·AIM:To observe the clinical and multimodal imaging features of retinopathy associated with novel coronavirus disease 2019(COVID-19)infection,investigate the related risk factors,and analyze the treatment and prognosis. ·METHODS:A total of 7 patients(7 eyes)with clinically confirmed COVID-19-associated retinopathy in Tianjin Medical University General Hospital from December 13,2022 to January 13,2023 were included in the study.All patients underwent color fundus photography,IR,spectral-domain optical coherence tomography(SD-OCT),fundus autofluorescein(FAF)and other ophthalmic examination and serological examination. ·RESULTS:Among the included patients,2 cases(2 eyes)of central retinal vein occlusion(CRVO)appeared differently from previous CRVO.The hemorrhagic features of CRVO were round or fusiform shape hemorrhagic spots with white centers.One of them,the von Willebrand factor antigen(vWF:Ag)level was increased to 161.8％.The other case was positive in serologic test for lupus anticoagulant.In 2 cases(2 eyes)of multiple evanescent white dot syndrome(MEWDS),FAF showed that dots of high spontaneous fluorescence were scattered in the posterior pole.The prognosis of 2 MEWDS were good after the treatment of glucocorticoids.The 3 cases(3 eyes)of acute macular neuroretinopathy(AMN)showed reddened brown lesions in the macular area,hyporeflective lesions with clear boundaries on IR,and high signal intensity in the ONL and ELM,EZ/IZ signal fracture on SD-OCT. ·CONCLUSION:COVID-19 may cause inflammatory storm,involving all layers of retinal tissues and blood vessels,leading to the occurrence of various retinal lesions.Hormone therapy may be effective and the prognosis is good in most cases.Roth spot can be seen in fundus hemorrhage of CRVO,lupus anticoagulant and increased vWF:Ag may be risk factors for CRVO after COVID-19.

Objective:To investigate the damage effect of different concentrations of N-methyl-D-aspartic acid (NMDA) to retinal ganglion cells (RGCs) in mice and explore the expression of long noncoding RNA (lncRNA) Tsix in the retina of mice with excitotoxicity as well as the protective effect of lncRNA Tsix on retina and RGCs.Methods:A total of 105 C57B6/J mice at 7-8 weeks of age were selected and randomly divided into the normal control group, 2 mmol/L NMDA group, 10 mmol/L NMDA group, 20 mmol/L NMDA group and 40 mmol/L NMDA group using a random number table method, with 21 mice in each group.In the normal control group, the mice were intravitreally injected with 1 μl of sodium chloride solution in the right eye, and mice were given intravitreal injection of 1 μl of different doses of NMDA according to grouping.At one week after the injection, the thickness of each retinal layer, the number of ganglion cell layer (GCL) cells and the number of RGCs were analysed and compared among different groups through optical coherence tomography (OCT), hematoxylin-eosin staining, retinal whole mount staining and immunofluorescence staining.RNAscope in situ hybridization was used to verify the expression of lncRNA Tsix in the GCL of different groups.The quantitative real-time PCR was used to detect the transcript levels of Tsix in different groups.This study was approved by an Ethics Committee of Tianjin Medical University (No.SYXK2018-0004), and the use of experimental animals was in accordance with the regulations of Tianjin Medical University and ARVO statement. Results:The OCT results showed that the total retinal thickness of mice in the 2, 10, 20 and 40 mmol/L NMDA groups were (255.00±6.63), (252.40±6.41), (248.67±6.20) and (229.11±10.37)μm, respectively, which were thinner than (269.60±20.01)μm in the normal control group, and the differences were statistically significant (all at P<0.05). Hematoxylin-eosin staining showed that the cells in the GCL of the normal control group were uniform and compact, and arranged in a single layer with large and round nuclei.In the NMDA groups, the cells were uneven in volume with vacuoles and nuclear pyknosis.The cell density in the GCL was decreased significantly with the increasing NMDA doses in NMDA groups in comparison with the normal control group, and the differences were statistically significant (all at P<0.05). In the 20 mmol/L NMDA group, the cell density in the GCL was reduced to half of the normal control group.The results of retinal whole mount staining showed that the density of β3-tubulin-positive RGCs was decreased significantly as the dose of NMDA increased in NMDA groups, and the differences were statistically significant compared with the normal control group (all at P<0.05). The number of RGCs in the 10 mmol/L NMDA group was reduced to half of that in the normal control group.RNAscope results showed that lncRNA Tsix was mainly expressed in the cytoplasm of the GCL cells.The proportion of lncRNA Tsix-positive cells was significantly reduced with the increase of the NMDA dose ( F=13.670, P<0.01). The quantitative real-time PCR results verified that the trend of Tsix expression was consistent with the RNAscope result. Conclusions:NMDA exerts a dose-dependent damage to the layer thickness of mouse retina and RGCs.The expression of lncRNA Tsix in mouse retina is mainly enriched in the cytoplasm of the cells in the GCL, and the transcript level of Tsix is reduced with the increase of NMDA concentration and have a protective effect on RGCs.

Objective:To study the methylation level of retinal gene promoter region in a rat model of type 1 diabetes (T1D) and investigate the correlation between DNA methylation level and retinal damage caused by T1D.Methods:Twenty male SD rats aged 8-10 weeks were randomly divided into a control group and a T1D group using a random number table.T1D model was established via a rat tail vein injection of streptozotocin (STZ). The same volume of sodium citrate buffer was injected in the same way in the control group.Body mass of the rats was monitored before and after the injection of STZ.Blood glucose concentration of the rats was detected three days and five weeks following the injection.Methylated DNA immunoprecipitation-chip (MeDIP-chip) technology was employed to analyze the DNA methylation in the CpG islands of retinal gene promoter regions of the rats.Methylation data were compared between the two groups and subjected to Gene Ontology (GO) and pathway enrichment analyses.This study protocol was evaluated and approved by the Institutional Animal Care and Use Committee of Tianjin Medical University, and the use and care of the animals were in accordance with the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health.Results:Compared to the normal control group, typical deregulated metabolic syndromes were found in the T1D group.including hyperphagia, polydipsia, polyuria, and loss of body weight.According to the results of MeDIP-chip analysis, 1 478 differentially methylated gene loci were detected in the T1D group compared to the normal control group, of which 689 were hypermethylated and 789 hypomethylated.Of these differentially methylated loci 768, 365 and 345 were located in high, intermediate, and low CpG-density promoters, respectively.GO analysis showed that the differentially methylated genes were involved in some molecular functions such as protein binding.The pathway analysis revealed that the hypermethylated genes in the rats of the T1D group were associated with mitogen-activated protein kinase (MAPK) and calcium signaling pathways; whereas the hypomethylated genes were associated with MAPK, Notch, and glutamatergic synapse signaling pathways.Conclusions:Methylation level of the majority of genes was altered in T1D rats.A differential methylation in the retinal gene promoter regions provides a preliminary theoretical basis for elucidating the molecular mechanism underpinning diabetic retinopathy and searching for novel therapeutic targets.

随着医学模式的改变,传统的教学方式已不能满足现代社会对医学人才的要求。PBL教学法则是由传统的以知识点为中心,教师为方向,学生被动学习的灌输式的教学方法,转变为以问题为中心,教师为导向,学生为主体的主动学习的实践式的教学方法。PBL合理的课程设计和大学生的自身特点,使其在高校教学中具有很大的可行性。