A principal goal of research on the retina is to prevent blindness by devising new therapies for diseases that cause photoreceptor dysfunction or loss. These diseases affect the photoreceptor/retinal pigment epithelium (RPE) region (from the choriocapillaris to the outer plexiform layer) and ultimately injure or destroy the rods and cones. The pathophysiological mechanism may be a direct attack on the photoreceptor, or it may involve the cellular and extracellular environment that supports photoreceptor viability. Recent advances in basic science and in clinical medicine make it possible now to conceive of new therapies that would prevent injury to photoreceptor cells, or repair already injured cells, or even replace injured or dead cells, such as the RPE, or the photoreceptors.
There is, of course, a precedent in ophthalmology for therapies that provide partial repair of the damaged retina. Two prime examples are retinal reattachment surgery for retinal detachment and the use of
Bok D, Hageman GS, Steinberg RH. Repair and Replacement to Restore SightReport From the Panel on Photoreceptor/Retinal Pigment Epithelium. Arch Ophthalmol. 1993;111(4):463-471. doi:10.1001/archopht.1993.01090040055030