Burgos R, Simó R, Audí L, Mateo C, Mesa J, García-Ramírez M, Carrascosa A
Endocrinology Department, Hospital Universitari, Vall d'Hebron, Barcelona, Spain.
Diabetologia. 1997 Sep;40(9):1107-9. doi: 10.1007/s001250050794.
Vascular endothelial growth factor (VEGF) plays a major role in the development of neovascularization in proliferative diabetic retinopathy (PDR). The source of intravitreous VEGF is presumably ischaemic retina, but increased levels derived from serum cannot be excluded. The aim of the study is to determine the intravitreous concentrations of VEGF in diabetic patients with PDR and to investigate whether serum VEGF could contribute to the intravitreous concentration. For this purpose, we studied 20 diabetic patients (5 IDDM and 15 NIDDM) with PDR in whom a vitrectomy was performed (group A). Non-diabetic patients (n = 13) with other conditions requiring vitrectomy served as a control group (group B). In both groups, VEGF was determined in serum and undiluted vitreous samples obtained simultaneously. Furthermore, serum VEGF was determined in 69 healthy control subjects (group C) and 39 diabetic patients without microvascular complications (group D). Vitreous and serum VEGF was determined by ELISA (R & D Systems, Abingdon, UK); intra-assay CV 3.8%, interassay CV 5.1%. Intravitreous concentrations of VEGF were strikingly higher in group A (median 1.75 ng/ ml, range 0.33-6.66) in comparison with group B (median 0.009 ng/ml, range 0.009-0.038); p < 0.0001. This difference remained significant after adjusting for intravitreous protein concentration (p < 0.05). Differences in serum VEGF among the groups included in the study were not found. We conclude that the high vitreous levels of VEGF observed in diabetic patients with PDR cannot be attributed to serum diffusion across the blood-retinal barrier. Therefore, intraocular synthesis is the main contributing factor for the high vitreous VEGF concentrations observed in PDR.
血管内皮生长因子（VEGF）在增殖性糖尿病视网膜病变（PDR）的新生血管形成过程中起主要作用。玻璃体内VEGF的来源大概是缺血性视网膜，但也不能排除来自血清的水平升高。本研究的目的是测定患有PDR的糖尿病患者玻璃体内VEGF的浓度，并研究血清VEGF是否会对玻璃体内浓度有影响。为此，我们研究了20例接受玻璃体切割术的患有PDR的糖尿病患者（5例胰岛素依赖型糖尿病和15例非胰岛素依赖型糖尿病）（A组）。将因其他情况需要进行玻璃体切割术的非糖尿病患者（n = 13）作为对照组（B组）。在两组中，同时测定血清和未稀释玻璃体液样本中的VEGF。此外，还测定了69名健康对照者（C组）和39例无微血管并发症的糖尿病患者（D组）的血清VEGF。通过酶联免疫吸附测定法（ELISA，R&D Systems，英国阿宾顿）测定玻璃体液和血清中的VEGF；批内变异系数3.8%，批间变异系数5.1%。与B组（中位数0.009 ng/ml，范围0.009 - 0.038）相比，A组玻璃体内VEGF浓度显著更高（中位数1.75 ng/ml，范围0.33 - 6.66）；p < 0.0001。在调整玻璃体内蛋白质浓度后，这种差异仍然显著（p < 0.05）。未发现研究中纳入的各组血清VEGF存在差异。我们得出结论，患有PDR的糖尿病患者中观察到的玻璃体内VEGF高水平不能归因于血清通过血视网膜屏障的扩散。因此，眼内合成是PDR中观察到的高玻璃体内VEGF浓度的主要促成因素。
