Cryotherapy enhances intravitreal dispersion of viable retinal pigment epithelial cells.

Proliferative vitreoretinopathy (PVR) is the most common cause of failure in retinal reattachment surgery. Giant retinal tears are associated with a particularly high incidence of PVR. It involves the formation of cellular membranes that contract and cause traction retinal detachments. Retinal pigment epithelial (RPE) cells are a major component of these cellular membranes. Displacement of viable RPE cells from their normal position into the vitreous cavity is necessary for membrane formation to occur. This study demonstrates that cryotherapy, but not diathermy, enhances intravitreal dispersion of viable RPE cells in bovine eyes in vitro. This suggests that in some circumstances, excessive cryotherapy may play an exacerbating role in the initiation of PVR.