增殖性糖尿病视网膜病变玻璃体SDF-1和VEGF的含量分析

研究增殖性糖尿病视网膜病变患者玻璃体基质细胞衍生因子（Stromalcell—derivedfactor-1。SDF-1）和血管内皮生长因子（Vascularendothelialgrowthfactor，VEGF）的浓度，及其相互作用关系。方法：酶联免疫吸附法（Enzyme-linkedimmunosorbentassay，ELISA）检测玻璃体内SDF-1和VEGF的含量，每个标本重复3次。实验组为增殖性糖尿病视网膜病变（Proliferativediabeticretinopathy，PDR）的住院患者30例，对照组为同期行玻璃体切除术的特发性黄斑裂孔患者12例。结果：PDR患者玻璃体VEGF的平均浓度为（2865．87±387．85）pg／ml，明显高于特发性黄斑裂孔组[（142．42±21．03）pg／ml，P〈0．0001]。增殖性糖尿病视网膜病变患者玻璃体SDF-1的含量平均为（298．40±24．57）pg／ml，对照组为（86．9l±15．89）pg／ml，两组的差异具有统计学意义（P〈0．0001）。在30例PDR患者玻璃体内VEGF和SDF-1的含量表现为正相关（Pearson相关系数r=0．62，P〈0．001）。结论：增殖性糖尿病患者玻璃体SDF-1和VEGF的含量均高于非糖尿病患者，提示SDF-1和VEGF共同参与了增殖性糖尿病视网膜病变患者病理性新生血管的形成过程。     

Ang‐2 upregulation correlates with increased levels of MMP‐9, VEGF,EPO and TGFβ1 in diabetic eyes undergoing vitrectomy

Purpose: Angiogenesis in diabetic retinopathy (DR) is a multifactorial process regulated by hypoxia‐induced growth factors and inflammatory cytokines. In addition to the angiogenic switch, the proteolytic processing and altered synthesis of the extracellular matrix are critical steps in this disease. This study was performed to evaluate the levels of matrix metalloproteinase‐2 and matrix metalloproteinase‐9 (MMP‐2 and MMP‐9), angiopoietin‐1 and angiopoietin‐2 (Ang‐1 and Ang‐2), vascular endothelial growth factor (VEGF), erythropoietin (EPO) and transforming growth factor‐β1 (totalTGFβ1) in the vitreous of diabetic eyes undergoing vitrectomy compared with control eyes operated because of macular hole or pucker. Methods: Prospective consecutive controlled observational study performed in the unit of vitreoretinal surgery in Finland during the years 2006–2008. Vitreous samples were collected before the start of the conventional 3‐ppp vitrectomy. Vitreous MMP‐2 and MMP‐9, Ang‐1 and Ang‐2, VEGF, EPO and TGFβ1 concentrations were measured from 69 patients with Type 1 or 2 diabetes and 40 controls. Results: Comparison of eyes with DR with controls revealed that the mean vitreous concentrations of proMMP‐2 (p = 0.0015), totalMMP‐2 (p = 0.0011), proMMP‐9 (p = 0.00001), totalMMP‐9 (p < 0.00001), Ang‐2 (p < 0.00001), VEGF (p < 0.00001), EPO (p < 0.00001) and totalTGFβ1 (p = 0.000026) were significantly higher in the former group. A multivariate logistic regression analysis suggested intravitreal Ang‐2 concentration being the key marker of PDR (p = 0.00025) (OR = 1507.9). Conclusion: The main new finding is that the intravitreal concentrations of Ang‐2 correlated significantly with MMP‐9, VEGF, EPO and TGFβ1 levels in diabetic eyes undergoing vitrectomy. Thus, these factors could promote retinal angiogenesis synergistically.     

Soluble IL-6 Receptor in Vitreous Fluid of Patients with Proliferative Diabetic Retinopathy

Purpose

To identify the biological reaction of soluble interleukin-6 receptor (sIL-6R) in the vitreous of patients with proliferative diabetic retinopathy (PDR).

