Search results for "Eye"
showing 10 items of 2511 documents
The SmartSight Project: Use of Electronic Glasses to Improve Impaired Fields of Vision
2020
Electronic glasses use advanced assistive technology that can improve function for persons with visual impairments. This paper presents work in progress in the SmartSight project, where existing versions of electronic glasses are adapted and tested for persons with the visual impairments; macular degeneration and retinitis pigmentosa. The project aims are to adapt and innovate electronic glasses for persons with impaired fields of vision and study the impact on the daily function and quality of life. In a pilot test of the electronic glasses, promising results were found that imply a big difference for persons with impaired vision. The outcome of the SmartSight project might change the clin…
Lipid nutrition and eye health
2010
Revue non indexée dans le JCR.; International audience; According to demographic forecasts, the elderly population will represent a growing part of the developed societies in the near future. Eye diseases are the second most prevalent pathologies after the age of 65 years. Age-related macular degeneration (AMD) is the leading cause of irreversible vision loss in western countries. The number of people suffering from ocular pathologies is expected to increase sharply in the near future, becoming a socio-economic burden. Recent data indicate that lipid nutrients may represent new tools in the prevention of eye diseases, and especially AMD.
Classification of SD-OCT Volumes Using Local Binary Patterns: Experimental Validation for DME Detection
2016
International audience; This paper addresses the problem of automatic classification of Spectral Domain OCT (SD-OCT) data for automatic identification of patients with Diabetic Macular Edema (DME) versus normal subjects. Optical Coherence Tomography (OCT) has been a valuable diagnostic tool for DME, which is among the most common causes of irreversible vision loss in individuals with diabetes. Here, a classification framework with five distinctive steps is proposed and we present an extensive study of each step. Our method considers combination of various pre-processings in conjunction with Local Binary Patterns (LBP) features and different mapping strategies. Using linear and non-linear cl…
24S-hydroxycholesterol and cholesterol-24S-hydroxylase (CYP46A1) in the retina: from cholesterol homeostasis to pathophysiology of glaucoma.
2011
http://www.sciencedirect.com/; International audience; Free cholesterol is the predominant form of cholesterol in the neural retina. The vertebrate neural retina exhibits its own capacity to synthesize cholesterol and meets its demand also by taking it from the circulation. Defects in cholesterol synthesis and trafficking in the neural retina has detrimental consequences on its structure and function, highlighting the crucial importance of maintaining cholesterol homeostasis in the retina. Our purpose was to give a review on the functioning of the retina, the role of cholesterol and cholesterol metabolism therein, with special emphasis on cholesterol-24S-hydroxylase (CYP46A1). Similar to th…
Induced Night-Vision by Singlet-Oxygen-Mediated Activation of Rhodopsin
2019
In humans, vision is limited to a small fraction of the whole electromagnetic spectrum. One possible strategy for enhancing vision in deep-red or poor-light conditions consists of recruiting chlorophyll derivatives in the rod photoreceptor cells of the eye, as suggested in the case of some deep-sea fish. Here, we employ all-atom molecular simulations and high-level quantum chemistry calculations to rationalize how chlorin e6 (Ce6), widely used in photodynamic therapy although accompanied by enhanced visual sensitivity, mediates vision in the dark, shining light on a fascinating but largely unknown molecular mechanism. First, we identify persistent interaction sites between Ce6 and the extra…
Tierexperimentelle untersuchungen zur rolle von entzündungsmediatoren bei der hornhautneovaskularisation
1984
Experimental investigations concerning the role of inflammatory compounds in corneal neovascularization.Natural and synthetic inflammatory compounds were implanted in the corneas of rabbits to clarify the question whether corneal neovascularization is induced by stromal edema alone, or by neovascular mediators. It could be demonstrated that prostaglandin E1 and E2 have an angiogenetic capacity, whereas their precursor (arachidonic acid) as well as PGA1, A2, B2, I2 and Thromboxan A2 were inactive in this regard.Histology showed that corneal neovascularization is always accompanied by the invasion of polymorphonuclear leukocytes. Corneal edema in the beginning of vascularization can be explai…
Phase retrieval for studying the structure of vitreous floaters simulated in a model eye
2021
We simulate vitreous floaters in a model eye and apply a phase retrieval algorithm to recover the structure of the vitreous floaters. The algorithm requires modulating the object under study by a r...
Opto-mechanical artificial eye with accommodative ability.
2015
The purpose of this study was to describe the design and characterization of a new opto-mechanical artificial eye (OMAE) with accommodative ability. The OMAE design is based on a second-pass configuration where a small source of light is used at the artificial retina plane. A lens whose focal length can be changed electronically was used to add the accommodation capability. The changes in the OMAE's aberrations with the lens focal length, which effectively changes the accommodative state of the OMAE, were measured with a commercial aberrometer. Changes in power and aberrations with room temperature were also measured. The OMAE's higher-order aberrations (HOAs) were similar to the ones of th…
Modulation transfer function in refractive-diffractive multifocal intraocular lenses in vitro
2007
Purpose: The optical quality of two types of multifocal, hybrid refractive-diffractive, intraocular lenses (IOL) is analyzed in vitro. Following the EN-ISO international standard, the IOLs’ modulation transfer functions (MTF) are determined for both distance and near vision. The behaviour of these curves when the pupil size varies is studied. Methods: The IOLs analyzed were: AcrySoft ResTor SN60D3 (Alcon) and Tecnis ZM900 (AMO). The MTF was calculated from the cross line-spread function recorded with the OPAL Vector System (Image Science Ltd. Oxford) by using fast Fourier transform techniques. The artificial eye model used simulates in vivo conditions of the anterior chamber including an ar…
The Internuclear Ophthalmoplegias
1993
Internuclear ophthalmoplegia (INO), which is caused by an ipsilateral medial longitudinal fasciculus (MLF) lesion, is characterized by adduction paresis of lateral gaze, usually with spared convergence [1–4]. In the opposite eye, abduction nystagmus and hypermetric abduction saccades are the main clinical and electro-oculographic abnormalities [1, 5, 6]. The origin of both is still debated. Abduction nystagmus has been explained by (a) an additional horizontal gaze paresis [7]; (b) vergence mechanisms aimed at alignment of the visual axes [8]; (c) interruption of descending excitatory projections from oculomotor nucleus internuclear neurons to contralateral abducens nucleus motoneurons [9];…