View clinical trials related to Retinitis Pigmentosa.
Filter by:This study is being done to determine if wearable text-to-speech (TTS) and visual pattern recognition (VPR) technology can be used to extend the capabilities of the Argus II to allow patients to read and recognize faces and objects. The Argus II retinal prosthesis can restore rudimentary forms of vision to patients with bare light-perception vision. Using the prosthesis, patients can identify obstacles, handles, switches, eating utensils and demonstrate improved navigation when used in conjunction with other ambulation-assist tools. Current limits in the resolution of the device prevent useful reading or face recognition. The FDA has approved the Argus II as a humanitarian device. Present-day wearable text-to-speech converters are also capable of object and face recognition. Such systems have been developed to assist with these tasks in patients with severe low-vision. ORCAM is a commercially-available eyeglass-mounted visual pattern recognition system capable of converting photographs of text to speech. It is comprised of a camera, a small belt-worn computer, pattern recognition software and a small audio transducer. ORCAM can acquire the image of a sheet of paper and read the text to the user through a small speaker adjacent to the ear. In addition, ORCAM can be trained to recognize faces and speak the name of the individual to the user. ORCAM can also be used to recognize everyday products after being programmed.
The objective of the study is to evaluate the safety, tolerability and efficacy of a single sub-retinal injection of BIIB112 in participants with X-linked retinitis pigmentosa (XLRP).
This study evaluates the changes in visual function at 12 months following a single injection of human retinal progenitor cells compared to sham treated controls in a cohort of adult subjects with RP.
Retinitis Pigmentosa (RP) is a devastating eye disease and at present there are no known treatment options that can alter the rate of vision loss. In a series of studies in animal models, the effects of exposing cones in the periphery of the retina to a large excess of oxygen results in progressive oxidative damage to cone photoreceptors and cone cell death. Compared to control patients, those with RP showed significant reduction in the reduced to oxidized glutathione ratio (GSH/GSSG) in aqueous humor and a significant increase in protein carbonyl content. This demonstration of oxidative stress and oxidative damage in the eyes of patients with RP, suggests that oxidative damage-induced cone cell death in animal models of RP may translate to humans with RP and support the hypotheses that (1) potent antioxidants will promote cone survival and function in patients with RP and (2) aqueous GSH/GSSG ratio and carbonyl content on proteins provide useful biomarkers of disease activity in this patient population. Orally administered N-Acetylcysteine (NAC) has been found to be a particularly effective antioxidant that promotes prolonged cone survival and maintenance of cone function in a mouse model of RP. There is good rationale to test the effect of NAC in patients with RP. The first step is to test different dosing regimens to identify the lowest dose that is able to restore aqueous GSH/GSSG ratio and reduce carbonyl adducts on aqueous proteins. In patients with Idiopathic Pulmonary Fibrosis, polymorphisms within the TOLLIP gene were found to influence outcomes of NAC-treated patients. The product of the TOLLIP gene, toll-interacting protein, is an inhibitory adaptor protein downstream of toll-like receptors, mediators of innate and adaptive immunity. The identification of the influence of TOLLIP polymorphisms on the effect of NAC in Idiopathic Pulmonary Fibrosis provides the rationale for collecting DNA and genotyping the same single nucleotide polymorphisms (SNPs) in the current trial. In addition to this candidate gene genetic analysis, patient RNA will be collected and banked for future transcriptome analysis. The rationale for this is to identify gene expression changes that modify disease progression in RP. There is substantial variability in the rate of progression among patients with RP. A patient who loses all vision early in life can have a sibling with the same mutation who maintains vision into advanced age. This suggests that modifier genes can have a major impact on cone survival. This study will test the hypothesis that the level of expression of gene products that contribute to the antioxidant defense system may influence cone cell death and hence the rate of loss of visual field. It is also possible that gene expression differences may contribute to differences in response to NAC. For these reasons collecting RNA samples from patients will allow next-generation sequencing in the future to understand the transcriptome background on which the study intervention has been performed.
