RETINAL-PIGMENT EPITHELIAL WOUND-HEALING IN-VIVO

Objective: To develop an in vivo rabbit model of retinal pigment epith elial wound healing that preserves the overlying retina. Methods: Hydr aulic debridement of the retinal pigment epithelium was performed in o ne eye of 35 pigmented rabbits by means of a pars plana vitrectomy app roach. Five of the 35 eyes were examined by stereoscopic color fundus photography, fluorescein angiography, and light microscopy on each of the following postoperative days: 0, 2, 4, 7, 14, 28, and 56. Results: Retinal pigment epithelial debridement with this technique results in apical decapitation of the retinal pigment epithelial cells followed by subsequent hydraulic removal of the residual nucleus-containing bas al cellular debris. The retinal pigment epithelium-denuded Bruch's mem brane was resurfaced mostly by a monolayer of flattened, hypopigmented retinal pigment epithelial cells within 4 days after debridement. Pro gressive retinal pigment epithelial hyperplasia also occurred beginnin g between postoperative days 2 and 4. Conclusions: Retinal pigment epi thelial wound healing after hydraulic debridement occurs rapidly and i n a manner initially consistent with sliding migration. Progressive re tinal pigment epithelial hyperplasia also occurs and may contribute to this repair process. Further investigation of retinal pigment epithel ial repair by means of this in vivo model may provide important insigh t into the pathogenesis and treatment of outer retinal disorders.