Improvement of ocular blood flow and retinal functions with puerarin analogs

Ischemic retinopathy and, particularly, age-related macular degeneration (AMD) are difficult eye diseases to treat. Since the etiology of these diseases is inadequate blood circulation in the retina and choroid, drugs which can improve blood circulation to these tissues should be beneficial to these diseases. Since fovea is avascular, AMD is closely related to choroidal vascular abnormalities, and drugs which show strong effects to increase choroidal blood flow would be particularly useful. Puerarin and all its derivatives, except ET (puerarin disubstituted with -CH2CH2OH), showed marked increase of choroidal blood flow at various time periods. Even ET showed a tendency to increase choroidal blood flow, though it was not statistically significant. As for b-wave recovery, all puerarin analogs showed strong recovery of retinal function after ischemic insult for 30 min. These results indicate that puerarin analogs could be used for the treatment of ischemic retinopathy, and AMD in particular.