Ballotini occlusion of retinal arteries. Collateral vessels.

IN a recent communication (Ashton and Henkind, 1965), the details of a method for embolizing retinal arteries in experimental animals were described, and a brief survey of the findings was provided. A most striking effect of arterial occlusion was the subsequent appearance of collateral vascular channels; these were predominantly arteriolar in nature, but in several instances anastomoses between adjacent retinal veins were noted. While such collateral arteriolar channels have occasionally been described in man, particularly following embolic blockage of branch retinal arteries, they have not been reported experimentally. The purpose of this communication is to describe the qollateral vessels seen in the retinae of cats, and to compare them with similar channels noted in human eyes. The relationship between collateral channels in the retina and those noted in other organs will also be discussed. Domestic cats (Felis domestica) were used in this study because their retinal vascular pattern closely resembles that of man.