Search results for "Foveal"
showing 10 items of 25 documents
Breaking down the word length effect on readers’ eye movements
2015
Previous research on the effect of word length on reading confounded the number of letters (NrL) in a word with its spatial width. Consequently, the extent to which visuospatial and attentional-linguistic processes contribute to the word length effect on parafoveal and foveal vision in reading and dyslexia is unknown. Scholars recently suggested that visual crowding is an important factor for determining an individual’s reading speed in fluent and dyslexic reading. We studied whether the NrL or the spatial width of target words affects fixation duration and saccadic measures in natural reading in fluent and dysfluent readers of a transparent orthography. Participants read natural sentences …
Optical coherence tomography of macular thickness after biaxial vs coaxial microincision clear corneal cataract surgery
2009
PURPOSE To evaluate macular thickness changes after biaxial microincision versus coaxial small incision cataract surgery using optical coherence tomography (OCT). METHODS This prospective, randomized, marked study comprised 70 patients (70 eyes) undergoing biaxial microincision surgery or conventional coaxial phacoemulsification. Patients were evaluated by Stratus OCT preoperatively and 1 day, 4 weeks, and 8 weeks postoperatively. Best-corrected visual acuity (BCVA), phacoemulsification power, and effective phacoemulsification time (EPT) were evaluated. RESULTS In the biaxial group, median foveal thickness changed from 160 microm preoperatively to 168 microm 8 weeks postoperatively (p=0.018…
Eye position tunes the contribution of allocentric and egocentric information to target localization in human goal-directed arm movements.
1997
Subjects were required to point to the distant vertex of the closed and the open configurations of the Muller-Lyer illusion using either their right hand (experiment 1) or their left hand (experiment 2). In both experiments the Muller-Lyer figures were horizontally presented either in the left or in the right hemispace and movements were executed using either foveal or peripheral vision of the target. According to the illusion effect, subjects undershot and overshot the vertex location of the closed and the open configuration, respectively. The illusion effect decreased when the target was fixated and when the stimulus was positioned in the right hemispace. These results confirm the hypothe…
Decreased Perifoveal Sensitivity Detected by Microperimetry in Patients Using Hydroxychloroquine and without Visual Field and Fundoscopic Anomalies
2015
Purpose. To evaluate the usefulness of microperimetry in the early detection of the ocular anomalies associated with the use of hydroxychloroquine.Methods. Prospective comparative case series study comprising 14 healthy eyes of 7 patients (group A) and 14 eyes of 7 patients under treatment with hydroxychloroquine for the treatment of rheumatologic diseases and without fundoscopic or perimetric anomalies (group B). A comprehensive ophthalmological examination including microperimetry (MP) and spectral-domain optical coherence tomography was performed in both groups.Results. No significant differences were found in mean MP foveal sensitivity between groupsP=0.18. However, mean MP overall sens…
Current Clinical Application of Microperimetry: A Review.
2018
Microperimetry (MP) is a technology that allows the study of retinal sensitivity at different foveal and parafoveal areas as well as eye fixation. It is a technique of functional evaluation, providing a direct correlation between anatomical and functional outcomes. There are a great variety of studies which evaluate the repeatability or reliability of measurements obtained with this technology and also describe and explore different clinical applications. MP has been shown to be useful in the characterization of sensory and motor conditions, such as amblyopia or nystagmus. Concerning ocular pathology, several studies have confirmed the usefulness of MP for evaluating and analyzing different…
Can parafoveal-on-foveal effects be obtained when reading an unspaced alphasyllabic script (Thai)?
2013
One controversial question in the field of eye movements and reading is whether there is evidence of parafoveal-on-foveal effects. This is an important issue because some models of eye movements in reading make quite different predictions in this respect (e.g., E-Z Reader vs. SWIFT models). The aim of the current study was to investigate if parafoveal-on-foveal effects occur when reading Thai, an unspaced, alphasyllabic orthography. Word frequency (high and low) of the word to the right of the currently fixated word was manipulated to examine if it would influence processing of the fixated word. Thirty-six participants read single sentences while having their eye movements monitored. There …
Comparison of Foveal, Macular, and Peripapillary Intraretinal Thicknesses Between Autism Spectrum Disorder and Neurotypical Subjects
2017
Purpose To compare thicknesses of intraretinal layers segmented by spectral-domain optical coherence tomography (SD-OCT) between autism spectrum disorder (ASD) and neurotypical (NT) individuals. Methods We performed 2 scans on 108 eyes from 54 participants (27 high-functioning ASD and 27 age- and sex-matched NT subjects): macular fast volume and peripapillary retinal nerve fiber layer (pRNFL). Macula was automatically segmented. The mean foveal and macular thickness of nine different layers and the thickness of nine pRNFL sectors were considered. Data from the right and left eyes were averaged for each participant. The results were compared between the ASD and NT groups. Associations betwee…
Retinal Imaging through Phakic Iris-Claw IOL.
2014
AbstractBackground: Phakic anterior chamber iris-fixated IOL (PIOL) are established for the correction of high myopia. These patients require attention to macular pathologies. This study was to evaluate the quality of imaging through the PIOLs. Methods: 54 eyes of 31 myopic and hyperopic patients with Verisyse®, Verisyse toric®, and Veriflex® phakic iris-fixated IOL were included. Mean preoperative refraction was −11.0 D and +5.7 D, respectively; mean follow-up time was 7.4 years (5–11 years). A matched control group was formed without PIOL implantation. OCT scans were performed and evaluated qualitatively and quantitatively. Results: In 52 eyes of 31 patients (96%), a 3D-OCT image and fund…
Vascular changes after vitrectomy for rhegmatogenous retinal detachment: optical coherence tomography angiography study
2020
Purpose: To analyse the postoperative foveal avascular zone (FAZ) area, superficial vessel density (SVD) and deep vessel density (DVD) and their correlation with functional (best-corrected visual acuity, BCVA) and anatomical outcomes (foveal macular thickness, FMT) after surgery for rhegmatogenous retinal detachment (RRD) repair. Method: Patients with RRD eyes, successfully treated with a single pars plana vitrectomy (PPV) with gas tamponade and a minimum 12 months follow-up, were re-examined. Foveal avascular zone (FAZ) area, SVD, DVD and FMT were evaluated by using optical coherence tomography angiography (OCTA) and compared to fellow eye. Results: Fifty-six patients with macula-on and 37…
Management of macular edema due to branch retinal vein occlusion with intravitreal injections of pegaptanib sodium
2009
Purpose To evaluate the efficacy of Pegaptanib Sodium as single therapy for macular edema due to non-ischemic branch retinal vein occlusion. Methods In this uncontrolled prospective pilot study 17 patients have been included with non-ischemic branch retinal vein occlusion. All of them showed macular edema in the OCT with central foveal thickness higher than 350 microns (mean, 541 +/- 140) and decrease in visual acuity lower than 0,5 Snellen ETDRS charts notation (mean, 0,16+/-0,14). After an initial injection of Pegaptanib Sodium evaluations were programmed every 5 weeks and further retreatments were developed in cases with macular thickness higher than 300 microns. No other therapies were …