Exploratory study of non-invasive,high-resolution functional macular imaging in subjects with diabetic retinopathy

AIM:To evaluate a high-resolution functional imaging device that yields quantitative data regarding macular blood flow and capillary network features in eyes with diabetic retinopathy(DR).METHODS:Prospective,cross-sectional comparative case-series in which blood flow velocities(BFVs)and noninvasive capillary perfusion maps(nCPMs)in macular vessels were measured in patients with DR and in healthy controls using the Retinal Functional Imager(RFI)device.RESULTS:A total of 27 eyes of 21 subjects were studied[9 eyes nonproliferative diabetic retinopathy(NPDR),9 eyes proliferative diabetic retinopathy(PDR)and 9 controls].All diabetic patients were type 2.All patients with NPDR and 5 eyes with PDR also had diabetic macular edema(DME).The NPDR group included eyes with severe(n=3)and moderate NPDR(n=6),and were symptomatic.A significant decrease in venular BFVs was observed in the macular region of PDR eyes when compared to controls(2.61±0.6 mm/s and 2.92±0.72 mm/s in PDR and controls,respectively,P=0.019)as well as PDR eyes with DME compared to NPDR eyes(2.36±0.51 mm/s and 2.94±1.09 mm/s in PDR with DME and NPDR,respectively,P=0.01).CONCLUSION:The RFI,a non-invasive imaging tool,provides high-resolution functional imaging of the retinal microvasculature and quantitative measurement of BFVs in visually impaired DR patients.The isolated diminish venular BFVs in PDR eyes compared to healthy eyes and PDR eyes with DME in comparison to NPDR eyes may indicate the possibility of more retinal vein compromise than suspected in advanced DR.

Educational, psychosocial, and clinical impact of SARS-CoV-2 (COVID-19) pandemic on medical students in the United States

BACKGROUND The coronavirus disease 2019(COVID-19)pandemic altered education,exams,and residency applications for United States medical students.AIM To determine the specific impact of the pandemic on US medical students and its correlation to their anxiety levels.METHODS An 81-question survey was distributed via email,Facebook and social media groups using REDCapTM.To investigate risk factors associated with elevated anxiety level,we dichotomized the 1-10 anxiety score into low(≤5)and high(≥6).This cut point represents the 25th percentile.There were 90(29%)shown as low anxiety and 219(71%)as high anxiety.For descriptive analyses,we used contingency tables by anxiety categories for categorical measurements with chi square test,or mean±STD for continuous measurements followed by t-test or Wilcoxson rank sum test depending on data normality.Least Absolute Shrinkage and Selection Operator was used to select important predictors for the final multivariate model.Hierarchical Poisson regression model was used to fit the final multivariate model by considering the nested data structure of students clustered within State.RESULTS 397 medical students from 29 states were analyzed.Approximately half of respondents reported feeling depressed since the pandemic onset.62%of participants rated 7 or higher out of 10 when asked about anxiety levels.Stressors correlated with higher anxiety scores included“concern about being unable to complete exams or rotations if contracting COVID-19”(RR 1.34;95%CI:1.05-1.72,P=0.02)and the use of mental health services such as a“psychiatrist”(RR 1.18;95%CI:1.01-1.3,P=0.04).However,those students living in cities that limited restaurant operations to exclusively takeout or delivery as the only measure of implementing social distancing(RR 0.64;95%CI:0.49-0.82,P<0.01)and those who selected“does not apply”for financial assistance available if needed(RR 0.83;95%CI:0.66-0.98,P=0.03)were less likely to have a high anxiety.CONCLUSION COVID-19 significantly impacted medical students in numerous ways.Medical student education and clinical readiness were reduced,and anxiety levels increased.It is vital that medical students receive support as they become physicians.Further research should be conducted on training medical students in telemedicine to better prepare students in the future for pandemic planning and virtual healthcare.

One in four patients with gastrointestinal bleeding develops shock or hemodynamic instability:A systematic review and meta-analysis

BACKGROUND Hemodynamic instability and shock are associated with untoward outcomes in gastrointestinal bleeding.However,there are no studies in the existing literature on the proportion of patients who developed these outcomes after gastrointestinal bleeding.AIM To determine the pooled event rates in the available literature and specify them based on the bleeding source.METHODS The protocol was registered on PROSPERO in advance(CRD42021283258).A systematic search was performed in three databases(PubMed,EMBASE,and CENTRAL)on 14^(th) October 2021.Pooled proportions with 95%CI were calculated with a random-effects model.A subgroup analysis was carried out based on the time of assessment(on admission or during hospital stay).Heterogeneity was assessed by Higgins and Thompson’s I^(2) statistics.The Joanna Briggs Institute Prevalence Critical Appraisal Tool was used for the risk of bias assessment.The Reference Citation Analysis(https://www.referencecitationanalysis.com/)tool was applied to obtain the latest highlight articles.RESULTS We identified 11589 records,of which 220 studies were eligible for data extraction.The overall proportion of shock and hemodynamic instability in general gastrointestinal bleeding patients was 0.25(95%CI:0.17-0.36,I^(2)=100%).In non-variceal bleeding,the proportion was 0.22(95%CI:0.14-0.31,I^(2)=100%),whereas it was 0.25(95%CI:0.19-0.32,I^(2)=100%)in variceal bleeding.The proportion of patients with colonic diverticular bleeding who developed shock or hemodynamic instability was 0.12(95%CI:0.06-0.22,I^(2)=90%).The risk of bias was low,and heterogeneity was high in all analyses.CONCLUSION One in five,one in four,and one in eight patients develops shock or hemodynamic instability on admission or during hospitalization in the case of non-variceal,variceal,and colonic diverticular bleeding,respectively.