Search results for "ocular"
showing 10 items of 1219 documents
Optical Coherence Tomography Angiography of Optic Disc in Eyes With Primary Open-angle Glaucoma and Normal-tension Glaucoma.
2019
PURPOSE To examine vessel density (VD) properties of the optic nerve head in eyes with ocular hypertension (OHT), high-tension glaucoma (HTG), and normal-tension glaucoma (NTG) and to evaluate associations on structural parameters of retinal nerve fiber layer (RNFL). METHODS Three groups of patients with OHT (n=15), HTG (n=36), and NTG (n=22), and a healthy control group (n=23) were included in this study. Peripapillary VD and optic disc flow area were measured using optical coherence tomography angiography, and peripapillary RNFL (pRNFL) thickness was determined. Global and sectoral analysis of optic nerve head vasculature and pRNFL thickness were measured. RESULTS Glaucomatous eyes had lo…
Relation between fixation disparity and the asymmetry between convergent and divergent disparity step responses
2007
Abstract The neural network model of Patel et al. [Patel, S. S., Jiang, B. C., & Ogmen, H. (2001). Vergence dynamics predict fixation disparity. Neural Computation, 13 (7), 1495–1525] predicts that fixation disparity, the vergence error for a stationary fusion stimulus, is the result of asymmetrical dynamic properties of disparity vergence mechanisms: faster (slower) convergent than divergent responses give rise to an eso (exo) fixation disparity, i.e., over-convergence (under-convergence) in stationary fixation. This hypothesis was tested in the present study with an inter-individual approach: in 16 subjects we estimated the vergence step response to a 1 deg disparity stimulus with a subje…
Temporal Structure of Human Gaze Dynamics Is Invariant During Free Viewing.
2015
We investigate the dynamic structure of human gaze and present an experimental study of the frequency components of the change in gaze position over time during free viewing of computer-generated fractal images. We show that changes in gaze position are scale-invariant in time with statistical properties that are characteristic of a random walk process. We quantify and track changes in the temporal structure using a well-defined scaling parameter called the Hurst exponent, H. We find H is robust regardless of the spatial complexity generated by the fractal images. In addition, we find the Hurst exponent is invariant across all participants, including those with distinct changes to higher or…
Avaliação da resposta de acomodação após tarefas visuais próximas usando diferentes dispositivos eletrônicos portáteis
2015
ABSTRACT Purpose: To assess the accommodation response after short reading periods using a tablet and a smartphone as well as determine potential differences in the accommodation response at various stimulus vergences using a Hartmann- Shack aberrometer. Methods: Eighteen healthy subjects with astigmatism of less than 1 D, corrected visual acuity of 20/20 or better, and normal findings in an ophthalmic examination were enrolled. Accommodation responses were obtained under three different conditions: accommodation system of the eye relaxed and visually stressed with a tablet and an smartphone for 10 min, at a distance of 0.25 m from the subject's eyes. Three measurements of accommodation res…
Monocular versus binocular pupillometry.
2004
Purpose To quantify differences between monocular and binocular pupil size measurement under scotopic and mesopic conditions. Setting Department of Ophthalmology, Johannes Gutenberg-University, and Department of Medical Biometry, Epidemiology and Informatics, University of Mainz, Mainz, Germany. Methods Computerized dynamic pupillometry (P2000 SA, Procyon Instruments Ltd.) was used at 3 illumination levels: scotopic at 0.03 lux, mesopic low at 0.82 lux, and mesopic high at 6.4 lux. One hundred forty eyes of 70 healthy volunteers without ocular pathology were examined. The subjects were divided into 2 groups. In the first group, the pupil diameter was measured binocularly first. In the secon…
Clinical Profiles of Premenstrual Experiences Among Women Having Premenstrual Syndrome (PMS): Affective Changes Predominate and Relate to Social and …
2014
Our objective for this study was to examine symptom severity among women suffering from premenstrual syndrome as well as associations between symptom severity and impairment. In a one-cycle prospective study, various premenstrual symptoms of 91 women were assessed. Tension and irritability were the most severe symptoms. Headache, irritability, self-deprecating thoughts, and depressed mood were the symptoms that were subjectively rated as the most burdensome. Significant correlations were found between the mean premenstrual severity and functional impairment. The severity of premenstrual affective symptoms was related to social impairment. The severity of psychological symptoms was correlate…
Systemic, environmental and lifestyle risk factors for dry eye disease in a mediterranean caucasian population
2022
Abstract Objectives To assess systemic, environmental and lifestyle risk factors for dry eye disease (DED) in a Mediterranean Caucasian population. Methods A cross-sectional study was performed on 120 Caucasian participants aged between 18 and 89 years (47.0 ± 22.8 years). Medical history, information regarding environmental conditions and lifestyle, Ocular Surface Disease Index, Dry Eye Questionnaire-5, non-Invasive (Oculus Keratograph 5 M) breakup time, tear film osmolarity and ocular surface staining parameters were assessed in a single clinical session to allow DED diagnosis based on the guidelines of the Tear Film and Ocular Surface Society Dry Eye Workshop II Diagnostic Methodology Re…
Olfactory Event-Related Potentials Reflect Individual Differences in Odor Valence Perception
2006
Investigating the neural substrates of perceived quality in olfaction using different odorants is intrinsically difficult. By utilizing individual differences in perceived quality of the odor of androstenone, we obtained a continuum of individual differences in rated valence of the same stimulus allowing investigations of its manifestation in the olfactory event-related potentials (ERPs). In an initial group consisting of 43 individuals that were screened for their verbal descriptors and sensitivity for the odor of androstenone, 22 normosmic volunteers were chosen forming 2 distinct groups with regard to verbal labels (‘‘body odor'' and ‘‘nonbody odor'') for androstenone while maintaining c…
Ocular Surface and Tear Film Changes in Older Women Working with Computers
2015
The aim of this work is to investigate changes in the ocular surface (OS) and tear film (TF) by means of questionnaire-based subjective symptoms, TF break-up time, Schirmer test, and TF analysis in women working with computers and to analyze the effects of the oral supplementation with antioxidants/omega 3 fatty acids (A/ω3) in the OS outcomes. Women aged 40–65 years (n=148) were recruited at the Administrative Offices of Valencia (Spain) and distributed into two age groups, 40–52 years (AGE1;n=87) and 53–65 years (AGE2;n=61), and then subdivided according to being (or not) computer users (CUG; NCUG) during the workday. Homogeneous subgroups were randomly assigned (or not) to the daily inta…
Femtosecond laser versus mechanical microkeratome laser in situ keratomileusis for myopia: Metaanalysis of randomized controlled trials.
2011
Purpose To examine differences in efficacy, accuracy, safety, and changes in aberrations between femtosecond and mechanical microkeratome laser in situ keratomileusis (LASIK) for myopia. Setting Department of Ophthalmology, Shanghai First People's Hospital Affiliated to Shanghai Jiaotong University, Shanghai, China. Design Evidence-based manuscript. Methods Data sources, including PubMed, Medline, EMBASE, and Cochrane Controlled Trials Register, were searched to identify potentially relevant prospective randomized controlled trials. Primary outcome measures were efficacy (uncorrected distance visual acuity ≥20/20), accuracy (±0.50 diopter mean spherical equivalent), and safety (loss of ≥2 l…