Promotion of graft survival by photothrombotic occlusion of corneal neovascularization
G. Corrent, T. J. Roussel, S. C. Tseng and B. D. Watson
Bascom Palmer Eye Institute, Department of Ophthalmology, University of Miami School of Medicine, FL 33101.
Corneal neovascularization may reduce the success of penetrating
keratoplasty. Photothrombosis using intravenous rose bengal and argon laser
irradiation has shown promise for occluding corneal vessels. It is
therefore conceivable that photothrombosis can improve the graft survival
in vascularized corneas. Using intracorneal 7-0 silk sutures as the
stimuli, corneal neovascularization was induced in 1 eye each of 19 New
Zealand white rabbits. Eleven eyes received photothrombosis. Successful
occlusion with subsequent regression was verified by corneal fluorescein
angiography. Three were assigned for observation. Six of 8 eyes receiving
grafts from an outbred rabbit donor after photothrombosis remained clear
during 6.5 to 18.5 weeks of follow-up, while vascularization and opacity
occurred in 7 of 8 control eyes without photothrombosis. These results
indicate that prior photothrombotic occlusion of corneal vessels can
significantly improve graft survival in this experimental model and may
have clinical applications.
