Detección de anticuerpos anti-SARS-CoV-2 en lágrimas: inmunidad de la superficie ocular frente a COVID-19 Detection of anti-SARS-CoV-2 antibodies in tears: ocular surface immunity to COVID-19

Objetivos: Evaluar la presencia de anticuerpos IgA e IgG específicos del SARS-CoV-2 en lágrima de sujetos no vacunados y vacunados contra la COVID-19 con antecedentes de infección SARS-CoV-2. Correlacionar los resultados en lágrima con los de saliva y sangre, datos clínicos y regímenes de vacunación. Métodos: Estudio transversal que incluyó sujetos con antecedentes de infección SARS-CoV-2, tanto no vacunados como vacunados contra la COVID-19. Se recogieron tres muestras: lágrima, saliva y sangre. Se analizaron IgA e IgG frente a S-1 SARS-CoV-2 con ELISA semicuantitativo. Resultados: 30 sujetos, edad media 36,4±10, varones 13/30 (43,3%) con historia de infección SARS-CoV-2 leve. 13/30 (43,3%) habían recibido un régimen de 2 dosis y 13/30 (43,3%) un régimen de 3 dosis de vacunación anti-COVID-19, 4/30 (13,3%) no vacunados. Todos los sujetos con vacunación completa presentaron IgA detectable en los tres biofluidos. Entre los no vacunados, se detectó IgA en 3/4 sujetos en lágrima y saliva, mientras que no se detectó IgG. No se observaron diferencias entre la pauta de vacunación de 2 y 3 dosis según los títulos IgA-IgG. Conclusiones: Anticuerpos IgA e IgG del SARS-CoV-2 están presentes en lágrima de pacientes con antecedentes de COVID-19 leve, lo que destaca el papel de la superficie ocular como primera línea de defensa frente a la infección. La mayoría de los sujetos no vacunados presentaron IgA a largo plazo en lágrima y saliva. La inmunización híbrida (infección natural más vacunación) parece potenciar las respuestas IgG mucosas y sistémicas. No se observaron diferencias entre la pauta de 2 y 3 dosis.

Effects of COVID-19 pandemic on glaucoma appointment scheduling in a tertiary hospital in London, UK.

PURPOSE: To investigate the impact of the delay in patient appointments caused by the COVID-19 pandemic and the triage system on the glaucomatous disease of patients in a London tertiary hospital. METHODS: Observational retrospective study that randomly selected 200 glaucoma patients with more than 3 months of unintended delay for their post-COVID visit and other inclusion and exclusion criteria. Demographic information, clinical data, number of drugs, best-corrected visual acuity (BCVA), intraocular pressure (IOP), visual field (VF) mean deviation (MD), and global peripapillary retinal nerve fibre layer (pRNFL) thickness were obtained from the pre- and post-COVID visit. At the post-COVID visit, the clinical outcomes subjective clinical concern and change of treatment or need for surgery were also annotated. The variables were stratified by glaucoma severity (according to the MD into early, moderate and advanced) and by delay time (more and less than 12 months) and analysed using SPSS. RESULTS: We included 121 eyes (from 71 patients). The median patient age was 74 years (interquartile range -IQR- 15), 54% were males and 52% Caucasians. Different glaucoma types and all glaucoma severities were included. When data was stratified for glaucoma severity, at the pre-COVID visit, significant differences in BCVA, CCT and IOP were observed and there were significantly higher values in the early glaucoma group. The median follow-up delay was 11 months (IQR 8), did not differ between the glaucoma severity groups and did not correlate to the glaucoma severity. At the post-COVID visit, significant differences in BCVA, IOP, and Global pRNFL thickness were observed between the glaucoma severity groups, as lower BCVA and higher IOP and pRNFL thickness were observed in the early glaucoma group. At the post-COVID visit there was cause for concern in 40 eyes: 5 were followed more closely, 22 had a change of treatment and 13 were booked for surgery (3 for cataract and 10 for glaucoma surgery). However, the number of eyes with causes for concern were similar between the glaucoma severity groups and there was no correlation between these clinical outcomes and the delay of the post-COVID visit. The number of topical hypotensive medications increased significantly after the post-COVID visit, higher number of medications were observed in the advanced glaucoma group. When differences of IOP, MD and pRNFL thickness between the pre and post-COVID visit, only the MD difference was significantly different between the glaucoma severity groups because it was higher in the severe group. When data was stratified for delay longer or shorter than 12 months, no differences were observed between the groups except at the pre-COVID visit, when the numbers of patients with MD deviation >-6 dB had longer delay time. When differences in IOP, MD and RNFL thickness were calculated, only the pRNFL thickness showed significant differences between the delay groups, because it was higher in the longer delay group. Finally, when paired analysis of the variables at the pre- and post-COVID visits, stratified by glaucoma severity and delay were conducted, although there were no significant differences in IOP in any group, the BCVA decreased significantly in the overall group and in the longer delay groups, the number of hypotensive drugs increased significantly overall and in the moderate and advanced glaucoma, the MD of the VF worsened significantly in the overall group and in the early glaucoma and longer delay groups and the pRNFL thickness decreased significantly in all groups. CONCLUSIONS: We document that delayed care impacts negatively on the glaucomatous disease of our patients because at the post-COVID visit there were reasons for clinical concern in a third of eyes that resulted in change of treatment or surgery. However, these clinical consequences were not related to IOP, glaucoma severity or delay time and reflect that the triage methods implemented worked adequately. The most sensitive parameter to indicate progression in our sample was the pRNFL thickness.

