Transplantation of intact sheets of fetal neural retina with its RPE in retinitis pigmentosa patients.
Purpose: To show the safety of transplanting sheets of fetal retina together with its RPE to patients with retinitis pigmentosa. Methods: Sheets of fetal neural retina and RPE together were transplanted into the subretinal space near the fovea unilaterally into the eyes of five patients with retinitis pigmentosa that had only light perception in both eyes. The patients were followed for six months. The main outcome measures were tissue typing of both donors and recipients, fluorescein angiography, multifocal electroretinogram (mfERG) testing, and clinical examination. No immunosuppressive medications were given. Results: No evidence of rejection was observed. Out to six months there was no evidence of tissue disintegration, retinal edema, or scarring. There was no change in vision, both by Snellen acuity and with mfERGs. Growth of the transplant was noted in two of five patients at six months versus two weeks. All patients typed were HLA mismatched with donor tissue. Conclusions: This study indicates that fetal retina can be transplanted together with its RPE and survive for at least 6 months without rejection. However, no improvement in vision was observed, possibly due to the severe retinal degeneration of the patients.