Multifocal electroretinogram assessments following intravitreal ranibizumab injection for macular edema secondary to branch retinal vein occlusion

Abstract

Objective To evaluate the functional and structural changes after intravitreal ranibi-zumab injection in patients with macular edema(ME)due to branch retinal vein occlusion(BRVO)using multifocal electroretinogram(mfERG)and optical coherence tomography(OCT). Methods Fourteen patients(14 eyes)with ME secondary to BRVO received intravitreal ranibizumab(0.5mg)injection from September 2014 to May 2015. OCT, mfERG and BCVA were measured at baseline, 1 and 3 months after treatment. The changes of BCVA, CMT, amplitude density and latency of P1 and N1 waves were observed. Results Patients had mean BCVA of(0.115 ± 0.062)at baseline, which improved significantly to(0.290 ± 0.089)after 3 months(t=4.874, P <0.05). The mean CMT before treatment was(482.00±136.86)μm and reduced significantly to(410.22±135.43)μm and(306.44±73.55)μm after 1 and 3 months respectively(t=3.562, 2.917, P <0.05). The amplitude densities of P1 wave in ring l after injection were significantly increased, and the latencies were decreased(P < 0.05). In affected areas, the amplitude densities of P1 and N1 waves were increased dramatically, and the latencies were decreased(P <0.05). Conclusions Intravitreal ranibizumab injection for ME secondary to BRVO can obtain a better visual acuity and reduce the CMT, at the same time, improve the retinal function of macular and affected area. Key words: Ranibizumab; Intravitreal injection; Branch retinal vein occlusion; Macular edema; Multifocal electroretinogram