Abstract
Purpose: :
PVR in RD is thought to originate from the Retinal Pigmentary Epithelium (RPE) . Due to poor intraoperative access with conventional vitrectomy, little attention has been given to the Ciliary Epithelium (CE), which is likely the localisation of retinal progenitor cells.
Methods: :
Three paraffin-embedded phtisic eviscerated human eyes with RD complicated by anterior and posterior PVR were studied with light microscopy. Normal eye exenterated for orbital tumor served as control. All cases were stained with H & E, and serial sections were immunostained for monoclonal antibody against VEGF, EGFR and the proliferation marker Ki67, as well as for polyclonal antibody glial fibrillary protein (GFAP), and neuron specific enolase (NSE).
Results: :
All cases with DR and PVR demonstrated hyperplasia and adenomatous-like proliferation of nonpigmentary pars plana CE; there was a mild and focal proliferation of pigmentary CE. Control retina and CE did not express Ki67; in DR and PVR, a moderate immunostaining for Ki67 was detected, prevalent at the basal layer of the pigmentary CE; there was no Ki67 expression elsewhere in the retina, especially in the RPE. EGFR was strongly expressed at the membrane of some pigmentary CE basal cells, whereas the detached retinal neuroepithelium presented a diffuse cystoplasmic expression.
Keywords: proliferative vitreoretinopathy • retinal detachment • ciliary body