Cryotherapy during Surgery for Giant Retinal Tears and Intravitreal Dispersion of Viable Retinal Pigment Epithelial Cells

Background: Retinal pigment epithelial (RPE) cells are a major component of contractile cellular membranes in proliferative vitreoretinopathy (PVR). Displacement of viable RPE cells into the vitreous cavity is necessary for membrane formation. This study examines the effect of cryotherapy during surgery for giant retinal tears on the dispersion of viable cells into the vitreous cavity. Methods: A total of seven eyes undergoing vitrectomy and retinal reattachment surgery were studied. Vitreous fluid from three eyes was aspirated immediately after cryotherapy; fluid from four eyes was aspirated after scleral indentation with the cryoprobe, but without cryotherapy. Colonies of pigmented cells routinely grew in flasks inoculated with fluid from eyes treated with cryotherapy. In contrast, flasks inoculated with fluid from eyes not treated with cryotherapy contained significantly fewer viable cells. Conclusion: Cryotherapy performed during retinal reattachment surgery in eyes with giant retinal tears is likely to enhance intravitreal dispersion of viable RPE cells. The findings in this study suggest that possible harmful effects of cryotherapy should be evaluated further and that alternative methods of creating a chorioretinal adhesion should be considered in cases with an especially high risk of PVR.