Purpose: To assess the vitreoretinal interface for the occurrence of posterior vitreous detachment after intravitreal injection of triamcinolone acetonide. Methods: This prospective interventional study included 40 eyes of 30 patients, all of them had macular edema due to different underlying diseases: Diabetic Macular edema (n = 29) Retinal vein occlusion (n = 5), Uveitis (n = 6). All eyes were indicated to receive one or more intravitreal injections of Triamcinolone Acetonide (IVTA). Mean injections were 2 (range 1-3). Each eye was injected in a separate session with the same dose (4 mg / 0.1 ml) and same surgical technique. Additional injections were given according to the clinical improvement and resolution of macular edema. Then they were followed for six months after the last injection by fundus biomicroscopy, B-mode ultrasonography and OCT to detect posterior vitreous detachment. All patients completed the study at the six-month visit Results: Posterior vitreous detachment occurred in 13 eyes out of total 40 eyes. It occurred after one month in 5 eyes, after 2 months in 3 eyes, after 3 months in 4 eyes and after 4 months in 1 eye. A significant correlation was found to older age (p=0.008), higher spherical equivalent (p