Transplantation of cultured rabbit retinal epithelium to rabbit retina using a closed-eye method.

We have developed a closed-eye technique for transplanting cultured rabbit retinal epithelial cells to Bruch's membrane of the rabbit. A glass micropipette containing a suspension of 3H-thymidine-labeled, cultured retinal pigment epithelial (RPE) cells is inserted through a pars plana incision and positioned adjacent to the neural retina. A jet stream from the pipette is used to make a small retinal hole and bleb detachment. Patches of host retinal epithelium lift off with the neural retina, creating areas of bare Bruch's membrane. The cell suspension is injected into the subretinal space, and labeled cells can be seen attached to Bruch's membrane as early as 1 hr later. The neural retina spontaneously reattaches within 24 to 48 hr, bringing photoreceptor outer segments in direct contact with the transplanted cells. Phagocytosis of outer segment material by transplanted cells can be seen as early as 24 hr after surgery. This closed-eye technique offers an advantage over the open-sky method used previously in that it allows for reattachment of the neural retina and at least a partial return of function in the transplanted retinal epithelium.