Risk of Retinal Vascular Occlusion among Patients with Covid-19 and Influenza A: A Multi-Centered Analysis

Purpose of Study: Severe COVID-19 infection has been associated with a hypercoagulable state, contributing to the formation of clots. Retinal vascular occlusion (RVO) is a common cause of vision impairment and is due to blockage of the retinal arteries and veins. There have been reported cases of patients with previous history of COVID-19 presenting with new RVO. Given the minimal research delving into this relationship, the purpose of this study was to investigate the short-term prevalence and risk for RVO following infection by COVID-19 compared to Influenza A. Methods Used: Two cohorts were created using TrinetX, a national federated electronic health record (EHR). The two cohorts consisted of patients with a history of COVID-19 (n=2,352,475) and patients with a history of Influenza A (n=67,065). Both cohorts were balanced using 1:1 propensity score matching (PSM) addressing demographics and medical comorbidities. Outcomes between the two cohorts were compared using adjusted risk ratios (aRR), with a confidence interval of 95%. Summary of Results: After PSM, two cohorts of 67,063 patients each were compared. Patients in the COVID-19 cohort had an average age of 41.4+/-23.0 years compared to 34.4+/-27.7 years in the Influenza cohort. Between the two cohorts, there was no significant difference in risk of developing retinal vascular occlusion (aRR [95% CI] = 0.72 [0.49,1.06];p=0.097) and patients with COVID-19 had a significantly lower risk for developing retinal vein occlusion (aRR [95% CI] = 0.45 [0.27,0.77];p=0.03). Incidence of retinal vascular occlusion was 0.1% between both cohorts. Retinal artery occlusion was excluded from analysis due to obfuscation of the data by the EHR. Conclusion(s): Between the two cohorts, there was no significant difference in risk for developing RVO within 120 days. However, while there was no significant difference, vascular occlusions were found at a relatively younger age than the general population. Although incidence of RVO was low between the two cohorts, both viruses could be considered a risk factor for development of RVO, particularly in younger patients lacking classic risk factors for the disease.

Highlights of the drug-induced liver injury literature for 2021.

INTRODUCTION: In 2021, over 3,000 articles on Drug-Induced Liver Injury (DILI) were published, nearly doubling the annual number compared to 2011. This review selected DILI articles from 2021 we felt held the greatest interest and clinical relevance. AREAS COVERED: A literature search was conducted using PubMed between 1 March 2021 and 28 February 2022. 86 articles were included. This review discusses new and established cases of hepatotoxins, including new FDA approvals and COVID-19 therapeutics. Developments in biomarkers and causality assessment methods are discussed. Updates from registries are also explored. EXPERT OPINION: DILI diagnosis and prognostication remain challenging. Roussel Uclaf Causality Assessment Method (RUCAM) is the best option for determining causality and has been increasingly accepted by clinicians. Revised Electronic Causality Assessment Method (RECAM) may be more user-friendly and accurate but requires further validation. Quantitative systems pharmacology methods, such as DILIsym, are increasingly used to predict hepatotoxicity. Oncotherapeutic agents represent many newly approved and described causes of DILI. Such hepatotoxicity is deemed acceptable relative to the benefit these drugs offer. Drugs developed for non-life-threatening disorders may not show a favorable benefit-to-risk ratio and will be more difficult to approve. As the COVID-19 landscape evolves, its effect on DILI deserves further investigation.

Post COVID-19 Vaccination-Associated Neurological Complications.

