Abstract
Purpose: :
To examine the effects of anti-VEGF antibody (bevacizumab) on the number of fenestrae in the rat choriocapillaris.
Methods: :
Twelve eyes from 12 male Wister rats were injected intravitreally with 0.125 mg of bevacizumab. The rats were perfusion fixated at 24 hours, 3 days or 7days after injection. Four untreated eyes were used as controls. Vibratome serial sections in 50-100µm thickness were made and processed for scanning electron microscopy. The surfaces of the choriocapillaris at RPE side were observed by scanning electron microscopy. The area in which fenestrae gathered closely and the number of fenestrae in the fenestrated area after administration of bevacizumab were measured and compared with those of control.
Results: :
In control, the fenestrated area was 71.06% of total area of luminal surface of choriocapillaris. The number of fenestrae in the fenestrated area was 69.09±7.54 /µm2 of fenestrated area. Overall number of the fenestration of the choriocapillaris was 49.23±7.19/µm2. In bevacizumab group, the fenestrated area was not changed in all time points. However, the numbers of fenestrae were reduced significantly to 52.94±4.41 at 24h, 55.56±3.64 at 3 days and 53.65±8.56 /µm2 of luminal surface at 7 days (ANOVA, p < 0.05). Therefore, overall numbers of the fenestrae were reduced significantly to 36.92±4.17, 38.05±3.29, and 37.57±6.72/µm2, respectively(ANOVA, p < 0.05).
Conclusions: :
Intravitreal bevacizumab injection may reduce perfusion from choriocapillaris. Patients treated by bavacizumab should be monitored carefully for long period of time.
Keywords: vascular endothelial growth factor • drug toxicity/drug effects • injection