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Objective:To compare and analyze the application of anti-vascular endothelial growth factor (VEGF) drugs for intravitreal injection in the real world before and after the establishment of one-stop intravitreal injection center, as well as the advantages and disadvantages of different management modes.Methods:A retrospective clinical study. A total of 4 015 patients (4 659 eyes) who received anti-VEGF drugs for ocular fundus diseases at the Tianjin Medical University Eye Hospital from July, 2018 to June, 2022 were included in the study. There were 2 146 males and 1 869 females. The ocular fundus diseases in this study were as follows: 1 090 eyes of 968 patients with wet age-related macular degeneration (wAMD); 855 eyes of 654 patients with diabetic macular edema (DME); 1 158 eyes of 980 patients with diabetic retinopathy (DR); 930 eyes of 916 patients with macular edema secondary to retinal vein occlusion (RVO-ME). A total of 294 eyes of 275 patients with choroidal neovascularization secondary to pathological myopia (PM-CNV); 332 eyes of 222 patients with other fundus diseases. A total of 13 796 anti-VEGF needles were injected. A total of 1 252 patients (1 403 eyes) from July 2018 to June 2020 were regarded as the control group. From July 2020 to June 2022, 2 763 patients (3 256 eyes) who received anti-VEGF treatment in the intravitreal injection center were regarded as the observation group. The total number of intravitreal injection needles, the distribution of anti-VEGF therapy in each disease according to disease classification, the proportion of patients who chose the 3+ on-demand treatment (PRN) regimen and the distribution of clinical application of different anti-VEGF drugs were compared between the control group and the observation group. The waiting time and medical experience of patients were investigated by questionnaire. χ2 test was used to compare the count data between the two groups, and t test was used to compare the measurement data. Results:Among the 13 796 anti-VEGF injections in 4 659 eyes, the total number of anti-VEGF drugs used in the control and observation groups were 4 762 and 9 034, respectively, with an average of (3.39±3.78) and (2.78±2.27) injections per eye ( t=6.900, P<0.001), respectively. In the control and observation groups, a total of 1 728 and 2 705 injections of anti-VEGF drugs were used for wAMD with an average of (5.14±4.56) and (3.59±2.45) injections per eye, respectively; a total of 982 and 2 038 injections of anti-VEGF drugs were used for DME with an average of (4.36±4.91) and (3.24±2.77) needles per eye, respectively. Additionally, a total of 942 and 2 179 injections of anti-VEGF drugs were injected for RVO-ME with an average of (3.98±3.71) and (3.14±2.15) injections per eye, respectively; a total of 291 and 615 injections of anti-VEGF drugs were injected for PM-CNV with an average of (3.31±2.63) and (2.99±1.69) injections per eye, respectively. A total of 683 and 1 029 injections of anti-VEGF drugs were injected for DR with an average of (1.60±1.26) and (1.41±1.05) injections per eye, respectively. The clinical application and implementation of "3+PRN" treatment were as follows: 223 (66.4%, 223/336) and 431 eyes (57.2%, 431/754) in the wAMD ( χ2=8.210, P=0.004), 75 (33.3%, 75/225) and 236 (37.5%, 236/630) eyes in the DME ( χ2=1.220, P>0.05), and 97 (40.9%, 97/237) and 355 eyes (51.2%, 355/693) in the RVO-ME ( χ2=7.498, P=0.006), 39 (44.3%, 39/88) and 111 eyes (53.9%, 111/206) in the PM-CNV ( χ2=2.258, P>0.05), respectively. In addition, the results of the questionnaire survey showed that there were significant differences between the control and observation groups regarding the time of appointment waiting for surgery ( t=1.340), time from admission to entering the operating room on the day of injection ( t=2.780), time from completing preoperative treatment preparation to waiting for entering the operating room ( t=8.390), and time from admission to discharge ( t=6.060) ( P<0.05). Conclusions:The establishment of a one-stop intravitreal injection mode greatly improved work efficiency and increased the number of injections. At the same time, the compliance, waiting time, and overall medical experience of patients significantly improved under centralized management.
