Search results for "Visual field"
showing 8 items of 118 documents
Optic neuropathy caused by type A botulinic toxin
2014
Purpose To report the development of an optical neuropathy after injection of type A botulinic toxin in a subject with blepharospasm. Methods Optical neuropathy was evaluated through a complete ophthalmologic examination consisting of bio-microscopy, tonometry and study of visual sharpness, colour test, visual field, OCT, fluorangiography and determination of VEPs. Results Intravenous therapy was begun with Metilprednisolone (20 mg/Kg/day) and Vitamin B6 associated with oral Citicoline, and there was a clear improvement down to normalization of the symptoms. After 6 months the Humphrey computerized visual field with central 30-2 program threshold test emphasised in ODx an upper half-field a…
Does Posterior Capsule Opacification Affect the Results of Diagnostic Technologies to Evaluate the Retina and the Optic Disc?
2014
The visual outcome obtained after cataract removal may progressively decline because of posterior capsular opacification (PCO). This condition can be treated by creating an opening in the posterior lens capsule by Nd:YAG laser capsulotomy. PCO optical imperfections cause several light reflection, refraction, and diffraction phenomena, which may interfere with the functional and structural tests performed in different ocular locations for the diagnosis and follow-up of ocular disease, like macular and optic nerve diseases. Some parameters measured by visual field examinations, scanning laser polarimetry, and optical coherence tomography (OCT) have changed after PCO removal. Imaging quality a…
Mapping of the human visual cortex using image-guided transcranial magnetic stimulation
2002
We describe a protocol using transcranial magnetic stimulation (TMS) to systematically map the visual sensations induced by focal and non-invasive stimulation of the human occipital cortex. TMS is applied with a figure of eight coil to 28 positions arranged in a 2x2-cm grid over the occipital area. A digitizing tablet connected to a PC computer running customized software, and audio and video recording are used for detailed and accurate data collection and analysis of evoked phosphenes. A frameless image-guided neuronavigational device is used to describe the position of the actual sites of the stimulation coils relative to the cortical surface. Our results show that TMS is able to elicit p…
P258 Combining tDCS with prismatic adaptation for non invasive neuromodulation of the motor cortex
2017
Introduction Prismatic adaptation (PA) shifts visual field laterally and induces lateralized deviations of spatial attention. Recently, it has been suggested that prismatic goggles are also able to modulate brain excitability ( Magnani, 2014 ), with cognitive after-effects documented even in tasks not necessarily spatial in nature ( Oliveri, 2013 ). Objectives The aim of the present study was to test whether prisms can modulate motor cortical excitability similarly as anodal transcranial direct current stimulation (tDCS) does; to test whether neuromodulatory effects obtained from tDCS and prismatic goggles could interact and induce homeostatic changes in brain excitability. Materials and me…
Relationship Between Visual Field Sensitivity and Retinal Nerve Fiber Layer Thickness Measured by Scanning Laser Polarimetry and Optical Coherence To…
2009
Purpose: To evaluate the correlation between automated achromatic perimetry (AAP) and the output of two retinal nerve fiber layer (RNFL) analysers: scanning laser polarimetry (GDx-VCC) and optical coherence tomography (OCT). Methods: Quantitative RNFL measurements with GDx-VCC and Stratus-OCT were obtained in one eye from 52 healthy subjects, 38 ocular hypertensive (OHT) patients and 94 glaucomatous patients. All patients underwent a complete examination, including AAP using the Swedish interactive threshold algorithm (SITA). The relationship between RNFL measurements and SITA visual field global indices were assessed by means of the following methods: analysis of variance, bivariate Pearso…
Cluster visual field progression and its relationship with optic disc changes
2015
Purpose Glaucoma diagnosis and follow up of progression is often based on structural and functional assessments. This study aimed to assess clustered progression and evaluate its correlation with the corresponding disc changes (RA sectors) obtained from HRT examinations. Methods 51 eyes from OHT and glaucoma patients with a minimum of 5 reliable visual ᴀ밄eld tests (HFA II i 24-2) and HRT with a follow-up >4 years were analyzed retrospectively. Linear regression of clusters deᴀ밄ned by the Glaucoma Hemiᴀ밄eld Test (GHT) was performed based on the mean threshold in each cluster. Global and sectoral rates of change in RAs were assessed and correlated with functional clustered measures. Cluste…
Anatomic and functional follow-up of patients with an idiopathic epiretinal membrane and a preserved visual acuity
2013
Purpose: To determine the anatomic and functional retinal modifications in patients with an idiopathic epiretinal membrane (ERM) and a preserved visual acuity (VA).Methods: Monocentric, prospective study in 24 eyes of 24 patients with an ERM and a VA better than 20/25. Recorded data were best corrected VA on ETDRS scale, retinal anatomic lesions on spectral-domain OCT, retinal sensitivities on microperimetry and macular and foveal thicknesses at 0 and 6 months.Results: At inclusion, mean VA was 84 ± 5 letters, mean macular sensitivity was 14.0 ± 1.4 decibels (dB) and mean foveal sensitivity was 14,4 ± 1,5 dB. Mean macular thickness was 351 ± 34 µm and mean foveal thickness was 348 ± 66 µm. …
Motion perception in early glaucoma
2013
Purpose: The aim of our study was to underline the changes in the movement perception for early glaucoma. Our working hypothesis consisted in inquiring if the impairment of the magnocellular pathway may modify the movement perception capabilities in the visual field, more particularly in its peripheral area.Methods: We included 14 healthy subjects and 14 patients with early primary open angle glaucoma. A moving target was presented on a semicircular screen (1.8 m diameter); participants were asked to localize the Ending Point (EP) of each movement. Each stimulus consisted in a white dot (0,72° of diameter) moving horizontally with the imposed velocity profile. Two different laws of motion w…