Effect of Intravitreal Bevacizmab on Retinal Circulation in Patients with Macular Edema Secondary to Branch Retinal Vein Occlusion

Taiji Nagaoka, Kenji Sogawa, Eiichi Sato, Atsushi Takahashi, Akitoshi Yoshida

Department of Ophthalmology, Asahikawa Medical College

Purpose. To investigate the effect of intravitreal bevacizmab (IVB) (Avastin, Roche, Basel, Switzerland) for macular edema secondary to branch retinal vein occlusion (BRVO) on the retinal microcirculation.

Methods. In this interventional case series, 28 consecutive, previously untreated eyes of 28 patients (mean age, 61.3 years) with macular edema secondary to BRVO were treated with one IVB (1.25 mg/0.05 mL) injection and followed for at least 3 months. Subjects were studied before, 1 week, and 1, 2, and 3 months after the injection. We measured the best-corrected visual acuity (BCVA) and central foveal thickness (CFT) using spectral-domain optical coherence tomography. We measured the retinal vessel diameter (D) and blood velocity (V) noninvasively and calculated the retinal blood flow (RBF) using a laser Doppler velocimetry system (CLBF Model 100, Canon, Tokyo, Japan). The RBF measurements were performed on both temporal venules, i.e., the occluded venule (V1) and the opposite venule (V2), in the affected eye and the equivalent venule (V3) in the contralateral eye.

Results. The BCVA increased and the CFT decreased after the IVB injection. There were no significant changes in D, V, or RBF in V1, V2 and V3 during follow-up.

Conclusion. The current results suggested that one IVB injection may have little effect on retinal microcirculation in patients with macular edema secondary to BRVO.