ISIS-DME - A prospective, randomized, dose-escalation intravitreal steroid injection study for refractory diabetic macular edema

Purpose: To determine safety and efficacy of intravitreal triamcinolone acetonide (IVTA) for refractory clinically significant diabetic macular edema (DME). Design: Prospective, randomized, dose-escalation pilot study comparing single injection of 2 mg versus 4 mg doses of IVTA. Methods: Inclusion criteria included clinically significant DME persisting >= 3 months after maximal laser treatment and visual acuity <= 20/40. Best-corrected ETDRS vision, intraocular pressure, presence of DME, and fluorescein angiography (FA) were evaluated at 3 months and 6 months after injection. Results: Mean change in visual acuity at 3 months compared to baseline was 7.1 letters (P = 0.01) in the 2 mg group and 12.5 letters in the 4 mg group (P < 0.0001). However, there was not a significant difference in visual improvement between the 2 mg and 4 mg dose groups (P = 0.11). Vision improved >15 letters at 3 months in 23% (3/13) of 2 mg group and in 33% (5/15) of 4 mg group (P = 0.69), and 0% (0/11) and 21% (3/14) at 6 months, respectively (P = 0.23). Visual improvement was more likely in cystoid-type DME than diffuse DME. Intraocular pressure rise of >10 mmHg occurred in 19% (3/16) of 2 mg group and 41% (7/17) of 4 mg group. Conclusions: Both doses of IVTA were well tolerated and had significant positive effects on refractory DME for short term. There were consistent trends throughout the study that suggest that a 4 mg IVTA may be more effective than a 2 mg dose. The benefit of IVTA was greater for cystoid-type DME.