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Objective:To characterize proteomic profile in aqueous humor of patients with high myopia using quantitative proteomic analysis.Methods:Sixty-eight age-related cataract patients were divided into high myopic cataract group and simple cataract group according to that they had high myopia or not, with 34 patients (34 eyes) in each group.Aqueous humor samples (100 μl/patient) were collected from each patient using a 1 ml tuberculin syringe during cataract surgery at Tianjin Medical University Eye Hospital from January 2019 to August 2019.Sixteen samples from each group were selected for protein quantification and comparison by BCA method.The differentially expressed proteins between the two groups were analyzed using label-free liquid chromatography tandem mass spectrometry.The function and signal transduction pathways of differentially expressed proteins were further analyzed by Gene Ontology enrichment and Kyoto Encyclopedia of Genes and Genomes.Eighteen aqueous humor samples from each group were selected to verify the results of mass spectrometry by enzyme-linked immunosorbent assay (ELISA). This study protocol adhered to the Declaration of Helsinki.The use of human samples was approved by an Ethics Committee of Tianjin Medical University Eye Hospital (No.2020KY[L]-40). Written informed consent was obtained from each patient prior to surgery.Results:The mean protein mass concentration of aqueous humor sample in the high myopic cataract group was (1 134.91±104.78) ng/L, which was significantly higher than that in the simple cataract group (706.71±85.43) ng/L, showing statistically significant difference ( t=11.977, P<0.01). A total of 463 proteins were identified and 86 proteins were found to be differentially expressed, including 49 up-regulated proteins and 37 down-regulated proteins in the two groups.These differentially expressed proteins were mainly protein-binding activity modulator, extracellular matrix protein, carrier protein, intercellular signal molecule, protein modifying enzyme and so on, accounting for 32.70%, 14.50%, 9.10%, 9.10% and 7.30%, respectively.Bioinformatics analysis showed that 86 differentially expressed proteins were mainly related to biological processes such as complement activation and regulation, acute inflammatory response, and extracellular matrix tissue remodeling.Among them, 21 differentially expressed proteins were enriched in the complement and coagulation cascades pathways, 15 in the extracellular matrix-receptor interaction pathway, and 8 in the PI3K-Akt signaling pathway.ELISA results showed that the expression trends of three randomly selected differentially expressed proteins of the two groups were consistent with the results of label-free quantitative proteomic analysis. Conclusions:There are significant changes in proteomic profiles of aqueous humor between the high myopia cataract patients and simple cataract patients.High myopia is closely associated with inflammation and immune interactions, and remodeling of extracellular matrix.
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Objective:To investigate the risk factors of postoperative vitreous hemorrhage (PVH) after vitrectomy for proliferative diabetic retinopathy (PDR).Methods:A case-control study was conducted.A total of 1 848 consecutive PDR patients (1 848 eyes) with vitreous hemorrhage receiving first pars plana vitrectomy (PPV) in Tianjin Medical University Eye Hospital from June 2012 to May 2019 were enrolled.There were 979 males and 869 females, with the average age of (55.72±10.39) years.All of the enrolled eyes underwent standard three-channel PPV.The subjects were followed up for 6 to 24 months, with the mean follow-up of (379.34±231.28) days.The eyes were divided into PVH group and non-PVH group according to whether the PVH occurred or not.The PVH group were further divided into early PVH group and late PVH group according to the occurrence time of PVH.There were 170 (9.19%) of 1 848 eyes developed PVH after surgery, including 17.64%(30/170) of eyes with early PVH and 82.36% (140/170) of eyes with late PVH.The PVH occurred at 6 to 450 days after surgery.Baseline systemic parameters including sex, age, diabetes duration, preoperative glycosylated hemoglobin (HbA1c) level, and ocular parameters including whether or not performing panretinal photocoagnlation, whether or not receiving treatment of anti-vascular endothelial growth factor (VEGF) three days before operation, lens status, whether or not being combined with neovascularization of iris (NVI), as well as intraoperative ocular parameters including whether or not having neovascularization of disc (NVD) bleeding, whether or not being combined with cataract phacoemulsification, whether or not receiving postoperative anti-VEGF, were analyzed by multivariate logistic regression analysis to identify the risk factors of PVH after PPV in PDR patients with VH.This study adhered to the Declaration of Helsinki, and the study protocol was approved by an Ethics Committee of Tianjin Medical University Eye Hospital (No.2019KY[L]-09).Results:Multivariate logistic regression analysis revealed that age ( OR=0.940, P<0.01), preoperative high HbA1c level ( OR=1.878, P<0.01), combined with retinal vein occlusion (RVO) ( OR=8.310, P<0.01), diabetes diet to control blood glucose ( OR=3.030, P<0.01), diabetes duration ( OR=1.044, P<0.01), history of hypertension ( OR=1.802, P<0.01), nephropathy or cardiovascular or cerebrovascular diseases ( OR=18.377, P<0.01), preoperative NVI ( OR=7.488, P<0.01), not combined with phacoemulsification surgery ( OR=1.628, P=0.023), NVD bleeding ( OR=2.691, P<0.01), postoperative anti-VEGF treatment ( OR=0.181, P<0.01), postoperative air tamponade ( OR=1.901, P=0.024) were associated with PVH.There were no significant differences in baseline, ocular and intraoperative ocular parameters between early PVH and late PVH groups (all at P>0.05). Conclusions:Younger age, preoperative high HbA1c level, combined with RVO, diabetes diet to control diabetes, diabetes duration, history of hypertension, nephropathy or cardiovascular or cerebrovascular diseases, preoperative NVI, uncombined with cataract surgery, NVD bleeding, without postoperative intravitreal anti-VEGF injection, postoperative air tamponade are the potential risk factors of PVH after PPV for PDR patients with VH.
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Objective:To analyze the risk factors of neovascular glaucoma (NVG) after 25G pars plana vitrectomy (PPV) in proliferative diabetic retinopathy (PDR).Methods:A retrospective study. From January 2017 to December 2018, 340 PDR patients (340 eyes) with vitreous hemorrhage (VH) who were first treated with PPV in Tianjin Medical University Eye Hospital were included in the study. Among them, 185 were male and 155 were female, with an average age of 55.79±10.82 years. The duration of diabetes was 13.01±7.70 years, the fasting blood glucose was 7.55±2.15 mmol/L. Nineteen patients combined coronary heart disease, and 20 patients combined cerebral infarction. All patients underwent best-corrected visual acuity (BCVA), intraocular pressure (IOP), non-contact fundus examination, and fundus color photographs. BCVA was measured using an international standard Snellen visual acuity chart, and the values were converted to logarithm of the minimum angle of resolution (logMAR) scores for data analysis. The baseline logMAR BCVA was 2.04±0.73, The baseline IOP was 15.45±2.93 mmHg (1 mmHg=0.133 kPa). The duration of VH was 2.98±1.46 months, ranged from 3 weeks to 6 months. Three hundred and forty eyes included 93 eyes of PDR Ⅳ stage (27.35%), 107 eyes of Ⅴ stage (31.47%), and 116 eyes of Ⅵ stage (34.12%), combined tractional retinal detachment (TRD) 83 eyes. All patients underwent 25G standard three channel vitrectomy through the pars plana of the ciliary body. Preoperative anti-VEGF injection was performed in 57 eyes, internal limiting membrane (ILM) peeling in 234 eyes, combined phacoemulsification cataract surgery in 262 eyes and 141 eyes intravitreal anti-VEGF injection at the end of surgery. The patients were followed up for at least 12 months, with an average follow-up time of 10.80±5.79 months. NVG was defined as the presence of neovascularization in the anterior chamber angle or iris with an IOP higher than 21 mmHg after vitrectomy. Kaplan-Meier method and Cox univariate and multivariate regression were used to analyze the relationship between baseline factors, ocular factors, surgical factors and the occurrence of NVG after surgery.Results:Among 340 eyes, 66 eyes (19.41%) developed NVG after vitrectomy during 12 months of observation, NVG occurred from 6 to 335 days after surgery, and the mean period between vitrectomy and developing NVG was 98.00±5.79 days. The incidence of NVG was 11.50%, 15.29% and 20.75%, respectively in the 3rd, 6th and 12th month after