Diabetic preretinal membranes. An immunohistochemical study
J. A. Jerdan, R. G. Michels and B. M. Glaser
Fibrovascular membranes removed during vitreous surgery from patients with
proliferative diabetic retinopathy were examined using indirect
immunofluorescence. Antisera against collagen types I, III, IV, and V,
attachment factors fibronectin and laminin, endothelial marker factor VIII,
and the glial-marker glial-fibrillary acidic protein were used to examined
the membranes. Seven of ten specimens contained cells staining positively
for glial-fibrillary acidic protein, either singly or in large clusters
within the membrane. Four of six membranes showed a well-developed vascular
bed surrounded by a dense collagenous matrix. The matrix stained strongly
with antiserum against both interstitial type I collagen and its associated
attachment factor, fibronectin. In contrast, only localized staining was
observed when antisera against both type IV collagen and its associated
attachment factor, laminin, were used, and this was concentrated in regions
of blood vessels and associated internal limiting membrane.
