Posterior Sub–Tenon’s Capsule Triamcinolone Injection Combined with Focal Laser Photocoagulation for Diabetic Macular Edema

Abstract

To investigate the efficacy of posterior sub-Tenon's capsule triamcinolone injection (PSTI) combined with focal laser (FL) photocoagulation in treatment of diffuse clinically significant diabetic macular edema (CSME). Prospective randomized clinical study. Sixty patients with diffuse CSME. We randomized the patients who had CSME into 2 treatment groups. A total of 30 eyes received macular focal and grid laser photocoagulation (MP), and the second group of 30 eyes received FL photocoagulation combined with PSTI (FL + PSTI). Clinical and visual evaluations were performed at baseline and 12 and 18 weeks after treatment, and the results were compared by statistical methods. Early Treatment Diabetic Retinopathy Study (ETDRS) visual acuity (VA) scores and clinical changes in macular edema. Before treatment, mean ETDRS VA scores were 45.9+/-12.7 (mean +/- standard deviation [SD]; range, 24-66) in MP (focal + grid laser) and 44.5+/-12.6 (range, 22-66) in the FL + PSTI group. Early Treatment Diabetic Retinopathy Study scores at 18 weeks were 46.4+/-14.2 (range, 20-70) after MP and 52.5+/-17.5 (range, 22-82) after FL + PSTI. Early Treatment Diabetic Retinopathy Study scores significantly improved in eyes that received FL + PSTI (P = 0.0001, paired t test). The FL + PSTI group had an increase of 12.4+/-7.1 (range, 5-26) ETDRS letters, and the MP group had an increase of 7.8+/-3.1 (range, 5-15) letters (P = 0.04, unpaired t test). Twelve of 30 (40%) cases in the MP group and 24 of 30 (80%) cases in the FL + PSTI group showed clinical improvement in macular edema according to the stereoscopic evaluation of fundus and fluorescein angiography (P = 0.003). Posterior sub-Tenon's capsule application of triamcinolone may improve early visual outcome in diffuse diabetic macular edema when combined with FL photocoagulation.