A Randomized Trial Comparing Suprachoroidal and Intravitreal Injection of Triamcinolone Acetonide in Refractory Diabetic Macular Edema due to Epiretinal Membrane

PURPOSE: To compare the efficacy and safety of suprachoroidal and intravitreal injection of triamcinolone acetonide in pseudophakic patients with refractory diabetic macular edema (DME) due to epiretinal membrane (ERM). Study Design. This study is a randomized clinical trial (RCT). Participants. Twenty-three nonvitrectomized pseudophakic eyes of 23 subjects (9 M and 14 F with mean age: 54.8 years) with refractory DME due to ERM. METHODS: The eyes were randomized to suprachoroidal triamcinolone acetonide injection 4 mg/0.1 ml (SCTA) (n = 13 eyes) or intravitreal triamcinolone acetonide 4 mg/0.1 ml (IVTA) (n = 10 eyes) and were evaluated at baseline and 1 and 3 months after injection to assess outcome measures. Main Outcome Measures. Changes in best-corrected visual acuity (BCVA) (primary outcome), central foveal thickness (CFT) by optical coherence tomography (OCT), and intraocular pressure (IOP) measurement (secondary). RESULTS: Baseline median BCVA (logMAR) was 1.0 (range 0.8–1.0) in both groups, improved within the SCTA group to 0.8 on the 1(st) and 3(rd) months, while in the IVTA group, median BCVA changed to 0.8 and 0.9 on the 1(st) and 3(rd) months, respectively. No significant differences were noted between groups regarding BCVA at baseline (P=0.927), and 1(st) (P=0.605) and 3(rd) months (P=0.313). Regarding mean CFT, no significant differences were observed at baseline (P=0.353) and at the first month (P=0.214) between both groups, while at the third month, CFT was significantly higher in the IVTA group (385 um) than in the SCTA group (323 um) (P=0.028). Mean IOP was significantly higher in the IVTA group (15 mmHg) on 1(st) month than in the SCTA group (12 mmHg) (P=0.011); after 3(rd) month, IOP was significantly higher within the IVTA group (18 mmHg) than SCTA (14 mmHg) (P=0.028). No significant difference was noted between both groups at baseline IOP (P=0.435). CONCLUSIONS: Both SCTA and IVTA are effective in reduction of CFT and improvement of patients' visual acuity, but with a higher recurrence rate and rise in IOP after IVTA when compared to SCTA. Both treatments have temporary effects with the possibility of recurrence of DME and the need for retreatment.