Objective-To evaluate the efficacy and safety of 1 mg and 4 mg doses of preservative-free intravitreal triamcinolone in comparison with focal/grid photocoagulation for the treatment of diabetic macular edema (DME).
Design-Multi-center randomized clinical trialParticipants-840 study eyes of 693 subjects with DME involving the fovea and visual acuity 20/40 to 20/320Methods-Eyes were randomized to focal/grid photocoagulation (N=330), 1 mg intravitreal triamcinolone (N=256), or 4 mg intravitreal triamcinolone (N=254). Retreatment was given for persistent or new edema at 4-month intervals. The primary outcome was at 2 years.
Main Outcome Measures-Visual acuity measured with the Electronic Early Treatment DiabeticRetinopathy Study (E-ETDRS) method (primary), optical coherence tomography (OCT)-measured retinal thickness (secondary), and safety.Results-At 4 months, mean visual acuity was better in the 4 mg triamcinolone group than in either the laser group (P<0.001) or the 1 mg triamcinolone group (P=0.001). By 1 year, there were no significant differences among groups in mean visual acuity. At the 16-month visit and extending through the primary outcome visit at 2 years, mean visual acuity was better in the laser group than in the other two groups (at 2 years, P=0.02 comparing the laser and 1 mg groups, P=0.002 comparing the laser and 4 mg groups, and P=0.49 comparing the 1mg and 4 mg groups). Treatment group differences in the visual acuity outcome could not be attributed solely to cataract formation. OCT results generally paralleled the visual acuity results. Intraocular pressure was increased from baseline by ≥10 mm Hg at any visit in 4%, 16%, and 33% of eyes in the three treatment groups, respectively,
Conflicts of interest statement:A complete list of all DRCR.net investigator financial disclosures can be found at www.drcr.net Publisher's Disclaimer: This is a PDF file of an unedited manuscript that has been accepted for publication. As a service to our customers we are providing this early version of the manuscript. The manuscript will undergo copyediting, typesetting, and review of the resulting proof before it is published in its final citable form. Please note that during the production process errors may be discovered which could affect the content, and all legal disclaimers that apply to the journal pertain. and cataract surgery was performed in 13%, 23%, and 51% of eyes in the three treatment groups, respectively.
NIH Public AccessConclusions-Over a 2-year period, focal/grid photocoagulation is more effective and has fewer side effects than 1 mg or 4 mg doses of preservative-free intravitreal triamcinolone for most patients with DME who have characteristics similar to the cohort in this clinical trial. The results of this study also support that focal/grid photocoagulation currently should be the benchmark against which other treatments are compared in clinical trials of DME.