Methods

The subjects were 45 patients (45 eyes) with vitreoretinal diseases. The patients were divided into three groups: the PDR group comprised 28 patients (28 eyes) with PDR; the pre-proliferative diabetic retinopathy (PPDR) group comprised seven patients (seven eyes) with PPDR combined with diabetic macular edema; and the nondiabetic group comprised ten patients (ten eyes) with idiopathic macular hole or idiopathic epiretinal membrane. Vitreous samples were obtained at vitrectomy. sIL-6R, vascular endothelial growth factor (VEGF), and protein concentration in vitreous samples were determined by enzyme-linked immunosorbent assay (ELISA). sIL-6R levels in serum were also determined by ELISA in nine of the 28 patients with PDR and in six healthy volunteers as controls.

Results

In vitreous fluid, the levels of sIL-6R in the PDR group, PPDR group, and nondiabetic group were 612.7 ± 233.8 (mean ± SD), 746.3 ± 523.1, and 215.4 ± 98.3?pg/ml, respectively. Vitreous levels of sIL-6R in the PDR and PPDR groups were significantly higher than those in the nondiabetic group (PDR group, P < 0.0001; PPDR group, P < 0.01). In serum, the levels of sIL-6R were 39.38 ± 9.43?ng/ml in the PDR group and 22.84 ± 5.32?ng/ml in the control group. sIL-6R levels in serum in the PDR group were significantly higher than those in the control group (P < 0.01). A partial correlation analysis showed a significant correlation between the levels of sL-6R and VEGF in the vitreous in the PDR group (r = 0.34, P < 0.05).

Conclusions

We conclude that the level of sIL-6R in vitreous fluid can be considered as a biomarker of PDR.?Jpn J Ophthalmol 2007;51:100–104 © Japanese Ophthalmological Society 2007

     

The Expression of GDF-15 in the Human Vitreous in the Presence of Retinal Pathologies with an Inflammatory Component

Purpose: The presence of growth differentiation factor-15 (GDF-15), a protein implicated in the regulation of the inflammatory response, was investigated in the vitreous of patients with vitreoretinal disorders.

Methods: Vitreous and plasma samples were collected from patients with idiopathic epiretinal membrane (IERM), macular hole (MH), rhegmatogenous retinal detachment (RRD), nucleus drop (ND), or proliferative diabetic retinopathy (PDR). GDF-15 concentrations were measured using ELISA.

Results: The vitreous levels of GDF-15 were higher in ND (5) and PDR (14) patients (1494?±?243 and 904?±?138?pg/mL, respectively) than RRD (3), MH (3), and IERM (8) patients (302?±?160, 288?±?24, and 254?±?91?pg/mL, respectively). The vitreous levels of GDF-15 were significantly higher in patients with inflammatory vitreoretinal disorders (p?Conclusions: This is the first report showing that GDF-15 appears to be expressed in the vitreous, and that its expression is significantly higher in the presence of a vitreoretinal disorder in which there is an inflammatory component.     

糖尿病视网膜病变患者玻璃体中肝细胞生长因子的含量检测

目的 定量研究肝细胞生长因子(hepatocyte growth factor, HGF)在糖尿病视网膜病变(diabetic retinopathy, DR)患者玻璃体中的水平，探讨HGF在增生性糖尿病视网膜病变 (proliferative diabetic retinopathy, PDR)等新生血管形成病理过程中的作用。 方法 采用双夹心酶联免疫吸附测定法检测对照组10只眼玻璃体以及单纯型DR组7只眼、PDR组33只眼和其它与新生血管生成有关的视网膜疾病组8只眼玻璃体切割手术中所取玻璃体内HGF的含量。PDR组中无虹膜新生血管者24只眼，伴虹膜新生血管者9只眼。 结果 玻璃体中HGF的含量对照组为（3.34±1.9）μg/L；单纯型DR组为（4.8±2.5）μg/L；PDR组中不伴虹膜新生血管生成者为（13.0±5.2）μg/L；PDR伴有虹膜新生血管生成者为（18.6±7.2）μg/L，其它与新生血管生成有关的视网膜疾病组为（12.1±8.9）μg/L。PDR组和其它与新生血管生成有关的视网膜疾病组玻璃体中HGF的含量比对照组显著升高(t=6.49, 5.70, 3.01, P<0.01)；PDR组中伴有虹膜新生血管生成者较PDR不伴虹膜新生血管生成者以及单纯型DR组玻璃体中HGF的含量均高，其差异有显著性意义(t=2.47, P<0.05或t=4.84, P<0.01)。 结论 在PDR和与新生血管生成有关的视网膜疾病患眼玻璃体内HGF的含量升高，提示HGF可能在视网膜新生血管生成的病理过程中起一定作用。 (中华眼底病杂志, 2002, 18: 131-13)     