PPV. The result of univariate analysis with the Cox regression analysis showed that the development of NVG at 12 months after surgery and age, combined coronary heart disease or cerebral infarction, combined with cataract phacoemulsification, ILM peeling, preoperative anti-VEGF injection had effect on postoperative NVG ( P<0.05). Ocular factors such as PDR staging, combined TRD, preoperative logMAR BCVA, preoperative intraocular pressure, etc. had no effect on the occurrence of NVG after surgery ( P>0.05). Combined cataract phacoemulsification surgery, internal limiting membrane peeling, surgical factors such as intracavity injection of anti-VEGF drugs 3 days before surgery, had an impact on the occurrence of NVG after surgery ( P<0.05). The meaningful variables of the Cox univariate analysis were incorporated into the multivariate Cox proportional hazard model for analysis, and the influencing factors of NVG after surgery were gradually regressed. The results showed that age, coronary heart disease or cerebral infarction, combined with phacoemulsification of cataract, and internal limiting membrane removal during surgery were independent risk predictors of NVG after surgery ( P<0.05). Conclusions:Younger, coronary heart disease or cerebral infarction, combined with cataract phacoemulsification are the risk factors of NVG in PDR patients after PPV. The removal of internal limiting membrane can reduce the incidence of NVG.
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Objective To observe the protective effect of polypyrimidine bundle-binding proteinrelated splicing factor (PSF) over-expression on RPE cell injury induced by advanced glycation end products (AGEs).Methods The human RPE cells cultured in vitro were divided into three groups:normal control group (N group),blank control group (N + AGEs group),empty vector control group (Vec + AGEs group),and PSF high expression group (PSF + AGEs).group).RPE cells in N group were routinely cultured;RPE cells in N + AGEs group were only transfected but did not introduce any exogenous genes combined with AGEs induction;Vec +AGEs group and PSF + AGEs group were transfected with pcDNA The empty vector or pcDNA-PSF eukaryotic expression plasmid was introduced into RPE cells and induced by AGEs.Except the N group,the other 3 groups of cells were transfected accordingly,and were stimulated with 150 μg/ml AGEs for 72 h after 24 h.HE staining and Hoechst 33258 staining were used to observe the effect of high PSF expression on the morphological changes of RPE cells;ROS level detection was used to analyze the effect of PSF high expression on the ROS expression of RPE cells induced by AGEs;MTT colorimetric method was used to detect the high PSF expression Effects on the viability of RPE cells;Western blot was used to detect the effects of different time and dose of PSF on the expression of heme oxygenase 1 (HO-1).Results HE staining and Hoechst 33258 staining observation showed that the cells in group N were full in shape,the nucleus was round,the cytoplasm was rich,and the staining was uniform;the cells in N + AGEs group and Vec + AGEs group were reduced in size,the eosinophilic staining was enhanced,and the nucleus was densely densely stained.Pyrolysis and even fragmentation;the morphology of cells in the PSF + AGEs group was still full,the cytoplasm staining was more uniform,and the nucleus staining was uniform.The results of MTT colorimetry showed that high expression of PSF can effectively improve the viability of RPE cells,but this effect can be effectively antagonized by ZnPP,and the difference is statistically significant (F=33.26,P＜0.05).DCFH-DA test results showed that compared with the N + AGEs group and Vec + AGEs group,the ROS production in PSF + AGEs group decreased,the difference was statistically significant (F=1 1.94,P＜0.05).Western blot analysis showed that PSF protein upregulated HO-1 expression in a time-and dose-dependent manner.The relative expression level of HO-1 at 24,48,and 72 h after PSF protein was significantly higher than that at 0 h,and the difference was statistically significant (F=164.91,P＜0.05).The relative expression level of HO-1 under the action of 0.1,0.5,1.0,1.5,and 2.0 μg PSF protein was significantly higher than 0.0 μg,and the difference was statistically significant (F=104.82,P＜0.05).Conclusion PSF may inhibit the production of ROS by up-regulating the expression of HO-1,thus protecting the RPE cells induced by AGEs.
