A simple staining method for blood vessels in flat preparations of ocular tissues.

We describe a technique for light microscopic visualization of the vasculature of the retina, choroid, ciliary body, and iris in flat preparations. The technique is based on the intravenous injection of horseradish peroxidase, the histochemical demonstration of this enzyme's activity, and the bleaching of the melanin that hinders the visualization of the injected vessels. This technique is reproducible and much simpler than other available methods in which dyes suspended in different media are injected directly into the ocular vessels.