Summary

Objectives: To evaluate the long-term efficacy and safety of an intravitreal injection of triamcinolone acetonide for clinically significant diabetic macular edema.

Methods: In a retrospective case series 31 diabetic patients with persistent, recurrent or diffuse clinically significant diabetic macular edema received a single 4 mg (0.1 ml) intravitreal triamcinolone acetonide injection and were followed for at least 6 months. The main outcome measures evaluated were classified as primary: visual acuity and central macular thickness, and secondary: intraocular pressure and cataract progression. Statistical analyses included Student’s t-test, chi-square test and the McNamar test.

Results: Best visual acuity results were observed 2.6 ± 2.4 months post-injection. At that time the mean foveal thickness had decreased by 37% from a baseline of 455 ± 100 to 288 ± 99 µ (P < 0.001) and the mean visual acuity improved from 6/42 to 6/23 (P < 0.001). Final mean visual acuity after an average of 10 ± 1.8 months follow-up (range 6–13 months) was identical to the baseline, although mean foveal thickness was still significantly lower than the initial thickness (368 ± 166 vs. 455 ± 100 µ, P < 0.01). Statistical analysis did not identify any pre-injection prognostic factors for improved visual acuity. The only complications that occurred were elevated intraocular pressure in 42% of patients and cataract progression in 21%. There was no endophthalmitis.

Conclusions: Intravitreal injection of triamcinolone acetonide for clinically significant diabetic macular edema is effective in reducing foveal thickness and improving visual acuity in the short term. Longer follow-up revealed that visual acuity returned to pre-injection values, even though a modest decrease in the foveal thickness persisted. Further studies are needed to evaluate the long-term efficacy in conjunction with laser photocoagulation treatment.