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Objective To investigate the inhibitory effect oflentivirus-mediated polypyrimidine bundle binding protein-associated splicing factor (PSF) on retinal neovascularization (RNV) in mice model of oxygeninduced retinopathy (OIR).Methods One hundred and twelve 5-day-old C57BL/6J mice were randomly divided into normal control group,simple OIR model group,OIR model + lentivirus empty vector treatment group (Vec group) and OIR model + PSF lentivirus treatment group (PSF group),with 16,32,32 and 32 mice,respectively.When the mice were 7 days old,the mice in the normal control group were fed in a routine environment,and the mice in the OIR model group,Vec group and PSF group were established OIR model.The mice in the Vec group and PSF group were given an intravitreal injection of 1 μl of lentiviral vector and PSF lentivirus (titer 1 × 10~ TU/ml) at the age of 12 days.No injection was performed in the normal control group and simple OIR group.RNV was evaluated by counting the number of pre-retinal neovascular cells and analysis of non-perfusion area by immunofluorescent staining of the mouse retina.Real-time quantitative PCR was applied to detect the mRNA expression of nuclear factor erythroid 2-related factor 2 (Nrf2) and hemeoxygenase1 (HO-1).Western blot analysis was applied to detect the protein expression ofNrf2,HO-1 and PSF.Results Of the normal control group,simple OIR model group,Vec group and PSF group,the number of pre-retinal neovascular cell nuclei were 0.00,14.36 ± 5.50,15.67 ± 4.96,8.13 ± 2.09,the non-perfusion area were 0.00％,(35.71 ± 2.81)％,(36.57 ± 4.53)％,(15.33 ± 4.75)％,respectively.The differences of the number of pre-retinal neovascular cell nuclei and non-perfusion area among 4 groups were significant (F=24.87,165.70;P＜0.05).Compared with the normal control group,there were more pre-retinal neovascular cell nucleis and larger nonperfusion area in the simple OIR model group and Vec group (P＜0.05).Compared with the simple OIR model group and Vec group,there were lower pre-retinal neovascular cell nucleis and smaller non-perfusion area in the PSF group (P＜0.05).Real-time quantitative PCR and Western blot showed that the mRNA expression of Nrf2,HO-1 (F=53.66,83.54) and protein expression ofNrf2,HO-1 and PSF (F=58.38,52.69,24.79) among 4 groups were significant (P＜0.05).The rnRNA expression ofNrf2,HO-1 and protein expression of Nrf2,HO-1 and PSF in the simple OIR model group and Vec group decreased significantly than those in the normal control group (P＜0.05).The mRNA expression ofNrf2,HO-1 and protein expression ofNrf2,HO-1 and PSF in the PSF group were increased significantly than those in the simple OIR model group and Vec group (P＜0.05).model group and Vec group (P＜0.05).Conclusion Intravitreal injection of lentivirus-mediated PSF inhibits RNV in mice model of OIR possibly through up-regulating the expression of Nrf2 and HO-1.
