Comparison of photocoagulation with combined intravitreal triamcinolone for diabetic macular edema

Purpose: To compare the efficacy between macular laser grid (MLG) photocoagulation and MLG plus intravitreal triamcinolone acetonide (IVTA; MLG+IVTA) therapy in diabetic macular edema (DME) patients.

Methods: A prospective, randomized, clinical trial was conducted of DME patients. A total of 60 eyes (54 patients) affected by DME were observed for a minimum of 6 months. Thirty eyes of 28 patients who received MLG treatment and 30 eyes of 26 patients who received the combined MLG+IVTA treatment were included in the study. Main outcome measures were BCVA and central macular thickness (CMT) as measured by optical coherence tomography (OCT) at 1, 3, and 6 months after treatment. Additionally, the authors examined retrospectively 20 eyes of 20 patients who were treated with only IVTA and compared with the 2 groups (MLG group and MLG+IVTA group).

Results: Baseline BCVA was 0.53 + or - 0.32 and CMT was 513.9 + or - 55.1 microm in the MLG group. At 1 and 3 months after treatment, the MLG group showed no significant improvement of BCVA and CMT, although there was significant improvement after 6 months. In the MLG+IVTA group, the baseline BCVA was 0.59 + or - 0.29 and CMT was 498.2 + or - 19.8 microm. After treatment, significant improvement of BCVA and CMT was observed at all follow-up time periods. When comparing the MLG group with the MLG+IVTA group, the latter had better results after 1 and 3 months, although at 6 months, there was no significant difference of BCVA and CMT between the 2 groups. Additionally, the IVTA group showed more improvement than the MLG group at 1 and 3 months but showed no significant difference at 6 months. In addition, the IVTA group showed no significant difference with the MLG+IVTA group at all follow-up time periods.

Conclusions: For DME patients, the combined MLG+IVTA treatment had a better therapeutic effect than the MLG treatment for improving BCVA and CMT at the early follow-up time periods. IVTA treatment alone could be an additional alternative therapeutic option to combined therapy.