Purpose
This study aims to investigate the short-term efficacy of single intravitreal ranibizumab injection (IVR) with macular edema secondary to branch retinal vein occlusion (BRVO) and the correlation between aqueous flare value and vascular endothelial growth factor (VEGF).
Methods
This study is a prospective case series. Sixteen eyes of 16 patients with macular edema secondary to BRVO were evaluated; 5 males and 11 females, mean age 71.3±2.0 years old. All 16 eyes had no treatment such as laser, steroid injection or vitrectomy before this study. Single IVR was performed to all 16 eyes. Aqueous humor samples were obtained just before IVR. Concentrations of VEGF in the aqueous humor were measured with an ELISA kit. Best corrected visual acuity (BCVA) using a standard Japanese Landolt visual acuity chart, aqueous flare values using a laser flare meter (FC-2000, Kowa, Japan) and central retinal thickness (CRT) using optical coherence tomography (CIRUSS OCT, Zeiss, Germany) were measured at baseline, 1 week, 1, 2, and 3 month after IVR. The data was shown with mean ± standard error, and statistical analyses were performed with paired t-test and Spearman's rank correlation coefficient. P value <0.05 was considered significantly.
Results
The results are shown in Table 1. The mean decimal BCVA and CRT at baseline were 0.5±0.1 (LogMAR) and 504.3±26.4 µm respectively. After IVR, the BCVA and CRT significantly improved at all periods compared with baseline (p<0.05). Aqueous flare value at baseline was 8.9±1.0 pc/ms, and it significantly decreased at 1 and 3 month after IVR (p<0.05).<br /> Concentration of VEGF in the aqueous humor was 203.1±180.4 pg/ml. Aqueous flare value at baseline was significantly correlated with VEGF (p<0.05). Spearman's rank correlation coefficient was 0.757. BCVA and CRT at baseline was not significantly correlated with VEGF (p>0.05).
Conclusions
The single IVR could improve aqueous flare value, BCVA and CRT in the eyes with macular edema secondary to BRVO. Aqueous flare value at baseline could have predicted the concentration of VEGF in aqueous humor noninvasively.