Expression of myofibroblast activation molecules in proliferative vitreoretinopathy epiretinal membranes

Purpose: Fibrotic disorders are associated with activation of fibroblasts into extracellular matrix‐secreting myofibroblasts expressing α‐smooth muscle actin (α‐SMA). Myofibroblasts are the predominant cellular component of proliferative vitreoretinopathy (PVR) epiretinal membranes. We investigated the expression of molecules involved in myofibroblast activation, migration and proliferation in PVR epiretinal membranes. Methods: Fifteen membranes were studied by immunohistochemical techniques using monoclonal and polyclonal antibodies directed against snail, fibroblast activation protein (FAP), CD44, hydrogen peroxide‐inducible clone‐5 (Hic‐5), galectin‐3, interleukin‐13 receptor α2 (IL‐13Rα2) and receptor for advanced glycation end products (RAGE). Results: Myofibroblasts expressing α‐SMA were present in all membranes. Myofibroblasts expressed nuclear immunoreactivity for Snail and Hic‐5, cytoplasmic immunoreactivity for FAP, IL‐13Rα2 and RAGE and membranous immunoreactivity for CD44. There was no immunoreactivity for galectin‐3. The number of cells expressing α‐SMA correlated significantly with the number of cells expressing Snail (r = 0.56; p = 0.03), Hic‐5 (r = 0.526; p = 0.044), IL‐13Rα2 (r = 0.773; p = 0.001) and RAGE (r = 0.734; p = 0.002). Conclusions: Snail, FAP, CD44, Hic‐5, IL13Rα2 and RAGE may be involved in proliferative events occurring in PVR.     

Circulating bone‐marrow‐derived endothelial precursor cells contribute to neovascularization in diabetic epiretinal membranes

Purpose: The role of vasculogenesis, recruitment and differentiation of circulating bone‐marrow‐derived endothelial precursor cells into mature endothelium in proliferative diabetic retinopathy (PDR) remains undefined. We investigated the presence of bone‐marrow‐derived endothelial precursor cells and the expression of the chemotactic pathway SDF‐1/CXCL12?CXCR4 in PDR epiretinal membranes. Methods: Membranes from eight patients with active PDR and nine patients with inactive PDR were studied by immunohistochemistry using antibodies against CD133, vascular endothelial growth factor receptor‐2 (VEGFR‐2), CD14, SDF‐1 and CXCR4. Results: Blood vessels expressed CD133, VEGFR‐2, CD14, SDF‐1 and CXCR4 in 10, 10, 10, seven and seven out of 17 membranes, respectively. There were significant correlations between number of blood vessels expressing CD34 and number of blood vessels expressing CD133 (r_s = 0.646; p = 0.005), VEGFR‐2 (r_s = 0.704; p = 0.002), CD14 (r_s = 0.564; p = 0.018) and SDF‐1 (r_s = 0.577; p = 0.015). Stromal cells in close association with blood vessels expressed CD133, VEGFR‐2, CD14 and CXCR4 in 10, 12, 13 and 14 membranes, respectively. The number of blood vessels expressing CD133 (p = 0.013), VEGFR‐2 (p = 0.005), CD14 (p = 0.008) and SDF‐1 (p = 0.005), and stromal cells expressing CD133 (p = 0.003), VEGFR‐2 (p = 0.013) and CD14 (p = 0.002) was significantly higher in active membranes than in inactive membranes. Conclusion: Bone‐marrow‐derived CD133⁺ endothelial progenitor cells and CD14⁺ monocytes may contribute to vasculogenesis in PDR.     

Expression of autotaxin and acylglycerol kinase in proliferative vitreoretinal epiretinal membranes

