Posterior Subtenon's Capsule Triamcinolone Acetonide Injection for the Treatment of Diabetic Macular Edema.

Purpose: To evaluate and compare the efficacy of posterior subtenon's triamcinolone injections versus grid laser photocoagulation (GLP) combined with posterior subtenon's triamcinolone injection in eyes with diabetic macular edema (DME).
Methods: In this prospective clinical study, 42 eyes with DME that showed a decrease in visual acuity (VA) were included. The first group consisted of 22 eyes that received a posterior subtenon's injection of 40 mg of triamcinolone acetonide under topical anesthesia. The second group of 20 eyes received macular GLP applied 1 month after subtenon's triamcinolone acetonide (STTA) injection. All patients were evaluated at baseline and 1 day; 1, 2, 4, 6, and 8 weeks; and 3 and 6 months after injection. In some patients, injections were repeated after 3 months. The main outcome measures were VA, central macular thickness (CMT), intraocular pressure, cataract progression, and frequency of complications.
Results: The mean baseline CMT for Group I was 456.85 ± 56.90 μm. The mean baseline CMT for Group II was 455.66 ± 57 μm. In the first group, mean CMTs for second week, 8th week, 12th week, and 6th month were 258.15, 276.50, 280.05, and 433.30 μm, respectively. In the second group, mean CMTs for second week, 8th week, 12th week, and 6th month were 261.42, 272.76, 284.71, and 291.76 μm, respectively. Before treatment, in the first group, the mean best-corrected visual acuity (BCVA) measured using a Snellen chart was 0.19, while the first week, third, and sixth month BCVA means were 0.59, 0.57, and 0.41, respectively. Before treatment, BCVA in the second group was 0.17, while the first week, third, and sixth month means were 0.61, 0.64, and 0.60, respectively. Treatment complications included cataracts in 4 eyes and glaucoma in 1 eye.
Conclusion: There is a temporary therapeutic effect of posterior subtenon's triamcinolone injection without laser photocoagulation. GLP improves VA and reduces the risk of recurrent macular edema after posterior STTA injection.