Purpose: To evaluate the effects of intravitreal injection of recombinant tissue plasminogen activator (TPA) for the treatment of refractory diabetic macular edema. Methods: A total of 27 patients with refractory diabetic macular edema with no evidence of posterior vitreous detachment were randomly assigned into follow-up (F/U) or TPA treatment groups. To control for the effects of intravitreal injection, an additional 14 patients with diabetic macular edema who were candidates for first-time intravitreal bevacizumab injection were enrolled as the IVB group. For the TPA and IVB groups, 25 mu g of TPA or 1.25 mg of bevacizumab, respectively, were intravitreally injected. Fundoscopy, optical coherence tomography, and B-scan ultrasonography were performed at 1 week, 1 month, and 3 months after initiation of the study. Results: The incidence of posterior vitreous detachment in fundoscopy over the follow-up period was 69.2% in the TPA group, which was significantly higher than that of the F/U and IVB groups (P = 0.001). Best-corrected visual acuity and changes in macular thickness did not significantly differ between the TPA and F/U groups over the 3-month period. Conclusion: Intravitreal TPA injection induces posterior vitreous detachment in patients with diabetic macular edema refractory to standard treatment but has no effect on macular thickness or best-corrected visual acuity within 3 months. RETINA 31:2065-2070, 2011