Purpose: To compare the results of intravitreal bevacizumab (IVB) injection alone or in combination with intravitreal 1 mg triamcinolone acetonide (IVT) in center-involved diabetic macular edema.
Methods: In this randomized clinical trial study, ninety-two eyes of 46 patients with bilateral center-involved diabetic macular edema and no previous treatment were included in the study. One eye of each patient was randomly assigned to 1.25 mg of IVB injection or combination of 1.25 IVB and 1 mg IVT. Evaluation of best-corrected visual acuity (BCVA), central macular thickness (CMT), intraocular pressure (IOP) and grading of lens opacity was conducted at baseline, and weeks 2, 4, 6, 8, 12 and 24 after treatment. Retreatment was performed at a 6-week interval whenever indicated based on CMT.
Results: Between the groups, BCVA changes were not statistically different until 24-week follow-up (P > 0.05), but at 24 weeks after treatment, BCVA improvement was significantly better in IVB group (P = 0.049). Significant CMT reduction was observed in each group along the follow-up period (P = 0.001). The mean CMT reduction was more significant in combination (IVB + IVT) group at 2 weeks of follow-up (P < 0.001), but CMT changes were not significant between the groups at weeks 12th and 24th after injection. Overall, retreatment was applied for 59 eyes up to 24 weeks (33 in the IVB group, 26 in the IVB + IVT group). Among patients with 2 or more injections, number of injections was significantly lower in IVB + IVT group (P = 0.043). Three eyes within IVB + IVT group developed IOP rise beyond 21 mmHg, which were controlled with topical anti-glaucoma medications within 1 week. Changes in lens opacity were not significant between two groups.
Conclusion: Eyes treated with IVB plus 1 mg IVT injections had more significant reduction in CMT in early post-injection, but this effect was transient. Although after 24 weeks visual acuity improvement was better in IVB group, combination therapy may decrease the number of injections. Combining 1 mg of intravitreal triamcinolone with bevacizumab was not accompanied with significant side effects.
Keywords: Bevacizumab; Macular edema; Triamcinolone.