Purpose: To determine whether pretreatment with intravitreal triamcinolone acetonide (IVTA) before laser photocoagulation is effective in eyes with diabetic macular edema (DME).
Methods: The study was a prospective, double-masked, placebo-controlled, clinical trial of eyes with DME and impaired vision (<or=20/40) randomized to IVTA 4 mg versus placebo 6 weeks before laser treatment. The main outcome measure was the proportion of eyes with improvement of best-corrected logarithm of minimum angle of resolution (logMAR) visual acuity of >or=5 letters after 6 months. Secondary outcomes were necessity of further treatment, change in central macular thickness, and incidence of adverse events.
Results: Eighty-four eyes of 54 participants were entered into the study, with 6-month data available for 81 (96%) of 84 eyes. Improvement of >or=5 logMAR letters was similar in eyes treated with IVTA before laser as placebo (18/42 [43%] IVTA vs. 16/34 [38%] laser alone; P = 0.807), as were retreatment rates at 6 months (22 [56%] IVTA vs. 21 [53%] laser alone; P = 0.727). Mean central macular thickness decreased by 50 microm (95% confidence interval, 10-96 microm) more in the IVTA treatment group than in the laser-alone group after 6 months (P = 0.016). Glaucoma therapy was necessary more frequently in IVTA-treated eyes than in those treated with laser alone (19/42 [45%] vs. 7/42 [17%]; P = 0.005).
Conclusions: Visual results and the need for further laser treatment at 6 months were no better in the IVTA group than in the laser-alone group, despite a better anatomic outcome reflected by reduction in mean central macular thickness. This study found no evidence of a synergistic effect of IVTA and laser photocoagulation for DME. (ClinicalTrials.gov number, NCT00148265).