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Objective:To observe the effect of pyrimidine bundle-binding protein-associated splicing factors (PSF) on the function of hypoxia-induced human retinal microvascular endothelial cells (hRMECs).Methods:A three-plasmid system was used to construct lentivirus (LV)-PSF. After LV-PSF infected hRMECs in vitro, the infection efficiency was measured by flow cytometry. Real-time quantitative PCR (RT-PCR) was used to detect the expression of PSF mRNA in hRMECs infected with LV-PSF. The experiment was divided into two parts, in vivo and in vitro. In vivo experiments: 20 healthy C57B/L6 mice at the age of postnatal 7 were randomly divided into normal group, oxygen-induced retinopathy (OIR) group, OIR+LV-Vec group, and OIR+LV-PSF group, each group has five mice. Mice in 3 groups were constructed with OIR models except the normal group and the mice in OIR group were not treated. The mice in the OIR + LV-Vec group and the OIR+LV-PSF group were injected with an empty vector (LV-Vec) or LV-PSF in the vitreous cavity, respectively. The effect of LV-PSF on the formation of retinal neovascularization (RNV) was observed then. In vitro experiments: hRMECs were divided into normal group, hypoxia group, vector group, and PSF high expression group. HRMECs in the normal group were cultured in vitro; hRMECs in the hypoxic group were restored to normal culture conditions for 3 h after 3 h of hypoxia stimulation; hRMECs in the vector group and PSF high expression group were infected with LV-Vec and LV-PSF for 48 h, and hRMECs were returned to normal culture conditions for 24 h with hypoxia stimulation for 3 h. The effect of PSF on cell proliferation was observed by MTT colorimetry. Cell scratch test and Transwell migration experiment were used to observe the effect of PSF on cell migration ability under hypoxia stimulation. RT-PCR was used to observe the mRNA expression of HIF-1α, VEGF and PSF in each group of cells.Results:The LV-PSF of stably expressing PSF was successfully constructed. The infection efficiency was 97% determined by flow cytometry. The level of PSF mRNA in hRMECs infected with LV-PSF was significantly increased and detected by RT-PCR. In vivo experiments: The RNV area of the mice in the OIR group and the OIR + LV-Vec group was significantly increased compared to the normal group ( t=18.31, 43.71), and the RNV area of the mice in the OIR + LV-PSF group was smaller than that in the OIR group ( t=11.30) and OIR + The LV-Vec group ( t=15.47), and the differences were statistically significant ( P<0.05). In vitro experiments: MTT colorimetry results showed that the proliferative capacity of hRMECs in the hypoxic group was significantly enhanced compared with the normal group ( t=2.57), and the proliferative capacity of hRMECs in the PSF high expression group was significantly lower than that of the normal, hypoxic, and vector groups ( t=5.26, 5.46, 3.73), the differences were statistically significant ( P<0.05). The results of cell scratch test showed that the hRMECs could be stimulated by the hypoxia stimulation for 3 hours to restore the normal condition for 24 hours or 48 hours ( t=8.35, 13.84; P<0.05). Compared with the vector group, cell migration rate in the PSF-high expression group was not significant ( t=10.99, 18.27, 9.75, 8.93, 26.94, 7.01; P<0.05). Transwell experiments showed that the number of cells stained on the microporous membrane was higher in the normal group and the vector groups, while the number of cells stained in the PSF high expression group was significantly reduced ( t=9.33, 6.15; P<0.05). The results of RT-PCR showed that the mRNA expression of HIF-1α and VEGF in hRMECs in the hypoxic and vector groups increased significantly compared with the normal group ( t=15.23, 21.09; P<0.05), but no change in the mRNA expression of PSF ( t=0.12, 2.15; P>0.05); compared with the hypoxia group and the vector group, the HIF-1α and VEGF mRNA expression in hRMECs in the PSF high expression group were significantly decreased ( t=10.18, 13.10; P<0.05), but the PSF mRNA expression increased ( t=65.00, 85.79; P<0.05). Conclusion:PSF can reduce the RNV area in OIR model mice. PSF may inhibit hypoxia-induced proliferation and migration of hRMECs through the HIF-1α/VEGF signaling pathway.