Macrophage migration inhibitory factor levels in the vitreous of patients with proliferative diabetic retinopathy

AIMS: To assess the potential role of macrophage migration inhibitory factor (MIF) in the pathogenesis of proliferative diabetic retinopathy (PDR). METHODS: MIF levels were assayed in the vitreous and paired serum samples of 73 consecutive patients with PDR (32 eyes) and macular hole or idiopathic epiretinal membrane (controls, 41 eyes). An enzyme linked immunosorbent assay technique was used to determine the concentrations of MIF. RESULTS: The median vitreous level of MIF was 11.93 ng/ml (range 4.16-103.85) in the patients with PDR, and 1.79 ng/ml (undetectable-8.93) in the controls. Vitreous levels in eyes with PDR were significantly greater than those in the controls (p<0.0001). Vitreous levels were significantly higher than serum levels in eyes with PDR (p=0.0026). MIF levels were significantly higher in the vitreous of PDR patients with severe fibrous proliferation than in those with slight proliferation (p<0.05). CONCLUSION: The results indicate increased levels of MIF in the vitreous of patients with PDR and a significant association between MIF levels and grades of fibrous proliferation, suggesting the possibility that MIF may play a part in the development of the proliferative phase of PDR.     

增生性糖尿病视网膜病变患者玻璃体内血管内皮生长因子的表达

目的 探讨增生性糖尿病视网膜病变(PDR)患者玻璃体内血管内皮生长因子(VEGF)的表达及相关影响因素.方法 病例对照研究.对50例(50只眼)接受玻璃体切除治疗的PDR患者进行分析.术中获取玻璃体标本,并用双抗体夹心酶联免疫吸附试验ELISA法对术中获取的玻璃体标本进行VEGF含量的定量检测,并分析增生性糖尿病视网膜病变患者玻璃体内VEGF的表达情况.平均随访9个月(6～26个月).用成组t检验比较PDR组和正常对照组玻璃体VEGF含量差异,以及硅油填充组与非硅油填充组VEGF含量差异.用方差分析方法比较PDR进展组、稳定组和好转组玻璃体VEGF含量有无差异.用单因素方差分析方法分析玻璃体VEGF含量对PDR术后疗效的影响.结果 PDR组玻璃体VEGF含量平均(592.4801±587.4267)ng/L,正常对照组玻璃体VEGF含量平均(131.3022±26.9192)ng/L.PDR组玻璃体VEGF含量高于对照组(t=3.2315,P＜0.05).术后PDR进展有10只眼(20%),稳定10只眼(20%),好转30只眼(60%).PDR进展组玻璃体VEGF含量显著高于PDR稳定和好转组(q=-3.3187,-4.0843;P＜0.05).术前未接受视网膜光凝组玻璃体VEGF含量显著高于接受全视网膜光凝或局部视网膜光凝组(q=-4.2187,-3.9672;P＜0.05).结论玻璃体VEGF表达与PDR严重程度有一定关系.术后PDR稳定或好转者玻璃体VEGF水平呈相对低表达.(中华眼科杂志,2009,45:206-209)     

Positive association of pigment epithelium-derived factor with total antioxidant capacity in the vitreous fluid of patients with proliferative diabetic retinopathy

BACKGROUND: Pigment epithelium-derived factor (PEDF), a glycoprotein with potent neuronal differentiating activity, was recently found to inhibit advanced glycation end product (AGE)-induced retinal hyperpermeability and angiogenesis through its antioxidative properties, suggesting that it may exert beneficial effects on diabetic retinopathy by acting as an endogenous antioxidant. However, the inter-relationship between PEDF and total antioxidant capacity in the eye remains to be elucidated. AIMS: To determine vitreous PEDF and total antioxidant levels in patients with proliferative diabetic retinopathy (PDR), and to investigate the relationship between them. METHODS: Vitreous levels of PEDF and total antioxidant capacity were measured by an ELISA in 39 eyes of 36 patients with diabetes and PDR and in 29 eyes of 29 controls without diabetes. RESULTS: Vitreous levels of total antioxidant capacity were significantly lower in patients with diabetes and PDR than in controls (mean (SD) 0.16 (0.05) vs 0.24 (0.09) mmol/l, respectively, p<0.001). PEDF levels correlated positively with total antioxidant status in the vitreous of patients with PDR (r = 0.37, p<0.05) and in controls (r = 0.41, p<0.05). Further, vitreous levels of PEDF in patients with PDR without vitreous haemorrhage (VH(-)) were significantly (p<0.05) decreased, compared with those in the controls or in patients with PDR with vitreous haemorrhage (VH(+); PDR VH(-), 4.5 (1.1) microg/ml; control, 7.4 (4.1) microg/ml; PDR VH(+) 8.5 (3.6) microg/ml). CONCLUSION: This study demonstrates that PEDF levels are associated with total antioxidant capacity of vitreous fluid in humans, and suggests that PEDF may act as an endogenous antioxidant in the eye and could play a protective role against PDR.     

