Department of Ophthalmology, School of Medicine, University of Occupational and Environmental Health, Kitakyushu, Fukuoka, Japan.
Retina. 2010 Mar;30(3):468-72. doi: 10.1097/IAE.0b013e3181bd2d7b.
The purpose was to study the histology of the fibrovascular membranes in proliferative diabetic retinopathy (PDR) with an intravitreal injection of bevacizumab.
Light and electron microscopic studies were performed on surgical specimens obtained during a pars plana vitrectomy from 6 PDR eyes after intravitreal injection of bevacizumab. The patients had preoperatively received no or scant retinal photocoagulations. The presence and distribution of CD34 was assessed as a marker of vascular endothelium using immunostaining. The presence of vascular endothelial growth factor was stained with a method of immunostaining. As controls, we examined 7 surgical specimens from 7 PDR eyes obtained during pars plana vitrectomy without bevacizumab therapy. All control patients had preoperatively received full or nearly full pan retinal photocoagulations.
Light microscopy showed that the CD34-positive vascular endothelial cells formed capillarylike structures in the fibrovascular membranes of all 13 PDR eyes. Vascular endothelial growth factor was positively stained in the vascular endothelium of both groups; however, the number of vascular endothelial growth factor-positive vascular endothelial cells significantly decreased in the fibrovascular membranes with intravitreal injection of bevacizumab. Electron microscopy showed the newly formed vascular endothelial cells with junctional complex in both groups.
The vascular endothelial cells with decreased expression of vascular endothelial growth factor are still present in the fibrovascular membranes of patients with PDR after intravitreal injection of bevacizumab.
本研究旨在通过玻璃体腔注射贝伐单抗，研究增生性糖尿病视网膜病变（PDR）的纤维血管膜的组织学特征。
对 6 例接受玻璃体腔注射贝伐单抗的 PDR 患者行玻璃体切割术获得的手术标本进行光镜和电镜检查。所有患者术前均未接受或仅接受少量视网膜光凝治疗。采用免疫组化法检测 CD34 的表达，评估其作为血管内皮标志物的存在和分布。采用免疫组化法检测血管内皮生长因子的存在。作为对照，我们还检查了 7 例接受玻璃体切割术但未接受贝伐单抗治疗的 PDR 患者的 7 例手术标本。所有对照患者术前均接受了全视网膜或近乎全视网膜光凝治疗。
光镜下，所有 13 例 PDR 眼的纤维血管膜中 CD34 阳性的血管内皮细胞形成毛细血管样结构。两组的血管内皮均呈血管内皮生长因子阳性染色，但玻璃体腔注射贝伐单抗后，纤维血管膜中血管内皮生长因子阳性的血管内皮细胞数量明显减少。电镜下，两组均可见到表达血管内皮生长因子减少的新生血管内皮细胞。
玻璃体腔注射贝伐单抗后，PDR 患者的纤维血管膜中仍存在表达血管内皮生长因子减少的血管内皮细胞。
