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find Keyword "retina" 206 results
  • THE EFFECT OF SUBRETINAL FLUID ON STIMULATING GROWTH OF CUL- TURED RETINAL PIGMENT EPITHELIAL CELLS. RETINAL GLIAL CELLS AND FIBROBLASTS

    OBJECTIVE :To investigale effect of subretinal fluld(SRF)on proliferalion of the cellular elements of PVR. METHOD:The effect of SRF of 28 patients with rhegmatogenous retinal detachment proliferation of the cultured human retinal pigment epithelial cells(RPE),retinal glial cells (RG),and fibroblast (FB)was observed and detected by the methods of cell-counting and 3H-TdR in DNA synthesis. RESULTS:The range of proliferatinn-stimulating activity was 52.5%~233.3%, 36.4% ~ 177.8%,55.4% ~277.8% above the baseline in 1:10 dilution of these 3 kinds ,of cellular elements,and there was no significant difference among them. CONCLUSION ;The stimulating effect of SRF on the cellular proliferation was thougt to be due to the actions from certain growth factors. (Chin J Ocul Fundus Dis,1996,12: 233-235)

    Release date:2016-09-02 06:21 Export PDF Favorites Scan
  • Clinical observation of microcystic macular edema before and after surgery for idiopathic epiretinal membrane

    ObjectiveTo observe the incidence and risk factors of microcystic macular edema (MME) in patients with idiopathic macular epiretinal membrane (IMEM) preoperatively and postoperatively. MethodsA retrospective case series study. From January 2017 to May 2021, 72 eyes of 72 patients with IMEM in Eye Hospital of Wenzhou Medical University at Hangzhou were included. There were 18 male and 54 female. Average age was 64.8±7.8 years. Eyes were all monocular. All patients received the examination of best corrected visual acuity (BCVA) by standard logarithmic visual acuity chart, which was represented logarithmic of minimum angle of resolution (logMAR). Optical coherence tomography was used to measure central macular thickness (CMT). MME was defined as small, vertically bounded cystic space located outside the fovea in the inner layer of the retina. According to the presence or absence of MME before surgery, the affected eyes were divided into two groups: non-MME group (35 eyes) and MME group (37 eyes). The difference of logMAR BCVA and CMT was statistically significant between Group A and B (t=3.117, 2.589; P=0.003, 0.012). All patients with IMEM were treated with 23G three-channels pars plana vitrectomy (PPV) with epiretinal membrane and inner limiting membrane (ILM) peeling. The two groups were further divided into four groups according to whether there was MME in the postoperative follow-up time. The group A1 was without MME before and after surgery, group A2 was without MME before surgery and with MME after surgery. The MME group was subdivided into the group with MME before surgery and without MME after surgery (group B1) and the group with MME before and after surgery (group B2). The mean follow-up time was 8.8±7.7 months. The same equipment and methods were used to exam the patients during the follow-up. Paired t test was used to compare the changes of MME, BCVA and CMT before and after surgery. The differences of CMT and BCVA among groups before and after surgery were compared by independent sample t test and one-way ANOVA. Logistic regression was used to analyze the influencing factors of MME before and after surgery, and multiple linear regression was used to analyze the influencing factors of postoperative BCVA. ResultsThere were 35 eyes in the non-MME group, 18 eyes (51.43%, 18/35) in the A1 group and 17 eyes (48.57%, 17/35) in the A2 group, respectively. There were 37 eyes in MME group, 6 eyes (16.22%, 6/37) in group B1 and 31 eyes (83.78%, 31/37) in group B2, respectively. At last follow-up, the logMAR BCVA was 0.10±0.12, 0.25±0.17, 0.09±0.11, 0.30±0.26 in group A1, A2, B1, and B2, respectively. Compared with the logMAR BCVA before surgery, the differences were statistically significant (t=3.779, 4.253, 7.869, 6.668; P<0.01). There was significant difference in logMAR BCVA among the four groups (F=4.460, P<0.01). There was a significant difference in logMAR BCVA between group A1 and group A2 (t=-2.930, P=0.006). There was no significant difference between group B1 and group B2 (t=-1.921, P=0.063). The CMT of group A1, A2, B1 and B2 were 371.83±73.24, 431.24±83.13, 407.00±28.07 and 425.19±70.97 μm, respectively. Compared with those before operation, the differences were statistically significant (t=5.197, 2.465, 3.055, 6.078; P<0.05). There was no significant difference in CMT among the four groups (F=2.597, P=0.059). Logistic regression analysis showed that pre-operation MME was correlated with pre-operation IMEM stage (β=1.494, P=0.004). New MME after surgery was correlated with age (β=0.153, P=0.013). Multiple linear regression analysis showed that postoperative visual acuity was significantly correlated with CMT before surgery and MME after surgery (β=0.001, 0.134; P=0.015, 0.019). ConclusionsPPV combined with epiretinal membrane and ILM peeling surgery for IMEM can improve visual acuity and decrease CMT. MME regress or regenerate after surgery. Age is an independent predictor of the risk of newly formed MME after surgery.