Purpose: Lysophosphatidic acid (LPA)/LPA₁ receptor pathway is involved in inflammation, angiogenesis and fibrosis. This study was conducted to analyse the expression of LPA‐producing enzymes, autotaxin (ATX) and acylglycerol kinase (AGK) and LPA₁ receptor, in proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR) epiretinal membranes. Methods: Nine active and 13 inactive membranes from patients with PDR and 21 membranes from patients with PVR were studied by immunohistochemistry. Results: In PDR membranes, vascular endothelial cells expressed ATX and AGK in 16 and 19 membranes, respectively. Stromal cells expressed ATX and AGK in 19 and 22 membranes, respectively. Immunoreactivity for LPA₁ receptor was noted in vascular endothelial cells and stromal cells in the five membranes stained for LPA₁ receptor. Numbers of blood vessels and stromal cells expressing CD34, ATX and AGK were significantly higher in active membranes than in inactive membranes. Significant correlations were detected between number of blood vessels expressing the panendothelial cell marker CD34 and number of blood vessels and stromal cells expressing ATX and AGK. In PVR membranes, spindle‐shaped myofibroblasts expressing α‐smooth muscle actin co‐expressed ATX, AGK and LPA₁ receptor. Conclusions: The LPA/LPA₁ receptor pathway may be involved in inflammatory, angiogenic and fibrotic responses in proliferative vitreoretinal disorders.     

Expression of advanced glycation end products and related molecules in diabetic fibrovascular epiretinal membranes

Purpose: To investigate associations between expressions of advanced glycation end products (AGEs), transforming growth factor‐β (TGF‐β), tumour necrosis factor‐α (TNF‐α) and integrins and correlations between their expression and level of vascularization and proliferative activity in diabetic fibrovascular epiretinal membranes. Methods: Membranes from eight patients with active proliferative diabetic retinopathy and nine patients with inactive proliferative diabetic retinopathy were studied by immunohistochemistry. Results: Blood vessels expressed AGEs, TGF‐β, TNF‐α and α_vβ₃ integrin in 5, 13, 8 and 8 membranes, respectively. Stromal cells expressed AGEs, TNF‐α and α_vβ₃ integrin in 15, 13 and 3 membranes, respectively. There was no immunoreactivity for α_vβ₅, α₅β₁ and α₂β₁ integrins. There were significant correlations between number of blood vessels expressing CD34 and number of blood vessels expressing AGEs (r_s = 0.496; P = 0.043), TGF‐β (r_s = 0.777; P < 0.001) and TNF‐α (r_s = 0.699; P = 0.002). There were significant correlations between number of blood vessels expressing AGEs and number of blood vessels expressing TGF‐β (r_s = 0.532; P = 0.028) and TNF‐α (r_s = 0.626; P = 0.007). The correlation between number of blood vessels expressing TNF‐α and α_vβ₃ integrin was significant (r_s = 0.617; P = 0.008). Number of blood vessels expressing CD34 (P = 0.001), TGF‐β (P = 0.006) and TNF‐α (P = 0.002) and stromal cells expressing AGEs (P = 0.001) and TNF‐α (P = 0.004) were significantly higher in active membranes than in inactive membranes. Conclusion: Interactions of AGEs, TGF‐β, TNF‐α and α_vβ₃ integrin might be involved in pathogenesis of proliferative diabetic retinopathy fibrovascular proliferation.     

玻璃体腔注射Bevacizumab对PDR患者增殖膜中CTGF及PEDF的影响

目的:研究增殖性糖尿病视网膜病变(PDR)玻璃体腔注射抗-VEGF药物bevacizumab后对增殖膜中结缔组织生长因子(CTGF)及色素上皮衍生因子(PEDF)的影响.方法:回顾2015-01/2016-12入本院行增殖性糖尿病视网膜病变治疗的患者117例126眼,采用病例对照的研究方法,将所选病例随机分为两组,分别为A组60例63眼和B组57例63眼.其中A组单纯进行玻璃体切割手术,B组患者在玻璃体切割术前玻璃体腔注射0.05mL/1.25mg bevacizumab.在手术中剥离取用两组患者的视网膜增殖膜进行染色,然后进行组织病理学观察,观察两组患者视网膜增殖膜中原始细胞和新生血管的变化,以及患者增殖膜中CTGF和PEDF因子的表达.结果:在对两组患者CTGF、PEDF因子表达进行观察发现,两组患者视网膜增殖膜中的CTGF和PEDF都在细胞质内表达.其中A组呈现出38眼阳性表达,阳性表达率为60.3%,相比于A组而言,B组的CTGF的阳性表达率92.1%明显更高,两组差异有统计学意义(P<0.05).而两组的PEDF阳性表达率分别为90.5%和95.2%,差异无统计学意义(P>0.05).结论:PDR患者在玻璃体腔注射抗VEGF药物bevacizumab后,视网膜的新生血管明显减少,有利于玻璃体切割手术的进行.且PDR患者玻璃体腔注射bevacizumab后,CTGF的阳性表达率明显增高,而PEDF因子在前膜上的表达则没有明显的变化.     

