Altered Ocular Surface Health Status and Tear Film Immune Profile Due to Prolonged Daily Mask Wear in Health Care Workers.

Prolonged daily face mask wearing over several months might affect health of the ocular surface and is reported to be associated with complaints of discomfort and dry-eye-like symptoms. We studied the ocular surface clinical parameters, tear soluble factors and immune cell proportions in ophthalmologists practicing within similar environmental conditions (n = 17) at two time points: pre-face-mask period (Pre-FM; end of 2019) and post-face-mask-wearing period (Post-FM; during 2020 COVID-19 pandemic), with continuous (~8 h/day) mask wear. A significant increase in ocular surface disease index (OSDI) scores without changes in tear breakup time (TBUT), Schirmer's test 1 (ST1) and objective scatter index (OSI) was observed Post-FM. Tear soluble factors (increased-IL-1ß, IL-33, IFNß, NGF, BDNF, LIF and TSLP; decreased-IL-12, IL-13, HGF and VEGF-A) and mucins (MUC5AC) were significantly altered Post-FM. Ex vivo, human donor and corneoscleral explant cultures under elevated CO2 stress revealed that the molecular profile, particularly mucin expression, was similar to the Post-FM tear molecular profile, suggesting hypercapnia is a potential contributor to ocular surface discomfort. Among the immune cell subsets determined from ocular surface wash samples, significantly higher proportions of leukocytes and natural killer T cells were observed in Post-FM compared to Pre-FM. Therefore, it is important to note that the clinical parameters, tear film quality, tear molecular factors and immune cells profile observed in prolonged mask-wear-associated ocular surface discomfort were distinct from dry eye disease or other common ocular surface conditions. These observations are important for differential diagnosis as well as selection of appropriate ocular surface treatment in such subjects.

Altered Ocular Surface Health Status and Tear Film Immune Profile Due to Prolonged Daily Mask Wear in Health Care Workers

Prolonged daily face mask wearing over several months might affect health of the ocular surface and is reported to be associated with complaints of discomfort and dry-eye-like symptoms. We studied the ocular surface clinical parameters, tear soluble factors and immune cell proportions in ophthalmologists practicing within similar environmental conditions (n = 17) at two time points: pre-face-mask period (Pre-FM;end of 2019) and post-face-mask-wearing period (Post-FM;during 2020 COVID-19 pandemic), with continuous (~8 h/day) mask wear. A significant increase in ocular surface disease index (OSDI) scores without changes in tear breakup time (TBUT), Schirmer's test 1 (ST1) and objective scatter index (OSI) was observed Post-FM. Tear soluble factors (increased-IL-1β, IL-33, IFNβ, NGF, BDNF, LIF and TSLP;decreased-IL-12, IL-13, HGF and VEGF-A) and mucins (MUC5AC) were significantly altered Post-FM. Ex vivo, human donor and corneoscleral explant cultures under elevated CO2 stress revealed that the molecular profile, particularly mucin expression, was similar to the Post-FM tear molecular profile, suggesting hypercapnia is a potential contributor to ocular surface discomfort. Among the immune cell subsets determined from ocular surface wash samples, significantly higher proportions of leukocytes and natural killer T cells were observed in Post-FM compared to Pre-FM. Therefore, it is important to note that the clinical parameters, tear film quality, tear molecular factors and immune cells profile observed in prolonged mask-wear-associated ocular surface discomfort were distinct from dry eye disease or other common ocular surface conditions. These observations are important for differential diagnosis as well as selection of appropriate ocular surface treatment in such subjects.

Induced pluripotent stem cell-based disease modeling and prospective immune therapy for coronavirus disease 2019.

The emergence of the novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic poses a never before seen challenge to human health and the economy. Considering its clinical impact, with no streamlined therapeutic strategies in sight, it is crucial to understand the infection process of SARS-CoV-2. Our limited knowledge of the mechanisms underlying SARS-CoV-2 infection impedes the development of alternative therapeutics to address the pandemic. This aspect can be addressed by modeling SARS-CoV-2 infection in the human context to facilitate drug screening and discovery. Human induced pluripotent stem cell (iPSC)-derived lung epithelial cells and organoids recapitulating the features and functionality of the alveolar cell types can serve as an in vitro human model and screening platform for SARS-CoV-2. Recent studies suggest an immune system asynchrony leading to compromised function and a decreased proportion of specific immune cell types in coronavirus disease 2019 (COVID-19) patients. Replenishing these specific immune cells may serve as useful treatment modality against SARS-CoV-2 infection. Here the authors review protocols for deriving lung epithelial cells, alveolar organoids and specific immune cell types, such as T lymphocytes and natural killer cells, from iPSCs with the aim to aid investigators in making relevant in vitro models of SARS-CoV-2 along with the possibility derive immune cell types to treat COVID-19.

Stem cell therapy in coronavirus disease 2019: current evidence and future potential.

The end of 2019 saw the beginning of the coronavirus disease 2019 (COVID-19) pandemic that soared in 2020, affecting 215 countries worldwide, with no signs of abating. In an effort to contain the spread of the disease and treat the infected, researchers are racing against several odds to find an effective solution. The unavailability of timely and affordable or definitive treatment has caused significant morbidity and mortality. Acute respiratory distress syndrome (ARDS) caused by an unregulated host inflammatory response toward the viral infection, followed by multi-organ dysfunction or failure, is one of the primary causes of death in severe cases of COVID-19 infection. Currently, empirical management of respiratory and hematological manifestations along with anti-viral agents is being used to treat the infection. The quest is on for both a vaccine and a more definitive management protocol to curtail the spread. Researchers and clinicians are also exploring the possibility of using cell therapy for severe cases of COVID-19 with ARDS. Mesenchymal stromal cells are known to have immunomodulatory properties and have previously been used to treat viral infections. This review explores the potential of mesenchymal stromal cells as cell therapy for ARDS.

Potential ocular and systemic COVID-19 prophylaxis approaches for healthcare professionals.

The COVID-19 pandemic has brought with it, innumerable challenges in healthcare, both through the direct burden of morbidity and mortality of the disease, and also by the curtailing of other essential albeit less emergency medical services to reduce the risk of community spread. Reports from around the world are showing mounting number of cases even in healthcare professionals spite of usage of adequate personal protective equipment. There are a number of factors which could account for this, be it the affinity of the virus to the respiratory and other mucosa or to patient risk factors for developing severe forms of the disease. In view of the growing need for resuming other medical services, it is essential to find newer ways to protect ourselves better, whether by systemic or topical mucosal prophylaxis with various medications or lifestyle changes promoting wellbeing and immunity. This article discusses additional prophylactic measures including drug repurposing or new indication paradigms to render protection. Certain medications such as chloroquine, trehalose, antihistaminics, and interferons used topically for various ocular conditions with reasonably good safety records are known to have anti-viral properties. Hence, can be harnessed in preventing SARS-CoV-2 attachment, entry, and/or replication in host cells. Similarly, use of hypertonic saline for nasal and oral mucosa and dietary changes are possible methods of improving our resistance. These additional prophylactic measures can be cautiously explored by healthcare professionals to protect themselves and their patients.