This study evaluates a novel collision warning device to help people with severe vision impairment or blindness avoid collisions with obstacles. The main hypothesis to be tested is that the device reduces the number of collisions with obstacles in everyday activities.
This pilot study will evaluate the visual response to infrared (IR) in humans after dark adaptation. The investigators plan to determine which wavelength and intensity the human eye is most sensitive too, using a broad spectrum light source and wavelength-specific bandpass filters. The investigators will then evaluate the electrophysiologic response in healthy humans to IR, followed by studies in those with specific retinal diseases. The long-term goal of this research is to better understand the role that IR plays in visual function, and whether this can be manipulated to allow for vision in certain retinal pathologies that result from loss of photoreceptor cells. The investigators central objective is to test the electrophysiologic response to IR in the dark-adapted retinal and visual pathways. The investigators central hypothesis is that IR evokes a visual response in humans after dark adaptation, and the characteristics of this response suggest transient receptor potential (TRP) channel involvement. The investigators rationale is that a better understanding of how IR impacts vision may allow for an alternative mechanism for vision in a number of diseases that cause blindness from the degradation or loss of function of photoreceptor cells. The investigators will test the investigators hypothesis with the following Aims: Aim 1: To determine the optimal IR wavelength for visual perception in dark-adapted human participants. The investigators hypothesize that the healthy human eye will detect IR irradiation, with a maximum sensitivity at a specific wavelength. Using a broad-spectrum light source with wavelength-specific bandpass filters, the spectral range of visual perception to IR will be evaluated. The same will be done on colorblind participants. Aim 2: To test the electrophysiologic response to IR in healthy humans after dark adaptation. The investigators hypothesize that IR will elicit an amplitude change on electroretinography (ERG) and visual evoked potential (VEP) responses after dark adaptation in healthy human participants. Participants will be tested with both test modalities to evaluate their response to IR. Aim 3: To test the electrophysiologic response to IR after dark adaptation in humans with certain retinal diseases. Participants with retinitis pigmentosa, age related macular degeneration and congenital stationary night blindness, will be tested. Results will be compared to baselines and to those of healthy participants. The investigators hypothesize that there will be a response to IR on ERG and VEP, which will provide clues to the retinal cell layer location of the response to IR and the nature of potential TRP channel involvement.
The aim of this single-centre study is to assess the safety and efficacy of the Retina Implant Alpha AMS (Retina Implant AG, Reutlingen, Germany) in participants with severe visual impairment secondary to outer retinal degeneration caused by retinitis pigmentosa (RP). The study is sponsored by the University of Oxford and funded by the National Institute for Health Research (UK).
This study evaluates the safety and effectiveness of the Intelligent Retinal Implants System (IRIS V2). Blind patient suffering from Retinitis Pigmentosa, Cone Rod Dystrophy, or Choroideremia are implanted with an Intelligent Retinal Implant Systeme. All subjects undergo ophthalmological examinations in predefined intervals after implantation. Ophthalmological examinations include funduscopy, slit lamp examination and OCT. All adverse events are recorded and analyzed. Efficacy is measured using functional vision and visual function tests before and after implantation as well as with the system on and system off.
The purpose of this study is to assess the safety and efficacy of intravitreal injections of Aflibercept (Eylea) in treating Cystoid Macula Oedema (CMO) in patients with underlying Retinitis Pigmentosa (RP).
The main objective of this study is to quantify vision parameters in subjects with concentric visual field constriction, and this in relation to the display on virtual reality goggles. More specifically: - The maximum brightness value for visual comfort (THRESHOLD_MAX) - The minimum value of the perceptible light contrast in low light perceptible (THRESHOLD_MIN) - The speed of light change adaptation in the range [THRESHOLD_MAX-THRESHOLD_MIN] and [THRESHOLD_MIN-THRESHOLD_MAX].