Subject(s)
Humans , Postoperative Complications , Vitrectomy , Vitreous Hemorrhage/etiology , Diabetic Retinopathy/surgery , Vitreous Hemorrhage/drug therapy , Preoperative Care , Triamcinolone/therapeutic use , Ocular Hypotension/etiology , Incidence , Risk Factors , Laser Coagulation , Angiogenesis Inhibitors/therapeutic use , Intravitreal Injections , Bevacizumab/therapeutic useABSTRACT
Our previous experimental work with tissue plasminogen activator (TPA) suggested the possibility of the clearance of vitreous hemorrhage by repetitive injections of low-dose TPA. We therefore investigated in rabbits the effect of both repeated injections of TPA and the change of the integrity of the vitreous body on the clearance of vitreous hemorrhage. Vitreous hemorrhage was produced by intravitreal injection of 0.05 ml of autologous whole blood in the pigmented rabbit eyes with intact vitreous or gas-compressed vitreous. Three intravitreal injections of 3-g TPA (total dose of 9 microgram), separated by 7-day intervals, were performed. The endpoint for vitreous hemorrhage clearance was defined as clear visualization of the posterior central retina of the rabbits. Regardless of whether gas compression vitrectomy was performed, repeated injections of low-dose TPA resulted in rapid clearance of fresh vitreous hemorrhage in approximately two to three weeks after the last TPA injection. No evidence of retinal toxicity was seen in all experimental groups. Repetitive injections of low-dose TPA may be effective in the treatment of fresh vitreous hemorrhage.
Subject(s)
Animals , Rabbits , Disease Models, Animal , Injections , Tissue Plasminogen Activator/administration & dosage , Vitreous Body/drug effects , Vitreous Hemorrhage/drug therapyABSTRACT
Tissue plasminogen activator(tPA) is a fibrin-specific fibrinolytic agent that has recently been shown to be effective in accelerating the clearance of hyphema. Intravitreal injection of tPA can promote rapid lysis of experimental intravitreal fibrin clots. The purpose of this study was to investigate the efficacy of intravitreal tPA injection for the treatment of vitreous hemorrhage in normal phakic non-vitrectomized rabbit eyes. Vitreous hemorrhages were produced by intravitreal injections of 0.05 ml of autologous whole blood in 25 rabbit eyes with intact vitreous. The injection of 25 or 100 micrograms of tPA in 15 eyes resulted in the clearance of vitreous hemorrhage in 99 +/- 19 or 34 +/- 6.5 days, respectively. This was significantly faster than in the control eyes in which the clearance was not seen until 131 +/- 17 days later. No tractional retinal detachment was observed.
Subject(s)
Animals , Rabbits , Retina/drug effects , Tissue Plasminogen Activator/therapeutic use , Vitreous Body/drug effects , Vitreous Hemorrhage/drug therapyABSTRACT
Os autores injetaram sangue total no humor vítreo de 16 coelhos. Dezesseis destes foram entäo tratados com metanossulfato de desferrioxamina B intramuscularmente. O seu escopo foi a avaliar o efeito dessa substância sobre o retorno do vítreo a sua transparência original. Os animais foram acompanhados por 16 semanas através de oftalmoscopia e retinografia, após o que os olhos foram encaminhados a exame histopatológico, para investigaçäo da presença de pigmento férrico. Os resultados näo demonstraram diferenças significativas entre os coelhos tratados e o grupo controle