Face mask use and effects on the ocular surface health: A comprehensive review.

In the COVID-19 period, face masks increased exponentially. Several studies suggest that the rise in ocular discomfort symptoms during the pandemic is mostly part of dry eye disease and that these are due to the effect of face masks, resulting in the newly described term MADE, for "mask-associated dry eye". The most commonly proposed mechanism states that wearing a face mask creates an unnatural upward airflow towards the ocular surface during expiration, although the increased temperature, humidity and levels of carbon dioxide of the exhaled air, stress, increased use of video display terminals, as well as changes in the ocular microbiota may contribute. Evidence supports that the use of face masks causes an increase in dry eye disease symptoms, a decreased tear break-up time, corneal epithelial trauma, periocular temperature changes and inflammatory markers secretion. Given that the use of masks may be frequent in some settings in the near future, it is important to establish its effects and consequences on the ocular surface.

One-Year Changes in Optic Nerve Head Parameters in Recovered COVID-19 Patients.

BACKGROUND: The main purpose was to evaluate the changes in peripapillary retinal nerve fiber layer (RNFL) thickness and vessel density (VD) in post-COVID-19 patients during 12-month follow-up. METHODS: In this prospective study, patients with COVID-19 who were attended in the Hospital Clinico San Carlos (Madrid, Spain) were included. All patients underwent a complete ophthalmological examination, optic nerve head optical coherence tomography (OCT), and OCT angiography (OCTA) using the Cirrus HD-OCT 5,000 with AngioPlex OCTA 1, 3, and 12 months after laboratory-confirmed diagnosis. Sociodemographic data, medical history, disease severity, and laboratory workup were registered. RESULTS: A total of 180 eyes of 90 patients with SARS-CoV-2 infection were included; the mean age was 55.5 ± 8.9 years, and 46 patients (51%) were females. The mean visual acuity was 0.76 ± 0.16, and no abnormalities attributable to SARS-CoV-2 were detected in the ocular or fundus examination. No differences in the OCT and OCTA data were found between severity groups in each visit (all P > 0.05). Overall, there was a decrease in RNFL global thickness ( P < 0.001) from the first to the last visit, and an increase in VD and flux index was noted in some sectors at the 12-month examination. A significant correlation was detected at 12 months between vascularization parameters and RNFL thickness. CONCLUSIONS: One year after SARS-CoV-2 infection, changes in peripapillary RNFL thickness and vascularization occur, possibly indicating a recovery in such parameters.

