Sildenafil for Treatment of Choroidal Ischemia

Age-Related Macular Degeneration (AMD) is a sight-threatening visual disturbance that affects the macula in older ages. It is irreversible if the pigment epithelium is lost (dry AMD), but wet AMD can be arrested or delayed with the use of intraocular injections of one of 3 different compounds. All three drugs are injected into the eye in minute doses of usually 0.1 ml. These are usually injected at 4 to 6 week intervals and treatment may be extended for several years. Different patterns of injection times are followed but usually are monthly for 12 or more months, or monthly for 3 months and then extended observation at one to two month intervals unless vision (visual acuity) declines or Optical Coherence Tomography-angiography (OCT-A) shows recurrence of fluid or increase in size or amount of drusen (deposits of lipofuscin) in the retina. Vitelliform macular degeneration is a disorder that causes visual loss due to drusen in the macula, which have been shown to be identical to the deposits seen in macular degeneration. The goal of therapy in this proposal is to use sildenafil to increase choroidal blood flow to treat dry AMD and slow the progression of visual loss in vitelliform and age-related dry AMD as well as other macular, retinal and choroidal degenerations and dystrophies, as well as reduce or eliminate the number of injections required by slowing down transformation of dry AMD to wet AMD in treated patients.