Matrix metalloproteinases and their natural inhibitors in fibrovascular membranes of proliferative diabetic retinopathy

AIM: To examine epiretinal membranes of proliferative diabetic retinopathy (PDR) for the presence of selective matrix metalloproteinases (MMPs) and their natural inhibitors (TIMPs), in order to determine whether neovascularisation and fibrosis, characteristic of this complication of diabetes mellitus, are associated with specific anomalies of MMP or TIMP expression. METHODS: The presence of selected MMPs and TIMPs was investigated in 24 fibrovascular epiretinal membranes of PDR, and the findings compared with that observed in 21 avascular epiretinal membranes of proliferative vitreoretinopathy (PVR) and five normal retinas. Specimens were examined for deposition of interstitial collagenase (MMP-1), stromelysin-1 (MMP-3), gelatinase A (MMP-2), gelatinase B (MMP-9), and three tissue inhibitors of metalloproteinases (TIMP-1, TIMP-2, and TIMP-3). RESULTS: The results showed that unlike normal retina, which constitutively expresses MMP-1 and TIMP-2, a large proportion of PDR membranes (> 62%) stained for MMP-1, MMP-2, MMP-3, MMP-9, TIMP-1, TIMP-2, and TIMP-3. There were no differences in the expression of these molecules when compared with PVR membranes. A characteristic staining for MMP-9 was observed within the perivascular matrix of PDR membranes, and there was a significant increase in TIMP-2 expression by PDR membranes (p= 0.036) when compared with PVR membranes. CONCLUSIONS: The findings that MMPs involved in degradation of fibrovascular tissue matrix, as well as TIMP-1 and TIMP-2, are found in a large proportion of PDR membranes, and that their expression does not differ from that of PVR membranes, suggest the existence of common pathways of extracellular matrix degradation in pathological processes leading to retinal neovascularisation and fibrosis.     

Myeloid-Related Protein-14/MRP-14/S100A9/Calgranulin B is Associated with Inflammation in Proliferative Diabetic Retinopathy

Purpose: To investigate the expression of the leukocyte proteins myeloid-related protein (MRP)-8 and MRP-14 in proliferative diabetic retinopathy (PDR) and the effect of MRP-8/MRP-14 (calprotectin) heterodimer on induction of proinflammatory factors in human retinal microvascular endothelial cells (HRMEC).

Methods: Epiretinal membranes from 20 patients with PDR and 10 patients with proliferative vitreoretinopathy (PVR), vitreous fluid samples from PDR and non-diabetic subjects and HRMEC were studied by immunohistochemistry and Western blot analysis.

Results: MRP-14 expression was localized in endothelial cells, leukocytes and myofibroblasts in all PDR membranes. MRP-8 expression was limited to intravascular leukocytes in 42% of the studied membranes. In PVR membranes, MRP-14 was expressed in leukocytes and myofibroblasts, whereas MRP-8 immunoreactivity was limited to leukocytes. MRP-14 was significantly upregulated in vitreous from PDR patients. MRP-8/MRP-14 (calprotectin) increased expression of intercellular adhesion molecule-1, but attenuated vascular cell adhesion molecule-1 expression in HRMEC.

Conclusions: Increased MRP-14 levels are associated with inflammation in PDR.     

Unbalanced Vitreous Levels of Osteoprotegerin,RANKL, RANK,and TRAIL in Proliferative Diabetic Retinopathy

Purpose: We investigated the expression of the proinflammatory and proangiogenic factor osteoprotegerin (OPG) and its ligands, receptor activator of nuclear factor-κB ligand (RANKL), tumor necrosis factor-related apoptosis-inducing ligand (TRAIL), and the receptor RANK in proliferative diabetic retinopathy (PDR).

Materials and methods: Vitreous samples from PDR and nondiabetic control patients and epiretinal membranes from PDR patients were studied by enzyme-linked immunosorbent assay, immunohistochemistry, and Western blot analysis.

Results: Vascular endothelial growth factor, OPG, and soluble RANK levels in vitreous samples from PDR patients were significantly higher than that in nondiabetic controls. Soluble TRAIL levels were significantly lower in PDR patients than that in nondiabetic control, whereas soluble RANKL levels did not differ significantly. RANKL, RANK, and TRAIL were expressed in vascular endothelial cells, myofibroblasts, and CD45-expressing leukocytes in PDR epiretinal membranes.

