Morphologic features and viability analysis of human detached retinal pigment epithelium in age-related macular degeneration.

PURPOSE

To evaluate the morphologic features and viability of human retinal pigment epithelium (RPE) cells captured from the pigment epithelium detachment (PED) region outside the choroidal neovascular membrane lesion in eyes with hemorrhagic age-related macular degeneration.

DESIGN

Prospective, observational case series.

METHODS

Five specimens of the RPE sheet were obtained from the PED region after choroidal neovascular membrane excision in 5 eyes of 5 patients during RPE transplantation for hemorrhagic age-related macular degeneration. The specimens were stained with hematoxylin and eosin and with periodic acid-Schiff. Immunohistochemistry analysis for RPE-65 and zonula occludens-1 also was performed. RPE cells from the PED region were cultured and passaged 5 times. Scanning and transmission electron microscopy were performed to analyze the specimens.

RESULTS

The RPE cells of the specimens contained brownish pigment and were autofluorescent in vitro. Periodic acid-Schiff staining revealed that the Bruch membrane below the RPE monolayer was not intact. The specimens demonstrated positive results for both zonula occludens-1 and RPE-65 staining. The RPE basement membrane in the specimen was observed by both scanning and transmission electron microscopy. Intercellular tight junctions among RPE cells of the specimen also were observed. RPE cells captured from the PED region were cultured successfully and were passaged 5 times.

CONCLUSIONS

The RPE sheet developed from the PED region outside the choroidal neovascular membrane lesion had tight intercellular junctions, a simple RPE basement membrane, and active cellular viability. This monolayer RPE sheet may be considered as a substitution for subfoveal RPE loss in eyes with hemorrhagic age-related macular degeneration.