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)
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 investigate the method and the effects of the surgical treatment of massive subretinal hemorrhage and vitreous hemorrhage associated with age-related macular degeneration. Methods A retrospective study of 14 consecutive patients underwent a complete pars plana vitrectomy. Retinotomy was carried out for removing subretinal hemorrhage by using balanced salt solution. Complete air-fluid exchange and gas or silicone oil tamponade were performed in all patients. The follow-up period was within 3～7 months. Results Atrophy of eyeball in 2 eyes (14.3%) postoperatively. Improvement of corrected final visual acuity and anatomical retinal reattachment were achieved in 12 (85.7%) of the 14 eyes postoperatively. Seven days after operation, muddy-sand-hemorrhage in anterior chamber occurred in 4(28.6%)of the eyes and paracenteses of anterior chamber were performed for these eyes. Conclusion Surgical intervention should be applied in the eyes with the massive subretinal hemorrhage associated with age-related macular degeneration in order to avoid the affected eyes becoming atrophic due to the subsequent complication of vitreous hemorrhage, anterior chamber muddy sand hemorrhage,ghost cell-glaucoma or retinal detachment. (Chin J Ocul Fundus Dis,2000,16:217-219)
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.
ObjectiveTo investigate the relationship between the posterior vitreous detachment (PVD) and the diabetic macular edema (DME).MethodsA total of 169 eyes with DME which were diagnosed by funduscopy，fundus fluorescein angiography (FFA) and optical coherence tomography (OCT) were retrospectively analysed. PVD and partial PVD were detected by OCT and biomicroscopy. The characterizations of OCT images of DME were analysed.ResultsIn 169 eyes, 156 (92.3%) had no PVD with the average thickness of fovea of 297 μm; 11 (6.5%) had complete PVD with the average thickness of fovea of 229 μm; 2 (1.2%) had partial PVD with the average thickness of fovea of 347 μm.ConclusionsOnly a few PVD were found in DME eyes, so traction of PVD may not be the main cause of DME. (Chin J Ocul Fundus Dis, 2003,19:341-343)
Vitreous is composed of transparent gel-like tissue with complex molecular structure, accounting for 80% of the volume of the eyeball. In addition to support the eye structure, vitreous has important functions such as regulating eye development, refraction and cellular barriers, participating in intraocular oxygen metabolism and the development of retinal diseases. Age, myopia and systemic diseases and other factors have an impact on vitreous function. Intra-vitreous injection and vitreous surgery may interfere with vitreous function, damage the intraocular metabolic balance. To better maintain intraocular metabolic balance and visual function, it is important to study vitreous metabolic function carefully and intervene it cautiously.
Objective To investigate the correlation between the vitreomacular adhesion (VMA) and exudative age-related macular degeneration (AMD). Methods A literature research was performed in PubMed, EMbase, Cochrane Library, CNKI and Wanfang database from January 2000 to December 2016. Case-control studies on the relationship between VMA or posterior vitreous detachment and exudative AMD were included in this analysis. Literature screening and data extraction were performed according to inclusion and exclusion criteria. The qualities of the literatures were evaluated according to the Newcastle-Ottawa Scale (NOS). Seven literatures were selected into meta-analysis. The NOS score was 9 points in 1 article, 8 scores in 4 articles, 7 points in 2 articles. A total of 947 eyes with exudative AMD, 638 eyes with dry AMD, and 618 eyes with controls were included. The correlation between exudative AMD and VMA were analyzed using the software Review manager 5.3. Results The prevalence of VMA in exudative AMD eyes was higher than that in controls [odds ratio (OR)=2.14, 95% confidence interval (CI)=1.19 - 3.84, P=0.010] and dry AMD eyes (OR=2.24, 95%CI=1.24 - 4.03, P=0.007). There was no difference in PVD prevalence among exudative AMD eyes, dry AMD eyes (OR=0.44, 95%CI=0.16 - 1.20, P=0.110) and controls (OR=0.70, 95%CI=0.41 - 1.18, P=0.180). Conclusion There is correlation between VMA and exudative AMD.
Purpose To evaluate the surgical effect of idiopathic macular hole (IMH)，with optical coherence tomography (OCT)． Methods To measure the diameter of holes and hole halos，the thickness of hole in edge，the changes of hole pattern in 19 cases (19 eyes) with IMH using OCT． Results By quantitatively measuring，OCT showed that after surgery the mean hole diameter lessened from （570．95plusmn;264．59 ）mu;m to （337．05plusmn;335．95）mu;m．The mean diameter of hole halo lessened from （1043．53plusmn;278．80）mu;m to （695．00plusmn;483．00）mu;m and the mean thickness of the hole edge thinned from （389．78plusmn;60．58）mu;m to （298．78plusmn;109．80）mu;m．In 17 eyes the holes become closed or reduced in size or the hole halo，and thinned in hole edge．The anatomic successful rate of the surgery is 89%． Conclusion OCT can objectively，accurately and effectively judge the anatomic effect of IMH surgery． (Chin J Ocul Fundus Dis，2000，16：71-138)
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)
Integrins is a family of multi-functional cell-adhesion molecules, heterodimeric receptors that connect extracellular matrix to actin cytoskeleton in the cell cortex, thus regulating various physiological and pathological processes. Risuteganib (Luminate®) is a novel broad-spectrum integrin inhibitor. Based on multiple biological functions of anti-angiogenesis, vitreolysis, and neuroprotection, risuteganib is hopeful in treating several fundus diseases such as diabetic macular edema, vitreomacular traction, and non-exudative age-related macular degeneration. By far, risuteganib has successfully met the endpoints for three phase 2 studies and is preparing to enter the phase 3 of diabetic macular edema clinical trials. Overall the risuteganib is safe with no serious ocular or systemic adverse events. Given the unique mechanism of action and longer duration of efficacy, intravitreal injection of risuteganib has the potential to serve as a primary therapy, or adjunctive therapy to anti-VEGF agents.