Search results for "Ocular"
showing 10 items of 1219 documents
Biaixos atencionals en l’esquizofrènia: una revisió bibliogràfica
2018
Antecedents: En la present revisió s’analitzen diverses investigacions on s’estudien els biaixos atencionals en el processament de la informació d’estímuls amb diferent valència emocional en persones amb esquizofrènia. Metodologia: Bases de dades PubMed i PsycINFO, articles complets en anglés, que utilitzen participants adults. L’objectiu és analitzar articles des de l’any 2000 al 2016 on s’estudien els biaixos atencionals en l’esquizofrènia. Pregunta de recerca: Existeixen biaixos atencionals en el processament de la informació davant estímuls amb diferent valència emocional ‒càrrega emocional agradable, desagradable o neutra‒ en persones amb esquizofrènia? Resultats: 22 articles, dels qua…
Approche nutritionnelle de la thérapie du syndrome de l'œil sec : prévention par les acides gras polyinsaturés
2008
Dry eye disease affects 15% of the population over the age of 65. It is characterized mainly by inflammation of the ocular surface (tear film, conjunctiva and cornea) which represents a relevant target for therapeutic strategies. The side effects and long-term intolerance of anti-inflammatory drugs give rise to an increasing interest for dietary components exhibiting anti-inflammatory properties, such as polyunsaturated fatty acids (PUFAs). In these studies, we developed a scopolamine-induced dry eye model in the rat that mimics changes occurring in Humans suffering from moderate dry eye. We described the time course of clinical signs, inflammation and mucin production loss. We investigated…
Is the nonREM–REM sleep cycle reset by forced awakenings from REM sleep?
2002
In selective REM sleep deprivation (SRSD), the occurrence of stage REM is repeatedly interrupted by short awakenings. Typically, the interventions aggregate in clusters resembling the REM episodes in undisturbed sleep. This salient phenomenon can easily be explained if the nonREM–REM sleep process is continued during the periods of forced wakefulness. However, earlier studies have alternatively suggested that awakenings from sleep might rather discontinue and reset the ultradian process. Theoretically, the two explanations predict a different distribution of REM episode duration. We evaluated 117 SRSD treatment nights recorded from 14 depressive inpatients receiving low dosages of Trimipram…
Accuracy and accommodation capability of a handheld autorefractor
2000
Purpose: To determine the accuracy of measurement by the Nikon Retinomax handheld autorefractor and its ability to relax accommodation. Setting: Pediatric Section, Department of Ophthalmology, University of Mainz, Germany. Methods: To perform a series of comparative measurements, autorefractor readings were obtained on healthy young adults (students) and on children aged 2 to 12 years. The autorefractor readings were compared with subjective refractions of the young adults and with cycloplegic retinoscopy of the children. Results: In adults, the accuracy of the handheld autorefractor measurements was comparable to that of conventional tabletop autorefractors. In children, the autorefractor …
Preoperative simulation of postoperative iris-fixated phakic intraocular lens position and simulation of aging using high-resolution Scheimpflug imag…
2006
To increase postoperative safety after implantation of iris-fixated phakic intraocular lenses (pIOLs), optimal preoperative evaluation and patient selection is mandatory. We present a new software tool in a high-resolution Scheimpflug imaging device that precisely simulates the postoperative position of an iris-fixated pIOL and also simulates the effect of aging on the pIOL's position.
Goldmann Tonometry After Hyperopic Laser In Situ Keratomileusis
2004
PURPOSE To identify differences in applanation tonometry between retreated and nonretreated eyes (primary LASIK eyes) 6 months after hyperopic laser in situ keratomileusis. METHODS In a prospective study 100 eyes (100 patients) underwent conventional hyperopic laser in situ keratomileusis under a 160-microm flap. Central Goldmann applanation tonometry was determined before and 6 months after surgery in 78 (78%) primary LASIK eyes and before surgery and 6 months after the retreatment date in 22 (22%) retreated eyes. RESULTS Preoperative mean tonometry was 14.96 +/- 1.96 mm Hg and 15.30 +/- 1.95 mm Hg in primary LASIK and retreated eyes, respectively. Six months after surgery it was 12.99 +/-…
Amplitude, Latency, and Peak Velocity in Accommodation and Disaccommodation Dynamics
2017
The aim of this work was to ascertain whether there are differences in amplitude, latency, and peak velocity of accommodation and disaccommodation responses when different analysis strategies are used to compute them, such as fitting different functions to the responses or for smoothing them prior to computing the parameters. Accommodation and disaccommodation responses from four subjects to pulse changes in demand were recorded by means of aberrometry. Three different strategies were followed to analyze such responses: fitting an exponential function to the experimental data; fitting a Boltzmann sigmoid function to the data; and smoothing the data. Amplitude, latency, and peak velocity of …
Evaluation of the practicality of optical biometry and applanation ultrasound in 253 eyes
2003
Abstract Purpose To evaluate the percentage of eyes that could not be measured using optical biometry and ultrasound applanation and the reasons. Setting Department of Ophthalmology, Johannes Gutenberg-University Hospital, Mainz, Germany. Methods Optical biometry (IOLMaster®, Carl Zeiss Meditec AG) and A-scan ultrasound biometry were performed consecutively in 253 eyes scheduled for cataract surgery the next day. Lens opacities were evaluated with the Opacity Lensmeter (Interzeag), and a slitlamp examination and measurement of visual acuity were performed. The 2 techniques were compared in terms of the rate of and reasons for primary measurement failure. Results Measurement with the IOLMast…
Anatomical correlates of ocular motor deficits in cerebellar lesions
2009
Humans are able to stabilize the images of moving targets on the retina by means of smooth pursuit eye movements. After the pontine level, all smooth pursuit pathways pass through the cerebellum. Previous animal studies gave evidence that two specific lesion sites within the cerebellum cause smooth pursuit disorders: those of the flocculus/paraflocculus and the vermis including lobule VI, VII, the uvula and the deep cerebellar nuclei. To date, there have been only a few lesion studies in patients with smooth pursuit disorders that do not allow direct comparison with a control group. In the present study, new lesion mapping techniques determined which cerebellar structures were involved in p…
The attentional blink demonstrates automatic deviance processing in vision.
2011
Rare deviations in serial visual stimulation are accompanied by an occipital N2 in the event-related potential [the visual mismatch negativity (vMMN)]. Recent research suggests that the vMMN reflects automatic processing of information on the sensory level as a basis for change detection. To directly test the hypothesis that the vMMN is independent from attention, a rapid-serial-visual-presentation paradigm was applied: Either 300 ms or 700 ms after the presentation of a target (T1) a rare position change was embedded in the stimulation which elicited a vMMN. In another condition participants had to detect a second target (T2) after T1: Importantly, within 300 ms after T1, T2 detection was …