Vitreous levels of angiopoietin 2 and vascular endothelial growth factor in patients with proliferative diabetic retinopathy

PURPOSE: To investigate the levels of angiopoietin-2 (Ang2) and vascular endothelial growth factor (VEGF) in the vitreous fluids of patients with proliferative diabetic retinopathy (PDR) and to ascertain their involvement, if any, in angiogenesis of PDR. DESIGN: Retrospective case-control study. METHODS: Forty-one eyes of 41 patients with proliferative diabetic retinopathy and 18 eyes of 18 patients with nondiabetic ocular diseases (control group). Nondiabetic control eyes included 11 with idiopathic macular hole and 7 with idiopathic epiretinal membrane. Vitreous fluid samples were obtained at vitrectomy, and the levels of Ang2 and VEGF were measured by enzyme-linked immunosorbent assay. RESULTS: Vitreous level (mean +/- SD) of Ang2 was significantly higher in patients with PDR (1,753 +/- 3,213 pg/ml) than in control patients (112 +/- 113 pg/ml) (P < .0001). The vitreous concentration of VEGF was also significantly higher in patients with PDR (812 +/- 1,108 pg/ml) than in control patients (1.7 +/- 4.4 pg/ml) (P < .0001). Both Ang2 and VEGF levels in eyes with active PDR were significantly higher than in those with inactive PDR. The vitreous concentration of Ang2 correlated significantly with that of VEGF in eyes with proliferative diabetic retinopathy ([correlation coefficient] rho = 0.497, P = .001). CONCLUSIONS: These data demonstrate an increase of Ang2 in the vitreous fluid of patients with PDR and suggest an association of Ang2 and VEGF with angiogenic activity in PDR.     

Profile of intraocular tumour necrosis factor‐α and interleukin‐6 in diabetic subjects with different degrees of diabetic retinopathy

Purpose: To assess and correlate the levels of inflammatory mediators in the eyes from non‐diabetic and diabetic subjects without retinopathy (NDR), with non‐proliferative diabetic retinopathy (NPDR) or with proliferative diabetic retinopathy (PDR) to corresponding erum levels. Methods: The levels of interleukin 1β, interleukin‐6 (IL‐6) and tumour necrosis factor‐α (TNF‐α) were analysed by an ELISA‐mimicking technique in the vitreous from 26 diabetic subjects with active PDR and 27 non‐diabetic subjects, or by a multiplex bead assay in the aqueous humour from 35 diabetic subjects with NDR/NPDR and 40 non‐diabetic subjects. Intraocular protein production was estimated in vitreous specimens by calculating a vitreous/serum ratio. Results: In the vitreous, IL‐6 was higher in diabetic [157.5 (25.0–1401.0) pg/ml; median (min–max)] than in non‐diabetic subjects [44.0 (5.0–4425) pg/ml; p = 0.021]. The vitreous/serum ratio was high (55.5:1 and 16:1, respectively), suggesting intraocular production. TNF‐α was lower in diabetic [18.0 (8.0–46.0) pg/ml] than in non‐diabetic subjects [22.0 (13.0–47.0) pg/ml; p = 0.034], but the vitreous/serum ratio was elevated in both groups (2:1 and 3.4:1, respectively). TNF‐α levels were higher in serum from diabetic subjects [9.0 (5.0–53.0) pg/ml versus 6.7 (3.0–11.0) pg/ml; p < 0.001]. Aqueous levels of inflammatory mediators did not differ between diabetic subjects with NDR/NPDR and non‐diabetic subjects despite elevated TNF‐α in serum [27.8 (6.8–153.7) pg/ml versus 16.4 (4.1–42.4) pg/ml; p = 0.021]. Conclusion: Intraocular inflammation seems to be involved in PDR but does not seem to be prominent in early retinopathy stages, i.e. NDR or NPDR. Diabetic subjects have an overall increased inflammatory activity compared to non‐diabetic subjects, as demonstrated by increased serum levels of TNF‐α.     

