Diabetic Retinopathy Research & Studies
Several new treatments are being investigated for diabetic retinopathy. New blood vessel growth and increased vascular permeability can lead to vision loss in people with diabetic retinopathy.
Researchers have focused on developing drugs that block the activity of VEGF, a protein that promotes the growth of new blood vessels in the eye, leading to vascular leakage. Three VEGF inhibitors that must be regularly injected into the eyebevacizumab (Avastin), ranibizumab (Lucentis), and pegaptanib (Macugen)are currently being studied in people with diabetic retinopathy.
A recent study comparing Avastin with focal laser treatment for diabetic macular edema demonstrated the potential of anti-VEGF drugs to be used as monotherapy or in combination with laser treatment. In addition, trials evaluating the VEGF inhibitors compared with focal laser treatment alone and in conjunction with laser treatment are under way.
Another experimental treatment involves corticosteroids, which are usually prescribed to relieve pain and inflammation caused by various disorders. But anecortave, triamcinolone, and fluocinolone are angiostatic corticosteroids that can also prevent new blood vessel growth and leakage from blood vessels in the eye.
Researchers theorize that these medications block the growth and movement of cells required for the formation of new blood vessels. They also think these corticosteroids may prevent leakage by preserving the tight spaces between the cells that line blood vessel walls. As with VEGF inhibitors, angiostatic corticosteroids require repeated intraocular injections.
These drugs are not approved by the FDA for the treatment of diabetic retinopathy but are under investigation by the Diabetic Retinopathy Clinical Research Network. This collaborative network helps support and evaluate multicenter research on diabetic retinopathy, diabetic macular edema, and associated conditions. The network was formed in 2002 and includes more than 150 participating sites with more than 500 physicians in the United States. DRCR.net, which is funded by the National Eye Institute, is currently working on several projects. The Wilmer Ophthalmological Institute at Johns Hopkins is one of its four core centers.