Proliferative vitreoretinopathy (PVR) is a common complication and major cause of blindness of ocular trauma. Many cytokines, including vascular endothelial growth factor (VEGF) and platelet-derived growth factor (PDGF), participate in the process of the pathogenesis of traumatic PVR. VEGF competitively inhibits binding of PDGF to its receptor (PDGFRα), enables indirect activation of PDGFRα by non-PDGF ligands, resulting in reduced p53 expression, cell proliferation and migration, which is a key point in the pathogenesis of traumatic PVR.
Objective To analyze the clinical risk factors of the occurrence of severe proliferative vitreoretinopathy (PVR) after scleral reattachment surgery. Methods A total of 4031 eyes of 4031 consecutive patients with reghmatogenous retinal detachment (RRD) and PVR (grade C1 or less), on whom the scleral buckling was performed, were retrospectively studied. Twenty-two clinical charac teristics of the patients (including the ocular tension, condition of lens and vitreous, characte ristics of retinal detachment, whether or not with choroidal detachment, et al) were recorded.In 4031 patients, 2660 were followed up for more than 3 months, and 72 (in PVR group) of the 2660 patients underwent the second surgery (vitre oretinal surgery) because of the occurrence of postoperative seve re PVR; in the other 2588 patients, 72 (72 eyes) with retinal reattachment for more than 3 months were selected randomly as the control. The data were analyzed in SPSS (10.0) software. Results Logistic regression analysis revealed that the significant risk factors for PVR were incomplete posterior vitreous detachment ( P＜0.001), intraocular pressure lt;7 mm Hg（1 mm Hg=0.133 kPa, P＜0.002）, and large retinal tear (gt;2 DD,P＜0.005). Conclusion Incomplete posterior vitreous detachment, intraocular pressure lt;7 mm Hg and large retinal tear of the patient with RRD may be the major risk factors for PVR. (Chin J Ocul Fundus Dis，2003，19：141-143)
Objective To detect the variation rule of different cellular components, extracellular matrix, matrix-metalloproteinases (MMPs), and tissue inhibitors of metalloproteinases（TIMPs）in proliferative membranes in proliferative vitreoretinopathy (PVR) with different courses of disease, and to investigate the remodeling mechanism of PVR. Methods Sixteen surgically excised specimens of proliferative membranes from patients with rhegmatogenous retinal detachment combined with PVR with the course of disease of 2 months to 8 years were selected. The different cellular component of retinal pigment epithelial (RPE) cells and glial cells, component of extracellular matrix including fibronectin, laminin，and collagen types Ⅰ to Ⅳ, and matrix metalloproteinases (MMP2, MMP9) and TIMP1 in proliferative membrane were labeled by immunohistochemical method. The variati on of those labeled components in proliferative membrane in PVR duration and the correlation between these components and the course of PVR were analyzed. Results As the duration of PVR increased,the expression of RPE cells, fibronectin and MMP2 decreased (Plt;0.05）,while glial cells,collagen type Ⅰ and Ⅲ increased (Plt;0.05）.The positive staining of laminin and collagen type Ⅱ and Ⅳ were found, but the association with PVR duration was not detected. A negative correlation between PVR duration and RPE cells, MMP2, and fibronectin respectively and a positive correlation between PVR duration and glial cells, collagen Ⅰand Ⅲ respectively were detected. MMP2 positively related with variation of fibronect in. Positive staining of MMP9 and TIMP1 was recorded but did not change with the variation of the disease course. Conclusion During the formation and development of proliferative membrane in PVR, RPE cells, glial cells, fibronectin, collagen type Ⅰand Ⅲ and MMP2 take part in the remodeling of proliferative membrane. (Chin J Ocul Fungdus Dis, 2006, 22:308-312)
Objective To investigate the expression of hepatocyte growth factor receptor (HGFR) in epiretinal membranes (ERM) of eyes with proliferative vitreoretinopathy (PVR) and cultured retinal pigent epithelium (RPE) cells. Methods Fifteen human epiretinal membranes were obtained from eyes undergone vitrectomy for rhegmatogenous retinal detachment complicated with PVR and observed by immunohistochemical examination to study the expression of HGFR. Using the immunohistochemical technique to evaluate the expression of HGFR in cultured RPE cells. Results In 6 membranes of PVR-grade C, HGFR were expressed in 5/6, and 7 cases were detected in 9 membranes of PVR-grade D.RPE cells express readily detectable levels of HGFR. Conclusion The findings indicate that HGF might be involved in the formation of epiretinal membranes in PVR. (Chin J Ocul Fundus Dis, 2002, 18: 221-223)