Evaluation of the perception of physical and emotional health of ophthalmologists in Spain and the influence of the COVID-19 pandemic Évaluation de la perception de la santé physique et émotionnelle des ophtalmologistes en Espagne et de l'influence de la pandémie de COVID-19

Objective: The main objective was to study the perception of physical and emotional health of Spanish ophthalmologists and their health habits, as well as the possible influence of the COVID-19 pandemic. Methods: An observational, cross-sectional, non-randomized, uncontrolled study was carried out among at Spanish ophthalmologists through an online survey of 47 questions on eating habits, tobacco, alcohol, physical exercise, workload, and perception of physical and emotional state. Results: Of a total of 2,179 ophthalmologists, 260 (11.9%) of whom 55% were men responded to the survey, with a mean age of 52.9 ± 11.4 years. 5.8% were smokers. 51.5% reported good physical health, with a mean Body Mass Index of 24.4 kg/m2. Overall, 53.5% reported depression, 66.9% tiredness, 34.6% difficulty sleeping, and 57.3% considered their work hard. Up to 28.5% of those surveyed had thought about leaving their job and 60.8% about reorganizing their workload. 91.9% would continue to choose Ophthalmology as a specialty. 36.2% reported an increase in workload, 42.3% worsening of physical state and 63.8% worsening of emotional state as a consequence of the COVID-19 pandemic. Conclusions: Spanish ophthalmologists have a positive perception of their physical and emotional health, despite having life habits that are not always healthy and feeling mostly down. The COVID-19 pandemic has had a negative influence on the physical and emotional health of ophthalmologists.

Retinal and peripapillary vessel density increase in recovered COVID-19 children by optical coherence tomography angiography.

PURPOSE: To evaluate retinal vascular changes in children who have recovered from coronavirus disease (COVID-19) using optical coherence tomography angiography (OCTA) and to compare the results with age-matched healthy children. METHODS: In this cross-sectional case-control study, children 6-18 years of age with laboratory-confirmed SARS-CoV-2 infection were compared with historic healthy controls. All participants underwent ophthalmological examination, including fundus photography and OCTA of the macular region and optic disk. COVID-19 children were examined 4-8 weeks after COVID-19 diagnoses. Demographic data, medical history, and COVID-19 symptoms were noted. OCTA parameters in the superficial capillary plexus (SCP) were analyzed according to ETDRS sectors and peripapillary quadrants. RESULTS: A total of 72 patients were included: 27 recovered COVID-19 children and 45 controls. Mean age for cases was 11.96 ± 3.8 years (18 females [66%]); for controls, 11.02 ± 2.0 years (29 females [64%]). Macular OCTA of the SCP showed a significant increase in retinal vessel density (VD) in recovered COVID-19 children compared with healthy controls in the inner ring (P = 0.001). Macular perfusion density (mPD) was also increased in the inner ring (P = 0.001). Peripapillary OCTA evidenced a significant higher flux index (FI) in all four quadrants (P < 0.001). CONCLUSIONS: Recovered COVID-19 children present increased retinal VD, mPD, and peripapillary FI shortly after recovery. Since the retinal vasculature is considered a unique window to assess microvascular changes, these findings may represent a potential in vivo biomarker of vascular abnormalities in COVID-19 children in other organs.

Novel Insights into the Transmission of SARS-CoV-2 Through the Ocular Surface and its Detection in Tears and Conjunctival Secretions: A Review.

SARS-CoV-2 is a highly transmissible virus that spreads mainly via person-to-person contact through respiratory droplets, or through contact with contaminated objects or surfaces from an infected person. At present we are passing through a phase of slow and painful understanding of the origin, epidemiological profile, clinical spectrum, and risk profile of the virus. To the best of our knowledge there is only limited and contradictory evidence concerning SARS-CoV-2 transmission through other routes. Importantly, the eye may constitute not only a potential site of virus replication but also an alternative transmission route of the virus from the ocular surface to the respiratory and gastrointestinal tract. It is therefore imperative to gain a better insight into the potential ophthalmological transmission route of the virus and establish directions on best practice and future models of care for ophthalmological patients. This review article critically evaluates available evidence on the ophthalmological mode of viral transmission and the value of earlier identification of the virus on the eye. More evidence is urgently needed to better evaluate the need for protective measures and reliable ocular diagnostic tests to diminish further pandemic spread.

Optic Nerve Head Vessel Density Assessment in Recovered COVID-19 Patients: A Prospective Study Using Optical Coherence Tomography Angiography.

