EXPERIMENTAL STUDIES ON THE VITREOUS: I. Experiments on Diffusion in the Vitreous and on Permeability of Its Surface Condensation Layer

CLINICAL experience and scattered experimental data indicate that diffusion in the vitreous is slow.¹ These observations were confirmed in systematic studies of Fischer² on diffusion of hemoglobin in arbitrarily divided samples of vitreous and in examinations on spreading of penicillin after intravitreal injection in the living eye.³ New information on this subject was gained by Kinsey, Grant and Cogan⁴ in determining the total movement of vitreous water, with deuterium oxide (heavy water; D²O) as a tracer substance. The authors concluded from their experiments that the movement of water in the rabbit vitreous was of a magnitude of about 85 cu. mm. per minute. Studies on the eye with radioactive sodium (Na²⁴) autographs⁵ provided instructive photographic imprints on diffusion of this normal body constituent in rabbit eyes under physiologic conditions. It was distributed homogeneously throughout the vitreous two to four hours after intraperitoneal