Purpose to compare Posterior Subtenon Triamcinolone acetonide (PSTA) injection either formulated or alone versus suprachoroidal triamcinolone in the management of diabetic macular edema.Methods This study is a prospective interventional study included 75 patients, divided into three groups, each group 25 patients. Group I received a combination of Triamcinolone Acetonide (TA) (40 mg) and VISCOAT, which a combination of sodium chondroitin sulfate (20 mg) and sodium hyaluronate (15 mg). The injection was done in the posterior subtenon space using NAGATA canula. Group II received TA (40 mg) in the posterior subtenon space. Group III underwent injection of 4 mg/100µl of TA in the supra choroidal space.Results We found a statistically significant difference between the three studied groups as regarding to BCVA and CMT at six months postoperative with highest median BCVA and lowest median CMT was observed in the formulated TA group. Conclusion We concluded that early treatment of DME by formulated TA is better than TA alone, and suprachoroidal TA in the form of increasing the BCVA and decreasing the CMT without any elevation of IOP.Trial registration number NCT05464953Date of registration 17/7/2022 (retrospectively registered)