PRECIS: Vascular diseases have been linked to alterations in optic nerve head perfusion. PURPOSE: The main objective was to investigate the changes in peripapillary vessel density (VD) in post coronavirus disease (COVID-19) patients. METHODS: In this prospective pilot exploratory study, patients with COVID-19 that were attended in the Emergency Department of Hospital Clinico San Carlos (Madrid) were included. All patients underwent optic nerve head optical coherence tomography angiography using the Cirrus HD-OCT 500 with AngioPlex OCTA (Zeiss, Dublin, CA) 4 and 12 weeks after diagnosis by positive reverse transcriptase-polymerase chain reaction test from nasopharyngeal swab at the Emergency Department. Sociodemographic data, medical history, disease severity, and laboratory work-up were collected. RESULTS: One hundred and eighty eyes of 90 patients with severe acute respiratory syndrome-coronavirus-2 (SARS-CoV-2) infection were included. None of the patients reported visual changes. Severe patients were older, more frequently hispanic, dyslipidemic, and presented lower lymphocytes counts, as well as increased ferritin, D-dimer, fibrinogen, and international normalized ratio levels. No changes in optic nerve head vascularization were observed when both visits were compared. No correlation was found between VD and clinical parameters, disease severity and laboratory work-up. CONCLUSIONS: Changes to peripapillary VD were not observed in patients with COVID-19 in the early months following diagnosis.

Retinal nerve fibre layer and ganglion cell layer changes in children who recovered from COVID-19: a cohort study.

OBJECTIVE: To investigate the optic nerve and macular parameters of children who recovered from COVID-19 compared with healthy children using optical coherence tomography (OCT). DESIGN: Cohort study. SETTING: Hospital Clinico San Carlos, Madrid. PATIENTS: Children between 6 and 18 years old who recovered from COVID-19 with laboratory-confirmed SARS-CoV-2 infection and historical controls were included. INTERVENTIONS: All patients underwent an ophthalmological examination, including macular and optic nerve OCT. Demographic data, medical history and COVID-19 symptoms were noted. MAIN OUTCOME MEASURES: Peripapillary retinal nerve fibre layer thickness, macular retinal nerve fibre layer thickness, macular ganglion cell layer thickness and retinal thickness. RESULTS: 90 patients were included: 29 children who recovered from COVID-19 and 61 controls. Patients with COVID-19 presented an increase in global peripapillary retinal nerve fibre layer thickness (mean difference 7.7; 95% CI 3.4 to 12.1), temporal superior (mean difference 11.0; 95% CI 3.3 to 18.6), temporal inferior (mean difference 15.6; 95% CI 6.5 to 24.7) and nasal (mean difference 9.8; 95% CI 2.9 to 16.7) sectors. Macular retinal nerve fibre layer analysis showed decreased thickness in the nasal outer (p=0.011) and temporal inner (p=0.036) sectors in patients with COVID-19, while macular ganglion cell layer thickness increased in these sectors (p=0.001 and p=0.015, respectively). No differences in retinal thickness were noted. CONCLUSIONS: Children with recent history of COVID-19 present significant changes in peripapillary and macular OCT analyses.

Reduced retinal vessel density in COVID-19 patients and elevated D-dimer levels during the acute phase of the infection.

PURPOSE: To describe macular vessel density and perfusion in COVID-19 patients using coherence tomography angiography (OCTA) and to investigate whether there is a correlation between retinal vascular abnormalities and clinical and laboratory parameters. METHODS: Cross-sectional analysis conducted at the Hospital Clinico San Carlos in Madrid, Spain. Patients with laboratory-confirmed COVID-19 that were attended in the Emergency Department (ED) from March 23 to March 29, 2020 were included. Fundus examination and OCTA were performed 4 weeks after being attended in ED. Macular OCTA parameters were analyzed and correlated with clinical (severity and hypoxemia- oxygen saturation < 92%) and laboratory parameters during hospital stay (D-Dimer-DD, lactate dehydrogenase-LDH and C-reactive protein-CRP). RESULTS: 80 patients were included, mean age 55(SD9) years old; 46.3% male. We reported macular vessel density and perfusion measurements in COVID-19 patients. Those patients with D-Dimer ≥ 500 ng/ml during SARS-CoV-2 infection had a decrease of central vessel density (mean difference 2.2; 95%CI 0.4-3.9) and perfusion density (mean difference 4.9; 95%CI 0.9-8.9) after the acute phase of COVID-19. These variations of vessel density and perfusion density were not documented in patients with LDH ≥ 500 U/L, CRP ≥ 10 mg/L and hypoxemia. CONCLUSIONS: COVID-19 patients showed short-term retinal vasculature abnormalities which may be related to a prothrombotic state associated with SARS-CoV-2 infection. Since the retinal microvasculature shares many morphological and physiological properties with the vasculature of other vital organs, further research is needed to establish whether patients with increased D-Dimer levels require more careful assessment and follow-up after COVID-19.

