4 Clinical Trials for Various Conditions
To demonstrate improved color vision in subjects with color vision deficiencies while wearing color-correcting lenses and after color-correcting lense use.
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.
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 to in healthy and color-blind participants by using a broad spectrum light source and wavelength-specific IR bandpass filters. 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 investigator's 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 investigator's hypothesis with the following Aims: Aim 1: Arm 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. Arm 2: To determine the optimal IR wavelength for visual perception in dark-adapted human participants who are colorblind. The investigators hypothesize that the colorblind 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.
Some patients with achromatopsia, an inherited disorder characterized by partial or complete loss of color vision, carry mutations in ATF6. ATF6 is a gene that is responsible for coding a protein that acts in response to endoplasmic reticulum (ER) stress. When the ATF6 protein is mutated, retinal function decreases, contributing to color blindness. The study aims to investigate whether an already FDA-approved drug, glycerol phenylbutyrate (PBA), can improve retinal function inpatients with achromatopsia caused by ATF6 mutations. Patients will be instructed to take three doses of PBA per day at equally divided time intervals and rounded up to the nearest 0.5 mL. The total dose of PBA will be 4.5 to 11.2 mL/m2/day (5 to 12.4 g/m2/day) and will not exceed 17.5 mL/day (19 g/day). Their condition will be monitored over the course of a minimum of 3 clinic visits that will consist of a number of retinal function tests, fundus examinations, and imaging procedures. Findings from the study could elucidate the potential for PBA to serve as a treatment for patients with ATF6-mediated a chromatopsia.