Purpose:
Autologous transplantation of retinal pigment epithelium (RPE) sheet may be helpful for the surgical treatment of age-related macular degeneration (AMD). We developed a new technique for autologous RPE transplantation. The graft is a sheet of partial-thickness RPE-choroid.
Methods:
27 pigmented rabbits were used for this study. After mechanical debridement of Bruch’s membrane, sheets of partial thickness RPE-choroid were transplanted to the subretinal space in 25 rabbits. The animals were examined by fundus photographs and fluorescein angiographs, and were sacrificed postoperatively at 1, 2, 4, 12, and 24 weeks. Eye cups containing the graft were examined by light microscopy and immunohistochemistry. In addition, two partial-thickness RPE-choroid sheets were analyzed by transmission electron microscopy (TEM).
Results:
TEM showed partial-thickness RPE-choroid graft consisted of RPE cells, Bruch’s membrane, choriocapillaries and ruptured middle vessels. Its thickness is about 50-60µm. Fluorescein angiography revealed neither fluorescein leakage nor stain at the graft at either early or late phase. Light microscopy revealed that in 17 experiments where the graft survived and the neural retina remained intact; but in 8 experiments with unsuccessful grafts, the neural retina degenerated. The implanted graft had revascularization and RPE cells were monolayered. In sections that the neural retina survived where the graft implanted, anti-CRALBP antibody labelled all RPE cells and rhodopsin in photoreceptor outer segments was positive. Figure showed that the graft survived at postoperative 2 weeks (A) and 24 weeks (B).
Conclusions:
Our study documented the feasibility and the histological outcome of autologous transplantation of partial-thickness RPE-choroid sheet. In humans, autologous transplantation of partial-thickness RPE-choroid sheets might become a treatment for AMD.
Keywords: retinal pigment epithelium • transplantation • age-related macular degeneration