Neovascularization in experimental retinal venous obstruction in rabbits.
OBJECTIVE
To investigate the later pathohistological changes in experimental retinal venous obstruction in rabbits.


METHODS
Experimental retinal venous obstruction was produced in retinal blood vessels of rabbits by trans-adventitial dropping of thrombin. Fundus observation was performed 3 months and 1 year thereafter. Retinal histological examinations were performed by fluorescein microscopy, light microscopy, and transmission electron microscopy.


RESULTS
Vessels with a rete mirabile and arteriovenous anastomosis were observed after 3 months. On a flat gelatin-fluorescein preparation, regions with no perfusion, thought to be areas of vascular occlusion in the periphery, were observed extensively. Clear leakage of gelatin-added fluorescein was noted from vessels in the periphery, and minute neovascularization with a rete mirabile from these vessels was confirmed. Newly formed retinal vessels were also observed by transmission electron microscopy. The endothelial cells of these newly formed vessels had a large nucleus, a number of ribosomes, and thin basement membrane. Proliferative changes included glial cells that had penetrated into the basement membrane of ghost vessels.


CONCLUSIONS
Our long-term observations confirmed that proliferative changes and neovascularization occurred in this model of retinal venous obstruction.
Tamura
M
M
Department of Ophthalmology, Hirosaki University School of Medicine, Hirosaki, Aomori, Japan.
D000818:Animals; D001485:Basement Membrane / Q000648:ultrastructure; D002199:Capillary Permeability; D002467:Cell Nucleus / Q000648:ultrastructure; D004730:Endothelium, Vascular / Q000648:ultrastructure; D005451:Fluorescein Angiography; D005654:Fundus Oculi; D023421:Models, Animal; D011817:Rabbits; D015861:Retinal Neovascularization / Q000175:diagnosis / Q000209:etiology*; D012169:Retinal Vein / Q000187:drug effects / Q000473:pathology; D012170:Retinal Vein Occlusion / Q000139:chemically induced / Q000150:complications*; D012270:Ribosomes / Q000648:ultrastructure; D013917:Thrombin / Q000633:toxicity
D013917:Thrombin