Search results for " visual"
showing 10 items of 1041 documents
Across space and time : infants learn from backward and forward visual statistics
2016
International audience; This study investigates whether infants are sensitive to backward and forward transitional probabilities within temporal and spatial visual streams. Two groups of 8-month-old infants were familiarized with an artificial grammar of shapes, comprising backward and forward base pairs (i.e. two shapes linked by strong backward or forward transitional probability) and part-pairs (i.e. two shapes with weak transitional probabilities in both directions). One group viewed the continuous visual stream as a temporal sequence, while the other group viewed the same stream as a spatial array. Following familiarization, infants looked longer at test trials containing part-pairs th…
Angioid streak-related choroidal neovascularization treated by intravitreal ranibizumab.
2010
PURPOSE The purpose of this study was to report the visual outcome of intravitreal therapy with ranibizumab of choroidal neovascularization secondary to angioid streaks after 1-year follow-up. METHODS Nine patients (age, 58 +/- 4 years; range, 53-65 years) were treated with off-label intravitreal injections of 0.3 mg ranibizumab. Primary outcomes were best-corrected visual acuity changes (Early Treatment Diabetic Retinopathy Study logarithm of the minimum angle of resolution and letters) and optical coherence tomography macular thickness changes. RESULTS Mean follow-up was 14 months (+/-2; range, 12-18 months). Mean visual acuity was 0.52 logarithm of the minimum angle of resolution and 30 …
Best-corrected visual acuity and retinal thickness are associated with improved cortical visual processing in treated wet AMD patients
2015
Purpose In response to anti-VEGF treatment for wet AMD retinal anatomy and visual acuity is often remedied. In our previous study, we showed that visual evoked potentials (VEP) improve following successful anti-VEGF treatment. The aim of this study was to investigate, how visual acuity and retinal thickness changes are reflected in VEP parameters. Moreover, we wanted to assess the feasibility of VEP as a novel monitoring tool for wet AMD patients. Methods A total of 16 patients and six control subjects were enrolled in this study. Patients received three bevacizumab intravitreal injections. At the beginning of the study and four to 6 weeks after the last injection, the best-corrected visual…
RESOLVING AMBIGUITIES IN ORIENTATION, MOTION, AND DEPTH DOMAINS
1992
Three different perceptual systems—orientation, motion, and depth—can recover a global perceptual organization from spatially correlated random multielement patterns. In all three cases the global structure composed of random elements is evaluated by mechanisms performing measurements in the energy domain within appropriately defined local space—time areas. The selective increase in energy of one fraction of the elements may dramatically change the whole perceptual organization of the stimulus. In specially devised patterns one and the same element can belong to two or more separate perceptual organizations, the perceptual salience of one of which can be reinforced by a luminance increment…
Refractive lens exchange with a multifocal diffractive aspheric intraocular lens
2012
PURPOSE: To evaluate the safety, efficacy and predictability after refractive lens exchange with multifocal diffractive aspheric intraocular lens implantation. METHODS: Sixty eyes of 30 patients underwent bilateral implantation with AcrySof® ReSTOR® SN6AD3 intraocular lens with +4.00 D near addition. Patients were divided into myopic and hyperopic groups. Monocular best corrected visual acuity at distance and near and monocular uncorrected visual acuity at distance and near were measured before and 6 months postoperatively. RESULTS: After surgery, uncorrected visual acuity was 0.08 ± 0.15 and 0.11 ± 0.14 logMAR for the myopic and hyperopic groups, respectively (50% and 46.67% of patients ha…
Contrast sensitivity loss in the peripheral visual field following laser in situ keratomileusis.
2007
We report a case of contrast sensitivity loss in the peripheral visual field following laser in situ keratomileusis (LASIK). A 50-year-old white man was referred to us for differences in visual perception in the peripheral field between the right eye, which had had LASIK, and the left eye, which was emmetropic. Linear meridional static perimetry was carried out in the 0- to 180-degree meridian using a Goldmann perimeter to assess the peripheral perimetric thresholds. There was a statistically significantly marked increased threshold in contrast sensitivity in the nasal and temporal fields from 40 degrees of eccentricity in the LASIK eye compared with that in the emmetropic eye. Eyes treated…
Dexamethasone for unresponsive diabetic macular oedema: optical coherence tomography biomarkers
2019
Purpose: To analyse the effects of intravitreal dexamethasone implant (DEX) in patients with diabetic macular oedema (DME) unresponsive to ranibizumab treatment, in relation to the inflammatory optical coherence tomography (OCT) retinal features, subfoveal neuroretinal detachment (SND) and hyperreflective retinal spots (HRS). Methods: Patients with DME poorly responsive to three injections of ranibizumab were treated with DEX. Best-corrected visual acuity (BCVA) and central macula thickness (CMT, measured by Spectralis SD-OCT) were assessed at baseline and at 1, 3, and 6 months. Results: Overall, 44 eyes were included in the study. In the whole group, mean BCVA (baseline 51.5 ± 8.3 letters)…
FDG-PET mapping the brain substrates of visuo-constructive processing in Alzheimer´s disease
2010
The anatomical basis of visuo-constructive impairment in AD is widely unexplored. FDG-PET can be used to determine functional neuronal networks underlying specific cognitive performance in the human brain. In the present study, we determined the pattern of cortical metabolism that was associated with visuo-constructive performance in AD. We employed two widely used visuo-constructive tests that differ in their demand on visual perception and processing capacity. Resting state FDG-PET scans were obtained in 29 probable AD patients, and cognitive tests were administered. We made a voxel-based regression analysis of FDG uptake to scores in visual test performance, using the SPM5 software. Perf…
Implicit binding of facial features during change blindness
2014
Change blindness refers to the inability to detect visual changes if introduced together with an eye-movement, blink, flash of light, or with distracting stimuli. Evidence of implicit detection of changed visual features during change blindness has been reported in a number of studies using both behavioral and neurophysiological measurements. However, it is not known whether implicit detection occurs only at the level of single features or whether complex organizations of features can be implicitly detected as well. We tested this in adult humans using intact and scrambled versions of schematic faces as stimuli in a change blindness paradigm while recording event-related potentials (ERPs). …
Direct costs of glaucoma and severity of the disease: a multinational long term study of resource utilisation in Europe
2005
International audience; Background: Resource utilisation and direct costs associated with glaucoma progression in Europe are unknown. As population progressively ages, the economic impact of the disease will increase. Methods: From a total of 1655 consecutive cases, the records of 194 patients were selected and stratified by disease severity. Record selection was based on diagnoses of primary open angle glaucoma, glaucoma suspect, ocular hypertension, or normal tension glaucoma; 5 years minimum follow up were required. Glaucoma severity was assessed using a six stage glaucoma staging system based on static threshold visual field parameters. Resource utilisation data were abstracted from the…