OBJETIVO: Evaluar la densidad vascular (DV) y la perfusión vascular (PV) retiniana en pacientes con COVID-19 mediante una angiografía por tomografía de coherencia óptica (OCTA), e investigar si existe una correlación entre las anomalías vasculares de la retina y los parámetros clínicos y de laboratorio. MÉTODOS: Análisis transversal realizado en el Hospital Clínico San Carlos, Madrid. Se incluyeron pacientes con diagnóstico confirmado de COVID-19 atendidos en el Servicio de Urgencias (SU) del 23 al 29 de marzo del 2020. Se realizó una exploración oftalmológica y OCTA cuatro semanas después de acudir al SU. Se analizaron los parámetros maculares de OCTA y se correlacionaron con parámetros clínicos (gravedad e hipoxemia-saturación de oxígeno < 92%) y de laboratorio durante la estancia hospitalaria (dímero D [DD], lactato deshidrogenasa [LDH] y proteína C reactiva [CRP]. RESULTADOS: Se incluyeron 80 pacientes, edad media 55 (DE nueve) años; 46,3% hombres. Las personas con DD > 500 ng/mL durante la infección por SARS-CoV-2 tuvieron una disminución de la DV central (diferencia de medias 2,2; IC 95% 0,4 a 3,9) y PV central (diferencia de medias 4,9; IC 95% 0,9 a 8,9) después de la fase aguda de COVID-19. Estas variaciones no se documentaron en los pacientes con LDH > = 500 U/L, CRP > = 10 mg/L y con hipoxemia. CONCLUSIONES: Los pacientes con COVID-19 mostraron anomalías de la vasculatura retiniana a corto plazo que pueden estar relacionadas con un estado protrombótico asociado con la infección por SARS-CoV-2. Dado que la microvasculatura de la retina comparte muchas propiedades morfológicas y fisiológicas con la vasculatura de otros órganos vitales, es necesario seguir investigando para determinar si los pacientes con niveles elevados de DD requieren una evaluación y un seguimiento más cuidadoso.

Reduced macular vessel density in COVID-19 patients with and without associated thrombotic events using optical coherence tomography angiography.

PURPOSE: Thrombotic events (TE) represent one of the major complications of SARS-CoV-2 infection. The objective is to evaluate vessel density (VD) and perfusion density (PD) by optical coherence tomography angiography (OCTA) in COVID-19 patients, and compare the findings with healthy controls. The secondary objective is to evaluate if there are differences in OCTA parameters between COVID-19 patients with and without associated TE. METHODS: Cross-sectional case-control study that included patients with laboratory-confirmed diagnosis of COVID-19 with and without TE related to the infection and age-matched healthy controls. Ophthalmological examination and OCTA were performed 12 weeks after diagnosis. Demographic data and medical history were collected. Macular OCTA parameters in the superficial retinal plexus were analyzed according to ETDRS sectors. RESULTS: Ninety patients were included, 19 (20%) COVID-19 patients with associated TE, 47 (49.5%) COVID-19 patients without TE, and 29 (30.5%) healthy controls. Fifty-three (55.7%) were male, mean age 54.4 (SD 10.2) years. COVID-19 patients presented significantly lower VD than healthy controls: central (p = 0.003), inner ring (p = 0.026), outer ring (p = 0.001). PD was also significantly decreased: outer ring (p = 0.003), full area (p = 0.001). No differences in OCTA parameters were found between COVID-19 patients with and without TE. CONCLUSIONS: OCTA represents a promising tool for the in vivo assessment of microvascular changes in COVID-19. Patients with SARS-CoV-2 infection show lower VD and PD compared to healthy controls. However, no differences were found between COVID-19 when considering TE. Prospective studies are required to further evaluate the retinal microvascular involvement of SARS-CoV-2 and its impact on the vasculature of other organs.