    Release date:2022-11-16 03:11 Export PDF Favorites Scan
  • Hep-A and Hep-B reduced vascular endothelial growth factor induced breakdown of blood-retinal barrier in mice

    Objective To investigate the effects of Hep-A and Hep-B on vascular endothelial growth factor (VEGF)-induced breakdown of blood-retinal barrier. Methods The mice were subcutaneously injected vehicle, Hep-A or Hep-B 10 mg/kg twice a day for 5 days. Then, 1 μl of 10-6mol/L VEGF were intravitreous injected. After 6 hours, 13.7×104Bq/g3H-mannital were injected intraperitoneally. The mice were sacrificed and the retinas, lungs, kidneys were removed and examined for radioactivity. The result were analyzed using SPSS software to calculate and compare retina/lung and etina/kidney leakage ratio among groups of different treatment. Result The retina/lung and retina/kidney leakage ratio were 0.38±0.04 and 0.21±0.03 respectively in normal mice; increased significantly to 1.05±0.11 and 0.46±0.04 respectively in model mice, both Plt;0.01 compared to those in normal mice; decreased to 0.59±0.06 and 0.32±0.03 respectively in mice treated with Hep-A, both Plt;0.01 compared to those in model mice; decreased 0.54±0.04 and 0.35±0.03 in mice treated with Hep-B,both Plt;0.01 compared to those in model mice. Conclusion Hep-A and Hep-B can significantly reduce VEGF-induced breakdown of blood-retinal barrier in mice. Chin J Ocul Fundus Dis,2004,20:352-354)

    Release date:2016-09-02 05:58 Export PDF Favorites Scan
  • The roles of Niacin in the treatment of diabetic retinopathy and its mechanism

    Objective To investigate the protective effect of Niacin on blood-retina barrier (BRB) in diabetic rats and related mechanism. Methods The male Wistar rats (60) were divided into control (CON) group, diabetes (DM) group and Niacin-treated (NA) group, 20 rats in each group. Rats diabetes models were induced with streptozotocin injection. Niacin (40 mg/kg·d) was administrated orally everyday in Niacin-treated group until sacrificed after 3 months. Pathological outcomes, total cholesterol (TC) and high-density lipoprotein (HDL) were evaluated at month 3. Optical microscopy was used to observe the retinal structure. The integrity of BRB and the vascular permeability was quantified by analyzing albumin leakage using Evans blue (EB) method. The relative expressions of Claudin-5, Occludin, zonula occluden (ZO)-1 and GPR109A mRNA in rat retinas were detected by reverse transcription PCR (RT-PCR) and relative expression of GPR109A, tumor necrosis factor (TNF)-α and interleukin (IL)-6 by Western blot. Results Compared to CON group, the TC content was increased and HDL content was decreased in DM group (t=4.034, 5.831; P < 0.05). Compared to DM group, the TC content was decreased and HDL content was increased in NA group (t=6.868, 3.369; P < 0.05). The retinal structure of CON group was normal. Pathological changes were found in the DM group, such as tumescent nuclei and disorganized structures. The retinal structure of NA group was similar to the control group. Evans blue dye that the microvascular leakage in DM group was increased compared with CON group (t=24.712, P < 0.05), while in NA group was decreased compared with DM group (t=16.414, P < 0.05). The mRNA expression of Occludin, Claudin-5, ZO-1 in DM group were decreased compared with CON group (t=11.422, 12.638, 12.060; P < 0.05), while in NA group were increased compared with DM group (t=5.278, 3.952, 8.030; P < 0.05). The mRNA expression of GPR109A in NA group were increased compared with DM group (t=5.053, P < 0.05). The protein expression of GPR109A, IL-6, TNF-αin DM group were increased compared with CON group (t=4.915, 11.106, 6.582; P < 0.05). Compared to DM group, the protein expression of GPR109A was increased (t=5.806, P < 0.05), while the protein expression of IL-6 and TNF-α were decreased (t=10.131, 5.017; P < 0.05). Conclusion Niacin has the protective effect for BRB by up-regulating GPR109A expression which may suppress inflammation.

