Background Retinal vascular disorders, such as diabetic retinopathy, hypertensive retinopathy, retinal hemorrhage, and retinal vein occlusion are significant causes of vision impairment and blindness worldwide. Diabetic retinopathy (DR) is the most common retinal vascular disorder and is the leading cause of vision loss among patients aged 25 to 74 years.

Aim to compare formulated Posterior Subtenon Triamcinolone acetonide (PSTA) injection versus Posterior Subtenon Triamcinolone acetonide alone versus suprachoroidal triamcinolone in the management of diabetic macular edema.

Inclusion Criteria:

• Diminution of vision due to diabetic macular edema.
• CMT ≥ 250 µ.
• Willing to participate in the study.

Exclusion Criteria:

• Unwilling to participate in the study, 2)
• Ischemic RVO,
• previous laser treatment
• Glaucoma, macular ischemia, cataract, vitreous hemorrhage, and neovascularization of the iris,
• patients with previous anti VEGFs or steroid injections or any eye surgery three months before the inclusion,
• Cardiac co-morbidities result in significant hemodynamic changes, 7)Respiratory diseases need treatment with antibiotics,
• Suffering from other chronic diseases as diabetes,
• Patient with allergy from triamcinolone acetonide.