Uses of thrombin in ocular surgery. Effect on the corneal endothelium.

Thrombin is a hemostatic factor that induces platelet aggregation and catalyzes the conversion of fibrinogen to fibrin. The potential for its increasing application to a variety of anterior and posterior segment surgery led us to investigate the in vitro effect of thrombin on the corneal endothelium in a sheep model. We examined freshly excised sheep corneas stained with alizarin red and trypan blue after exposure to two different concentrations of thrombin for four hours. The structure of the corneal endothelium appeared to be intact even after prolonged exposure to thrombin at concentrations of 100 and 1000 U/mL. Thrombin appears to be nontoxic to the corneal endothelium in this experimental model.