Abstract
Purpose:
To determine whether there is a significant correlation between the change of the retinochoroidal thickness and blood flow (BF) after intravitreal bevacizumab for macular edema secondary to branch retinal vein occlusion (BRVO).
Methods:
Fourteen eyes of 14 patients with macular edema due to BRVO were treated with an intravitreal injection of 1.25 mg/0.05 mL of bevacizumab at the Nagoya University Hospital from March 2013 to August 2013. The BF on the optic nerve head (ONH) and the choroid was determined by laser speckle flowgraphy (LSFG, LSFG-NAVI®, Softcare). The mean blur rate (MBR) and waveform variables, e.g., skew and blowout time (BOT), were determined at 1 week, and 1, 2, and 3 month(s) after the injection. Standardized ophthalmic examinations including the best-corrected visual acuity (BCVA), intraocular pressure (IOP), and thickness of the retina and choroid were performed at the same times. The retinochoroidal thickness was measured at the macula by enhanced depth imaging OCT (Spectralis®, Heidelberg Engineering).
Results:
The mean retinal thickness was 609 µm before, and 319 µm at 1 week, 252 µm at 1 month, 385 µm at 2 months, and 370 µm at 3 months after the injection. The thickness after the injection was significantly thinner than that at the baseline for all times (ANOVA, P<0.05). The BCVA was also significantly improved after the injection (ANOVA, P<0.05). On the other hand, the mean choroidal thickness was 178 µm before and 170 µm at 1 week, 162 µm at 1 month, 166 µm at 2 months, and 167 µm at 3 months after the injection. The difference in the thicknesses of the choroid was not significant (ANOVA, P>0.05). Additionally, there were no significant differences in the mean MBR, the skew, and the BOT at the ONH and the mean MBR of the choroid.
Conclusions:
These findings indicate that the intravitreal injection of bevacizumab does not affect the BF and choroidal thickness in eyes with BRVO. The absence of significant changes in the BF in the ONH and the choroid, and the choroidal thickness in eyes after the intravitreal bevacizumab suggests that bevacizumab does not alter the blood flow autoregulation mechanism in the retina and choroid.
Keywords: 688 retina •
505 edema •
436 blood supply