To compare the intraocular pressure (IOP) in diabetic macular edema (DME) patients and macular edema associated with branch retinal vein occlusion (BRVO) patients after intravitreal preservative-free Triamcinolone injection. Methods

This study included 36 patients diagnosed with DME and 44 patients diagnosed with BRVO with macular edema. Both groups were treated with intravitreal preservative-free Triamcinolone (Maqaid®, Wakamoto Pharmaceutical Co., Ltd., Tokyo, Japan) injection, and we compared the IOPs of the two groups determined before injection and at 1, 2, 3, and 6 months after injection. We also compared the IOP elevation ratios and durations, and central foveal thickness (CFT) changes using optical coherence tomography. Results

In both groups, there was no statistical significance in the IOP before injection and at 1, 2, 3, and 6 months after injection. However, the IOP elevation ratio in the DME patients (38.9%) was significantly higher than that in the BRVO patients (15.9%) ( p = 0.02). The duration of IOP elevation in the DME patients (1.14 ± 1.85 months) was significantly longer than that in the BRVO patients (0.30 ± 1.20 months) ( p = 0.03). When the IOP was not controlled, we used IOP-lowering agents, and two patients in the DME were treated with glaucoma surgery. There was no statistical significance in the CFT before injection and at 1, 2, or 3 months after injection between the two groups ( p = 0.72, p = 0.26, p = 0.66, p = 0.34, respectively). However, the CFT after 6 months was 328 ± 103 µm in the DME group and 434 ± 189 µm in the BRVO; this difference was significant ( p < 0.01). Conclusions

Intravitreal injection of preservative-free Triamcinolone was effective in the treatment of both DME patients and macular edema patients associated with BRVO. Furthermore, Triamcinolone was more safely injected in macular edema associated with BRVO patients than in DME patients.