Vitrectomy for diabetic macular edema with posterior subtenon injection of triamcinolone acetonide

Purpose: To assess the efficacy and safety of posterior subtenon injection of triamcinolone acetonide (TA) for diabetic macular edema (DME). Methods: Forty-three eyes (43 patients) with DME scheduled to undergo vitrectomy (Vit) were randomly assigned to one of 2 groups, Vit with TA (Vit+TA) or Vit without TA (Vit). The 22 eyes in the Vit+TA group received a posterior subtenon injection of TA during surgery. The 21 eyes in the Vit group did not receive an injection of TA. Visual acuity (VA), foveal thickness (FT), intraocular pressure (IOP), and blood glucose level (BGL) were measured before and after surgery and differences were analyzed for statistical significance (p<0.05) by Student's t-test. Results: Recovery of VA was faster in the Vit+TA group than in the Vit group. However, there was no significant difference between the 2 groups in VA at 6 months after surgery. FT was decreased in both groups after surgery, and at 1 month after surgery FT was significantly less in the Vit+TA group than in the Vit group. In the Vit+TA group, IOP 1 week after surgery was significantly higher than preoperative IOP (p=0.02), and the BGL the day after surgery was somewhat higher than preoperative BGL (p=0.06). Conclusion: Intraoperative posterior subtenon injection of TA may be useful to decrease macular edema and to improve VA within 1 month after vitrectomy for DME. However, intraoperative TA injection may lead to increased IOP and BGL postoperatively. Patients who have undergone Vit+TA for DME should be followed carefully after surgery.