Search results for "Visual acuity"
showing 10 items of 456 documents
The Prevalence of Amblyopia in Germany
2015
Amblyopia is a condition in which reduced visual acuity is not directly caused by an organic defect (1). Amblyopia can develop when an infant or small child suffers from strabismus. Although both eyes are healthy, different images are formed on each fovea centralis (where vision is sharpest) and on other corresponding locations on the retina; this is in contrast to individuals without strabismus. To prevent double vision the child’s brain suppresses the image produced by one eye. Complete visual ability cannot develop in this eye during the sensitive phase of visual development (2). Approximately half of amblyopia cases (3) are caused by uncorrected higher refractive errors, which are frequ…
Evaluation of a new nomogram for Ferrara ring segment implantation in keratoconus
2021
AIM: To evaluate the short-term clinical outcomes of Ferrara rings in keratoconus using an optimized nomogram developed after several years of research and retrospective analysis of clinical data. METHODS: This prospective longitudinal non-comparative clinical trial evaluated 88 eyes of 88 patients (age 18-62y) with keratoconus diagnosis from two Spanish centers. Ferrara ring segment (AJL Ophthalmic) implantation was performed in all cases, using the mechanical procedure in 25 eyes (28.4%) and a femtosecond laser-assisted procedure in 63 eyes (71.6%). The ring segments implanted in each case were selected using a new optimized nomogram that considered variables such as anterior corneal asph…
A new trifocal corneal inlay for presbyopia
2021
[EN] Corneal inlays (CIs) are the most recent surgical procedure for the treatment of presbyopia in patients who want complete independence from the use of glasses or contact lenses. Although refractive surgery in presbyopic patients is mostly performed in combination with cataract surgery, when the implantation of an intraocular lens is not necessary, the option of CIs has the advantage of being minimally invasive. Current designs of CIs are, either: small aperture devices, or refractive devices, however, both methods do not have good performance simultaneously at intermediate and near distances in eyes that are unable to accommodate. In the present study, we propose the first design of a …
Color stimuli perception in presence of light scattering.
2006
Perception of different color contrast stimuli was studied in the presence of light scattering: in a fog chamber in Clermont-Ferrand and in laboratory conditions where light scattering of similar levels was obtained, using different light scattering eye occluders. Blue (shortest wavelength) light is scattered in fog to the greatest extent, causing deterioration of vision quality especially for the monochromatic blue stimuli. However, for the color stimuli presented on a white background, visual acuity in fog for blue Landolt-C optotypes was higher than for red and green optotypes on the white background. The luminance of color Landolt-C optotypes presented on a LCD screen was chosen corresp…
Femtosecond‑LASIK outcomes using the VisuMax®‑MEL® 80 platform for hyperopia and hyperopic astigmatism refractive surgery
2021
The present study evaluated the efficacy, the safety and the predictability of the Femtosecond laser-assisted in situ keratomileusis (Femto-LASIK) procedure for hyperopia and hyperopic astigmatism. We retrospectively analyzed the postoperative 12-month evolution of 593 eyes with hyperopia and hyperopic astigmatism that underwent Femto-LASIK treatment. The procedure was predictable and effective. No eye lost 2 lines of corrected distance visual acuity (CDVA), demonstrating a safety profile of the procedure. Nine percent of the eyes gained at least one line of CDVA. The accuracy of the spherical equivalent after 12 months was 74% within ±1.0 diopter (D) of emmetropia. The refractive outcomes …
Prevalence of visual impairment and refractive errors in an urban area of Mexico
2019
AIM: To determine the distribution of refractive errors in a school-age population in Quintana Roo (Mexico) in the framework of an international cooperation campaign for the prevention of blindness. METHODS: A sample of 2647 school-age children (ranging from 5 to 14 years old) with a mean age of 9.1±1.9 years old were tested by trained volunteers for distance visual acuity (VA) and refractive errors. The first screening examination included uncorrected distance visual acuity (UDVA) and VA with a +2.00 D lens. Inclusion criteria for a second complete cycloplegic eye examination performed by an optometrist were UDVA <20/25 (0.10 logMAR or 0.8 decimal) and/or VA with +2.00 D ≥20/25. RESULTS: A…
Intravitreal anti-vascular endothelial growth factors, panretinal photocoagulation and combined treatment for proliferative diabetic retinopathy: a s…
2020
Purpose: to conduct a systematic review with network meta‐analysis (NMA) of randomized clinical trials (RCTs) comparing panretinal photocoagulation (PRP) versus anti‐vascular endothelial growth factor (VEGF) treatment alone or in combination with PRP, for proliferative diabetic retinopathy (PDR).Methods: PubMed, Medline and Embase databases were searched for RCTs comparing PRP versus intravitreal anti‐VEGF therapy and/or combined PRP and intravitreal anti‐VEGF for PDR. The primary outcome measures were the mean best corrected visual acuity (BCVA) change and the regression of neovascularization. Mean change of central macular thickness (CMT), the subgroup analyses of patients without diabeti…
Radiäre Optikusneurotomie (RON) bei retinalen Zentralvenenverschlüssen
2007
Background Compression in the lamina cribrosa is discussed as a reason for central retinal vein occlusion. Radial optic neurotomy should release the pressure and increase venous blood outflow. Patients and methods In a clinical trial 27 eyes with central retinal vein occlusion (22 eyes with clinical ischaemia, 5 eyes with continuous disc oedema and visual acuity below 4/10) underwent surgical decompression by vitrectomy and radial optic neurotomy. During surgery the intravenous pressure in the central vein was tested by infusion dynamometry before and right next to the incision. Follow up-time minimally was 1.5 years. Results Infusion dynamometry demonstrated a decrease of the central vein …
Implantable collamer lens with central hole: 3-year follow-up.
2018
Luis Fern&aacute;ndez-Vega-Cueto,1 Carlos Lisa,1 Jos&eacute; J Esteve-Taboada,2 Robert Mont&eacute;s-Mic&oacute;,2 Jos&eacute; F Alfonso1,3 1Department of Surgery, Fern&aacute;ndez-Vega Ophthalmological Institute, Oviedo, Spain; 2Department of Optics and Optometry and Visual Sciences, University of Valencia, Valencia, Spain; 3School of Medicine, University of Oviedo, Oviedo, Spain Purpose: To evaluate the long-term predictability, stability, safety, and efficacy of the V4c Visian implantable collamer lens (ICL) with central hole to correct myopia.Patients and methods: One hundred and eighty-four eyes of 92 patients were evaluated during 3 years after implantation of …
2017
Purpose To compare two surgical approaches for treating encapsulated blebs after trabeculectomy with mitomycin C, in terms of the development of intraocular pressure and progression of glaucoma in a long-term follow up: 1. bleb needling alone vs. 2. a combined approach of needling with additional transconjunctival scleral flap sutures, to prevent early ocular hypotony. Methods Forty-six patients with failing blebs after trabeculectomy with mitomycin C were enrolled in this study. Patients received either needling revision alone (group 1; n = 23) or a combined needling with additional transconjuctival flap sutures, if intraoperatively the intraocular pressure was estimated to be low (group 2…