PURPOSE: Neurological sequelae after COVID-19 vaccination are rare. We investigated the possible pathogenesis behind the development of neurological complications within a short period after Saudi residents received a COVID-19 vaccine. PATIENTS AND METHODS: We evaluated 18 patients who recently received a COVID-19 vaccine (Comirnaty and Vaxzevria vaccines) and presented with neurological complications to the Saudi German Hospitals in Jeddah, Saudi Arabia. Neurologists assessed the patients' clinical presentation, radiological investigations, and laboratory findings. RESULTS: Three patients who received the first dose of the Vaxzevria vaccine experienced severe cerebral venous thrombosis, two of them were complicated by intracranial hemorrhage. Their laboratory investigations showed very high d-dimers and severe thrombocytopenia, which have been linked to higher mortality and poor outcome. Ischemic stroke occurred in eight cases (44.4%) with a predominance in older male patients. Three patients presented with seizures, two had optic neuritis. Guillain-Barré syndrome (GBS) and Miller Fisher syndrome (MFS) occurred in two male patients following vaccination with Comirnaty. CONCLUSION: Neurological complications after COVID-19 vaccinations are very rare, and only a few cases have been reported worldwide. The shared pathophysiological basis between COVID-19 viral infection and COVID-19 vaccines stands behind the very rare neurological complications resulting from the hypercoagulable state triggered by the general inflammatory condition. We suspect some differences in the pathogenesis of ischemic stroke caused by COVID-19 infection and COVID-19 vaccines, which render COVID-19 vaccine-associated ischemic stroke more responsive to treatment. To date, no definitive association between the vaccine and GBS has been proven by any strong evidence, but it has recently been added as a very rare side effect of the Janssen COVID-19 vaccine. No possible links of Miller Fisher syndrome to COVID-19 vaccines have been reported before the one reported in this study.

Evaluating the Risk of Retinal Vascular Occlusion among COVID-19 patients

Purpose : SARS-CoV-2, the viral infection that causes COVID-19, is known to induce a hypercoagulable state in patients. While there have been isolated reports of retinal vascular occlusion among patients with a pre-existing COVID-19 infection, research into this topic remains scant. Therefore, the purpose of this study is to investigate the shortterm prevalence and risk for retinal vascular occlusion between COVID-19 and influenza A patients. Methods : TrinetX is a national, federated database that was utilized in this retrospective cohort analysis. At the time of the study, electronic medical records from over 80 million patients across 57 healthcare organizations were analyzed to create two cohorts of patients. At the time of the analysis, 1,224,770 patients with a previous history for COVID19 were compared to 61,555 patients with a previous history for influenza A. Then, 1:1 propensity score matching (PSM) was utilized to balance each cohort by demographics and comorbidities (age, sex, BMI, history of hypertension, chronic lower respiratory disease, diabetes mellitus, nicotine dependence, heart failure, and alcohol related disorders). Adjusted risk ratios (aRR) using 95% confidence intervals (CI) were used to assess risk of retinal vascular occlusion 120 days after initial diagnosis for COVID-19 or influenza A. Results : Before PSM, COVID-19 patients were at significantly lesser risk for retinal vascular occlusion within 120 days of initial diagnosis than influenza A patients (aRR [95% CI] = 0.58 [0.42,0.8];p<0.001). However, the incidence for influenza patients to develop retinal vascular occlusion was very small (0.1%). After PSM, two balanced cohorts of 61,555 patients were compared to one another and revealed that there is no significant difference in developing a retinal vascular occlusion after a previous diagnosis of COVID19 or influenza A (0.92 [0.58,1.46];p=0.725). Likewise, the incidence for retinal vascular occlusion remained very small (0.1% between both cohorts) (Table 1). Conclusions : This is the first large-scale study investigating the risk of retinal vascular occlusion among COVID-19 and influenza A patients. We found that each cohort was at similar risk for developing retinal vascular occlusion within 120 days. Likewise, the incidence for retinal vascular occlusion was miniscule among patients in this study.