ObjectiveTo observe the longterm effect of suramin on the inhibition of proliferation of human retinal pigment epithelial (RPE) cells in vitro. MethodsRPE cells grown in 9 pieces of 96well plate (12 wells each plate) were divided into experimental and control group, with 6 wells in each group. The concentration of 0.1 ml RPE cells in each well is 5×104 cells/ml. After the change of the medium, RPE cells were treated with suramin (250 μg/ml) in experimental group while treated with nothing in the control group. The medium of the 2 groups were changed to the normal medium after 4 days. At the 1st, 2nd, and 4thday after the addition of suramin and at the 1st, 2nd, 3rd, 5th, 6th, 7th, 9th , 11th and 13th day after removing suramin, 1 plate was randomly selected to stop culturing, and the proliferation of RPE cells were detected by methyl thiazolyl tetrazolium (MTT) assay. ResultsUnder reversed microscope, RPE cells in control group were fused completely at the 7th day after inoculation. The extracellular space of RPE cells in experimental groups was larger than that in the control group, and remained unfused at the 13th day after inoculation. The inhibitory rate of proliferation of RPE cells at the first day after treated with suramin was 14.85% and increased to the highest 25.79% at the 4th day. The first day after the suramincontaining media was removed, the inhibitory rate decreased to 12.35%, and then raised gradually to over 20% at the 3rd to 5th day. Finally, the rate drop to 14.71%. ConclusionSuramin has the long-term effect on the inhibition of RPE cells induced by serum, especially the inhibitive effect after the remove of suramin, which indicates the specific double-peak inhibition during the whole process.(Chin J Ocul Fundus Dis, 2005,21:25-27)
Objective To investigate the inhibitive effect of E2F decoy oligodeoxynucleotides (E2F decoy ODNs) on cultured human retinal pigment epithelial (HRPE) cells.Methods E2F decoy ODNs or scramble decoy ODNs at varied concentrations were put into the HRPE cells mediated by lipofectamineTM2000. The proliferative activity of HRPE was detected by methythiazolyl-terazollium assay, and the competitive combinative activity of E2F decoy ODNs and transcription factor E2F was detected by electrophoresis mobility-shift assay. Results The proliferation of HRPE was inhibited markedly by E2F decoy ODNs at the concentration of 0.2 μmol/L (P=0.002) in a dose-dependent manner but not by scrambled decoy. The results of electrophoresis mobility-shift assay showed that the combinative activity of transcription factor E2F was abolished completely by E2F decoy ODNs. Conclusions E2F decoy ODNs may sequence-specifically inhibit the combinative activity of transcripti on factor E2F,and inhibit the proliferation of HRPE cells.(Chin J Ocul Fundus Dis，2004，20：182-185)
Objective To observe the effect of medicineinduced posterior vitreous detachment (PVD) on proliferative vitreoretinopathy (PVR). Methods PVR was induced in the left eyes of 24 pigmented rabbits by intravitreal injection with platelet rich plasma. The rabbits were randomly divided into two experimental groups (group A and B) and one control group with 8 eyes in each group. Three hours later, the eyes in group A and B and the control group underwent intravireal injection with 1 U plasmin 0.05 ml+20 U hyaluronidase 0.05 ml, plasmin 0.1 ml, and balance salt solution 0.1 ml, respectively. The grade of PVR was recorded 1, 7, and 28 days after the intravitreal injection, and the eyes were examined by flash electroretinogram (FERG), B-scan, and retinal histopathological examination. Results The PVR models of rabbit eyes were induced successfully. On the 7th day after injection, complete and partial PVD was found in 5 and 3 eyes respectively in group A; partial PVD in 5 eyes and no complete PVD was observed in group B; there was no PVD in the other 3 eyes in group B and also in the eyes in the control group. On the 28th day after intravitreal injection, PVR grade of group A and B were both obviously lower than that of the control group（D=75.6, 98.9；P=0.003，P=0.011）; On the 7th and 28th day after injection, the b-wave amplitude in group A and B was significantly higher than that in the control group; PVR grade of the PVD eyes was lower than that of nonPVD eyes; PVR grade of the complete PVD eyes was only 0～1. Conclusions Three hours after the PVR models of rabbit eyes were induced, complete PVD induced by intravitreal injection of plasmin combined with hyaluronidase could prevent the development of PVR of rabbit eyes in some degree; partial PVD induced by plasmin alone or combined with hyaluronidase could relieve the development of PVR.