Conclusions: Dysregulated expression of OPG/RANKL/RANK pathway and TRAIL might be related to inflammation and angiogenesis in PDR.     

Upregulation of RAGE and its ligands in proliferative retinal disease

We sought to study the presence of the receptor for advanced glycation endproducts (RAGE) and its ligands, advanced glycation endproducts (AGEs), S100/calgranulins and amphoterin (high mobility group box 1 protein; HMGB1), in the vitreous cavity and epiretinal membranes (ERMs) of eyes of patients with proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR). Undiluted vitreous specimens were collected from 30 eyes of 30 patients undergoing pars plana vitrectomy for repair of retinal detachment (RD) secondary to PDR (n = 15) or PVR (n = 15). The vitreous samples obtained from 10 eyes undergoing macular hole repair were used as controls. Epiretinal membranes were obtained from eight eyes with PDR and from 10 eyes with PVR. The levels of AGEs in the vitreous were measured using ELISA. The vitreous levels of soluble RAGE (sRAGE), S100/calgranulins and amphoterin were measured using Western blot analyses. The localization of RAGE and its ligands in ERMs was determined with immunohistochemistry. The vitreous levels of sRAGE were significantly increased in both PDR and PVR (p < or = 0.05) compared to control vitreous. In both PDR and PVR, the vitreous levels of AGEs (p < or = 0.01), S100/calgranulins (p < or = 0.05), and amphoterin (p < or = 0.01) were also elevated compared to control eyes. Expression of RAGE was detected in six of eight ERMs from eyes with PDR and eight of 10 ERMs from eyes with PVR. Many cells expressing RAGE also expressed vimentin, suggesting a glial cell origin. Ligands for RAGE were also detected in ERMs, with AGEs detected in five eyes with PDR and eight eyes with PVR. Similarly, S100 and amphoterin ERM expression was observed in six eyes with PDR; these ligands were also expressed in ERMs from eyes with PVR (8 and 7 cases, respectively). We conclude that RAGE and its ligands are increased in the vitreous cavity of eyes with PDR and PVR and are present in ERMs of eyes with these proliferative retinal disorders. These findings suggest a role for the proinflammatory RAGE axis in the pathogenesis of proliferative retinal diseases.     

Basic fibroblast growth factor mRNA, bFGF peptide and FGF receptor in epiretinal membranes of intraocular proliferative disorders (PVR and PDR)

Basic fibroblast growth factor (bFGF) has been shown to be involved in epiretinal membrane formation in proliferative vitreoretinal disorders. However, up to now, little knowledge exists, as to the actual cellular source of this potent mitogen.We examined 20 epiretinal membranes from patients with proliferative diabetic retinopathy (PDR) (n = 12) and proliferative vitreoretinopathy (PVR) (n = 8) for the presence of bFGF peptide, fibroblast growth factor receptor-1 (FGFR-1) and bFGF messenger ribonucleic acid (mRNA).Using a specific antibody, we detected bFGF peptide in most (8/10) examined PDR membranes and in all (8/8) PVR membranes. Moreover, we found positive staining for the corresponding receptor.Local production of bFGF in epiretinal membranes was confirmed by nonisotopic in situ hybridisation for bFGF mRNA in some (4/7) examined PDR membranes and some (3/4) examined PVR membranes. All membranes which contained bFGF mRNA were also positive for bFGF peptide.In conclusion, bFGF is produced and stored in epiretinal membranes. Together with the corresponding receptor, bFGF may play a role in the auto- and paracrine control of the proliferative processes at the vitroretinal interface.Abbreviations aFGF acidic fibroblast growth factor - bFGF basic fibroblast growth factor - FGFR-1 fibroblast growth factor receptor-1 - mRNA messenger ribonucleic acid     

CD146/Soluble CD146 Pathway Is a Novel Biomarker of Angiogenesis and Inflammation in Proliferative Diabetic Retinopathy

