A new method for vascular occlusion. Photochemical initiation of thrombosis
S. K. Nanda, D. L. Hatchell, J. S. Tiedeman, J. J. Dutton, M. C. Hatchell and T. McAdoo
A new photochemical method has been used to produce focal thrombosis and
occlusion of the blood vessels on the surface of the myelin wings of rabbit
retinas. Following intravenous injection of rose bengal, the vessels next
to the disc on the nasal wing were exposed to filtered light (550 nm, the
absorption maximum of rose bengal) for four minutes. As a control, the
vessels on the temporal wing of each rabbit eye were exposed to filtered
light for four minutes before the injection of rose bengal. Complete
vascular occlusion was produced on the nasal wing in all eyes, with no
visible alterations on the temporal wing. Progressive reopening of the
arteries on the nasal wing was observed at three days, with reopening of
the veins visible by seven days. Reperfusion of capillaries had occurred by
21 days. Light and electron microscopic examination of blood vessels on the
nasal wing after light exposure with rose bengal showed disrupted
endothelial cells in all exposed blood vessels and platelet aggregates in
the arteries and arterioles. No morphologic abnormalities were observed in
the temporal wings. This method should be useful in studying the effects of
vascular occlusion in the retina and could lead to a new treatment modality
for subretinal, iris, or corneal neovascularization.