Detecting SARS-CoV-2 RNA in conjunctival secretions: Is it a valuable diagnostic method of COVID-19?

The main purpose of this study is to evaluate the presence of viral RNA of severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) in conjunctival swab specimen of coronavirus disease 2019 (COVID-19) patients with and without conjunctivitis to establish the diagnostic value of reverse transcription-polymerase chain reaction (RT-PCR) in each case and to describe its clinical characteristics. A cross-sectional study was conducted at the Hospital Clinico San Carlos of Madrid, Spain. Thirty-six subjects from the COVID admission unit with laboratory-confirmed SARS-CoV-2 infection were included. Conjunctival swabs were collected from 18 patients with conjunctivitis and 18 patients without conjunctivitis and RT-PCR was performed. Conjunctival swab was collected from both eyes of 36 patients (72 eyes), detecting SARS-CoV-2 RNA in conjunctival swab of two patients (5.5%). Among the 18 patients with conjunctivitis, only one of them (5.5%) showed positive results. Likewise, SARS-CoV-2 RNA was detected in one patient without conjunctivitis (5.5%). The mean age of the 36 patients was 67.9 years (range, 28-92 years) and the male-to-female ratio was 0.44 (16:20). The mean days since the onset of COVID-19 symptoms until conjunctivitis manifestation was 8 (range, 1-24 days). The mean duration of the conjunctivitis was 3 days (range, 1-7 days). SARS-CoV-2 RNA may be detected in conjunctival swabs of both patients with and without conjunctivitis. This study revealed the same rate of positive results amongst the group with and without conjunctivitis, suggesting that detecting SARS-CoV-2 in ocular fluids is not conditioned on the presence of conjunctivitis. The presence of SARS-CoV-2 RNA in ocular samples highlights the role of the eye as a possible route of transmission of the disease.

Optic nerve and macular optical coherence tomography in recovered COVID-19 patients.

PURPOSE: To investigate the peripapillary retinal nerve fiber layer thickness (RNFLT), macular RNFLT, ganglion cell layer (GCL), and inner plexiform layer (IPL) thickness in recovered COVID-19 patients compared to controls. METHODS: Patients previously diagnosed with COVID-19 were included, while healthy patients formed the historic control group. All patients underwent an ophthalmological examination, including macular and optic nerve optical coherence tomography. In the case group, socio-demographic data, medical history, and neurological symptoms were collected. RESULTS: One hundred sixty patients were included; 90 recovered COVID-19 patients and 70 controls. COVID-19 patients presented increases in global RNFLT (mean difference 4.3; CI95% 0.8 to 7.7), nasal superior (mean difference 6.9; CI95% 0.4 to 13.4), and nasal inferior (mean difference 10.2; CI95% 2.4 to 18.1) sectors of peripapillary RNFLT. Macular RNFL showed decreases in COVID-19 patients in volume (mean difference -0.05; CI95% -0.08 to -0.02), superior inner (mean difference -1.4; CI95% -2.5 to -0.4), nasal inner (mean difference -1.1; CI95% -1.8 to -0.3), and nasal outer (mean difference -4.7; CI95% -7.0 to -2.4) quadrants. COVID-19 patients presented increased GCL thickness in volume (mean difference 0.04; CI95% 0.01 to 0.07), superior outer (mean difference 2.1; CI95% 0.8 to 3.3), nasal outer (mean difference 2.5; CI95% 1.1 to 4.0), and inferior outer (mean difference1.2; CI95% 0.1 to 2.4) quadrants. COVID-19 patients with anosmia and ageusia presented an increase in peripapillary RNFLT and macular GCL compared to patients without these symptoms. CONCLUSIONS: SARS-CoV-2 may affect the optic nerve and cause changes in the retinal layers once the infection has resolved.

Reduced retinal vessel density in COVID-19 patients and elevated D-dimer levels during the acute phase of the infection.

