MAR 25, 2014
This prospective study found that intracameral recombinant tissue plasminogen activator (r-tPA) is safe and effective for the treatment of refractory fibrin reaction after cataract surgery.
The use of r-tPA, a serum protease activated by fibrin, is based on the rationale that catalyzing the conversion of plasminogen into plasmin induces fibrin breakdown into fibrinogen and disappearance of the fibrin reaction.
Subjects included 40 patients (40 eyes) who developed anterior chamber fibrin reaction after cataract surgery and failed to respond to intensive topical and subconjunctival steroids. R-tPA injection (25 µg/0.1 mL) was administered a mean of 20.3 days postoperatively (range, 10 to 49 days).
One day after treatment, 80 percent achieved complete clearance of the fibrin reaction, while 20 percent achieved partial clearance. At one month, the reaction completely resolved in 95 percent of patients. Mean visual acuity improved from 0.61 ± 0.38 logMAR before treatment to 0.45 ± 0.37 logMAR one month later (P = 0.06).
The authors note that despite the high rate of complete resolution of the fibrinous reaction after just one day, visual acuity improvement was documented only at one week and one month of follow-up. Indeed, visual acuity was slightly worse at the one-day examination compared with the preoperative value. The authors assume this is due to the presence of inflammatory mediators in the anterior chamber soon after r-tPA injection.
They conclude that intracameral application of r-tPA hastens fibrin absorption and may help to avoid the complications associated with long-standing intraocular inflammation. Further investigations are needed to determine the optimal dosage and long-term effect of treatment, including changes in corneal endothelial cell counts.