myopic (spherical equivalent [SE] ≤ -5.0 diopters [D]) cases with MMD (N = 348), and two sets of cont…
Reproducibility of digital image analysis for measuring corneal haze after myopic photorefractive keratectomy.
1997
Purpose To evaluate the usefulness of digital image analysis for quantifying corneal haze by determining the reproducibility of its measurements at the corneal plane. Methods In a prospective study, 20 randomly selected eyes that had undergone myopic photorefractive keratectomy were photographed focusing the slit beam on their anterior corneal surface. Each photograph was examined using computer image analysis techniques that detect the edge of the reticular pattern of the image. Quantification of the difference between two areas, treated and adjacent untreated cornea, each containing 3,750 pixels with a resolution of 256 gray levels, was performed. Intra-analyzer variation was determined b…
Axial Elongation following Cataract Surgery during the First Year of Life in the Infant Aphakia Treatment Study
2012
PURPOSE To compare ocular axial elongation in infants after unilateral cataract surgery corrected with a contact lens (CL) or primary intraocular lens (IOL) implantation. METHODS Baseline axial length (AL) was measured at the time of cataract surgery (1-6 months) and at age 1 year. AL at baseline and age 1 year and the change in length/mo were analyzed in relation to treatment modality, cataractous versus fellow eye, and age at surgery using linear mixed models. RESULTS Mean baseline AL did not differ between the CL and IOL groups for either cataractous or fellow eyes. Eyes with cataracts were shorter than fellow eyes by an average of 0.6 mm (95% confidence interval [CI], 0.4-0.8 mm; P < 0.…
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…
Symptomatic accommodative and binocular dysfunctions from the use of flat-panel displays
2018
AIM: To determine the presence of symptomatic accommodative and non-strabismic binocular dysfunctions (ANSBD) in a non-presbyopic population of video display unit (VDU) users with flat-panel displays. METHODS: One hundred and one VDU users, aged between 20 to 34y, initially participated in the study. This study excluded contact-lens wearers and subjects who had undergone refractive surgery or had any systemic or ocular disease. First, subjects were asked about the type and nature of eye symptoms they experienced during VDU use. Then, a thorough eye examination excluded those subjects with a significant uncorrected refractive error or other problem, such as ocular motility disorders, vertica…
Posterior chamber phakic intraocular lenses to improve visual outcomes in keratoconus patients
2016
The aim of this review is to summarize the results of using posterior chamber phakic intraocular lenses (pIOLs) to restore quality of vision in keratoconus patients. These pIOLs can correct the refractive errors associated with keratoconus and can also be combined with other surgical techniques to improve the results.
Subjective Satisfaction in Long-term Orthokeratology Patients
2013
Purpose: To AU3 evaluate the subjective satisfaction in visual stability, night vision complains, and light distortion phenomena, and also the number of hours and days per week of lens wear, in patients with myopia undergoing orthokeratology (OK) treatment for at least 1 year. Methods: A visual analog scale (VAS) questionnaire containing 18 items was administered to 44 patients, 29 women and 15 men (mean age, 24.39 6 9.11 years), with a baseline spherical equivalent refractive error of 22.40 6 0.94 diopters and astigmatism up to 20.5 diopters. Average treatment period by the time of data collection was 19 6 7 months. Patients rated their satisfaction with the correction, with complaints of …
Depth of focus through different intraocular lenses in patients with different corneal profiles using adaptive optics visual simulation
2011
PURPOSE: To evaluate the depth of focus with monofocal intraocular lenses (IOLs) in patients with different corneal profiles using adaptive optics (AO) visual simulation. METHODS: An AO visual simulator (crx1, Imagine Eyes) was used to simulate the aberration pattern of three monofocal IOLs (Acrysof IQ SN60WF [Alcon Laboratories Inc]; Akreos Adapt AO [Bausch & Lomb]; and Triplato [AJL Ophthalmic]) of different optic designs. Five groups were considered: patients without any corneal refractive surgery (normal cornea group) and with prior low and high myopic and hyperopic ablations (low myopic ablation, high myopic ablation, low hyperopic ablation, and high hyperopic ablation groups). De…