[Vitreal-induced RPE cell traction. Investigation of pathological vitreous samples in an in vitro contraction model]

The aim of this study was to quantify the contraction of retinal pigment epithelium cells (RPE) induced by bioactive factors in pathological vitreous samples.

Using an in vitro contraction assay, the contraction-stimulating activity of vitreous samples of different vitreoretinal pathologies was evaluated. Transdifferentiated porcine RPE cells were placed on hemispherical type I collagen gel. After exposure to pathological vitreous samples derived from different entities (physiological (n=6), rhegmatogenous retinal detachment (n=11), proliferative vitreoretinopathy (PVR) (=10), proliferative diabetic retinopathy (n=6)) the induced gel contraction was determined.

The specific activity of the unclassified samples was 0.04 (median, range: 0-0.08). Vitreous samples derived from patients diagnosed as having any grade of PVR displayed a specific activity of 0.45 (median, range: 0.03-1.45). Samples removed from patients with rhegmatogenous retinal detachment disclosed a specific activity of 0.13 (median, range: 0.01-0.93). The specific activity of vitreous samples removed from patients with diabetic retinopathy had a specific activity of 0.17 (median, range: 0.06-0.29). The mean specific and total activities of these groups were significantly elevated above the unclassified or baseline values (p<0.05).

Pathological vitreous samples of different vitreoretinal pathologies contain sufficient amounts of biologically active factors to induce extracellular matrix contraction.