Successful cotransplantation of intact sheets of petal retina with retinalpigment epithelium

PURPOSE. Many retinal diseases, such as macular degeneration, affect both r etinal pigment epithelium (RPE) and photoreceptors. Therefore, retinal repa ir may require transplantation of both tissues together as a cograft. METHODS. AS recipients of retina-RPE cografts, 7- to 10-week-old albino Roy al College of Surgeons rats that lose their photoreceptors because of a pig ment epithelium defect were used. Freshly harvested intact sheets of RPE wi th neural retina from pigmented normal rat fetuses were gel embedded for pr otection and transplanted into the subretinal space. RESULTS. After 6 to 7 weeks, with the support of the cografted RPE sheet, t ransplanted photoreceptors developed fully in organized parallel layers in the subretinal space. Immunohistochemistry for rhodopsin, rod alpha-transdu cin, and S-antigen and peanut agglutinin labeling for cone interphotorecept or matrix domains suggested that the photoreceptors in the graft were capab le of normal function. CONCLUSIONS. Freshly harvested intact sheets of fetal RPE and retina, trans planted together into the subretinal space, can develop a normal morphology . Such transplants have the potential to benefit retinal diseases with dysf unctional RPE and photoreceptors.