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  • Research on exudate segmentation method for retinal fundus images based on deep learning

    Objective To automatically segment diabetic retinal exudation features from deep learning color fundus images. Methods An applied study. The method of this study is based on the U-shaped network model of the Indian Diabetic Retinopathy Image Dataset (IDRID) dataset, introduces deep residual convolution into the encoding and decoding stages, which can effectively extract seepage depth features, solve overfitting and feature interference problems, and improve the model's feature expression ability and lightweight performance. In addition, by introducing an improved context extraction module, the model can capture a wider range of feature information, enhance the perception ability of retinal lesions, and perform excellently in capturing small details and blurred edges. Finally, the introduction of convolutional triple attention mechanism allows the model to automatically learn feature weights, focus on important features, and extract useful information from multiple scales. Accuracy, recall, Dice coefficient, accuracy and sensitivity were used to evaluate the ability of the model to detect and segment the automatic retinal exudation features of diabetic patients in color fundus images. Results After applying this method, the accuracy, recall, dice coefficient, accuracy and sensitivity of the improved model on the IDRID dataset reached 81.56%, 99.54%, 69.32%, 65.36% and 78.33%, respectively. Compared with the original model, the accuracy and Dice index of the improved model are increased by 2.35% , 3.35% respectively. Conclusion The segmentation method based on U-shaped network can automatically detect and segment the retinal exudation features of fundus images of diabetic patients, which is of great significance for assisting doctors to diagnose diseases more accurately.

    Release date:2024-07-16 02:36 Export PDF Favorites Scan
  • Analysis of factors affecting the visual outcome after vitrectomy for idiopathic macular hole

    ObjectiveTo investigate the factors correlated with the visual outcome of idiopathic macular holes (IMH) after vitreoretinal surgery. MethodsA total of 57 eyes of 57 patients with IMH were included. There were 43 females (43 eyes) and 14 male (14 eyes), mean age was (60.46±4.79) years. All the eyes underwent best corrected visual acuity (BCVA), slit-lamp microscope, three-mirror contact-lens and optical coherence tomography (OCT) examinations. BCVA were examined with interactional visual chart and recorded with logarithm of the minimum angle of resolution (logMAR) acuity. The minimum diameter and base diameter of macular holes and central retinal thickness (CRT) were detected by OCT. The average logMAR BCVA of 57 eyes was 0.98±0.41. The minimum diameter and base diameter of macular holes were (479.53±164.16) μm and (909.14±278.65) μm. All the patients underwent pars plana vitrectomy combined with phacoemulsification cataract extraction and intraocular lens implantation. The mean follow-up period was (173.44±147.46) months. The relationships between final BCVA and these parameters were examined by single and multiple regression analysis. The valuable influence factors were filtrated and formulated using multiple linear regression models. ResultsAt the final follow-up, the logMAR BCVA of 57 eyes was 0.44±0.31, the CRT was (158.79±86.96) μm. The final BCVA was positive related to minimum diameter of macular holes and preoperative BCVA (r=0.420, 0.448; P=0.001, 0.000), negative related to postoperative CRT (r=-0.371, P=0.004). There was no relationship between the final BCVA and base diameter of macular holes, age and follow-up (r=0.203, -0.015, 0.000; P=0.130, 0.913, 0.999). The incidence of preoperative BCVA for postoperative BCVA was bigger than preoperative minimum diameter of macular holes (P=0.008, 0.020). ConclusionThe preoperative minimum diameter of macular holes and BCVA are related to postoperative BCVA in IMH eyes.

