Objective To explore the correlation between retinal extracellular edema and vitreous contraction in rabbits. Methods Seventeen pigmented rabbit models with retinal vein occlusion (RVO)was set up by laser photocoagulation. Retinal vascularity area was pathologically examined 1 month later.The vitreous gellength under the gravity condition and the percentage of its weight in the rabbits with extraeellular edema was observed. The mechanisms were investigated by Western immunoblotting of type II collagen.Results Extracellular edema was found in 13 experimental eyes 1 month after the formation of RVO (76.5~) with contracted vitreous gel and released watery liquid, and the a component of type II collagen was cross-linked together to form high-molecular-weight components of 1] and 7, which weakened the stability of collagen net structure.Conclusions Vitreous contraction and retinal extracellular edemawere correlated. The main reason may be the cross-links of vitreous collagen that damages the stability of collagen structure. (Chin J Ocul Fundus Dis，2004，20：2-32)
Objective To describe cultured human retinal pigment epithelial (RPE) cells transdifferentiation and investigate the effects of human vitreous fluid on the morphologic and cytoskeleton changes of RPE cells in vitro. Methods Cytoskeleton characteristics in the 2nd, 5th, 8th passage of RPE cells in normal culture, which included cytokeratin 18 (CK18) and α-smooth muscle actin (α-SMA) were analyzed by Western blot. RPE cells were cultured in human vitreous-conditioned medium (VCM) at the concentration of 1∶4 for 6 days, morphologic changes were examined by light and electron microscopy, and cytoskeleton characteristics were analyzed by imunocytochemistry and Western blot. Results During culture in vitro, RPE cells lost epithelial characteristics and aquired fibroblast-like phenotype. The expression of CK18 was the highest at the 5th passage, and it decreased in the following passage, but α-SMA increased gradually. The morphologic transdifferentiation from epithelial to fibroblast-like cells of RPE was accelerated by VCM. Ultrastructural changes such as decreased microvilli and gradually increased rough endoplasmic reticulum and Golgi complex were found during the cultivation. CK18 produced by RPE cells decreased in VMC (P＜0.05), and α-SMA increased (P＜0.01). Conclusion Morphologic changes in epithelialmesenchymal transdifferenetiation of RPE cells are stimulated by VCM and accomplied by the shift of cytoskeleton proteins, The results imply that cells migration may be decreased and contraction may be enhanced in VCM. It may suggest that vitreous accelerates the pathogenesis of PVR and RPE cells play an important role. (Chin J Ocul Fundus Dis, 2002, 18: 289-292)
Purpose To investigate the effects of human vitreous fluid on proliferation of cultured human retinal pigment epithelial (RPE) cells and vascular endothelial cell lines(VEC304). Methods Human RPE cells and VEC304 were cultured and treated in different human vitreous-conditioned medium (VCM) with or without serum, vitreous volume concentrations of VCM were 1∶8, 1∶4 and 1∶2. Cells proliferation was assayed by tetrazolium (MTT) colorimetry at the 2nd, 4th and 6th day respectively. Results In the presence of serum, 1∶4, 1∶2 VCM had a significantly stimulative effect on RPE cells proliferation compared with control group at the 2nd, 4th, and 6th day retrospectively (P＜0.01), but exerted a bly inhibitory effect on VEC304 proliferation compared with control group at the 2nd, 4th, and 6th day retrospectively (Plt;0.05). In the absence of serum, only 1∶2 VCM had a stimulative effect on RPE cells growth compared with control group at the 2nd day (P＜0.05) and obviously at the 4th and 6th day respectively (P＜0.01). Conclusion Human vitreous fluid influences human RPE cells and VEC304 growth in vitro. This result suggests that vitreous may play different role in proliferative vitreoretinopathy and intraocular neovascular disease. (Chin J Ocul Fundus Dis, 2002, 18: 140-142)
PURPOSE: To investigate the treatment of severe bacterial endophthalmitis. METHODS:The curative effects of vitrectomy after intravitreal antibiotics and steroids (IVAS)for the treatment of 23 patients with bacterial endophthalmitis (group I)and vitrectomy and IVA at the same time for the treatment of 28 patients with bacterial endopbthalmitis (group I)were analyzed retrospectively. RESULTS: The rate of curative effects of two groups were similar,while the marked curative effects in group I (47.8% )was significantly higher than that of the group I (17.9%). The average period of eliminating infiamation of group I was longer than that of group I , and the incidence of postoperative retinal detachment of group Ⅱ was 3 times more than that of group I . CONCLUSION :It was indicated that vitrectomy after IVAS may increase the security of vitrectomy and the curative effects of severe bacterial ndophthalmitis.
