眼内液中PEDF、VEGF含量变化对糖尿病视网膜病变的意义

目的:测定增殖型糖尿病视网膜病变(PDR)患者房水、玻璃体及血清中色素上皮源性因子(PEDF)、血管内皮生长因子(VEGF)的浓度变化,并探讨其变化的来源及临床意义.方法:以41只糖尿病视网膜病变患眼为研究对象,其中16只继发虹膜新生血管(NVI),21只特发性黄斑裂孔(MH)患眼作为对照.应用酶联免疫吸附法(ELISA),分别测定3组患眼房水、玻璃体、血清中PEDF、VEGF的质量浓度.采用单因素方差分析比较3组房水、玻璃体、血清中PEDF及VEGF的水平,采用Pearson相关性检验分析房水中PEDF、VEGF水平与血清、玻璃体中的关系,并分别分析3种眼内液中PEDF与VEGF的关系.结果:房水中PEDF浓度在对照组、PDR无继发NVI组、PDR继发NVI组依次降低,VEGF浓度依次升高,玻璃体中PEDF、VEGF浓度具有类似的变化趋势.房水PEDF、VEGF水平与血清的无明显相关性,与玻璃体的呈一定正相关性.眼内液中PEDF浓度与VEGF浓度呈负相关.结论:眼内液PEDF水平降低、VEGF水平升高可能对PDR的发生、发展起到重要作用.PDR发展过程中,房水中这两种因子的浓度变化可能主要受眼局部病变影响.PEDF、VEGF分别作为血管抑制因子和血管刺激因子的代表,其眼内分布失衡可能是促成NVI及视网膜新生血管发生的重要因素.

Alteration of intraocular pigment epithelium-derived factor and vascular endothelial growth factor in patients with diabetic retinopathy

AIM: To determine the aqueous, vitreous, serum levels of pigment epithelium-derived factor (PEDF)and vascular endothelial growth factor(VEGF)in patients with proliferative diabetic retinopathy(PDR), and to speculate on the source of the change in concentration and to discuss its clinical significance.METHODS:Forty-one eyes with proliferative diabetic retinopathy were included in the study, 16 of which were complicated by neovascularization of iris (NVI).Twenty-one eyes with idiopathic macular hole (MH)were as controls. The aqueous, vitreous, serum levels of PEDF and VEGF of all the groups were determined with ELISA. PEDF, VEGF and the levels in the three groups were compared with analysis of variance (ANOVA). The PEDF, VEGF concentrations in aqueous,vitreous and serum were analyzed with Pearson correlation test,and the correlation of PEDF and VEGF levels was also analyzed with Pearson correlation test.RESULTS:The aqueous levels of PEDF decreased significantly in sequence in groups of control, PDR without NVI, PDR with NVI. VEGF levels increased coordinately. The similar findings existed in vitreous samples. The PEDF,VEGF levels in aqueous were not correlated significantly with those in serum,but correlated positively with those in vitreous. The intraocular levels of PEDF had a negative correlation to those of VEGF.CONCLUSION:The reduction of intraocular PEDF level and elevation of intraocular VEGF level may play an important role in the occurrence and progression of PDR. In the development of PDR, the PEDF,VEGF levels in aqueous may be mainly effected by local pathological changes, as anti-angiogenic and pro-angiogenic factors, their unbalanced intraocular distribution may promote the angiogenesis of the iris and retina.