Three-Year Follow-up of a Randomized Trial Comparing Focal/Grid Photocoagulation and Intravitreal Triamcinolone for Diabetic Macular Edema

Abstract

Macular edema is a frequent manifestation of diabetic retinopathy and an important cause of impaired vision in individuals with diabetes.^1-3 The Diabetic Retinopathy Clinical Research Network (DRCR.net) conducted a trial in 840 eyes of 693 subjects to evaluate intravitreal triamcinolone (1- and 4-mg doses) compared with focal/grid photocoagulation for the treatment of diabetic macular edema (DME).⁴ The study found that there was an initial beneficial effect of 4 mg of triamcinolone on retinal thickening and visual acuity at 4 months compared with a 1-mg dose or with focal/grid photocoagulation. However, the benefit diminished thereafter, and at 2 years, mean visual acuity was better in the laser group than in either of the other 2 groups (comparing the laser and 1-mg groups, P = .02; comparing the laser and 4-mg groups, P = .002). Optical coherence tomography (OCT) results paralleled the visual acuity results. Both triamcinolone doses, especially the 4-mg dose, were associated with an increased incidence of elevated intraocular pressure and cataract surgery.⁴