Results from a subset of patients who completed the 3-year follow-up of the Diabetic Retinopathy Clinical Research Network (DRCR.net) trial comparing focal/grid photocoagulation and intravitreal triamcinolone are consistent with previously published 2-year results, according to a report in the Archives of Ophthalmology.1 The 3-year data do not indicate a long-term benefit in visual acuity for 1- or 4-mg doses of preservative-free intravitreal triamcinolone compared with focal/grid photocoagulation for the treatment of diabetic macular edema.

In the randomized trial, eyes with diabetic macular edema and visual acuities of 20/40 to 20/320 were randomly assigned to focal/grid photocoagulation or 1 mg or 4 mg of triamcinolone. Although the primary trial outcome was assessed at 2 years, 115 eyes in the laser group, 93 eyes in the 1-mg triamcinolone group, and 98 eyes in the 4-mg triamcinolone group had 3-year follow-up data at the time the trial ended.

Between 2 and 3 years, more eyes improved than worsened in all three treatment arms. Mean visual acuity increased by more than 5 letters in the laser group vs no mean change in each triamcinolone group. Moreover, 51 eyes in the laser group, 23 eyes in the 1-mg group, and 37 eyes in the 4-mg group had improvement of 10 or more letters from baseline to 3 years, and 14, 24, and 22 eyes, respectively, had worsening of 10 or more letters.

Optical coherence tomography demonstrated that eyes in all 3 treatment groups had a decrease in central subfield thickness from year 2 to 3. At 3 years, central subfield thickness was less than 250 μm in 75 eyes in the laser group, 37 eyes in the 1-mg triamcinolone group, and 45 eyes in the 4-mg triamcinolone group.

Based on the 3-year cumulative probability of cataract surgery for all eyes that were phakic at baseline, 83% eyes receiving 4-mg triamcinolone will require cataract surgery, compared with 31% in the laser group and 46% in the 1-mg group (P 7lt; .001). Conversely, it is predicted that few eyes will require surgery due to glaucoma. Mean intraocular pressure was 6 mm Hg in the laser group, 17 mm Hg in the 1-mg triamcinolone group, and 16 mm Hg in the 4-mg triamcinolone group, with 6 eyes, 14 eyes, and 10 eyes, respectively, having an intraocular pressure greater than 21 mm Hg.

  1. Diabetic Retinopathy Clinical Research Network (DRCR.net), Beck RW, Edwards AR, Aiello LP, Bressler NM, Ferris F, Glassman AR, Hartnett E, Ip MS, Kim JE, Kollman C. Three-year follow up of a randomized trial comparing focal/grid photocoagulation and intravitreal triamcinolone for diabetic macular edema. Arch Ophthalmol. 2009;127(3):: 245-251.