PurposeInflammation, angiogenesis and fibrosis are pathological hallmarks of proliferative diabetic retinopathy (PDR). The CD146/sCD146 pathway displays proinflammatory and proangiogenic properties. We investigated the role of this pathway in the pathophysiology of PDR.MethodsVitreous samples from 41 PDR and 27 nondiabetic patients, epiretinal fibrovascular membranes from 18 PDR patients, rat retinas, human retinal microvascular endothelial cells (HRMECs) and human retinal Müller glial cells were studied by ELISA, Western blot analysis, immunohistochemistry and immunofluorescence microscopy analysis. Blood-retinal barrier breakdown was assessed with fluorescein isothiocyanate-conjugated dextran.ResultssCD146 and VEGF levels were significantly higher in vitreous samples from PDR patients than in nondiabetic patients. In epiretinal membranes, immunohistochemical analysis revealed CD146 expression in leukocytes, vascular endothelial cells and myofibroblasts. Significant positive correlations were detected between numbers of blood vessels expressing CD31, reflecting angiogenic activity of PDR, and numbers of blood vessels and stromal cells expressing CD146. Western blot analysis showed significant increase of CD146 in diabetic rat retinas. sCD146 induced upregulation of phospho-ERK1/2, NF-κB, VEGF and MMP-9 in Müller cells. The hypoxia mimetic agent cobalt chloride, VEGF and TNF-α induced upregulation of sCD146 in HRMECs. The MMP inhibitor ONO-4817 attenuated TNF-α-induced upregulation of sCD146 in HRMECs. Intravitreal administration of sCD146 in normal rats significantly increased retinal vascular permeability and induced significant upregulation of phospho-ERK1/2, intercellular adhesion molecule-1 and VEGF in the retina. sCD146 induced migration of HRMECs.ConclusionsThese results suggest that the CD146/sCD146 pathway is involved in the initiation and progression of PDR.     

Interleukin (IL)-6, Interleukin (IL)-8 Levels and Cellular Composition of the Vitreous Humor in Proliferative Diabetic Retinopathy,Proliferative Vitreoretinopathy,and Traumatic Proliferative Vitreoretinopathy

Purpose: To investigate the interleukin (IL)-6 levels, IL-8 levels, and cellular composition of the vitreous humor in patients with proliferative diabetic retinopathy (PDR), proliferative vitreoretinopathy (PVR), and traumatic PVR. Methods: Vitreous samples from 14 patients with PDR, 10 patients with PVR, and 10 patients with traumatic PVR were analyzed. Fifteen cadaver eyes were used as controls. Cytokine levels were measured by ELISA. Results: Elevated IL-6 levels were detected in the vitreous of 12 (85.7%) of the PDR patients, eight (80%) of the PVR patients, and all (100%) of the traumatic PVR patients. None of the control IL-6 results were elevated. Vitreous IL-8 levels were elevated in 12 (85.7%) of the PDR patients, six (60%) of the PVR patients, all (100%) of the traumatic PVR patients, and one (6.7%) of the control eyes. Cytological examination of the vitreous specimens revealed a predominance of macrophages (50%) in the PDR samples and a predominance of retinal pigment epithelial (RPE) cells (60%) in the PVR samples. In contrast, neutrophils predominated (88%) in the traumatic PVR samples. Conclusion: The findings suggest that IL-6 and IL-8 may be involved in the pathogenesis of PDR, PVR, and traumatic PVR. High proportions of RPE cells and macrophages are associated with elevated IL-6 and IL-8 levels in the vitreous of PDR and PVR patients; however, the fact that these cells are not predominant in traumatic PVR suggests that different immune response mechanisms may be active in the pathogenesis of these disorders.     

Morphological study on the intraocular proliferative membrane of proliferative diabetic retinopathy and proliferative vitreoretinopathy

The membranes from 42 eyes with PDR and 8 eyes with PVR were removed during vitreous surgery. In 12 of those with PDR and 3 of the cases with PVR, the reproliferated membranes formed beneath silicone oil (SO) were removed and were histologically and immunohistochemically examined, using morphometrical quantitative analysis. In each case, area coefficient, fibrous content and the number of new vessels, and thick basement membranes, increased wall cells and multilayer basement membranes of new vessels were studied. In both PDR and PVR, the number of cells per unit area tended to be increased with the period of time after SO was injected, while the percentage of fibrous components did not change. The Percentage of occurrence of each type of new vessels was almost the same in both primary and reproliferative PDR membranes. In the primary proliferative PDR membranes, endothelial cell proliferation was found predominantly, while glial hyperplasia was predominant in the primary proliferated PVR membranes and the reproliferated membranes under SO of PDR and PVR.     

