Coagulation properties of intraocular humors and cerebrospinal fluid

Clinical observations indicated a prompt cessation of episcleral capillary bleeding after exposure of those tissues to aqueous humor during intraocular surgery. Based on this observation, both aqueous and vitreous humors were obtained from eyes provided by an eye bank and from human eyes prior to intraocular surgery. Samples of cerebrospinal fluid also were obtained from two patients, one with optic atrophy and another with nutritional amblyopia. A total of 49 specimens were studied. Aqueous humor shortened the average ear lobe puncture bleeding time from 4.74 +/- 0.2 to 1.13 +/- 0.1 minutes. Varying dilutions of aqueous humor, up to a dilution of 1:16, shortened prothrombin and partial thromboplastin times when compared with normal control plasma without aqueous. Vitreous humor shortened partial thromboplastin time but had no effect on prothrombin time. The effect of cerebrospinal fluid on prothrombin and partial thromboplastin times was similar to the aqueous, but to a lesser degree.