Microendoscopy of the anterior segment vasculature in the rabbit eye

Intraocular microendoscopy is introduced as a new method which allows a direct in vivo observation of the microvasculature of the eye. Using video equipment, a quantitative evaluation of changes in vessel diameters, e.g. after administration of vasoactive agents, and an estimation of blood oxygenation are possible. Experimental studies with fluorescent dyes can also be performed using special filters. In albino rabbits, no apparent vascular disturbances were observed under certain experimental conditions. Touching a ciliary process with the tip of the endoscope immediately resulted in a vasodilation and stoppage of blood flow, surprisingly in the affected area only. After epinephrine, the locally traumatized ciliary processes remained unchanged while the vessels of the neighboring ciliary processes constricted intensely. After reduction of the intraocular pressure the major ciliary processes began to swell. A leakage of fluorescein-dextran was only found in the iridial ciliary processes.