Retinitis pigmentosa: rod photoreceptor rescue by a calcium-channel blocker in the rd mouse

Retinitis pigmentosa is an inherited degenerative disease of photoreceptors leading to blindness. A well-characterized model for this disease is provi ded by the retinal degeneration mouse, in which the gene for the rod cGMP p hosphodiesterase is mutated, as in some affected human families. We report that D-cis-diltiazem, a calcium-channel blocker that also acts at light-sen sitive cGMP-gated channels, rescued photoreceptors and preserved visual fun ction in the retinal degeneration mouse. The long record of diltiazem presc ription in cardiology should facilitate the design of clinical trials for s ome forms of retinitis pigmentosa.