Laser Versus Vitrectomy Versus Intravitreal Triamcinolone Injection for Diabetic Macular Edema

Inclusion Criteria: 1. Patient with type 1 or type 2 diabetes 2. Visual acuity (VA) : 0.1≤ VA \< 0.5 (35 ≤ ETDRS score \< 70) 3. Patient with diffuse diabetic macular edema , as defined by :§ Retinal thickening involving the center of the macular on biomicroscopy§ AND diffuse leakage on fluorescein angiography . 4. Macular thickness in the central area 1000 µm in diameter ³ 300 µm. 5. Patient with :· Either diffuse diabetic macular edema · Or combined diffuse and focal diabetic macular edema with persistent diffuse macular edema 6 months after laser treatment of the focal edema . 6. Systolic blood pressure ≤ 160 mmHg and diastolic blood pressure ≤ 90 mmHg., 7. HbA1c \< 10%. Exclusion Criteria: 1. Patient with tractional diabetic macular edema, as defined by· A taut, thickened posterior hyaloid on biomicroscopy AND/OR· a thickened , highly reflective posterior hyaloid on OCT , partially detached from the posterior pole, and exerting a traction on the macula 2. Active proliferative diabetic retinopathy (ETDRS stage 61 or more severe) 3. Structural damage to the center of the macula in the study eye likely to preclude improvement in visual acuity following the resolution of macular edema, including atrophy of the retinal pigment epithelium, subretinal fibrosis, laser scar(s), or organized central hard exudate plaque³ 1 disk area 4. Hypertensive retinopathy 5. Epiretinal membrane. 6. Rubeosis irides . 7. Patient requiring immediate panretinal photocoagulation or panretinal photocoagulation performed within the past 6 months . 8. History of chronic glaucoma in the study eye 9. History of elevated intraocular pressure ≥30 mm Hg and/or alteration of visual field 10. Concomitant therapy with systemic or topical ocular corticosteroids within the last 15 days . 11. Cataract surgery in the study eye within the past 6 months, Yttrium-Aluminum-Garnet (YAG) laser capsulotomy within the past 6 months, 12. Aphakia 13. Patient with pseudophakic macula edema 14. Unstable medical status including glycemic control and blood pressure. Patients in poor glycemic control who, within the last 4 months, initiated intensive insulin treatment (a pump or multiple daily injections) should not be enrolled. 15. Chronic renal failure 16. Pregnant or nursing (lactating) women