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Objective:To observe the safety and effectiveness of patching retinal breaks with Healaflow in 27G vitrectomy combined with air tamponade in the treatment of rhegmatogenous retinal detachment (RRD).Methods:Clinical-based prospective continuous study. From March 2017 to May 2018, 51 eyes of 50 RRD patients diagnosed in Tianjin Medical University Eye Hospital were included in the study. All eyes were treated with 27G vitrectomy, and laser photocoagulation was performed around retinal hiatus and denaturation zone after complete retinal reattachment. A blunt 27G needle was used to completely cover the surface of the retinal tear with the Healaflow. The injection amount was determined according to the size of the retinal tear, and the standard was that the tear was completely contained. There was no postoperative position limitation. The average follow-up was 15.8±6.3 months. The primary and final anatomic attachment rate, BCVA after operation, the intraoperative and postoperative complications, the recurrence of retinal detachment and so on were recorded.Results:51 eyes of 50 patients were enrolled, including 29 males (58.0%) and 21 females (42.0%). The average age was 58.5±1 years. A single break was present in 28 eyes (54.9%) and 2 to 5 breaks in 23 eyes (45.1%). The macula was involved in 32 eyes (62.7%) and attached in 19 eyes (37.3%) intraoperatively. Initial reattachment was achieved in 50 eyes (98.0%) and final reattachment in 51 eyes (100.0%). The logMAR BCVA before and 3 months after operation were 0.95±0.80 and 0.22±0.17, respectively. The difference of logMAR BCVA between before and after operation was significant ( t=7.336, P<0.001). The intraocular pressure was elevated transiently in 31 eyes (60.8%). No other complications occurred during follow-up. Conclusion:The treatment of primary RRD with 27G vitrectomy combined with Healaflow patch and air tamponade is a safe, effective and convenient method with high success rate and rapid recovery of visual function.
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Neural stem cell is a kind of stem cells that can differentiate into neural and glial cells. While Müller cells, the main endogenous neural stem cell in retina,have the features to reentry into the cell cycle and differentiate into neural cells after retinal damage. Although it is highly effective for retinal Müller cell differentiation spontaneously after retinal injury in vertebrates, this feature is rigorous restricted in mammals. Recently, some transcription factors,such as Ascl1, Sox2, Lin28, Atoh7, are sufficient to drive quiescent Müller cells back in proliferation to generate new retinal neurons. Moreover, combining Ascl1 expression with a histone deacetylase inhibitor can bypass the limitation and increase the generation of new neurons in the adult retina. These regenerated neurons integrate the existing neuronal network and are able to respond to light, indicating that they can likely be used to restore vision. While these results are extremely promising, the regenerative response is still limited, likely because the proliferative capacity of mammalian Müller cells is low compared to their zebrafish counterparts. It is indeed necessary to identify new factors increasing the efficiency of the regenerative response.
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Objective To investigate the relationship between exposure intensity and illumination time of blue light and replicative senescence of rat retinal pigment epithelial (RPE) ceils.Methods Thirty-six 12-14 weeks Wistar rats were kept in the cage with a blue-light bulb [(450±10) nm],and were randomly divided into four groups (no light,nature light,500 lx light and 1000 lx light illumination),each has nine rats.The rats in each group were further divided into three subgroups according to illumination time (one month,two months or three months).Eyeballs were collected after intraperitoneal injection of 10% chloral hydrate.The right eye of each rat was embedded in paraffin and sectioned for hematoxylin-eosin (HE)staining,while frozen sections of the left eye were stained for the senescence-associated β-galactosidase (SA-β-Gal).The data were analyzed by SPSS11.5 statistical software.Results The amounts of SA-β-Gal positive RPE cells were significantly different between all groups under the same illumination time 17 (P=0.000),and between all subgroups of different illumination time with same exposure intensity (P＜0.01)except for the control group (no light).Conclusion Blue-light can induce replicative senescence in rat RPE cells in an intensity and time-dependent manner.