[Experimental therapeutic modalities for retinitis pigmentosa]

Retinitis Pigmentosa (RP) is a heterogeneous group of inherited diseases that cause retinal degeneration, often leading to blindness. Over the last decade, significant insights have been obtained into the mechanisms underlying retinal degeneration in RP. This improved understanding of the pathogenesis of RP, combined with advances in molecular and cellular biology methods as well as electro-optical technologies, have contributed to renewed interest and increasing efforts to design novel therapeutic approaches for RP. In the first part of this review (Harefuah, April 2003), we summarized recent developments in the fields of gene therapy for RP, the use of neurotrophic growth factors, and attempts to alter disease progression by vitamins and nutritional modifications. In this second part of the review, retinal and retinal pigment epithelium transplantation, the potential use of stem cells to replace degenerating retinal cells and attempts to develop a retinal prosthesis using electro-optical devices are described. The exciting progress made in these various experimental directions raises hope that slowing or preventing the progression of retinal degeneration in RP patients, and perhaps even partial restoration of visual function in RP, is within reach.