2005-14: rt-PA administration by retinal branch vein route for Central Retinal Vein Occlusion (CRVO) - A Randomized - Conventional Therapy controlled - Trial
Central retinal vein occlusion (CRVO) is a frequent retinal disorder. In the literature ischemic CRVO (iCRVO) and non-ischemic CRVO with an initial visual acuity of lower than 0.1 Snellen have a poor chance to improve visual acuity. At this moment no curative treatment is available. Current therapy is aimed at the prevention of neovascular glaucoma. Preliminary results by Weiss et al. suggest a benefit, i.e. improvement of visual acuity, by branch retinal vein cannulation with injection of 4 ml of 200 μg/ml rt-PA, a potent thrombolytic agent. In ischemic stroke or acute myocard infarction, a dose of 100 mg rt-PA is routinely administrated by IV perfusion. In the reports using the intra-retinal vein injection of a total dose of 0.8 mg rt-PA, no extra-ocular adverse effects were noted. The studies published are non-controlled, non-randomized case series, in which it is unclear if spontaneous resolution of non-ischemic CRVO (with a visual acuity higher than 0.1, which is known to improve spontaneously) confounds results. Regarding the frequency of the disease, the poor visual acuity outcome, the lack of curative treatment, and the promising results of non-controlled case series, a rigorous prospective randomized study of the described technique is indicated. In this phase, only the patients with minimal chance of visual acuity improvement, (i.e. the patients with a initial visual acuity of less than 0.1), are included in the study.