Stem Cell-Based Therapy for Diseases of the Retinal Pigment Epithelium: From Bench to Bedside

Age-related macular degeneration (AMD) represents a leading cause of blindness in the elderly, and Stargardt's macular dystrophy (SMD) is the most common form of juvenile-onset macular degeneration. Dry AMD and SMD share an underlying pathophysiology, namely dysfunction and ultimately loss of the retinal pigment epithelium (RPE), suggesting that RPE transplantation may offer a potential treatment strategy for both patient populations. Stem cells have emerged as a promising source of replacement RPE. During the past 15 years, extraordinary strides have been made in the identification, characterization, and differentiation of stem cells. Recently, this large body of basic science and preclinical research has been translated to patient care with the publication of results from Phase 1/2 trials demonstrating safety of transplantation of human embryonic stem cell (hESC)-derived RPE into patients with AMD and SMD. While significant challenges remain before dry AMD and SMD become treatable diseases, the goal has become more tangible.