Retinal pigment epithelial repopulation in monkeys after submacular surgery
T. L. Valentino, H. J. Kaplan, L. V. Del Priore, S. R. Fang, A. Berger and M. S. Silverman
Department of Biology, St Louis (Mo) University, USA.
BACKGROUND: Transplantation of retinal pigment epithelium may be a
treatment for retinal diseases, such as age-related macular degeneration
and hereditary macular degeneration. Before transplantation studies are
undertaken, questions concerning repopulation of retinal pigment epithelial
cells in situ and photoreceptor repair after submacular surgery need to be
addressed. METHODS: We removed the retinal pigment epithelium from Bruch's
membrane in the macaque monkey in the macula and outside the vascular
arcades. This model allowed the study of in situ retinal pigment epithelium
regrowth and photoreceptor repair for 9 months following debridement.
RESULTS: Fluorescein angiography revealed a window defect in the area of
denuded retinal pigment epithelium. Histologic studies revealed repopulated
nonpigmented retinal pigment epithelial cells in the denuded areas in both
the early and late periods. At 9 months, the repopulated retinal pigment
epithelium was associated with repaired, normal-appearing photoreceptor
outer segments. Retinal pigment epithelium regrowth was observed only if
Bruch's membrane was intact. CONCLUSIONS: Repopulation of retinal pigment
epithelium in the adult primate can occur rapidly and can support the
repair of damaged photoreceptors following submacular surgery.
