This 75YO female presented with an acute counting fingers central retinal artery occlusion. Triton color imaging shows a small area of papillomacular sparing, and swept-source OCT shows inner retinal hyperreflectivity. The retinal opacification completely resolved 10 weeks later with the development of extensive disc collaterals. Vision at counting fingers.
Learning Points:
Collateral vessels are dilated, pre-existing vessels that bypass an occlusion. These are seen in the posterior pole most commonly following retinal venous occlusions. Disc collaterals are exceedingly rare with arterial occlusions and were first described by Nettleship in 1891 (Ragge and Hoyt, Br J Ophthalmology 1992;76:186-188). The endothelial tight junctions are intact so they don’t leak angiographically. This helps to differentiate them from neovascularization which does leak.
