Purpose: To describe the changes in retinal thickness (RT) and visual acuity over time in patients with clinically significant diffuse diabetic macular edema (DME) after intravitreal injection of triamcinolone acetonide (IVTA) and to compare patients with and without previous laser treatment.
Methods: A total of 23 eyes with clinically significant DME received a 4-mg IVTA injection. Twelve eyes were refractory to macular laser treatment (group 1), and 11 eyes received IVTA as primary therapy (group 2). Visual acuity and changes in macular thickening shown by optical coherence tomography were evaluated 48 hours after injection, every 7 days for 1 month, and at 3 months and 6 months of follow-up.
Results: RT decreased in all eyes in both groups. The reduction of edema was maximal in the first 7 days after IVTA and tended to remain stable for 3 months. The decrease in RT over time was significant in both groups (P < 0.001). At 6 months, RT had increased in almost all eyes. Visual acuity improved quickly, to a maximum at 2 weeks in both groups, after which it remained stable for 3 months and then decreased. Improvement in visual acuity over time was significant in both groups (P < 0.001). The temporal characteristics of the changes in RT and visual acuity were similar in the two groups (P < 0.05).
Conclusions: IVTA was effective in reducing clinically significant DME and improving visual acuity in eyes with and without previous laser treatment. Its action was maximal in the first week and lasted approximately 3 months in this study.