Active clinical trials for "Retinitis"

The purpose of this study is to see if it is safe to stop maintenance therapy in HIV-positive patients with treated and healed CMV retinitis (eye disease) who have responded well to anti-HIV (antiretroviral) therapy. The current therapies available to treat CMV retinitis are long-term therapies. However, it may be safe to stop long-term anti-CMV therapy in patients with healed CMV retinitis and stable CD4 counts resulting from taking a combination of at least 2 antiretroviral drugs.

The proposed project seeks to provide object recognition as a feature in a retinal implant system. Participants will be able to direct an object recognition application to find a desired object in the field of view of the head-mounted camera, and to direct the participant's view towards it through the presentation of a recognizable icon. A prototype system will be developed and evaluated in human subjects in phase I. A full system implementation and a second phase of the trial will be completed in phase II.

Blindness can be caused by many ocular diseases, such as diabetic retinopathy, retinal vein occlusion, age-related macular degeneration, pathologic myopia and glaucoma. Without timely diagnosis and adequate medical intervention, the visual impairment can become a great burden on individuals as well as the society. It is estimated that China has 110 million patients under the attack of diabetes, 180 million patients with hypertension, 120 million patients suffering from high myopia and 200 million people over 60 years old, which suggest a huge population at the risk of blindness. Despite of this crisis in public health, our society has no more than 3,000 ophthalmologists majoring in fundus oculi disease currently. As most of them assembling in metropolitan cities, health system in this field is frail in primary hospitals. Owing to this unreasonable distribution of medical resources, providing medical service to hundreds of millions of potential patients threatened with blindness is almost impossible. To solve this problem, this software (MCS) was developed as a computer-aided diagnosis to help junior ophthalmologists to detect 13 major retina diseases from color fundus photographs. This study has been designed to validate the safety and efficiency of this device.

The purpose of this study is to evaluate subjects with X-linked retinitis pigmentosa caused by RPGR-ORF15 mutations in a clinical setting to fully characterize their condition, measure testing variability, and estimate rates of progression of clinical parameters.

Vision testing is a fundamental part of every optometry and ophthalmology assessment. Traditional vision testing charts are not able to measure vision below a certain level. Vision in this range is classified as counting fingers (CF), hand movements (HM) and light perception (LP). These measures are not very accurate or easily quantifiable. They are also poorly understood in terms of impact on quality of life. This study aims to assess new methods for measuring the vision of patients with very low vision.

In this study, markers of oxidative stress will be measured in the aqueous humour and plasma of RP patients compared to controls.

This multinational study will investigate the inheritance of genetic retinal degeneration in families of different nationalities and ethnic backgrounds in order to identify the genes that, when altered, cause retinal degeneration. The retina is a light-sensitive membrane lining the back part of the eye. It relays vision signals to the brain, which the brain interprets into sight. When the retina degenerates, vision is altered and possibly lost. The findings of this study should help improve diagnosis and methods of treatment for these disorders. Participating institutions include: the National Institutes for Health in Bethesda, Maryland; the University of Miami in Florida; the Casey Eye Institute in Portland, Oregon; the Byrd Health Sciences Center in Morgantown, West Virginia; the University of Texas Southwestern Medical School in Dallas, Texas; the University of Tennessee Health Sciences Center in Memphis; the Prasad Eye Institute in Hyderabad, India; National Center of Excellence in Molecular Biology in Lahore, Pakistan; and the Jules Gonin Hospital in Lausanne, Switzerland. Patients with retinitis pigmentosa and closely related diseases such as Usher syndrome, snowflake vitreoretinal dystrophy and Bietti crystalline dystrophy may be eligible for this study. Participants undergo the following tests and procedures: Medical and surgical history, including family history of vision problems. Examination to clarify the type of retinal degeneration. Eye examination, including tests of color vision, field of vision and ability to see in the dark Electroretinogram to test the function of visual cells. For this test, the patient sits in a dark room for 30 minutes with his or her eyes patched. Then, a small electrode (silver disk) is taped to the forehead and the eye patches are removed. The surface the eyes is numbed with eye drops, and contact lenses are placed on the eyes. The patient looks inside a large dark globe that emits a series of light flashes. Then a light is turned on inside the globe and more lights flash. The contact lenses sense small electrical signals generated by the retina when the light flashes. Hearing tests for patients with a personal or family history of deafness. Tests include an audiogram, ear examination and test of middle ear function. For middle ear function testing, the patient feels a little air pressure change for a moment and hears some tones. Another test requires the patient to sit quietly with electrodes on the head, forehead and earlobes. Balance testing, including walking in a straight line, standing with eyes closed in the dark and other tests of coordination, and caloric testing. For the caloric testing, any ear wax in the ear canal is removed before the test begins. Then, electrodes are placed on the skin near the eyes and on the forehead. A small amount of cool (sometimes cold) or warm water is instilled into each ear canal, first one and then the other. Blood sample collection for genetic testing.

