Ocular blood flow in dogs using radiolabelled microspheres.

We used radioactive microspheres of different sizes to determine the rate of blood flow through the various parts of the eye in dogs. The use of either 15 +/- 5 microns or 25 +/- 5 microns microspheres gave reproducible measurements of total ocular and uveal blood flows. Using these sphere sizes, retinal flow was found to be close to 1% of the total ocular blood flow and showed poor reproducibility due in part to the small number of spheres trapped in the retinal vessels.