Abstract
Abstract: :
Purpose: Surgical removal of choroidal neovascular membranes in patients with exudative macular degeneration is associated with the partial loss or damage of the retinal pigment epithelium (RPE) cell layer as well as the disruption of the integrity of the photoreceptor-RPE complex resulting in poor visual outcome. Because of the difficulty in obtaining autologous RPE cells, transplantation of autologous iris pigment epithelium (IPE) into the subretinal space has been suggested as an adjunct to membrane extraction to achieve stabilization and possibly improvement of visual acuity. This study was intended to examine whether IPE cells transplanted to the subretinal space after membrane extraction are tolerated without damaging the neural retina. Methods: Autologous IPE cells were transplanted to the subretinal space in a series of 20 consecutive patients with CNV secondary to AMD or high myopia and idiopathic CNV, who were undergoing removal of the subretinal fibrovascular membrane. IPE cells were harvested by iridectomy, isolated, and transplanted as a suspension to the subretinal space without culturing. The site of transplantation was evaluated by funduscopy, fluorescein angiography, and scanning laser ophthalmoscopic (SLO) microperimetry. Visual acuity was measured with ETDRS charts at defined time intervals. Results: Thirteen of the 20 patients were followed for a period of at least three years after IPE transplantation; 2 patients had died and 5 refused further examination. In thirteen patients no evidence of an immunologic response was observed at any time during the 3-year follow-up. Angiographically no chronic macular edema or recurrent CNV was apparent. Two patients showed improved visual acuity of more than 2 ETDRS lines, 8 patients had stable visual acuity, and 3 patients had reduced visual acuity of more than 2 ETDRS lines compared to the initial visual acuity. Central fixation was not regained or preserved in these patients. Conclusions: Transplanted autologous IPE cells were well tolerated in the subretinal space for the three years of follow-up and did not adversely affect photoreceptors function. Stabilization of visual acuity was achieved in the majority of patients after IPE translocation. These results suggest that IPE cells may be a suitable substitute for RPE cells to be transplanted to the subretinal space after CNV removal in patients with exudative macular degeneration.
Keywords: 308 age-related macular degeneration • 607 transplantation • 357 clinical (human) or epidemiologic studies: treatment/prevention assessment/controlled clinical trials