Purpose  

To evaluate the effect of three intravitreal injections of bevacizumab (IVB) alone or combined with triamcinolone (IVT) in the first injection for treatment of refractory diabetic macular edema (DME).

Methods  

In this prospective, placebo-controlled, randomized clinical trial, 115 eyes of 101 patients with refractory DME were included. Subjects were randomly assigned to one of the three study arms: 1) three injections of IVB (1.25 mg/0.05 ml) at 6-week intervals, 2) combined IVB and IVT (1.25 mg/0.05 ml and 2 mg/0.05 ml respectively) followed by two injections of IVB at 6-week intervals, and 3) sham injection (control group). The primary outcome measure was change in central macular thickness (CMT). Secondary outcome measures were change in best-corrected logMAR visual acuity (BCVA ) and incidence of potential adverse events.

Results  

Central macular thickness was reduced significantly in both the IVB and IVB/IVT groups. At week 24, CMT change compared to the baseline was −95.7 μm (95% CI, −172.2 to −19.26) in the IVB group, −92.1 μm (95% CI, −154.4 to −29.7) in the IVB/IVT group, and 34.9 μm (95% CI, 7.9 to 61.9) in the control group. There was a significant difference between the IVB and control groups (P = 0.012) and between the IVB/IVT and control groups (P = 0.022). Improvement of BCVA was initiated at weeks 6 and 12 in the IVB/IVT and IVB groups respectively. In terms of BCVA change compared to the baseline at 24 weeks, the differences between the IVB and control groups (P = 0.01) and also between the IVB/IVT and control groups (P = 0.006) were significant. No significant differences were detected in the changes of CMT and BCVA between the IVB and IVB/IVT groups (P = 0.99). Anterior chamber reaction was noticed in eight (19.5%) and seven (18.9%) eyes respectively in the IVB and IVB/IVT groups the day after injection, and it resolved with no sequel. Elevation of IOP occurred in three eyes (8.1%) in the IVB/IVT group.

Conclusion  

Three consecutive intravitreal injections of bevacizumab had a beneficial effect on refractory DME in terms of CMT reduction and BCVA improvement. Addition of triamcinolone in the first injection seemed to induce earlier visual improvement; however, it did not show any significant additive effect later during follow-up.