RPE-mediated collagen gel contraction. Inhibition by colchicine and stimulation by TGF-beta.

Retinal detachment secondary to proliferative vitreoretinopathy (PVR) is often precipitated by traction on the retina from preretinal membranes and traction on the vitreous base. Contraction and proliferation of retinal pigment epithelial (RPE) cells appear to play an important role in the pathogenesis of PVR. Contraction of collagen gels by human RPE cells was evaluated as a model of tractional forces on the vitreous gel. The area of collagen gels with admixed RPE cells in 15-mm wells was measured daily. The collagen gels contracted to less than 50% of original area in 89% of wells. Colchicine (0.01-1 microM) inhibited RPE-induced collagen gel contraction, whereas 1 ng/ml of transforming growth factor-beta enhanced it. Potential stimulators or inhibitors of RPE-mediated gel contraction can be tested using this model.