This study will investigate whether medication for cytomegalovirus (CMV) retinitis-a viral infection of the eye-can safely be stopped in HIV-infected patients whose immune function has improved from anti-HIV therapy. Medicines taken to fight CMV infection (ganciclovir, foscarnet, and cidofovir) can cause serious side effects, such as low blood counts and kidney damage. Stopping these medications may, therefore, be beneficial. Patients with HIV infection who develop CVM retinitis usually have very low levels of infection-fighting white blood cells called CD4 cells-less than 50 cells per microliter of blood. New anti-HIV medications have been able to raise CD4 levels and improve immune function in many patients. This study will see if patients with CD4 levels above 150 cells per microliter can fight CVM retinitis without additional anti-CVM drugs. HIV-infected patients with CVM retinitis will have a physical examination and complete eye examination. These tests will be repeated after 2 weeks. If there is no evidence that the CMV infection has progressed, and if it is in a location that is not immediately sight-threatening, anti-CMV medications will be stopped. Patients will be examined every 2 weeks for 3 months and then every 3 weeks for the next 3 months. Patients whose CD4 count has remained above 100 after 6 months will continue to be followed every 4 weeks until the CVM infection becomes active again. At that time, anti-CVM medicines will be re-started. Patients will also have blood and urine samples taken to test for levels of HIV and CMV in the blood and urine, and will be interviewed about their vision and how it affects daily activities.

Understudied drugs will be administered to children per standard of care as prescribed by their treating caregiver and only biological sample collection during the time of drug administration will be involved. A total of approximately 7000 children aged <21 years who are receiving these drugs for standard of care will be enrolled and will be followed for up a maximum of 90 days. The goal of this study is to characterize the pharmacokinetics of understudied drugs for which specific dosing recommendations and safety data are lacking. The prescribing of drugs to children will not be part of this protocol. Taking advantage of procedures done as part of routine medical care (i.e. blood draws) this study will serve as a tool to better understand drug exposure in children receiving these drugs per standard of care. The data collected through this initiative will also provide valuable pharmacokinetic and dosing information of drugs in different pediatric age groups as well as special pediatric populations (i.e. obese).

Some patients with HIV/AIDS suffer from a dangerous viral infection of the retina (and other organs) called cytomegalovirus infection (CMV). The medications currently used to treat CMV all have serious side effects. AIDS patients are prone to this infection because their immune system produces a lower number of CD4+T lymphocytes, the type of blood cells that fight viral infections. Some new HIV medications strengthen the immune system. This study will investigate the possibility that CMV patients on these HIV medications can develop immune systems strong enough to fight CMV without CMV medication. The study will enroll a maximum of 15 adult HIV/AIDS patients who have a CD4+T cell count over 150 cells/microliter and who have inactive CMV retinitis that is not immediately sight threatening. It is expected to last approximately 2 years. Each prospective participant will have a physical examination and complete eye examination, including retina photographs, with the eye examination and retina photographs repeated 2 weeks later. If there is no evidence of active CMV retinitis, the participant will be enrolled in the study, and CMV medication will be stopped. The participant will have physical and eye examinations every 2 weeks for the first 3 months of the study, and every 3 weeks for the next 3 months. After 6 months, the frequency of the examinations will be 2-8 weeks, depending on the participant's CD4 count. After one year, a participant with a CD4 count remaining over 150 cells/microliter may return to the care of a local ophthalmologist with HIV/CMV experience, revisiting the clinical center every 6 months. The participant's CMV medication will be restarted when CMV retinitis becomes active, which will terminate participation in the study.