Effects of silicone oils on corneal endothelial permeability

Silicone oils, varying by viscosity and manufacturer, were infused into rabbit anterior chambers. Polydimethyl-siloxane oil, 5000 cps, increased corneal endothelial permeability to inulin (mw 5000) and dextran (mw 60000) when measured in vitro at 1, 4 and 7 days after ocular infusion. The effects of five other oils were measured at 7 days after infusion. Four of the oils increased endothelial permeability and induced similar morphological changes. Dow Corning Medical Fluid 360 had no effect on either permeability or morphology of the endothelium. These results show that contact of most silicone oils with corneal endothelium rapidly induces physiological and morphological changes. If these oils, when used as a retinal tamponade, gain access to the cornea they should be removed quickly to avoid the rapid initiation of physiologic changes.