fibrin and Hyphema

to evaluate the efficacy and the safety of low dose intraocular tissue plasminogen activator (rt-PA) in the treatment of traumatic hyphema and postoperative fibrinous membrane.. Six microg to 10 microg of rt-PA was injected into the anterior chamber to treat severe fibrinous postoperative membranes and total traumatic hyphemae.. Thirteen eyes of 13 patients were treated. Four cases of traumatic hyphema and 9 cases of fibrinous membranes were included. Complete fibrinolysis within 24 hours was observed in 4 cases (30.8%). A partial success was noted in 7 eyes (53.8%). No beneficial effect was observed in two cases of traumatic hyphema associated with intravitreal hemorrhage after penetrating trauma. No side effect attributable to rt-PA occurred.. Low dose intraocular rt-PA appears to be safe and effective in the treatment of postoperative fibrinous membrane and endocular hemorrhage limited to the anterior chamber.

Topics: Adolescent; Adult; Aged; Child; Eye Injuries; Female; Fibrin; Fibrinolytic Agents; Humans; Hyphema; Inflammation; Male; Middle Aged; Ophthalmologic Surgical Procedures; Postoperative Complications; Recombinant Proteins; Tissue Plasminogen Activator

to evaluate the efficacy and the safety of low dose intraocular tissue plasminogen activator (rt-PA) in the treatment of traumatic hyphema and postoperative fibrinous membrane.. Six microg to 10 microg of rt-PA was injected into the anterior chamber to treat severe fibrinous postoperative membranes and total traumatic hyphemae.. Thirteen eyes of 13 patients were treated. Four cases of traumatic hyphema and 9 cases of fibrinous membranes were included. Complete fibrinolysis within 24 hours was observed in 4 cases (30.8%). A partial success was noted in 7 eyes (53.8%). No beneficial effect was observed in two cases of traumatic hyphema associated with intravitreal hemorrhage after penetrating trauma. No side effect attributable to rt-PA occurred.. Low dose intraocular rt-PA appears to be safe and effective in the treatment of postoperative fibrinous membrane and endocular hemorrhage limited to the anterior chamber.

Topics: Adolescent; Adult; Aged; Child; Eye Injuries; Female; Fibrin; Fibrinolytic Agents; Humans; Hyphema; Inflammation; Male; Middle Aged; Ophthalmologic Surgical Procedures; Postoperative Complications; Recombinant Proteins; Tissue Plasminogen Activator

To determine the maximum tolerated dose (MTD) of enoxaparin, a low molecular weight heparin (LMWH) was used during repeat vitrectomy for rhegmatogenous retinal detachment with proliferative vitreoretinopathy (PVR) and severe diabetic retinopathy.. From 25 patients, 29 eyes undergoing repeat vitrectomy for PVR (CP3 or greater) or severe diabetic retinopathy were included in the study. Patients had previously undergone an average of 2.1 previous vitrectomies (range 1-5). Enoxaparin was added to the infusion fluid in an escalating dose from 0.1 IU/ml to 6.0 IU/ml as tolerated. Intraoperative bleeding, postoperative fibrin, hyphema and vitreous hemorrhage were graded in an unmasked fashion using previously described grading scales.. All patients completed the study, and the study was able to achieve the 6.0 IU/ml maximum dose on the dose escalation schedule. No patient experienced dose-limiting toxicity. Analysis showed no increase in intraoperative bleeding complications between low dose (1.0 IU/ml) enoxaparin (Mann-Whitney Test, P=0.029).. Enoxaparin dose escalation did not result in a dose-dependent increase in acute side effects. The establishment of a well-tolerated dose of enoxaparin during repeat vitrectomy for PVR and severe diabetic retinopathy (6.0 IU/ml) provides a foundation for future studies.

Topics: Diabetic Retinopathy; Enoxaparin; Female; Fibrin; Fibrinolytic Agents; Humans; Hyphema; Infusion Pumps; Intraoperative Complications; Male; Maximum Tolerated Dose; Middle Aged; Prospective Studies; Reoperation; Vitrectomy; Vitreoretinopathy, Proliferative; Vitreous Hemorrhage

To report the use of intracameral urokinase for dissolving fibrin or blood clots after glaucoma surgery.. Four eyes of four patients who had undergone glaucoma surgery developed an anterior chamber fibrin or blood clot and increased intraocular pressure. Urokinase was injected into the anterior chamber in each patient to dissolve the clot.. In all cases, urokinase injection resulted in reduction of intraocular pressure. No adverse effects of urokinase injection were detected during the short follow-up period.. Urokinase may be a safe, inexpensive, and convenient alternative to tissue plasminogen activator for dissolving fibrin or blood clots after glaucoma surgery. Additional studies are warranted to evaluate the long-term safety of intracameral injection.

