Immunohistochemical Study of Periretinal Memberanes in Proliferative Vistreoretinopathy

ABSTRACT

We Performed an immunohistochemical study to identify the cellular components and involvement of immune mechanism in proliferative vitreoretinopathy, which is a major cause of delayed filure of retinla surgery. The 17 specimens of periretinal membranes -including vitreal membranes- were surgically obtained during the pars plana vitrectomy. The clinical diagnoses were idiopathic or traumatic retinal detachment (9 eyes), proliferative diabetic retinopathy (6 eyes), and pars plannitis (2 eyes). The labeled streptavidin-biotin immunoperoxidase method was used for immunohistochemical stain. The following antigens were detected in periretinal membranes cytokeratin in 8 (of 17 cases studied for this antigen), glial fibrillary acidic protein (GFAP) in 9 (of 17), vimentin in 15 (of 17), HLA-DR in 14 (of 17). The macrophages and T lymphocyte expressing CD4 or CD8 markers, were not found in any of the membranes. These results suggest that cellular components of periretinal membranes are consists of retinal pigment epithelial cells, glial cells, and fibroblast. The identification of macrophage and T lymphocytes all met with failure. Also, strong positivity of HLA-DR antigen may indicate involvement of the immune mechanism during the course of proliferative vitreoretinopathy.