Therapeutic Efficacy of Intravitreal Injection of Tissue Plasminogen Activator for Macula Edema Due to Central Retinal Vein Occlusion

Abstract

Purpose: : To evaluate the therapeutic efficacy of intravitreal injection of tissue plasminogen activator (tPA) for macular edema (ME) due to a central retinal vein occlusion (CRVO).

Methods: : Twenty one eyes of 21 patients with a CRVO–associated ME were treated with an intravitreal injection of tPA. The estimated duration of symptoms ranged from 2 to 24 weeks (mean 8 weeks). The tPA (40,000 units of monteplase) was injected into the vitreous cavity through the pars plana with a 30G needle following paracentesis. The best–corrected visual acuity (BCVA), OCT–determined foveal thickness, fluorescein angiography, and full–field electroretinography (ERG) were measured before and 1 week, 1, 3 and 6 months after tPA.

Results: : The BCVA was improved by more than 2 lines in 13 eyes (62%) and remained stable in 4 eyes (19%) at 6 month postoperatively. The ME was temporary increased in 4 eyes (19%) at 1month after tPA but was markedly reduced in all eyes at 6 months after the tPA injection. The preoperative mean foveal thickness was 776 µm which was significantly reduced to 499 µm at 1 week, 449 µm at 1 month, 368 µm at 3 month and 275 µm at 6 month postoperatively. The a– and b–wave amplitudes of the rod–cone ERG were significantly reduced at 1 month after tPA. The photopic b–wave amplitudes were reduced at 1 and 3 months after tPA injection.

Conclusions: : Intravitreal injection of tPA may be effective for treating ME associated with a CRVO but may be toxic to the retina. Additional careful investigations are needed to show the advantage of tPA over the natural course.

Keywords: vascular occlusion/vascular occlusive disease • electroretinography: clinical • vitreous