Topics: Aged; Anterior Chamber; Fibrin; Fibrinolysis; Glaucoma, Neovascular; Humans; Hyphema; Injections; Intraocular Pressure; Male; Middle Aged; Plasminogen Activators; Thrombolytic Therapy; Urokinase-Type Plasminogen Activator

Tissue plasminogen activator (tPA) has been used to treat severe postcataract and vitrectomy fibrinous membranes, but intraocular bleeding has occurred with doses of 25 micrograms or higher. We report three patients, one with nonclearing total hyphema and uncontrollable intraocular pressure and two with severe fibrinous membrane formation, who had treatment with low-dose (4 micrograms to 6 micrograms) intraocular tPA. Although the fibrinous membranes or hyphema resolved in all three patients, they recurred and bleeding that required additional treatment occurred in one patient. Intraocular low-dose tPA may minimize the risk of corneal and retinal toxicity and may be considered an alternative treatment in intractable cases. However, secondary intraocular hemorrhage can occur, and the timing between the initial vascular injury, treatment with tPA, and subsequent bleeding may reduce the risk of further hemorrhaging.

Topics: Adult; Aged; Anterior Chamber; Cataract Extraction; Child; Cornea; Corneal Injuries; Eye Diseases; Eye Injuries, Penetrating; Fibrin; Humans; Hyphema; Injections; Keratoplasty, Penetrating; Male; Postoperative Complications; Recombinant Proteins; Tissue Plasminogen Activator

Tissue plasminogen activator is a potent thrombolytic agent that recently has been used to treat postvitrectomy fibrin formation. However, a recent report noted anterior and posterior segment bleeding following intracameral tissue plasminogen activator injection. In this study, we performed lensectomy and vitrectomy in 20 rabbits. A retinal blood vessel was incised to stimulate intraocular hemorrhage; bleeding was controlled and vitreous hemorrhage aspirated. Postoperatively, one eye received a 0.1-mL injection of tissue plasminogen activator (25 micrograms); the other received balanced salt solution. The eyes receiving tissue plasminogen activator had a 28% incidence of increased anterior chamber blood and a 61% incidence of increased intravitreal blood. There was no evidence of postinjection bleeding in eyes receiving balanced salt solution. Most cases of bleeding occurred within 24 hours of tissue plasminogen activator injection. Administration of tissue plasminogen activator in the setting of segmented blood vessels may lead to intraocular hemorrhage.

Topics: Animals; Fibrin; Hyphema; Lens, Crystalline; Postoperative Care; Rabbits; Random Allocation; Retinal Hemorrhage; Tissue Plasminogen Activator; Vitrectomy; Vitreous Hemorrhage

To characterize the pathophysiology of hyphema clearance, we studied changes in the facility of outflow in experimental hyphema in freshly enucleated rabbit eyes. Hyphemas, with washed normal or sickled red cells (RBCs) (suspended in isotonic phosphate buffer to obtain a hematocrit value comparable to that of whole blood) and occupying 50% to 100% of the anterior chamber volume, caused a marked cell "crowding" in the chamber angle and an increase in the outflow resistance; the facility stabilized at a value 60% lower than the control (p = < 0.001). No significant change in outflow facility was observed in hyphemas of either RBC type occupying 25% of the anterior chamber volume (p = N.S.). Whole blood hyphema occupying 50% of the anterior chamber volume reduced the facility of outflow by 80% of the control mock aqueous value (p = < 0.001); a comparison with 50% hyphema produced by washed RBCs indicated a significant contribution by the plasma (fibrin) component (p = 0.0025) in increasing the resistance to outflow.

Topics: Anemia, Sickle Cell; Animals; Anterior Chamber; Aqueous Humor; Erythrocytes; Fibrin; Humans; Hyphema; Intraocular Pressure; Rabbits