Soluble cellular adhesion molecules in proliferative vitreoretinopathy and proliferative diabetic retinopathy.

PURPOSE. To measure vitreous levels of soluble intercellular adhesion molecule-1 (sICAM-1) and soluble vascular cellular adhesion molecule-1 (sVCAM-1) in the eyes of patients with retinal detachment (RD) due to proliferative diabetic retinopathy (PDR) or proliferative vitreoretinopathy (PVR) and to determine whether the levels of these mediators correlated with clinical parameters of disease. METHODS. Undiluted vitreous specimens were collected from 50 eyes of 48 patients undergoing vitrectomy for traction RD due to PDR (21 specimens) and recurrent RD due to PVR (19 specimens). Control vitreous specimens were obtained from patients undergoing macular hole repair (10 specimens). The levels of sICAM-1 and sVCAM-1 were measured in each sample by specific enzyme-linked immunoadsorbent assays. RESULTS. Vitreous levels of sICAM-1 were significantly increased in vitreous specimens from both PVR (median +/- SD; 12.0 +/- 76.3 ng/ml; P < 0.01) and PDR (8.4 +/- 24.0 ng/ml; P < 0.01) when compared to vitreous from eyes with macular holes (0. 3 +/- 4.2 ng/ml). Vitreous levels of sVCAM-1 were significantly increased in both PVR (36.5 +/- 255.2 ng/ml; P < 0.001) and PDR (26. 2 +/- 93.5 ng/ml; P < 0.01) when compared to control vitreous (17.7 +/- 7.8 ng/ml). The vitreous levels of sICAM-1 were higher in cases of PDR which developed recurrent proliferative disease (P < 0.01) and recurrent RD (P = 0.01), whereas the levels of sICAM-1 in PVR and sVCAM-1 in PDR and PVR did not significantly correlate with these clinical parameters. CONCLUSIONS. Soluble forms of ICAM-1 and VCAM-1 are increased in the vitreous cavity of patients with RD due to PDR or PVR, reflecting the inflammatory nature of these conditions and suggesting a possible role for these mediators in the pathogenesis of proliferative retinal disease. The vitreous levels of these sCAMs at the time of surgery may serve as a marker of inflammation, but their specific levels do not predict the likelihood of recurrent proliferation or surgical anatomic success in most cases of PVR and PDR.     

Levels of human tissue kallikrein in the vitreous fluid of patients with severe proliferative diabetic retinopathy

The aim of this study was to determine the levels of human tissue kallikrein in the vitreous fluid of patients with severe proliferative diabetic retinopathy (PDR). Tissue kallikrein levels were measured using a specific ELISA (range: 0.4-25 ng/ml) in 7 vitreous fluids from eyes with severe PDR. Seven vitreous samples from eyes which underwent vitrectomy because of rhegmatogenous retinal detachment served as non-PDR controls. Enzymatic activity was also tested by an amidolytic assay using a chromogenic substrate. In the PDR patients, vitreous tissue kallikrein was <0.4 ng/ml (5 eyes) or very low (0.52 and 0.58 ng/ml). Vitreous tissue kallikrein was <0.4 ng/ml in all non-PDR controls. These results were confirmed by the amidolytic test. Results suggest that vitreous tissue kallikrein probably plays either a secondary or no role in the pathogenesis of PDR.     

Risk evaluation of outcome of vitreous surgery for proliferative diabetic retinopathy based on vitreous level of vascular endothelial growth factor and angiotensin II