Objective To reveal the fibrillar network in vitreous and the effect of plasmin on this network.Methods 20 vitreous gels of freshly slaughtered pigs were divided into 2 groups, the gels in first group were digested by 3 Uplasmin (3 U/ml) at 37c for 24 hours respectively, the second group received the same PBS as control. After digestion, gels were fixed in neutral buffered formalin solution. Samples from vitreous base, cortex and the central region were observed by the technique of freeze etching electron microscopy.Results In vitreous collagen fibril network was in a three-dimensional array, collagen fibril density showed marked differences, central vitreous had the sparse fibril density, the cortex denser and the basal vitreous densest. After digestion by plasmin, the collagen fibrillar network was destructed.Conclusion Collagen fibrils in vitreous present spatial arrangement regularly, plasmin can lead to destruction of the fibrillar network.(Chin J Ocul Fundus Dis，2003，19：179-181)
Objective To observe the efficacy of vitreoretinal surgery in the treatment of early traumatized eyes with no light perception. Methods We performed vitreoretinal surgery on 17 eyes of early traumatized eyes with no light perception.The patients were followed up for 2～14 months. Results Retinal reattachment was achieved in 11 eyes after srugery.8 eyes got visual acuity better than light perception postoperatively.Visual acuities of 5 eyes were better than 0.05 and the best one reached to 0.2. Conclusion Timely vitreoretinal surgery is valuable to the early traumatized eyes with no light perception.Retinal reattachment is the most important thing for the treatment of this kind of cases. (Chin J Ocul Fundus Dis，2000，16：213-284)
Objective To investigate the retinal toxicity and verify the safe dose of intravitreal injecting fluconazole. Methods Twelve healthy adult white rabbits were divided at random into 6 groups：a normal control group and 5 groups received intravitreal injection of a single dose of fluconazole ranging from 10 to 200 mu;g respectively.Retinal toxicity was examined by ophthalmoscopy, electroretinography, light and transmission electron microscopy (TEM) on the third and fourteenth day after injection. Results The ultrastructures of the retinal tissues of the normal control group and fluconazole 10～150 mu;g groups were normal on the third and fourteen day after injection.The light microscopy and TEM showed that cells of all the retinal layers in the 200 mu;g group revealed apparent degenerative changes on the fourteenth day after injection, and the light microscopic picture showed the vacuolar degeneration of outer segments of photoreceptors, the nuclei in outer nuclear layer drop out into inner segments, the vacuolar degeneration of nerve fiber layer, and the proliferation of pigment epithelium. TEM revealed expansion of paranucl eus space and karyopyknosis of the bipolar cells, the swelling of nerve fibers and disappearance of the synapses in the inner plexiform layer, the vacuolation and disappearance of microvilli of the pigment epithelium cells. Conclusion The safe dose of fluconazole injected intravitreally should be 100～150 mu;g. (Chin J Ocul Fundus Dis，2000，16：139-212)
Objective To investigate the effect of long-term intraocular retention of domestic perfluorocarbon liquid (PFCL) on morphology and histology of ocular tissues. Methods A total of 18 New-Zealand rabbits were randomly divided into 3 experimental groups, whose left eyes underwent intraocular injection with 0.3, 0.6, and 1.0 ml PFCL, respectively. All of the right eyes of the rabbits were in the control group. The morphological, electrophysiological and histological changes of the ocular tissue were observed 4, 8, and 12 weeks after the injection. Results No clinically significant retinopathy but only mild morphological changes were found in group 1 and 2, while obvious morphological and histological changes were found in group 3. Mild morphological and histological changes were found in all of the rabbits 4-8 weeks after the injection while significant ones were found 8-12 weeks after the injection. The results of electroretinography indicated a statistically significant decline of amplitude of b wave in group 3. Conclusions Long-term intraocular retention of few PFCL may cause mild histological changes but not affect the clinical function. Plentiful PFCL remains in eyes may lead to toxic reaction to the ocular tissue. (Chin J Ocul Fundus Dis, 2006, 22: 128-130)
Blood-retina barrier destruction, nerve injury, formation of neovascularization and fibroblast proliferation membrane are important pathological changes of DR, which are related to the combined effects of various vitreous cytokines. VEGF is mainly involved in increasing retinal vascular permeability and inducing neovascularization. Pigment epithelium derived factor is vital reducing vascular permeability and neuroprotection; IL plays a key role in mediating inflammatory response. TNF-α is related to inflammation, which is significantly up-regulated by hypoxia. TGF-β is an important cytokine regulating cell proliferation and differentiation. Connective tissue growth factor can promote the growth, migration and adhesion of endothelial cell. In addition, many other molecular mechanisms have not been fully elucidated, and further study on the molecular mechanism of DR is urgent. With the further study of molecular mechanism, the early intervention and targeted treatment of DR will be more effective.
