View clinical trials related to Diabetic Retinopathy.
Filter by:Patients enrolled in the original Early Treatment Diabetic Retinopathy Study at the Clinical Center at Johns Hopkins Wilmer Eye Institute will be invited for a follow-up visit at the National Eye Institute. Visual function will be assessed with manifest refraction and standardized visual acuity measurement. The progression of retinopathy will be evaluated by ocular exam and fundus photography. A brief medical history will be obtained. The goal of this study is to evaluate the long-term results of patients whose diabetic retinopathy was treated with different strategies of scatter and/or focal laser photocoagulation.
The efficacy of laser photocoagulation treatment for diabetic retinopathy has been demonstrated by several National Eye Institute (NEI) sponsored clinical trials. The Diabetic Retinopathy Study (DRS) demonstrated that scatter photocoagulation reduces the risk of blindness from diabetic retinopathy. The Early Treatment Diabetic Retinopathy Study (ETDRS) extended these findings by providing information on when to initiate scatter photocoagulation and by demonstrating that focal treatment was effective in treating macula edema. The Krypton Argon Regression Neovascularization Study (KARNS) showed that scatter photocoagulation with krypton red laser was just as safe and effective as the argon blue-green laser in the treatment of proliferative diabetic retinopathy. Unfortunately, there is little data on the long term effects of photocoagulation on visual function. The first objective of this study is to assess the long term effects of photocoagulation for diabetic retinopathy. A second objective is to provide additional information on the risk of progression of cataracts in persons with diabetes. All patients previously treated with laser photocoagulation (focal and/or scatter) are eligible to participate in this long term study. The first priority will be given to patients who participated in the ETDRS and KARNS because of the wealth of information available regarding the details of their treatment and course after treatment. Study evaluations will include a standard ophthalmic examination, fluorescein angiography, lens and fundus photography.
The purpose of this study is to evaluate possible mechanisms of central visual loss in patients with diabetes mellitus. The visual loss of interest to be investigated is that associated with macular edema (prior to and following laser photocoagulation treatment) and that associated with panretinal photocoagulation. The evaluation will be performed with psychophysical testing, i.e., static perimetry and contrast sensitivity function. Of particular interest, the mechanisms of visual loss associated with macular edema (prior to and following laser photocoagulation) will be further investigated. Photoreceptor-mediated visual loss will be assessed by measurements of the Stiles-Crawford effect. Visual loss mediated by post-receptoral retinal changes will be assessed by measuring the Westheimer spatial desensitization/sensitization effect.
The purpose of this project is to diagnose and evaluate ocular and related tissues with various diseases such as conjunctival, corneal, uveal, vitreoretinal and optic nerve disorders, ocular degenerative, metabolic or genetic diseases and tumors. These will be studied using light microscopy, electron microscopy, confocal microscopy, immunohistochemistry, molecular pathological including polymerase chain reaction and in situ hybridization, as well as measuring the functions of cellular organelles, e.g., mitochondrial function. Lymphocytes in the peripheral blood as well as other involved biopsied tissues and ocular tissue will be compared and categorized by disease. Cytokines, chemokines or growth factors and/or other released molecules in the blood and ocular fluids will be also analyzed. Elucidating the relationship between the infiltrating cells, ocular resident cells, and their products in various diseases will help us to make diagnoses and increase our understanding of human ocular disorders. Patients who require eye surgery to treat an eye disease or other disease in which the eye is involved may participate in this study. Samples of eye tissue and fluid that are normally removed and discarded during eye surgery will instead be given to researchers for study. The tissues will be examined under microscope and studied using sophisticated chemical and biological tests. Immune cells from blood samples may also be examined. These studies will help better understand and diagnose the various eye diseases and to develop more attractive therapies.
To determine whether photocoagulation helps prevent severe visual loss from proliferative diabetic retinopathy. To determine whether a difference exists in the efficacy and safety of argon versus xenon photocoagulation for proliferative diabetic retinopathy.
To evaluate the safety and efficacy of the investigational drug sorbinil, an aldose reductase inhibitor, in preventing the development of diabetic retinopathy and neuropathy in persons with insulin-dependent diabetes.
To compare two therapies, early vitrectomy and conventional management, for recent severe vitreous hemorrhage secondary to diabetic retinopathy. Conventional management includes vitrectomy if hemorrhage fails to clear during a waiting period of 6 to 12 months or if retinal detachment involving the center of the macula develops at any time. To compare early vitrectomy and conventional management in eyes that have good vision but a poor prognosis because they are threatened with hemorrhage or retinal detachment from very severe proliferative retinopathy. To study the natural history of severe proliferative diabetic retinopathy.
To evaluate whether red krypton laser treatment is as effective at causing regression of diabetic disc neovascularization as treatment with the blue-green argon laser, when both lasers are used with identical panretinal photocoagulation patterns. To assess the vision of study patients. To test the feasibility of a prototype NEI-sponsored multicenter clinical trial in which participating clinics are not financially reimbursed and in which both the Coordinating and Fundus Photograph Reading Center functions are carried out by staff of the NEI Biometry and Epidemiology Program.
To evaluate the effectiveness of both argon laser photocoagulation and aspirin therapy in delaying or preventing progression of early diabetic retinopathy to more severe stages of visual loss and blindness. To help determine the best time to initiate photocoagulation treatment in diabetic retinopathy. To monitor closely the effects of diabetes mellitus and of photocoagulation on visual function. To produce natural history data that can be used to identify risk factors and test etiologic hypotheses in diabetic retinopathy.