PURPOSE: To describe macular vessel density and perfusion in COVID-19 patients using coherence tomography angiography (OCTA) and to investigate whether there is a correlation between retinal vascular abnormalities and clinical and laboratory parameters. METHODS: Cross-sectional analysis conducted at the Hospital Clinico San Carlos in Madrid, Spain. Patients with laboratory-confirmed COVID-19 that were attended in the Emergency Department (ED) from March 23 to March 29, 2020 were included. Fundus examination and OCTA were performed 4 weeks after being attended in ED. Macular OCTA parameters were analyzed and correlated with clinical (severity and hypoxemia- oxygen saturation<92%) and laboratory parameters during hospital stay (D-Dimer-DD, lactate dehydrogenase-LDH and C-reactive protein-CRP). RESULTS: 80 patients were included, mean age 55(SD9) years old; 46.3% male. We reported macular vessel density and perfusion measurements in COVID-19 patients. Those patients with D-Dimer≥500ng/ml during SARS-CoV-2 infection had a decrease of central vessel density (mean difference 2.2; 95%CI 0.4-3.9) and perfusion density (mean difference 4.9; 95%CI 0.9-8.9) after the acute phase of COVID-19. These variations of vessel density and perfusion density were not documented in patients with LDH≥500U/L, CRP≥10mg/L and hypoxemia. CONCLUSIONS: COVID-19 patients showed short-term retinal vasculature abnormalities which may be related to a prothrombotic state associated with SARS-CoV-2 infection. Since the retinal microvasculature shares many morphological and physiological properties with the vasculature of other vital organs, further research is needed to establish whether patients with increased D-Dimer levels require more careful assessment and follow-up after COVID-19.

Hypercytokinemia in COVID-19: Tear cytokine profile in hospitalized COVID-19 patients.

The aim of this study is to analyze the concentrations of cytokines in tear of hospitalized COVID-19 patients compared to healthy controls. Tear samples were obtained from 41 healthy controls and 62 COVID-19 patients. Twenty-seven cytokines were assessed: interleukin (IL)-1b, IL-1RA, IL-2, IL-4, IL-5, IL-6, IL-7, IL-8, IL9, IL-10, IL-12, IL-13, IL-15, IL-17, eotaxin, fibroblast growth factor basic, granulocyte colony-stimulating factor (G-CSF), granulocyte-monocyte colony-stimulating factor (GM-CSF), interferon (IFN)-γ, interferon gamma-induced protein, monocyte chemo-attractant protein-1, macrophage inflammatory protein (MIP)-1a, MIP-1b, platelet-derived growth factor (PDGF), regulated on activation normal T cell expressed and secreted, tumor necrosis factor-α and vascular endothelial growth factor (VEGF).In tear samples of COVID-19 patients, an increase in IL-9, IL-15, G-CSF, GM-CSF, IFN-γ, PDGF and VEGF was observed, along with a decrease in eotaxin compared to the control group (p < 0.05). A poor correlation between IL-6 levels in tear and blood was found. IL-1RA and GM-CSF were significantly lower in severe patients and those who needed treatment targeting the immune system (p < 0.05). Tear cytokine levels corroborate the inflammatory nature of SARS-CoV-2.

Conjunctivitis in COVID-19 patients: frequency and clinical presentation.

PURPOSE: The purpose of this study was to evaluate the frequency and clinical presentation of conjunctivitis in hospitalized patients with COVID-19. METHODS: A cross-sectional study was conducted at the Hospital Clinico San Carlos of Madrid, Spain. A total of 301 subjects from the COVID admission unit with laboratory-confirmed SARS-CoV-2 infection were included. The presence and clinical characteristics of conjunctivitis were evaluated. Laboratory, radiological, and clinical results in patients with and without conjunctivitis stratified by sex were analyzed. RESULTS: Of the 301 subjects included, 180 patients (59.8%) were male and the median age was 72 years (IQ 59-82). Overall, 35 patients (11.6%) were diagnosed with acute conjunctivitis. We found no relationship between the COVID-19 severity score and the presence of conjunctivitis (P = 0.17). However, conjunctivitis was more frequent in males with moderate clinical severity and in women classified as clinically mild. The natural history of the disease seems to be a rapid self-limited conjunctivitis that improves without treatment and does not affect visual acuity nor associate short-term complications. CONCLUSIONS: Approximately, 1 out of 10 hospitalized non-critical COVID-19 patients presents conjunctivitis during the disease. Compared with other viral conjunctivitis, we found distinctive clinical findings that could guide defining and differentiating conjunctivitis in COVID-19 patients. TRIAL REGISTRATION NUMBER: 20/336_E_COVID.