Alteraciones en el nervio óptico y retina en pacientes con COVID-19. Una revisión teórica / Alterations in the optic nerve and retina in patients with COVID-19. A theoretical review

El objetivo de la presente investigación es identificar y sistematizar las afectaciones generadas por el SARS-CoV-2 en el nervio óptico y en la retina de pacientes jóvenes, adultos y adultos mayores que padecieron COVID-19 en el período del 2019 al 2022. Se realizó una revisión teórica documental (RTD) en el marco de una investigación para determinar el estado actual del conocimiento del tema objeto de estudio. La RTD contempla el análisis de publicaciones en las bases de datos científicas PubMed/Medline, Ebsco, Scielo y Google. Se encontraron un total de 167 artículos de los cuales se estudiaron a profundidad 56 artículos; se evidencia el impacto de la infección por COVID-19 en la retina y el nervio óptico de los pacientes contagiados, tanto durante la fase aguda como en la recuperación posterior. Entre los hallazgos reportados sobresalen: neuropatía óptica isquémica no arterítica anterior y posterior, neuritis óptica, oclusión vascular central o de rama, maculopatía medial aguda paracentral, neurorretinitis, así como también diagnósticos concomitantes como enfermedad posible de Vogt Koyanagi Harada, síndrome de múltiples puntos blancos evanescentes (MEWDS), retinopatía Purtscher-like, y otros (AU)

The objective of this research is to identify and systematize the medical conditions generated by SARS-CoV-2 on the optic nerve and retina of young, adult, and elderly adults who suffered from COVID-19 in the period 2019-2022. A theoretical documentary review (TDR) was conducted within the framework of an investigation to determine the current state of knowledge of the subject under study. The TDR includes the analysis of publications in the scientific databases PubMed/Medline, Ebsco, Scielo and Google. A total of 167 articles were found, of which 56 were studied in depth, and these evidence the impact of COVID-19 infection on the retina and optic nerve of infected patients, both during the acute phase and in subsequent recovery. Among the reported findings, the following stand out: anterior and posterior non-arteritic ischemic optic neuropathy, optic neuritis, central or branch vascular occlusion, paracentral acute medial maculopathy, neuroretinitis, as well as concomitant diagnoses such as possible Vogt-Koyanagi-Harada disease, multiple evanescent white dot syndrome (MEWDS), Purtscher-like retinopathy, among others (AU)

COVID-19 and the Eye: Ocular Manifestations, Treatment and Protection Measures.

The novel pandemic coronavirus disease 2019 (COVID-19) leading to health and economic problems worldwide is caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Although COVID-19 mainly occurs as a lower respiratory tract infection, there is multiorgan involvement in infected patients. The disease is transmitted from person to person through air droplets or contact with contaminated surfaces. SARS-CoV-2 leads to this systemic involvement by attaching to angiotensin-converting enzyme 2 (ACE2) receptors located on several human cells. Since SARS-CoV-2 RNA has been found in tears of infected patients, ocular surface may allow the virus to transmit to nasopharynx via the nasolacrimal duct. This narrative review aims to sum up all segmental ocular complications, ocular adverse effects of COVID-19 treatment, and preventive measures suggested to minimize the SARS-CoV-2 transmission between patients and ophthalmologists by reviewing currently available literature.

NK-lysin peptides ameliorate viral encephalopathy and retinopathy disease signs and provide partial protection against nodavirus infection in European sea bass.

Antimicrobial peptides (AMP) comprise a wide range of small molecules with direct antibacterial activity and immunostimulatory role and are proposed as promising substitutes of the antibiotics. Additionally, they also exert a role against other pathogens such as viruses and fungi less evaluated. NK-lysin, a human granulysin orthologue, possess a double function, taking part in the innate immunity as AMP and also as direct effector in the cell-mediated cytotoxic (CMC) response. This molecule is suggested as a pivotal molecule involved in the defence upon nervous necrosis virus (NNV), an epizootic virus provoking serious problems in welfare and health status in Asian and Mediterranean fish destined to human consumption. Having proved that NK-lysin derived peptides (NKLPs) have a direct antiviral activity against NNV in vitro, we aimed to evaluate their potential use as a prophylactic treatment for European sea bass (Dicentrarchus labrax), one of the most susceptible cultured-fish species. Thus, intramuscular injection of synthetic NKLPs resulted in a very low transcriptional response of some innate and adaptive immune markers. However, the injection of NKLPs ameliorated disease signs and increased fish survival upon challenge with pathogenic NNV. Although NKLPs showed promising results in treatments against NNV, more efforts are needed to understand their mechanisms of action and their applicability to the aquaculture industry.

