Retinal vascular caliber changes after intravitreal triamcinolone treatment for diabetic macular edema.

PURPOSE To describe the changes in retinal vascular caliber in response to a single injection of intravitreal triamcinolone (IVTA) in patients with refractory diabetic macular edema. METHODS Prospective data from a randomized clinical trial were used. The effects of IVTA versus sham injections in patients with refractory diabetic macular edema were evaluated in a randomized clinical trial involving 69 eyes of 43 patients. Of these, 28 eyes (15 IVTA and 13 sham) of 21 patients had gradable retinal photographs at the baseline and 3-month follow-up visit for analysis in the present study. Retinal vascular caliber was measured from digital fundus photographs and summarized as central retinal artery (CRAE) and vein (CRVE) equivalents in all eyes at baseline and at the 3-month follow-up visit. RESULTS Over the 3 months of the study, there was a significant reduction compared to baseline in retinal arteriolar (147.8 microm vs. 140.0 microm, P = 0.047) and venular (219.5 microm vs. 198 microm, P = 0.039) caliber in eyes treated with IVTA. There was no change in retinal arteriolar (139.9 microm vs. 139.2 microm, P = 0.878) or venular (220.3 microm vs. 217.6 microm, P = 0.534) caliber in those treated with sham injections. CONCLUSIONS IVTA has a significant narrowing effect on both retinal arteriolar and venular diameter in eyes with diabetic macular edema (ClinicalTrials.gov number, NCT00148330).