Sildenafil for Treatment of Choroidal Ischemia

The hypothesis of this study is to determine if there is a benefit afforded by the use of systemic Sildenafil to patients with choroidal and retinal degenerations and dystrophies, such as vitelliform degeneration, dry and reticular age-related macular degeneration (AMD) as well as patients with hereditary and acquired retinal dystrophies such as retinitis pigmentosa and central serous retinopathy.

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.

Choroidal Ischemia, Vitelliform Macular Dystrophy, Age-related Macular Degeneration, Central Serous Retinopathy, Retinitis Pigmentosa

Participants are assigned to the investigational sildenafil arm with a dose of 40-80mg daily, or the records review arm when taking sildenafil off-label.

Medical record review for participants that are prescribed Sildenafil off-label as part of standard of care treatment for disease.

Initial Sildenafil dosage will be weight dependent. Participants will start at 40 mg daily (20mg in the morning, 20 mg in the evening) or 60 mg daily (40mg in the morning and 20 mg in the evening). Sildenafil dosage may be increased to up to 80mg daily (20-40mg in the morning and 20-40mg in the evening) based on the response to lower doses. If the participant has not had improvement after initial treatment, the dose may be increased, at the discretion of the study physician.

Patients are evaluated for progression of disease/dystrophy via visual acuity (improved/stable/worsened) and appearance of fluid layer and drusen on OCT testing.

Inclusion Criteria: Diagnosis of retinal and choroidal degenerations (reticular or vitelliform AMD or vitelliform-type subretinal drusen) or hereditary or acquired retinal dystrophies (retinitis pigmentosa or central serous retinopathy) Exclusion Criteria: Diagnosis of heart disease requiring use of nitrates Inability to be examined monthly or bi-monthly

Coleman DJ, Silverman RH, Rondeau MJ, Lloyd HO, Khanifar AA, Chan RV. Age-related macular degeneration: choroidal ischaemia? Br J Ophthalmol. 2013 Aug;97(8):1020-3. doi: 10.1136/bjophthalmol-2013-303143. Epub 2013 Jun 5.

Coleman DJ, Lee W, Chang S, Silverman RH, Lloyd HO, Daly S, Tsang SH. Treatment of Macular Degeneration with Sildenafil: Results of a Two-Year Trial. Ophthalmologica. 2018;240(1):45-54. doi: 10.1159/000486105. Epub 2018 Apr 25.