US National Trends in Ophthalmic Procedures During the COVID-19 Pandemic

Purpose : To evaluate the relationship between COVID-19 case volume and ophthalmic procedural volume during the pandemic. Methods : A retrospective cohort study using TriNetX (Cambridge, MA, USA), a federated electronic health records research network comprising multiple large health organizations in the United States. Monthly Current Procedural Terminology (CPT)- specific volumes per HCO were clustered chronologically to calculate average volumes into three-month seasons to calculate average volumes. Seasonal averages from a combination of 2018 and 2019 data were used to provide a baseline comparison to pre-pandemic procedural volume. An aggregate of the total pandemic period (March 2020-August 2021) was compared to the corresponding figures in pre-pandemic timeframes. Results : 670,541 unique ophthalmic procedures from among 573 HCOs between March 2018 and August 2021 were included. Intravitreal injections was the most prevalent procedure with 320,106 occurrences. Phacoemulsification cataract surgery was the second most prevalent (N = 176,095) procedure with 144,816 uncomplicated (82.2%) and 31,279 complicated (17.8%). Intravitreal injections had the highest mean seasonal volume per HCO for each of the five COVID-19 pandemic seasons. From March 2020-August 2021, a mean pandemic volume of 266.7 (SD = 15) was observed, a 5% decrease (p<0.05) in procedures compared to pre-pandemic mean of 280.8 (SD = 26.1). During the five COVID-19 pandemic seasons, the seasonal mean volume almost always differed from pre-pandemic comparisons. Spring 2020 exhibited the sharpest seasonal decrease in procedural volume (88%). Spring 2021 had the largest count of significant increase in procedure volume (18%). Aggregate mean volume per HCO showed significant decreases for 11 out of 17 procedures in the 12-month March 2020-February 2021 timeframe and significant decreases for 10/17 procedures over the 18-month March 2020-August 2021 timeframe. A relative inverse relationship between COVID-19 case volume and ophthalmic procedure volume was observed. Conclusions : This study highlights the relative inverse relationship between COVID-19 cases and ophthalmic procedure volume in the US. Reduction in procedural volume may result in delayed care with potential for vision loss. Awareness and understanding of these trends could help ophthalmologists prepare should a similar cycle occur in the setting of the omicron and future variants.

National trends of ophthalmic-related procedures during the COVID-19 pandemic

Purpose : The COVID-19 pandemic has caused significant disturbances as stay-at-home restrictions have prevented adequate healthcare delivery. This investigation aimed to assess the pandemic's impact on the incidence of ophthalmic-related procedures compared to the pre-pandemic period. Methods : TriNetX (Cambridge, MA, USA) is a real-time, federated healthcare database that was used in this retrospective review. At the time of the study, the database included 60 million unique electronic medical records (EMR) of patients from 41 healthcare organizations (HCOs) across the US. The goal of this study was to analyze the incidence of new ophthalmic procedures that were performed during a period of the COVID-19 pandemic from April 1, 2020 - September 30, 2020. April 2020 was used as the start date as this was the first full month when national lockdown measures were implemented in the USA. Similar incidence data was also extracted from the corresponding time frame of April to July in 2018 and 2019. The 2020 data was then compared to a pooled 2018-2019 data of the same time period through descriptive analyses and an independent samples ttest. Results : The incidence between fourteen types of ophthalmic procedures experienced a statistically significant reduction between April 1 to September 30, 2020 when compared to overlapping months in 2018 and 2019. Thirteen of the fourteen procedures saw at least a 32.0% decrease in incidence. These procedures included: Keratorefractive surgery (-60.3% change, p<0.001), keratoplasty (-58.4% change, p<0.001), cataract surgery (-50.5% change, p<0.001), pterygium (-49.0% change, p<0.001), oculoplastic (-47.7% change, p<0.001), YAG capsulotomy (-44.3% change, p<0.001), strabismus (-43.2% change, p=0.004), laser trabeculoplasty (-40.1% change, p<0.001), retina surgery (-38.5% change, p<0.001), glaucoma (-36.1% change, p<0.001), panretinal laser photocoagulation (-33.9% change, p<0.001), and intravitreal injection (-32.0% change, p<0.001). The incidence of global trauma during the COVID-19 pandemic was similar to identical months in 2018- 2019. Conclusions : The significant reduction in ophthalmic procedures during the COVID-19 pandemic suggests that patients are delaying ophthalmic care in the US. Further research is necessary to determine the future implications of this disruption in the care of ophthalmic patients during the COVID-19 pandemic.

Clinical and Laboratory Findings of COVID-19 in High-Altitude Inhabitants of Saudi Arabia.

