[Proliferative vitreoretinopathy. On the significance of protein transfer through the blood-retina barrier].

In several studies, unphysiologically high concentrations of different proteins have been measured in the vitreous of patients with proliferative vitreoretinopathy (PVR). It has not yet been determined whether these high values result from the alteration of the blood-retina barrier (BRB) or whether the proteins are produced intraocularly. In the present study we measured the concentrations of IgG and complement factor C4 in vitreous aspirates and plasma samples from patients with PVR (n = 15). We calculated an IgG and C4 index analogous to the IgG index in routine cerebrospinal fluid chemistry, which is used to estimate the rate of intrathecal IgG synthesis. Comparison of the C4 index revealed no significant difference between patients and controls. Although a higher IgG index was demonstrated in pathologic vitreous, no intravitreal cells that are able to synthesize IgG have been found. These findings suggest that high levels of IgG and C4 are related to an elevated transfer at the disrupted BRB.