Objective: To observe the clinical efficacy of minimally invasive vitreous surgery (MIVS) for special rhegmatogenous retinal detachment (RRD) in children and adolescents. Methods: A retrospective clinical comparative study. Fourteen eyes with special type of RRD in 14 children and adolescents who received the MIVS treatment from January 2014 to January 2019 in Ophthalmology Department of The First Affiliated Hospital Ophthalmology of Air Force Military Medical University, were included in this study. Among them, 8 eyes from 8 males and 6 eyes from 6 females. The age of them ranged from 5 to 17, with the mean age of 12.64±4.11 years. The course of disease was ranged from 1 d to 1 year, and the average of it was 30 d. All the eyes developed the special type RRD, including pseudophakic and aphakic retinal detachment, giant retinal tear with retinal detachment, choroidal detachment associated with retinal detachment, and RRD with ocular dysplasia. In the 14 eyes, there was 2 eyes with retinal detachment in 1 quadrant, 4 eyes in 2 quadrants, 1 eye in 3 quadrants and 7 eyes in total 4 quadrants. All the eyes were treated with 23G or 25G MIVS and filled with irrigation solution, air and silicone oil. In addition, 10.4 months' follow-up for average after surgery were taken to observe the occurrence of retinal reattachment, BCVA and related complications in the eyes. Results: In the 14 eyes, 13 (92.9%) of them attained retinal reattachment and 1 eye (7.1%) got a poor retinal reattachment after one operation. At the last follow-up, all the 14 eyes (100.0%) attained retinal reattachment and 5 of them at the filling state of silicone oil. The vision of 8 eyes (57.1%) were improved, 4 eyes (28.6%) have no notable changes and 2 eyes decreased (14.3%). During the operation, iatrogenic retinal breaks were occurred in 1 eye, and silicone oil entered underneath the retina in 1 eye. After the operation, 1 eye suffered a relapse of retinal detachment after the removal of silicone oil and then were filled with it again. Conclusions MIVS is a safe and effective way to treat the special type RRD among the children and adolescents. The rate of retinal reattachment is 92.9% after one surgery and 100.0% at the last follow-up. Therefore, MIVS can help most of eyes with special type RRD to get a stable and improved vision.

Objective To investigate whether vascular endothelial cells in choroidal neovascularization whether hypoxia condition can up-regulate SNAI1 and activate matrix metalloproteinase (MMP)2 and MMP9 therefore to participate in choroidal neovascularization(CNV).Methods Sixteen SPF male C57 mice aged 6-8 weeks were divided into control group and model group.CNV models were induced by retinal laser photocoagulation,and flatmount and frozen sections of retinal pigment epithelium (RPE)-choroid-sclera compound were prepared at 7 days after modeling.The CNV in flat-mount was examined by Isolectin B4 staining,and the location of SNAI1,MMP2 and MMP9 in frozen sections was determined by immunofluorescence technology.The expression of SNAI1,MMP2 and MMP9 at mRNA level in CNV was detected by real-time fluorescence quantitative PCR (real-time PCR).The use and care of experimental animals complied with Statement for the Use of Animals in Ophthalmic and Visual Research.The RF/6A cells were divided into normoxia group and hypoxia group and cultured for 24 hours in 5％ CO2condition and mix condition of 94％ N2,5％ CO2 and 1％ O2,respectively.The expression of SNAI1,MMP2 and MMP9 in the cells at mRNA and protein levels was detected by real-time PCR and Western blot assay,respectively.Small interfering RNA of SNAI1 (siSNAI1) was transfected into the cells,and then the expression of MMP2 in the cells at mRNA and protein levels was detected by real-time PCR and Western blot assay,respectively,and the migrating number of the cells was assayed by Transwell chamber assay.Results CD31 and SNAI1 positive-response cells were seen in RPE-choroid-sclera flat-mounts under the laser scanning confocal microscope.The relative expression levels of SNAI1mRNA and MMP2 mRNA in RPE-choroid-sclera tissues were higher in the model group than those in the control group (SNAI1 mRNA:1.291 ±0.060 vs.0.759±0.074,P =0.001;MMP2 mRNA:1.610±0.424 vs.0.772 ±0.080,P =0.044).The expression of MMP9 mRNA was not significantly elevated between model group and control group (P＞0.05).The relative expression level of MMP2 mRNA was higher in comparison with MMP9 mRNA in the model group (P＜0.01).The relative expressions of hypoxic induced factor 1α (HIF-1α),SNAI1 and MMP2 at mRNA level and protein level in RF/6A cells were significantly higher in the hypoxia group than those in the normoxia group (all at P＜0.05) and no considerable difference was seen in MMP9 mRNA expression between the two groups (P＞0.05).The relative expressions of MMP2 mRNA in the cells were 0.217±0.036 and 0.818±0.105,and those of MMP2 protein in the cells were 0.236±0.009 and 1.043±0.120 in the hypoxia+siSNAI1 group and only hypoxia group,respectively,with significant differences between them (P =0.002,0.003).The migrating number of the cells was (254.60 ±71.31)/field in the hypoxia+siSNAI1 group,which was significantly less than (534.10±96.21) /field in the control group (P =0.029).Conclusions The hypoxic environment at CNV can activate MMP2 by up-regulating the expression of SNAI1,which promotes the migration of vascular endothelial cells and therefore participates in CNV formation,and the intervention of SNAI1 activation under the hypoxic condition can inhibit this process.

AIM:To investigate the application of virtual reality(VR)technology in ocular trauma teaching for medical students.METHODS: A total of 90 medical students who participated in the Ophthalmology teaching program between November 2022 and April 2024 were recruited as subjects. Using a case-control method, 45 students in the case group attended traditional ocular trauma teaching program combined with VR virtual simulation experiments, and 45 students in the control group solely attended traditional ocular trauma teaching program. After the teaching practice, the two groups were compared in terms of their examination performance of theoretical knowledge and case analysis, learning ability(evaluated by the Self-Directed Learning Rating Scale), and the satisfaction survey on the quality of teaching; the statistical analyses were performed using t-test or Chi-square test.RESULTS: The scores of theoretical knowledge and case analysis examinations of the case group were significantly higher than those of the control group, and the differences were statistically significant(scores of theoretical knowledge examination: 57.27±2.78 vs 53.91±3.20; scores of case analysis examination: 35.71±3.73 vs 32.67±5.52, both P<0.05). The scores of the Self-Directed Learning Rating Scale of the case group were significantly higher than those of the control group(P<0.05), and the satisfaction with teaching quality of the case group was significantly higher than that of the control group(P<0.05).CONCLUSION: VR-enabled teaching of ocular trauma can effectively improve medical students' mastery of theoretical knowledge and practical skills, enhance students' self-directed learning ability and improve teaching satisfaction.