Retinal pigment epithelium wound healing in human Bruch's membrane explants.
OBJECTIVE
To compare retinal pigment epithelium (RPE) resurfacing on the RPE basement membrane and inner collagenous layer (ICL) in human submacular Bruch's membrane explants.


METHODS
Debridements were created in RPE-choroid-sclera explants (mean donor age 71.91 +/- 7.76 years) to create defects exposing the RPE basement membrane (RPEbm(+) defects), the ICL immediately below the RPE basement membrane (superficial ICL, [SICL]) or deeper layers of the ICL (DICL). Eleven pairs of eyes--four pairs with one eye having an RPEbm(+) defect and the fellow eye having an SICL defect and seven pairs with corresponding RPEbm(+) and DICL defects--were observed for 10 days by visualizing RPE ingrowth with 4',6'-diamino-2-phenylindole (DAPI) filters. At day 10, specimens were processed for scanning electron microscopy.


RESULTS
Resurfacing of localized RPE defects occurred to some degree in all 11 pairs of eyes. No significant difference in the percentage of resurfacing of RPEbm(+) defects (67.35% +/- 18.82%) and SICL defects (64.26% +/- 16.07%) was observed although healing of the SICL showed more variability in the morphology of RPE cells migrating into the defect. Significant differences in healing were observed between pairs with RPEbm(+) defects versus DICL defects (84.07% +/- 15.35% and 54.00% +/- 14.54% resurfacing, respectively). RPE ingrowth into DICL defects exhibited the greatest morphologic variability.


CONCLUSIONS
RPE basement membrane supports RPE resurfacing of localized RPE defects. The deeper portion of the ICL of aged submacular human Bruch's membrane does not support RPE resurfacing to the same extent as does the RPE basement membrane. The poor RPE resurfacing observed in DICL defects mimics the histopathological findings in patients with age-related macular degeneration after excision of choroidal new vessels.
Wang
Hao
H
University of Medicine and Dentistry of New Jersey-New Jersey Medical School, Newark, New Jersey 07103-2499, USA.
Ninomiya
Yoshihiko
Y
Sugino
Ilene K
IK
Zarbin
Marco A
MA
D000368:Aged; D000369:Aged, 80 and over; D001485:Basement Membrane / Q000502:physiology / Q000648:ultrastructure; D016570:Bruch Membrane / Q000502:physiology* / Q000648:ultrastructure; D002455:Cell Division; D002465:Cell Movement / Q000502:physiology; D002470:Cell Survival; D003646:Debridement; D005260:Female; D006801:Humans; D008297:Male; D008855:Microscopy, Electron, Scanning; D008856:Microscopy, Fluorescence; D008875:Middle Aged; D009924:Organ Culture Techniques; D010857:Pigment Epithelium of Eye / Q000293:injuries* / Q000502:physiology* / Q000648:ultrastructure; D012038:Regeneration / Q000502:physiology*; D014945:Wound Healing / Q000502:physiology*