Objective: To evaluate the feasibility of conducting a randomized, controlled trial of thrombolytic therapy for central retinal vein occlusion (CRVO) using tissue plasminogen activator (TPA); to establish relative efficacy and safety of various dosing regimens.
Design and patients: Ninety-six patients with CRVO were treated with TPA between May 1986 and December 1992. Prior to patient enrollment, a standardized, detailed protocol was developed for evaluation and treatment of all patients. This included standard protocols for determining eligibility, reporting complications, performing photography and electroretinography, and measuring visual acuity.
Main outcome measures: Best corrected visual acuity at 6 months, systemic and ophthalmic treatment complications.
Results: At 6 months' follow-up, 42% (n = 89) of eyes gained three or more lines of vision from pretreatment levels (average gain, 5.1 lines), 37% remained stable, and 21% lost three or more lines. Of eyes with 20/100 or worse pretreatment vision (n = 32), 59% gained three or more lines vision (average gain, 6.4 lines), 31% remained stable, and 9% lost three or more lines. One patient suffered a fatal stroke. Three patients developed intraocular bleeding during TPA administration.
Conclusion: Thromobolytic therapy with TPA appears to be a promising, albeit risky, new treatment; conclusive evaluation of safety and efficacy awaits a multicenter, randomized, clinical trial; feasibility of such a trial has been established by this study.