Detection of eicosanoids in epiretinal membranes of patients suffering from proliferative vitreoretinal diseases

AIM—Arachidonic acid is metabolised via lipoxygenase to 15-HETE (15-hydroxyeicosatetraenoic acid) and 15-HPETE (15-hydroperoxyeicosatetraenoic acid), which are believed to influence proliferation in tissue culture. 15-HETE is the reduction product of 15-HPETE. Cell proliferation is believed to be decreased by 15-HPETE and increased by 15-HETE. The aim of this study was to investigate epiretinal membranes for the presence of these lipoxygenase products and to compare membranes from different disease processes.
METHODS—Epiretinal membranes of 15 patients suffering from proliferative vitreoretinopathy (PVR, n=7) and proliferative diabetic retinopathy (PDR; n=8) were removed during vitrectomy and analysed by means of thin layer chromatography. The plates were evaluated by digital image analysis.
RESULTS—Both 15-HETE and 15-HPETE were identified in membranes from eyes of patients with PVR and PDR with HETE values significantly higher (p<0.05) than HPETE values (HETE/HPETE ratio = 5.2).
CONCLUSION—This study demonstrates that eicosanoids are present in the epiretinal membrane tissue of patients with PVR and PDR. Considering that HETE increases cell proliferation while HPETE inhibits it, it is conceivable that eicosanoids are an additional factor contributing to the regulation of membrane growth in proliferative retinal disorders. Thus, inhibition of lipoxygenase could be a therapeutic approach in these diseases.

     

TGF-beta1, TGF-beta receptor II and ED-A fibronectin expression in myofibroblast of vitreoretinopathy

PURPOSE: Formation of scarlike epiretinal membranes (ERMs) constitutes potentially the end stage of evolution of proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Among various cellular populations, ERMs contain cells with contractile features typical of myofibroblasts. The current study was conducted to investigate the presence of transforming growth factor (TGF)-beta1, TGF-beta receptor II (RII) and ED-A fibronectin (FN), the main inducers of myofibroblastic differentiation in ERMs in PDR and PVR. METHODS: Samples of ERM were obtained from 23 patients during microsurgery for PVR or PDR. Electron microscopy, immunohistochemistry, and confocal microscopy with antibodies recognizing beta-smooth muscle (SM) actin, desmin, TGF-beta1, TGF-beta receptors I and II, and ED-A FN were performed. RESULTS: alpha-SM actin was detected in all ERMs, whereas desmin was present in 50% of the cases. ED-A FN was expressed in all ERMs in close relation with alpha-SM actin-positive myofibroblasts. In addition, TGF-beta1 and TGF-beta R II were always present, TGF-beta RII being expressed in both alpha-SM actin-positive and negative fibroblastic cells. CONCLUSIONS: Myofibroblast accumulation is a key event in ERM-associated traction retinal detachment occurring during PVR and PDR. The current results suggest that the presence of alpha-SM actin-positive myofibroblasts is probably dependent on the concomitant neoexpression of TGF-beta1, TGF-beta RII, and ED-A FN. The results furnish new data on the mechanism of alpha-SM actin stimulation in fibroblasts in a human pathologic setting.     

增生性玻璃体视网膜疾病眼内液血管内皮生长因子的表达

目的 观察增生性玻璃体视网膜疾病患者眼内液（房水、玻璃体）中血管内皮生长因子（VEGF）含量的变化规律，探讨VEGF在增生性玻璃体视网膜疾病发展变化中的作用。 方法 采用双抗体夹心酶联免疫吸附试验(ELISA)定量检测增生性玻璃体视网膜病变（PVR）、视网膜静脉阻塞（RVO）、增生性糖尿病视网膜病变（PDR）、新生血管性青光眼（NVG）患者组及正常对照组房水、玻璃体VEGF含量。 结果 PVR、RVO、PDR、NVG患者组房水及玻璃体VEGF含量均高于正常对照组，其差异均有统计学意义(P<0.05)；NVG、PDR、RVO、PVR患者组房水及玻璃体VEGF含量依次降低 ，其差异有统计学意义(P<0.05)；PVR、RVO、PDR、NVG患者组和正常对照组玻璃体VEGF含量均高于房水VEGF含量，其差异有统计学意义(P<0.05)；PVR患者病史与房水、玻璃体VEGF含量呈负相关（r分别为－0.819、－0.823，P＜0.05）；RVO患者病史与房水、玻璃体VEGF含量呈正相关（r分别为0.913、0.929，P＜0.05）；PDR患者玻璃体积血时间与房水、玻璃体VEGF含量呈正相关（r分别为0.905、0.920，P＜0.05）。 结论 增生性玻璃体视网膜疾病患者房水及玻璃体VEGF含量明显增高，VEGF可能在增生性玻璃体视网膜疾病发展变化中起着重要的作用。 (中华眼底病杂志， 2006， 22：313-316）     