Vascular Damage May Mimic Retinitis and Optic Neuritis in COVID-19.

Ophthalmologic nvolvement in SARS-CoV-infected patients is variegated. One of the ophthalmologic pathologies is optic neuritis. Optic neuritis in SARS-CoV-infected patients may precede the classical pulmonary manifestations of COVID-19 and can be unilateral or bilateral. Optic neuritis has been repeatedly reported in COVID-19 patients and may occur with or without affection of other cranial nerves. Since cerebro-spinal fluid parameters can be abnormal in COVID-19 associated optic neuritis, these patients require a spinal tap. Before diagnosing SARS-CoV-2 associated optic neuritis various differentials need to be excluded. Since SARS-CoV-2 causes endothelial damage complicated by thrombus formation and thromboembolism, ophthalmologic vascular complication due to an infection with SARS-CoV-2 such as anterior ischemic optic neuropathy (AION), central retinal artery occlusion (CRAO), and retinal vein occlusion need to be excluded. CRAO may result from arterial hypertension, myocarditis, heart failure, Takotsubo syndrome, atrial fibrillation, or atrial flutter, frequent cardiac complications of COVID-19. Since CRAO can be accompanied by ischemic stroke, patients with SARS-CoV-2 associated optic neuritis need to undergo a cerebral MRI.

Coronavirus-induced autoimmunity.

The pandemic of Coronavirus disease 2019 (COVID-19), caused by a new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has spotlighted the link between viral infection and autoimmunity. In this review, we focus on coronavirus-induced autoimmunity based on evidence from experimental animal models, SARS-CoV infection with in vitro studies of molecular mimicry and COVID-19 with several clinical reports of autoimmune manifestations of this disease. Further studies will be needed to better characterize the role of SARS-CoV-2 in the development of autoimmunity.

Ocular Pathology and Occasionally Detectable Intraocular Severe Acute Respiratory Syndrome Coronavirus-2 RNA in Five Fatal Coronavirus Disease-19 Cases.

INTRODUCTION: In December 2019, the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) pandemic broke out. The virus rapidly spread globally, resulting in a major world public-health crisis. The major disease manifestation occurs in the respiratory tract. However, further studies documented other systemic involvement. This study investigates histopathologic eye changes in postmortem material of coronavirus disease 2019 (COVID-19) patients. METHODS: Sections of formalin-fixed, paraffin-embedded eyes from 5 patients (10 eyes) who died of COVID-19 at the University Hospital in Basel were included. Gross examination and histological evaluation were performed by 3 independent ophthalmopathologists. Immunohistochemical staining was performed using antibodies against fibrin, cleaved caspase 3, and ACE-2. Five enucleated eyes of patients not infected with SARS-CoV-2 served as control group. All cases have been studied for presence of SARS-CoV-2 RNA by means of reverse transcription PCR and RNA in situ hybridization (ISH). The choroidal vessels of one case were analyzed with electron microscope. RESULTS: Ophthalmopathologically, 8 eyes from 4 patients displayed swollen endothelial cells in congested choroidal vessels. No further evidence of specific eye involvement of SARS-CoV-2 was found in any of the patients. In the 8 eyes with evidence of changes due to SARS-CoV-2, immunohistochemical staining demonstrated fibrin microthrombi, apoptotic changes of endothelial and inflammatory cells. In control eyes, ACE-2 was detectable in the conjunctiva, cornea, retina, and choroidea and displayed significantly lower amounts of stained cells as in COVID-19 eyes. SARS-CoV-2 RNA was detectable in both bulbi of 2/5 patients, yet ISH failed to visualize viruses. Electron microscopy showed no significant results due to the artifacts. DISCUSSION/CONCLUSION: As already described in other organs of COVID-19 patients, the ophthalmological examination revealed-microthrombi, that is, hypercoagulation and vasculopathy most probably due to endothelial damage. A possible viral spread to the endothelial cells via ACE-2 provides one pathophysiological explanation. The expression of ACE-2 receptors in the conjunctiva hints toward its susceptibility to infection. To what extend eyes, function is disrupted by SARS-CoV-2 is subject to further studies, especially in the clinic.

