We have a range of in vitro preparations for studying the anatomy, physiology and pharmacology of different components of the ocular circulation. At the smallest end of the scale we are able to study the vasoactive properties of individual retinal vessels.
Tiny tubes are inserted into either end of the vessel and test solutions are passed through the vessel in much the same way that blood normally flows. This is technically very demanding since the vessels are typically only 100 microns in diameter.
Potentially vasoactive drugs can be added into the perfusing solution and the effects on the diameter of the vessel determined.