To evaluate the efficacy of intravitreal dexamethasone implants for the treatment of macular edema (ME) due to branch retinal vein occlusion (BRVO) according to the duration of symptoms.

Thirty-one patients who received an intravitreal dexamethasone implant for ME due to BRVO were included in this retrospective study. The patients were divided into 2 groups. Group A included eyes with symptom duration less than 12 weeks and Group B included eyes with symptom duration of 12 weeks or longer. The main efficacy outcomes such as best-corrected visual acuity (BCVA) and central macular thickness (CMT) were measured at baseline and every 4 weeks over 24 weeks. Retreatment criteria included an increased CMT of 150 µm or reduction of logarithm of the minimal angle of resolution (log MAR) scores of at least 0.2.

The CMT and BCVA improved significantly at each follow-up compared with the baseline ( p < 0.001, p < 0.05, respectively). At 4 and 8 weeks after the first injection, CMT in Group A (285.3 ± 19.9, 276.1 ± 23.1 µm, respectively) was less than in Group B (310.3 ± 37.5, 318.1 ± 39.6 µm; p = 0.033, p = 0.001, respectively). At 4 weeks, the BCVA in Group A was better than in Group B ( p = 0.009). Rate and timing of recurrence were not different between the 2 groups ( p > 0.05). At 24 weeks, Group A showed less CMT and better BCVA compared with Group B ( p = 0.043, p = 0.041, respectively).

The intravitreal dexamethasone implant significantly reduced the CMT and improved BCVA in patients with ME due to BRVO. Patients with shorter symptom duration showed better anatomical and functional outcomes over 24 weeks. Early treatment with the intravitreal dexamethasone implant could produce better clinical results.