Background: SARS-CoV-2, the causative agent of COVID-19, continues to cause a worldwide pandemic, with more than 147 million being affected globally as of this writing. People's responses to COVID-19 range from asymptomatic to severe, and the disease is sometimes fatal. Its severity is affected by different factors and comorbidities of the infected patients. Living at a high altitude could be another factor that affects the severity of the disease in infected patients. Methods: In the present study, we have analyzed the clinical, laboratory, and radiological findings of COVID-19-infected patients in Taif, a high-altitude region of Saudi Arabia. In addition, we compared matched diseased subjects to those living at sea level. We hypothesized that people living in high-altitude locations are prone to develop a more severe form of COVID-19 than those living at sea level. Results: Age and a high Charlson comorbidity score were associated with increased numbers of intensive care unit (ICU) admissions and mortality among COVID-19 patients. These ICU admissions and fatalities were found mainly in patients with comorbidities. Rates of leukocytosis, neutrophilia, higher D-dimer, ferritin, and highly sensitive C-reactive protein (CRP) were significantly higher in ICU patients. CRP was the most independent of the laboratory biomarkers found to be potential predictors of death. COVID-19 patients who live at higher altitude developed a less severe form of the disease and had a lower mortality rate, in comparison to matched subjects living at sea level. Conclusion: CRP and Charlson comorbidity scores can be considered predictive of disease severity. People living at higher altitudes developed less severe forms of COVID-19 disease than those living at sea level, due to a not-yet-known mechanism.

Mental Health of COVID-19 Patients-A Cross-Sectional Survey in Saudi Arabia.

Background: This study aims to investigate the mental health of COVID-19 patients in Saudi Arabia. Method: A cross-sectional study was carried out targeting confirmed cases of COVID-19 in Saudi Arabia. Due to travel and time constraints as well as the accessibility of patients, cases were included from East Jeddah Hospital, King Abdulaziz Hospital, and the Oncology Center in Jeddah. The data were collected using a predesigned self-administered questionnaire. The questionnaire addressed COVID-19 cases, personal data, medical history, smoking, traveling abroad, and work-related conditions. Additionally, data regarding contact level with COVID-19 cases were considered. The mental health statuses of the patients were assessed using a validated Arabic version of the Hospital Anxiety and Depression (HAD) scale. The study included 261 COVID-19 patients whose ages ranged from 18 to 65 years. Results: The survey findings revealed that 13% of COVID-19 patients had a borderline level of anxiety, 26.8% were considered anxiety cases, while 60.2% were normal. The findings also revealed that 29.9% had a borderline level of depression, 18.4% were considered depression cases, while 51.7% were normal. Conclusions: This study concluded that COVID-19 patients experience anxiety and depression, and as the COVID-19 epidemic continues to spread, the results of the study are particularly useful in developing a strategy to psychologically support COVID-19 patients.

Successful Use of Virtual Microscopy in the Assessment of Practical Histology during Pandemic COVID-19: A Descriptive Study.

BACKGROUND: Practical knowledge and skills of microscopy has classically been delivered for medical students using conventional microscopes (CMs). Using virtual microscopy (VM) in teaching practical histology was established during distance learning for Taif medical students during COVID 19 pandemic period. However, the suitable assessment methods for student performance during distance learning are still debatable. We focused on how to ensure the learner's achievement of course practical outcomes and learning domain. AIMS AND OBJECTIVES: This study aimed to ascertain whether using VM to evaluate student learning in practical Histology during distance education programs and if moving to VM affecting students' scores. MATERIALS AND METHODS: For the first time, we used VM during online objective structural practical examination (OSPE) of 3rd year medical students. Different sets of virtual slides were given for students at the time of assessment, then different tasks were described and each student was asked to finalize his/her task during the designed time. A specific rubric was designed for the evaluation of student work. Moreover, student perceptions of VM as teaching and assessment method were assessed using online survey. Post examination psychometric analysis of VM OSPE was done and compared with previous OSPE results of the same batch of students. RESULTS: The average student score was 4.63 ± 0.51 with no significant difference from previous student's scores. The net students' feedback was positive. Their average satisfaction on all items ranged from 3.7 to 4.25 on Likert scale. Students recorded the easy image access at any time and place with VM as the most distinctive feature. CONCLUSION: Our results indicated that VM is not only an effective method in teaching histology but also it is an assessment method for measuring student performance during online assessment.