Human photoreceptor transplantation in retinitis pigmentosa. A safety study

OBJECTIVE: To establish the technical feasibility and safety of photoreceptor transplantation in retinitis pigmentosa. METHODS: A sheet of human photoreceptor cells was harvested from 2 human cadaveric eyes with a vibratome and transplanted into the subretinal spaces of 2 patients with advanced retinitis pigmentosa and visual acuity of no light perception by means of submacular surgery techniques. Preoperative and postoperative electrophysiologic testing, fundus photography, fluorescein angiography, and scanning laser ophthalmoscopy were performed. RESULTS: Twelve months after photoreceptor transplantation, the visual acuity of each patient remained no light perception. The temporal edge of the retinotomy in 1 patient was folded but was not associated with a retinal detachment. The patients were not immunosuppressed, and there was no evidence of rejection of the allogeneic transplant. Cystoid macular edema, uveitis, and macular pucker were not observed. CONCLUSION: A sheet of adult human photoreceptor cells can be harvested from human cadaveric eyes and safely transplanted to the subretinal spaces of patients with retinitis pigmentosa without systemic immunosuppression.