Evaluation of the Role of Intravitreal Tissue Plasminogen Activator in Treatment of Refractory Diabetic Macular Edema

Inclusion Criteria: 1. type 2 diabetes 2. Non proliferative diabetic retinopathy(NPDR) stage of diabetic retinopathy 3. patients with refractory DME CSME (patients with the last MPC at least 3 months before and no improvement was observed in BCVA, macular thickness inOCT, clinical examination and fundus photographs of patients ) 4. Absence of PVD in the B-scan 5. Absence of PVD in OCT of macular area and optic disk 6. Absence of PVD in slit lamp biomicroscopy(SLE) 7. the last PRP session was at least 3 months ago. 8. Absence of traction on macula in clinical examination and OCT Exclusion Criteria: 1. One eye patients 2. Patients who are candidates for intraocular surgery. 3. Patients with the history of glaucoma or ocular hypertension 4. Patients with a history of vitrectomy in the study eye 5. Not being able to refer for the next visits 6. Eyes with cataract that makes the assessment of the macula impossible. 7. Intraretinal hemorrhage at fovea that will interfere with OCT. 8. BCVA ≤ 0.1