AIMS: To ascertain whether measurement of the vitreous fluid levels of vascular endothelial growth factor (VEGF) or angiotensin II (Ang II) could predict the outcome of vitreous surgery in patients with proliferative diabetic retinopathy (PDR). METHODS: A prospective observational case study was performed in 61 consecutive patients (61 eyes) with PDR who underwent vitreoretinal surgery. Vitreous fluid samples were obtained during surgery. The VEGF level in vitreous fluid and plasma was determined by enzyme linked immunosorbent assay, while the Ang II level was measured by radioimmunoassay. Patients were prospectively followed for 6 months and the postoperative outcome was analysed by logistic regression analysis. RESULTS: No improvement and/or progression of PDR was seen in 15 (25%) of the 61 eyes. Vitreous levels of VEGF and Ang II were significantly higher in eyes with progression of PDR than in eyes with regression of PDR (p = 0.0044, and p = 0.0178, respectively). Multivariate logistic regression analysis showed that the vitreous VEGF level increased along with the progression of PDR after vitreous surgery (odds ratio 2.48, p = 0.0008). CONCLUSION: A high vitreous fluid VEGF level is associated with a significant risk of postoperative progression of PDR. The vitreous level of VEGF at the time of surgery may be a useful predictor of the outcome.     

Levels of pentosidine in the vitreous of eyes with proliferative diabetic retinopathy,proliferative vitreoretinopathy and retinal detachment

Background Advanced glycosylation end products (AGEs) are thought to play an important role in the pathophysiology of diabetes. Particularly, these products have been implicated in the pathogenesis of proliferative diabetic retinopathy. The majority of these products are formed from a vast range of precursor molecules, the variable chemical nature of which contributes to AGE heterogeneity. There is a growing population of structurally defined AGE adducts such as pyrraline, pentosidine, CML and crossline that have been found to be elevated in diabetic tissues. In the present study, the levels of the glycoxidation product pentosidine were determined in vitreous samples obtained during vitrectomy from eyes with proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR), and retinal detachment (RD). Samples from cadaveric control eyes were also included in the study. The levels of pentosidine were compared among the groups. Methods Seventy-three vitreous samples were collected from eyes undergoing vitrectomy for PDR (n=33), PVR (n=28) and RD (n=12). Eighteen samples from cadaveric control eyes were also included in the study. A modified Bradford’s method was used to assay protein content, and vitreous levels of pentosidine were determined by high-performance liquid chromatography after acid hydrolysis and pretreatment with SP-Sephadex. Statistical analyses were performed using a two-sided Mann–Whitney U test. Results The levels of pentosidine [median (interquartile range)] were 0.92 (0.55–1.26) pmol/mg of protein in the PDR cases, 1.12 (0.46–1.80) pmol/mg of protein in PVR, and 1.02 (0.24–1.44) pmol/mg of protein in RD. In the cadaveric control eyes pentosidine levels were 0.97 (0.68–1.30) pmol/mg of protein. The pentosidine levels of the four groups did not differ significantly. Conclusions The levels of the glycoxidation product pentosidine (expressed as pmol/mg of protein) in the vitreous of eyes with PDR do not differ significantly from those in the vitreous of eyes with PVR, RD or cadaveric control eyes. Although these results do not refute the findings of previous studies that evaluated globally total AGE levels and the existence of diabetic vitreopathy, further investigation is needed to fully understand their relevance in this multifactorial disorder. None of the authors has a financial interest in any product mentioned. The authors have full control of all primary data and they agree to allow Graefe’s Archive for Clinical and Experimental Ophthalmology to review their data if requested.     

Expression of thrombospondin‐2 as a marker in proliferative diabetic retinopathy

Purpose: To determine the expression of the endogenous anti‐angiogenic and pro‐fibrotic matricellular protein thrombospondin (TSP)‐2 and its receptors CD36 and CD47 in proliferative diabetic retinopathy (PDR). In addition, we examined the expression of TSP‐2 in the retinas of diabetic rats. Methods: Epiretinal membranes from 14 patients with PDR and nine patients with proliferative vitreoretinopathy were studied by immunohistochemistry. Vitreous samples from 30 PDR and 25 nondiabetic patients were studied by enzyme‐linked immunosorbent assay. Vitreous samples and retinas of rats were examined by Western blotting. Results: In epiretinal membranes, vascular endothelial cells and myofibroblasts expressed TSP‐2, CD36 and CD47. In PDR membranes, significant correlations were observed between numbers of blood vessels expressing the panendothelial cell marker CD34 and numbers of blood vessels and stromal cells expressing TSP‐2, CD36 and CD47. The numbers of blood vessels and stromal cells expressing CD34, TSP‐2, CD36 and CD47 were significantly higher in membranes with active neovascularization when compared with those with quiescent disease. Thrombospondin‐2 levels in vitreous samples from PDR patients were significantly higher than those in control patients without diabetes (p < 0.001). Western blot analysis revealed a significant increase in the expression of intact and cleaved TSP‐2 in vitreous samples from PDR patients and in the retinas of diabetic rats compared to nondiabetic controls. Conclusions: Upregulation of TSP‐2 may be a protective mechanism against inflammation and angiogenesis associated with PDR.     