    Release date:2016-10-21 09:40 Export PDF Favorites Scan
  • Research progress of surgical treatment of myopic foveoschisis

    Myopic foveoschisis (MF) has mild early symptoms, however, its course is progressive. When the secondary macular detachment or macular hole occurs, it can cause severe vision loss. Therefore, it is generally believed that MF patients should undergo surgical intervention early after the onset of symptoms to prevent them from further developing into a macular hole or macular hole retinal detachment.It is generally believed that the traction of the vitreous cortex and posterior scleral staphyloma to the retina plays an important role in the occurrence and development of MF. The operation mode is divided into vitreoretinal surgery and macular buckling, the former release the retinal traction via the vitreous body and the latter reattaches the retina via the extrascleral approach. There is no consensus on whether to perform internal limiting membrane peeling and gas tamponade in vitreoretinal surgery and the fovea-sparing internal limiting membrane peeling has become a hot topic in recent years. Compared with vitreoretinal surgery, macular buckling can release the traction of the retina caused by posterior scleral staphyloma, but it cannot relieve the traction in the tangential direction of the retina. Vitreoretinal surgery and extrascleral surgery seems to make up the shortcomings of both, however, the effect of treatment on patients still needs further verification. In clinical work, it is necessary to conduct individualized analysis of MF patients, weigh the advantages and disadvantages of each operation, and choose the most suitable operation mode for patients with different conditions. In the future, the emphasis of our work is to develop operation mode with great curative effect and less complications.

    Release date:2022-01-19 03:48 Export PDF Favorites Scan
  • Clinical characteristics and candidate gene mutational screening in children with cone and cone-rod dystrophy

    Objective To analyze the clinical characteristics and to screen for causative mutations in CRX and GUCY2D genes in children with cone or cone-rod dystrophy. Methods Clinical data and genomic DNA was collected from 18 children with cone or cone-rod dystrophy, aged from 4 months to 8 years. The coding sequence of the cone-rod homeobox (CRX) gene and two exons of the retinal-specific guanylate cyclase GUCY2D gene (exons 2 and 8) were analyzed by using polymerase chain reaction(PCR) and heteroduplex combined with single-strand conformational polymorphism (heteroduplex-SSCP) analysis. Results All of the 18 patients manifested obvious visual impairment. Nystagmus, photophobia and mild ocular fundus changes were found in 13, 8,and 7 cases respectively. Normal fundus was seen in 11 cases. The visual acuity was less than 0.3 in 4 cases and was unable to measure in the other 14 cases because they were too young. Clinical ocular manifestation s between cone and cone-rod dystrophy were overlapped. Mutation in the CRX and G UCY2D genes was not detected in the 18 children with cone and cone-rod dystrophy . Conclusion Visual impairment appeared more early and obvious than fundus changes in children with cone or cone-rod dystrophy. Mutation in the CRX gene may not contribute to this series of patients with cone and cone-rod dystrophy. (Chin J Ocul Fundus Dis, 2001,17:293-295)

    Release date:2016-09-02 06:03 Export PDF Favorites Scan
  • Research progress of subretinal fibrosis associated with neovascular age-related macular degeneration

    The severe visual impairment caused by neovascular age-related macular degeneration (nAMD) is associated with macular neovascularization (MNV) invasion and subretinal fibrosis (SF). Excessive SF can lead to subretinal scarring, irreversible damage to photoreceptors, retinal pigment epithelium, and choroid tissue, resulting in permanent visual impairment in nAMD patients. The pathogenesis of SF is complex, involving many pathological processes such as tissue repair after injury, inflammation, and related signaling pathways and cytokine complex. Current experimental treatments for SF only target inhibition of a single cytokine. Timely and effective inhibition of the formation and progression of MNV and early identification of risk factors for SF are crucial to improving the prognosis of nAMD patients.

    Release date:2024-04-10 09:54 Export PDF Favorites Scan
  • Peripapillary Subretinal hemorrhage

    Objective To investigate the clinical characteristics and the related factors of peripapillary subretinal hemorrhage (PPSRH). Methods The clinical documents of fundus fluorescein angiography (FFA) of 23 patients (23 eyes) with PPSRH were retrospectively analyzed. Results All of the 23 eyes was myopes with middle or slight degree, and the corrected visual acuity was≥1.0. Among the 23 patients, 9 eyes were PPSRH, 13 eyes were PPSRH with disc hemorrhage, and 1 eye was PPSRH with disc and vitreous hemorrhage. All of the PPSRH was localed at the nasal edge of optic disc. Through FFA the hemorrhage showed blocked fluorescence and the optic disc showed nodular hyperfluorescence at the late phase, and nothing abnormal in the unaffected eyes. Conclusion PPSRH might be related to buried optic disc drusen. (Chin J Ocul Fundus Dis, 2002, 18: 96-97)

    Release date:2016-09-02 06:01 Export PDF Favorites Scan
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