Purpose: To evaluate prospectively the efficacy and safety of one intravitreal injection of 4 mg triamcinolone acetonide for refractory diffuse diabetic macular edema.
Methods: Seventeen patients with bilateral diabetic macular edema unresponsive to laser photocoagulation. In all patients, one eye was injected, and the other served as a control. The intervention consisted in intravitreal injection of 4 mg triamcinolone acetonide. The main outcome measure was central macular thickness (CMT) at 4, 12 and 24 weeks, measured by Optical Coherence Tomography. Secondary outcomes were Early Treatment Diabetic Rentinopathy Study (ETDRS) scores, intraocular pressure and cataract PROGRESSION.
Results: Before injection, mean +/- SD CMT was 566.4 +/- 182.4 mum in injected eyes. Four, 12, and 24 weeks after injection, it was 228.4 +/- 47.5 mum, 210.9 +/- 87.2 mum and 358.5 +/- 160.5 mum respectively. CMT was significantly lower in injected eyes vs. control eyes except 24 weeks after injection because of a recurrence of macular edema in 9/17 injected eyes. Mean +/- SD gain in ETDRS score was significantly better in injected eyes vs. control eyes 4, 12 and 24 weeks after TA injection. In 9 of the 17 injected eyes, intraocular pressure exceeded 24 mmHg and was controlled by topical medication.
Conclusion: In the short-term, intravitreal injection of triamcinolone effectively reduces macular thickening due to diffuse diabetic macular edema and improves visual acuity in most cases. The long-term effect of this treatment and predictive factors of visual recovery remain to be elucidated.