ObjectiveTo observe the level of microparticles in the vitreous of patients with proliferative diabetic retinopathy (PDR), and preliminarily explore the role of microparticles in the pathogenesis of PDR.MethodsA case control study. From January to December 2018, 54 cases of 54 eyes of PDR patients (PDR group) and 20 cases of non-diabetic retinopathy patients (control group), who were diagnosed and treated with vitrectomy (PPV) in the Department of Ophthalmology, Tianjin Medical University General Hospital vitreous samples were included in the study. Among 54 eyes in the PDR group, there were 42, 21, and 17 eyes with vitreous hemorrhage (VH), traction retinal detachment (TRD), and previous intravitreal injection of drugs, respectively. Among the 20 eyes of the control group, idiopathic macular hole, idiopathic anterior macular membrane, vitreous macular traction syndrome, and complete lens dislocation were 6, 6, 2, and 6 eyes, respectively. The PDR group was divided into uncombined TRD group and combined TRD group according to PDR stage and whether TRD occurred, with 33 and 21 eyes, respectively. According to the presence or absence of VH, they were divided into groups with VH and without VH, with 42 eyes and 12 eyes, respectively. According to whether anti-vascular endothelial growth factor (VEGF) drugs were injected into the intravitreal cavity 3 days before PPV, they were divided into anti-VEGF drug group and no anti-VEGF drug group, with 17 eyes and 37 eyes respectively. The levels of retinal photoreceptor cells (RMP), platelets (PMP), endothelial cells (EMP) and phosphatidylserine (PS-MP) expressing on the membrane surface in the sample were detected by flow cytometry. The comparison between the two groups of samples was performed by t test, and the comparison between multiple groups of samples was performed by one-way analysis of variance or Mann-Whitney test.ResultsCompared with the control group, the vitreous RMP level of the PDR group was significantly decreased, and the EMP and PMP levels were significantly increased. The differences were statistically significant (t=−2.361, 5.064, 3.531; P=0.018, ＜0.001, 0.001). There was no statistically significant difference in PS-MP levels between the two groups (t=−1.617, P=0.110). Compared with the TRD group, the levels of RMP and PMP in the vitreous of the TRD group were significantly increased, and the difference was statistically significant (t=−2.221, −2.098; P=0.031, 0.041). The level of EMP in the vitreous body of the anti-VEGF drug group was significantly lower than that of the non-anti-VEGF drug group, however, it was still higher than the control group. The difference was statistically significant (Z=−2.430, −2.499; P=0.015, 0.012). The level of PMP in the vitreous body of the eye without VH was significantly higher than that in the group with VH, and the difference was statistically significant (t=−3.097, P=0.003).ConclusionsThe elevated levels of EMP and PMP in the vitreous of PDR patients may be related to the damage of retinal capillaries; intravitreal injection of anti-VEGF drugs before surgery can reduce the level of EMP. VH may be related to the procoagulant effect of PMP.