View clinical trials related to Blindness.
Filter by:This study is a longer-term follow-up study for patients who have been administered AAV2/5-OPTIRPE65 in the Phase I/II, open label, non-randomised, two-centre, dose escalation trial in adults and children with retinal dystrophy associated with defects in RPE65.
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.
A clinical trial of AAV2/5 vector for patients with Defects in RPE65
MGT005 is a natural history study to collect longitudinal prospective data from patients with Leber Congenital Amaurosis associated with defects in RPE65.
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 evaluate the use of an artificial vision system called Brainport system in blind patients To investigate visual, and oculomotor (eye motion) mechanisms involved in the use of the Brainport system.
The purpose of this study is to determine whether frozen corneas are as safe and effective as fresh corneas for use as carriers with the Boston Keratoprosthesis type I (KPro) over long term follow-up. Corneal transplantation is typically performed using fresh, transparent corneas. With KPro surgery, the corneal transplant only serves as a carrier to suture the KPro in place. The cornea used in KPro surgery does not need to be clear like a normal transplant. Frozen corneal tissue can be used to repair the cornea in cases of emergency but the tissue is not transparent and does not allow good vision. We hypothesize that frozen grafts are equivalent as fresh grafts when used as carrier for the KPro.
Clinical evidence for effects of plant anthocyanins on vision, and particularly night vision is controversial. Two clinical trials were conducted to investigate whether blueberry juice consumption affected visual dark adaptation, functional night vision, and recovery after photo-bleaching of the retina. One trial (S2) employed a 3 week intervention and washout period, and two doses of blueberries plus a placebo. The other trial (L1) employed a 12 week intervention plus an 8 week washout and tested one blueberry juice dose against a juice placebo.
The investigators are testing a Light-emitting Diode (LED) flashlight from First-Light™ USA called the Tomahawk MC Tactical Light to determine the range of colors people are able to see with these flashlights at night. The flashlight has been designed to reduce visibility of the user and uses a combination of green and red LED lamps to achieve this. In this study investigators wish to determine how well a subject can differentiate colors at night in a quantifiable manner. Investigators will use the Farnsworth Munsell 100 hue test which requires the user to put shades of red, green, blue and yellow into progressive color order which is scored according to the manufactures specifications.
Patients suffering from symptomatic carotid artery stenosis, transient ischemic attacks (TIAs), amaurosis fugax or stroke receive either Revacept (single dose) plus antiplatelet monotherapy or monotherapy alone. Patients receive a single dose of trial medication by intravenous infusion for 20 minutes. Patients are followed up one and three days after treatment, at 3 months and by a telephone interview at 12 months.