The development of severe proliferative vitreoretinopathy after retinal detachment surgery

A prospective clinical study was conducted to determine wether preoperative proliferative vitreoretinopathy (PVR), grade B, was a significant risk factor in the development of severe PVR after surgery for retinal detachment repair. Two series of consecutive retinal detachments associated with horseshoe retinal tears were compared. The first series included 40 eyes of 40 patients with preoperative PVR, grade O - A. The second series included 30 eyes of 27 patients with preoperative PVR, grade B. All eyes were operated on with conventional microsurgical techniques. At the first operation, no vitrectomies were carried out in any eyes. The incidence of postoperative PVR, grades C and D, was 20% (6/30 eyes) after a single operation in the series of eyes with preoperative PVR, grade B as compared to 0% in the series of eyes with preoperative PVR, grade O - A. The difference between the two groups was statistically significant (P = 0.01). It was also found that the incidence of postoperative proliferative PVR was significantly higher in eyes with preoperative vitreous hemorrhage (30.7%) as compared to eyes with no preoperative vitreous hemorrhage (0%;P = 0.02). Incomplete posterior vitreous detachment without collapse of the vitreous gel occurred significantly more frequently in eyes with preoperative proliferative vitreoretinopathy, grade B (68.4%, than in eyes with preoperative proliferative vitreoretinopathy, grade O - A(27.5%;P = 0.02).     

Immunohistochemical study of extracellular matrix components in epiretinal membranes of vitreoproliferative retinopathy and proliferative diabetic retinopathy

PURPOSE: The migration, proliferation, differentiation, and adhesion of cells and other cellular functions are influenced by the surrounding extracellular matrix in normal and wound healing conditions. The formation of epiretinal membranes, a wound healing process, is a serious complication of retinal diseases, the most important being proliferative diabetic retinopathy (PDR) and proliferative vitreoretinopathy (PVR). In the present study, the authors investigated the expression of various extracellular matrix components and in particular tenascin, fibronectin, laminin, collagen IV, and MMP-3 glycoprotein as well as the expression of glial fibrillary acidic protein in each type of epithelial membrane in order to elucidate the role of these molecules in the formation of these two types of membranes. METHODS: The authors performed immunohistochemistry in 14 PVR and 14 PDR membranes, using antibodies against the above mentioned extracellular matrix components. Tenascin and fibronectin were observed as major components in the extracellular matrix, while laminin and collagen type IV were detected as minor components in both types of membranes. A higher fibronectin expression in PVR compared with PDR membranes was found (p=0.0035). A positive relationship of its expression with the proliferative activity (p=0.15) and collagen type IV expression (p<0.0001) was also observed. RESULTS: Tenascin expression was positively correlated with glial fibrillary acidic protein positive cells in PDR membranes (p=0.04). Collagen type IV localized around vessels was observed with high levels in PDR membranes (p=0.0031). CONCLUSIONS: The results indicated that the extracellular matrix components seem to be involved in PVR and PDR, contributing to tissue remodeling and perhaps by different pathogenetic pathways, which could reflect different stages of development in these two types of membranes.     

Pathomorphology of membranes appearing in proliferative vitreoretinopathies

Immunohistochemical techniques were used to investigate the cell content of epiretinal membranes occuring in proliferative vitreoretinopathy (PVR) and proliferative diabetic retinopathy (PDR). Ten epiretinal membranes were obtained during surgery from eyes with PVR and five from eyes with PDR. This material was studied histopathologically and immunohistochemically. Retinal pigment epithelial cells, glial cells, macrophages, T lymphocytes and type IV collagen were identified in these membranes. The findings indicate that the cells mentioned possess a potential role in creating vitreoretinal membranes in PVR and PDR.