6 Clinical Trials for Various Conditions
This is an analysis of tests of near vision. Visual perception testing using a novel program on an interactive three dimensional electronic device: Autostereoscopic dynamic near games for monocular visual acuity, stereopsis and color are compared with other conventional or similar tests.
The prospective pilot study will address the critical need for more precise characterizations of the acute visual effects of the drug psilocybin by measuring the impact of acute psilocybin intoxication on a perceptual task known as visual surround suppression, compared to an active placebo control.
In this research study we want to test how people understand a visual scene when the same image is presented to both the eyes, but portions of these images are altered in terms of contrast, depth or in some cases motion.
The timing and quality of sleep is governed by environmental and physiologic factors. Environmental factors, especially ambient lighting can impact the circadian system and alter the timing and structure of sleep. Light exposure can also acutely alter neural activation state and impair sleep. These effects all demonstrate marked sensitivity to short-wavelength blue light with maximal sensitivity in the 460-480 nm range. The alerting effects of blue light in the evening persist for at least 3-4 hours after the lights are turned off, and can disturb subsequent sleep. Avoiding these deleterious effects of light exposure prior to sleep on subsequent sleep would be beneficial to sleep quality and potentially health. The investigators will compare the effects of two light sources, equated for visual stimulus (lux), on multiple non-visual responses to light. The investigators will compare a 90 lux exposure of a commercially available Compact Fluorescent Light (CFL) with a novel LED white light source that is depleted in the short-wavelength visible range (Biological Illumination LCC, FL). In a within-subject design, the investigators will test the hypotheses that exposure to a blue-depleted LED as compared to a CFL exposure at (1) 90 lux or (2) 50 lux will cause significantly: 1. Less melatonin suppression between melatonin onset and bedtime; 2. Less subjective and objective alerting responses before bedtime; 3. Less disruption of nocturnal sleep structure and quality.
This study will examine whether direct current (DC) polarization (electrical stimulation) of the visual cortex can cause a temporary improvement of vision in an amblyopic eye of an adult. Amblyopia (also called lazy eye) is reduced vision in an eye, caused by abnormal brain processing of visual information. In amblyopia, the visual cortex (the part of the brain that processes visual information) favors the other eye and suppresses the image from the amblyopic eye. Amblyopia in children is treated by patching or blurring the good eye, which forces the child to use the amblyopic eye and overcome suppression by the brain. This treatment only works in children 8 years old and younger, however. Electrical stimulation of the brain can temporarily change the function of the visual cortex in adults with good vision, but its influence on the visual function of people with amblyopia is unknown. If DC polarization can improve vision in amblyopic eyes in adults, it would show that the visual cortex is still plastic, and it might help researchers develop a treatment for adults with amblyopia in the future. Patients 18 years of age and older with amblyopia caused by crossing in or turning out of the eyes in childhood or by a difference in near- or farsightedness between the eyes may be eligible for this study. Candidates are screened with a medical history and complete eye examination, including a glaucoma screening and checks of vision, in- or out-turning of the eyes, depth perception, need for glasses, and the interior structures of the eyes. Participants undergo two study sessions, scheduled at least 24 hours apart, involving the following procedures: * Examination: Before each session, the patients' distance vision, contrast sensitivity (ability to see fading letters), and ability to read small print are checked in both eyes. * DC polarization: Patients receive either 20 minutes of electrical stimulation or 20 minutes of sham stimulation (each patient will receive both electrical and sham stimulation on different days). * Repeat examination: Immediately after the stimulation and again 20 minutes later, patients undergo repeat visual function testing. Those who show any differences in visual function 20 minutes after the stimulation are examined again 1 hour after the stimulation. Patients in whom the effect continues after 1 hour are examined again after 1 week.
RATIONALE: Drugs used in chemotherapy, such as cyclophosphamide, etoposide phosphate, and carboplatin, work in different ways to stop the growth of tumor cells, either by killing the cells or by stopping them from dividing. Giving more than one drug (combination chemotherapy) may kill more tumor cells. Mannitol may help chemotherapy work better by making it easier for these drugs to get to the tumor. Chemoprotective drugs, such as acetylcysteine and sodium thiosulfate, may protect normal cells from the side effects of chemotherapy. Giving acetylcysteine together with mannitol, combination chemotherapy, and sodium thiosulfate may be an effective treatment for malignant brain tumors. PURPOSE: This phase I trial is studying the side effects and best dose of acetylcysteine when given together with mannitol, combination chemotherapy, and sodium thiosulfate in treating children with malignant brain tumors.