Provoked iris ischaemia in the rabbit: A fluorescien angiographic study.

We studied experimental anterior segment ischaemia in rabbits by fluorescein angiography of the iris. Nine rabbits were subjected to diathermy occlusion of one or both long posterior ciliary arteries or to disinsertion and reattachment of up to 4 rectus muscles. Occlusion of one LPCA or up to 3 recti had only a minor ischaemic effect on the iris vessels. Occlusion of both LPCAs produced necrosis of the anterior segment or ischaemia of the iris detectable by angiography. Disinsertion of 4 recti produced small patches of transient ischaemia in those areas of the iris most distal from the LPCAs. When further surgery is planned after retinal detachment cyclodiathermy or strabismus operations, fluorescein angiography is a useful indicator of the vascular status of the iris and hence of the possibility of necrosis of the anterior segment.