View clinical trials related to Blindness.
Filter by:A recombinant adeno-associated virus serotype 2 (rAAV2) vector has been altered to carry the human RPE65 (hRPE65) gene. This vector has been shown to restore vision in animal models that resemble human RPE65-associated Leber congenital amaurosis (LCA), an incurable retinal degeneration that causes severe vision loss. The proposed study is an open label, Phase I clinical trial of subretinal rAAV2-CBSB-hRPE65 administration to individuals with RPE65-associated retinal disease. Five cohorts will be included in this trial. Cohorts 1, 2 and 4 will consist of individuals 18 years of age and older. Cohorts 3 and 5 will consist of individuals between the ages of 8 and 17, inclusive. Enrollment in Cohorts 3 and 5 will begin only after confirming the safety of rAAV2-CBSB-hRPE65 administration in the older groups of participants. This trial will lead to a greater understanding of the safety and thereby potential value of gene transfer in RPE65-associated retinal disease and will have implications for other forms of retinal degenerative disease amenable to this type of intervention. The goal of this clinical trial is to determine the safety of uniocular subretinal administration of rAAV2-CBSB-hRPE65 in individuals with RPE65-associated retinal disease. Ocular and systemic toxicity will be assessed prior to and following vector administration to determine if there are adverse changes that may be associated with vector administration.
To measure colour vision in patients with a blue light filtering lens implant in one eye and non-tinted implant in the other eye (and compared this group with a control group with bilateral non-tinted implants) and to determine whether blue light filtering lenses limit colour vision
Bacterial corneal ulcers are a leading cause of pediatric blindness in underdeveloped countries due to a lack of antibiotic availability and affordability, among other reasons. Povidone-iodine, an inexpensive and readily available broad-spectrum antimicrobial agent, may be an effective and affordable treatment for corneal ulcers, allowing preservation of sight for those afflicted with this disease.
This is a two-year proof-of-concept study to evaluate a new Virtual Reality (VR) "holographic" sound system for use as an audiological Orientation and Mobility (O&M) training tool
The goal of this project is to evaluate the Smart Wheelchair Component System (SWCS) for power wheelchairs and the Smart Power Assistance Module (SPAM) for manual wheelchairs in realistic indoor environments with target users performing realistic tasks. We will combine group trials involving individuals who have a visual impairment (but do not have a mobility impairment) with several single-case studio involving individuals who have a visual and mobility impairment. Our long-term objective is to provide independent mobility to veterans with mobility and sensory impairments.
The purpose of the research project is to develop and evaluate an emergency egress system for persons with visual impairment, which would use existing lighted exit signage to provide egress information at a distance of up to 100 feet.
Patients sometimes report subjective visual effects when taking sildenafil. Our study set out to measure these in a controlled setting. Subjects were asked to detect patterns presented on a monitor screen.
This study will determine if the brain regions in blind people that would normally be involved in vision are used instead to remember touch. Blind people have an enhanced sense of touch compared to sighted people, and they also perform better on tests for certain kinds of memory. This study will examine and compare the results of a touch memory test in blind and sighted people to determine what brain areas are involved in responding to touch. Blind people and sighted volunteers between 18 and 80 years of age who have no psychiatric problems or neurological problems (other than blindness) may be eligible for this study. Candidates are screened with a medical interview and examination. Participants undergo one or both of the following procedures: Behavioral experiment Sighted participants are blindfolded during this experiment. Subjects sit comfortably in front of a table. They are presented with a number of surfaces placed on a table one at a time and are given 10 seconds to feel each surface with the index finger on their dominant hand. They must concentrate and memorize the surfaces as best they can. After a 15-minute break, they are again presented with a series of surfaces and given 10 seconds to feel each one. This time, they must say as quickly as possibly whether the surface is one they touched previously or is a new surface. Functional MRI MRI uses a strong magnetic field and radio waves to obtain images of body organs and tissues. In this study, subjects undergo MRI scanning of the brain while performing the same touch test described above. For the MRI, the subject lies on a table that slides into the scanner. The MRI machine detects change in the brain regions involved in performing the task.
This study will examine whether blind people develop changes in the brain that improve memory function. Previous studies have shown that blind people, on average, perform better in memory tasks than sighted people. A possible reason for this is that parts of the brain that process visual information in sighted individuals are engaged in processing mnemonic (remembering) information in blind people. Blind and sighted people 18 years of age and older are eligible for this study. Healthy, sighted individuals may participate in Part 1 of the study, which is designed to find appropriate words to use in tests for Part 2 of the study. Part 2 will include sighted people and blind people. It will examine whether the (visual) brain in blind people is processing mnemonic information in a way that helps with day-to-day memory functions. Blind participants in this study must have lost their sight by age 4. Candidates will be screened with a medical interview and examination and a brief test of short-term and long-term verbal memory. Sighted patients will also be tested for visual memory and for handedness. Part 1 - Word Recognition Testing (2 sessions) - Session 1: Participants listen to a number of words over a loudspeaker and try to remember them for a memory test that will be given 30 minutes later. For the test, subjects listen to words again and press one of three buttons as quickly as possible after hearing the word. The buttons signal whether the subject does or does not recognize the word with a 1) high level of confidence or 2) low level of confidence. - Session 2: Participants hear a noun over a loudspeaker and have to find an appropriate verb for it, such as the verb (read) for the noun (book). Part 2 - MRI Scanning and TMS Experiments (5 - 7 sessions) - Magnetic resonance imaging (MRI): Participants perform the same procedures as described above for Part 1 while undergoing MRI of the brain. For this test, the subject lies on a table inside the MRI scanner - a narrow cylindrical tube with a strong magnetic field. Scanning time varies from 20 minutes to 3 hours, with most scans lasting between 45 and 90 minutes. (Earphones are used to hear the words for this test instead of a loudspeaker.) - Transcranial magnetic stimulation (TMS): Participants undergo TMS while performing the same procedures described for Part 1. For TMS, a wire coil is held over the scalp. A brief electrical current is passed through the coil, creating a magnetic pulse that stimulates the brain. Subjects may hear a click and feel a pulling sensation on the skin under the coil. There may be a twitch in muscles of the arm or leg. During the TMS, electrical muscle activity is recorded through the electrodes with a computer or other recording device. Each session lasts a maximum of 3 hours.
The project objective is to validate the types of eye trackers that may most effectively be employed in the rehabilitation evaluation and training of people with central scotomas. The eye trackers will include the three basic types of eye trackers, namely, 1)electrophysical, 2) front surface trackers, and 3) retinal trackers.