Meridional Flow From the Corona Ciliaris Through the Pararetinal Zone of the Rabbit Vitreous

¹ Department of Ophthalmology, College of Medical Science, University of Minnesota, Minneapolis, Minn.

From the data we have obtained we are led to the conclusion that in the in vivo rabbit eye there is a stream of fluid in the pararetinal vitreous flowing posteriorly from the corona ciliaris. This flow occurs in a well-ordered pattern best described as a meridional floto pattern. Fluid, moves from this stream through the retina apparently in extracellular spaces but faster and with a different pattern than is observed under conditions which presumably favor diffusion into the retina. The difference of formazan distribution in the retinal epithelium compared to the formazan staining pattern in the overlying tissue leads to the hypothesis that the retinal epithelial cells may be secreting a fluid, into the choroidal blood. In addition there appears to be a well-ordered unidirectional diffusion field, of fluid, from the corona ciliaris to all points of the retina. This field is well ordered in the sense that it is approximately parallel to the sides of a cone with a base in the plane of the equator of the lens and, an apex on the optic axis near the retina. Within such a cone the moveinent most often observed was that ivhich one would expect from diffusion of the tracer unaltered, by flow or unidirectional diffusion of the solvent. Both the meridional flow and the diffusion field require the integrity of the blood supply to the eye since appreciable posteriorly oriented, movement of the injected tracer was not observed in eyes injected in situ in the isolated head.

Note:
Supported by funds of the Hill Foundation Research Professorship in Ophthalmology (1960-1961).