Objective: To report the results of repeated intravitreal injections of triamcinolone acetonide for treatment of diffuse diabetic macular edema.
Design: Retrospective interventional comparative study.
Participants: The investigation included a study group (the responders) of 19 patients (22 eyes) with diffuse diabetic macular edema, who showed an improvement in visual acuity after an intravitreal injection of approximately 20 mg triamcinolone acetonide, and who received a second intravitreal injection 10.0+/-3.8 months after the first injection. A control group consisted of 31 patients with diffuse diabetic macular edema without treatment during follow-up.
Methods: Intravitreal injection of approximately 20 mg triamcinolone acetonide.
Main outcome measures: Visual acuity and intraocular pressure.
Results: Follow-up after the second injection was 9.1+/-4.9 months. Four patients received a third injection at 9.7+/-3.7 months after the second injection, with a follow-up after the third injection that was at 7.9+/-11.5 months. After the second and third injections, visual acuity increased significantly (P = 0.002 and P = 0.068, respectively) by 1.8+/-2.1 and 4.0+/-2.6 Snellen lines, respectively. Eleven eyes (50%) showed an improvement in visual acuity by at least 2 Snellen lines after the second injection, and 3 patients (75%) experienced a gain in visual acuity by at least 2 Snellen lines after the third injection. Intraocular pressure increased significantly (P<0.01) after each injection, and returned to baseline values before each reinjection. Visual acuity improvement (P>0.05) and intraocular pressure rise did not differ significantly (P>0.55) between the various injections. Improvement in visual acuity and rise of intraocular pressure lasted approximately 6 to 8 months after each injection.
Conclusions: Intravitreal injection of approximately 20 mg triamcinolone acetonide may repeatedly lead to an improvement in visual acuity and a rise of intraocular pressure in patients with diffuse diabetic macular edema. The duration of the effect after each injection is approximately 6 to 8 months. Tachyphylaxis in visual acuity or intraocular pressure outcomes were not observed.