Possible involvement of endothelin-1 and nitric oxide in the pathogenesis of proliferative diabetic retinopathy.

BACKGROUND: Overproduction of endothelin-1 (ET-1) and nitric oxide (NO) in the retina is demonstrated in experimental diabetic animals. To clarify the possible involvement of ET-1 and NO in the pathogenesis of diabetic retinopathy, the authors examined the vitreous levels of these principal endothelium-derived vasoactive substances in patients with proliferative diabetic retinopathy (PDR). METHODS: Vitreous fluid was taken from patients with PDR (ET-1, n = 12; NO, n = 12) and from patients with macular holes as controls (ET-1, n = 10; NO, n = 10) at vitreous surgery. Endothelin-1 and NO metabolites were measured by radioimmunoassay and high-performance liquid chromatography based on the Griess method, respectively. RESULTS: Endothelin-1 levels (mean +/- SE) were 21.5 +/- 1.7 pg/mL in the vitreous of patients with PDR and 16.7 +/- 0.7 pg/mL in the vitreous of patients with macular hole. There was a significant difference between patients with PDR and controls (P = 0.009, Mann-Whitney). Nitrate (NO3) was 49.8 +/- 5.0 micromol/L in patients with PDR and 24.2 +/- 2.8 micromol/L in patients with macula hole; it was also significantly elevated in patients with PDR (P = 0.004, Mann-Whitney), whereas nitrite (NO2) was not detected in this study. CONCLUSION: These results indicate that ET-1 and NO may be related in the pathogenesis of PDR.     

Correlation between angiotensin-converting enzyme, vascular endothelial growth factor, and matrix metalloproteinase-9 in the vitreous of eyes with diabetic retinopathy

PURPOSE: To investigate the involvement of angiotensin-converting enzyme (ACE) with angiogenic factors, vascular endothelial growth factor (VEGF), and matrix metalloproteinase (MMP)-9 in the vitreous of eyes with proliferative diabetic retinopathy (PDR). DESIGN: Observational case series. METHODS: Angiotensin-converting enzyme activity in the vitreous was measured by using a synthetic substrate for ACE. VEGF and MMP-9 concentrations were determined by enzyme-linked immunosorbent assay. RESULTS: Vitreous ACE activity was significantly higher in eyes with PDR (1.4 +/- 1.3 mU/ml) than in eyes with macular holes (0.22 +/- 0.11 mU/ml). Vitreous VEGF concentration in the eyes with PDR (1067 +/- 1076 pg/ml) was significantly higher than in eyes with macular holes (34 +/- 5.5 pg/ml). Vitreous MMP-9 concentration was also significantly higher in eyes with PDR (7.5 +/- 3.8 ng/ml) than in eyes with macular holes (4.2 +/- 1.4 ng/ml). Significant correlations between ACE and VEGF (P < .01) and between ACE and MMP-9 (P < .01) were observed in the vitreous of eyes with PDR. CONCLUSIONS: Angiotensin-converting enzyme was significantly correlated with angiogenic factors, VEGF and MMP-9, in the vitreous of eyes with PDR.     

A proposed new classification for diabetic retinopathy: the concept of primary and secondary vitreopathy

BACKGROUND: Many eyes with proliferative diabetic retinopathy (PDR) require vitreous surgery despite complete regression of new vessels with pan retinal laser photocoagulation (PRP). Changes in the vitreous caused by diabetes mellitus and diabetic retinopathy may continue to progress independent of laser regressed status of retinopathy. Diabetic vitreopathy can be an independent manifestation of the disease process. AIM: To examine this concept by studying the long-term behavior of the vitreous in cases of PDR regressed with PRP. MATERIALS AND METHODS: Seventy-four eyes with pure PDR (without clinically evident vitreous traction) showing fundus fluorescein angiography (FFA) proven regression of new vessels following PRP were retrospectively studied out of a total of 1380 eyes photocoagulated between March 2001 and September 2006 for PDR of varying severity. Follow-up was available from one to four years. RESULTS: Twenty-three percent of eyes showing FFA-proven regression of new vessels with laser required to undergo surgery for indications produced by vitreous traction such as recurrent vitreous hemorrhage, tractional retinal detachment, secondary rhegmatogenous retinal detachment and tractional macular edema within one to four years. CONCLUSION: Vitreous changes continued to progress despite regression of PDR in many diabetics. We identifies this as "clinical diabetic vitreopathy" and propose an expanded classification for diabetic retinopathy to signify these changes and to redefine the indications for surgery.     

