Neovascularization from the scleral wound as the cause of vitreous rebleeding after vitrectomy for proliferative diabetic retinopathy
Sawa, H.; Ikeda, T.; Matsumoto, Y.; Niiya, A.; Kinoshita, S.
Nippon Ganka Gakkai Zasshi 102(3): 200-206
1998
ISSN/ISBN: 0029-0203 PMID: 9558843 Document Number: 489272
Vitreous hemorrhage recurred in 11 eyes out of a series of 120 eyes treated by vitrectomy for proliferative diabetic retinopathy during a 10-month period. Neovascularization from the scleral wound, or fibrovascular proliferation, was identified as the cause of rebleeding in 4 eyes from findings during revitrectomy. None of the 4 eyes showed retinal disorders attributable as the cause of rebleeding. Rebleeding in these 4 eyes developed after an average of 9.0 weeks after initial surgery. The proliferative membrane was oval in shape and expanded from the residual vitreous which had been incarcerated in the scleral wound. The proliferative membrane obtained during revitrectomy was poor in cellular components and contained extracellular matrix. Blood vessels of various sizes were also present. Electron microscopically, the membrane was rich in extracellular components. It contained two types of cells, i.e., high and low electron density cells. These cells often had microvilli and seemed to be of epithelial origin. The findings show that vitreous rebleeding may develop from fibrovascular proliferation from the scleral wound after diabetic vitrectomy. the proliferated membrane showed histological similarities with the fibrovascular proliferation usually seen in the diabetic retina and may represent a type of anterior proliferation secondary to retinal ischemia.