[Transplantation of retinal pigment pithelium (RPE) following CNV removal in patients with AMD. Techniques, results, outlook]

Abstract

Neovascular age-related macular degeneration (AMD) has become the leading cause for severe visual loss in all industrialized nations. Surgical excision of choroidal neovascularizations (CNV) is technically feasible but invariably associated with inadvertent removal of corresponding retinal pigment epithelium (RPE) and subsequent atrophy of the choriocapillaris, with the latter two layers being a prerequisite for normal photoreceptor function. To cover the RPE defect both heterologous and homologous RPE cell suspensions have been injected into the subretinal space. The lack of functional improvement has been attributed to various factors including RPE cell dedifferentiation, failure of adherence to Bruch's membrane as well as development of a regular RPE cell monolayer. Therefore, techniques for translocating intact autologous RPE cell sheets have been sought and preservation of foveal neurosensory functions has recently been successfully demonstrated. Besides translocation of a full-thickness RPE/Bruch's membrane/choroid patch outside the macular area, superfluous choroidal tissue may be ablated intraocularly using an excimer laser prior to translocation. Besides recent pharmacological approaches including anti-VEGF agents, these surgical developments open new perspectives for patients with neovascular AMD.