血管内皮细胞生长因子、谷氨酸、γ-氨基丁酸与增生性糖尿病视网膜病变的新生血管形成

目的 探讨血管内皮细胞生长因子(vascular endothelial growth factor,VEGF)、谷氨酸与-γ-氨基丁酸(γ- aminobutyric acid,GABA)在增生性糖尿病视网膜病变(proliferative diabetic retinopathy,PDR)新生血管形成中的作用。 方法 用定量双夹心酶联免疫吸附法检测25例PDR患者27只眼玻璃体VEGF含量,用高效液相色谱法检测其玻璃体氨基酸含量,并与14例特发性黄斑裂孔患者14只眼中玻璃体VEGF、谷氨酸和GABA的含量相比较。分析玻璃体VEGF含量与氨基酸含量的相关关系。 结果 PDR组患者玻璃体VEGF含量(中位数0.41 ng/ml,四分位间距0.54 ng/ml)显著高于对照组(中位数0.017 ng/ml,四分位间距0.01 ng/ml)(P<0.001)。PDR组患者玻璃体谷氨酸含量[(11.7±3.0) μmol/L]和GABA含量[(7.2±3.9)μmol/L]亦显著高于对照组谷氨酸含量[(5.8±0.7)μmol/L]和GABA含量[(3.3±2.9)μmol/L](P<0.05)。 相关分析表明,谷氨酸、GABA均与VEGF含量有显著正相关关系。 结论 PDR患者玻璃体谷氨酸、GABA含量增高表明有视网膜缺血,它们与VEGF含量的正相关关系为视网膜缺血诱导新生血管产生提供了生物化学依据,也为PDR的治疗提供了新思路。(中华眼底病杂志,2000,16:162-165)     

Soluble TNF receptors in vitreoretinal proliferative disease

PURPOSE: To measure vitreous levels of soluble TNF-receptors (sTNF-Rs) types I and II in eyes with rhegmatogenous retinal detachment (RRD), uncomplicated or complicated with proliferative vitreoretinopathy (PVR), and in eyes with proliferative diabetic retinopathy (PDR). To examine whether there is any relationship between vitreous levels of sTNF-Rs and clinical features of these conditions and between vitreous sTNF-Rs and TNFalpha levels and serum levels of sTNF-RS: METHODS: Vitreous levels of sTNF-Rs and TNFalpha were measured by enzyme-linked immunosorbent assay in 30 eyes with PVR, 30 eyes with uncomplicated RRD, and 29 eyes with PDR. Vitreous from eyes of 10 deceased donors and 9 eyes with macular holes served as control specimens. Serum levels of sTNF-Rs were measured in 17 patients with PDR and 21 patients with PVR. RESULTS: Vitreous levels of sTNF-Rs I and II were increased in eyes with PVR, RRD, and PDR when compared with control eyes (P < 0.002). However, vitreous levels of sTNF-Rs I and II were higher in eyes with PVR than in eyes with RRD (P < 0.01) or PDR (P < 0.03). This contrasted with the findings that serum sTNF-Rs were higher in PDR than in PVR (P < 0.016) and that vitreous levels of TNFalpha were higher in eyes with PDR than in eyes with PVR (P < 0.0005). In PVR, vitreous sTNF-Rs levels were associated with the duration of retinal detachment, number of previous external operations, and grade of severity, whereas in PDR these levels were not related to the type or duration of diabetes or its complication with traction retinal detachment. CONCLUSIONS: These observations suggest the existence of TNF inhibitory mechanisms within the eye during retinal processes of inflammation and angiogenesis. That high vitreous levels of sTNF-Rs relate to severity of retinopathy suggests that these molecules may constitute reactive products of inflammation. Effective control of TNFalpha activity by sTNF-Rs within the retinal microenvironment may determine the outcome and severity of retinal proliferative conditions.