Using bioinformatic protein sequence similarity to investigate if SARS CoV-2 infection could cause an ocular autoimmune inflammatory reactions?

Although severe acute respiratory syndrome coronavirus 2 (SARS CoV-2) infection have emerged globally, findings related to ocular involvement and reported cases are quite limited. Immune reactions against viral infections are closely related to viral and host proteins sequence similarity. Molecular Mimicry has been described for many different viruses; sequence similarities of viral and human tissue proteins may trigger autoimmune reactions after viral infections due to similarities between viral and human structures. With this study, we aimed to investigate the protein sequence similarity of SARS CoV-2 with retinal proteins and retinal pigment epithelium (RPE) surface proteins. Retinal proteins involved in autoimmune retinopathy and retinal pigment epithelium surface transport proteins were analyzed in order to infer their structural similarity to surface glycoprotein (S), nucleocapsid phosphoprotein (N), membrane glycoprotein (M), envelope protein (E), ORF1ab polyprotein (orf1ab) proteins of SARS CoV-2. Protein similarity comparisons, 3D protein structure prediction, T cell epitopes-MHC binding prediction, B cell epitopes-MHC binding prediction and the evaluation of the antigenicity of peptides assessments were performed. The protein sequence analysis was made using the Pairwise Sequence Alignment and the LALIGN program. 3D protein structure estimates were made using Swiss Model with default settings and analyzed with TM-align web server. T-cell epitope identification was performed using the Immune Epitope Database and Analysis (IEDB) resource Tepitool. B cell epitopes based on sequence characteristics of the antigen was performed using amino acid scales and HMMs with the BepiPred 2.0 web server. The predicted peptides/epitopes in terms of antigenicity were examined using the default settings with the VaxiJen v2.0 server. Analyses showed that, there is a meaningful similarities between 6 retinal pigment epithelium surface transport proteins (MRP-4, MRP-5, RFC1, SNAT7, TAUT and MATE) and the SARS CoV-2 E protein. Immunoreactive epitopic sites of these proteins which are similar to protein E epitope can create an immune stimulation on T cytotoxic and T helper cells and 6 of these 9 epitopic sites are also vaxiJen. These result imply that autoimmune cross-reaction is likely between the studied RPE proteins and SARS CoV-2 E protein. The structure of SARS CoV-2, its proteins and immunologic reactions against these proteins remain largely unknown. Understanding the structure of SARS CoV-2 proteins and demonstration of similarity with human proteins are crucial to predict an autoimmune response associated with immunity against host proteins and its clinical manifestations as well as possible adverse effects of vaccination.

Optical coherence tomography angiography findings in patients with COVID-19.

OBJECTIVE: To examine the changes in choriocapillaris and retina caused by coronavirus disease 2019 (COVID-19) by comparing optical coherence tomography angiography (OCTA) findings of COVID-19 patients and healthy controls. METHODS: The study and control groups consisted of 54 eyes of 27 participants, each. Patients and controls underwent OCTA examination. Foveal zone vessel density and parafoveal zone vessel density (for 4 quadrants: nasal, temporal, superior, inferior) were calculated for both superficial and deep capillary plexuses. Additionally, choriocapillaris flow and foveal avascular zone areas were calculated. RESULTS: For the parafoveal area in the study group, vessel density was significantly lower in the superior and nasal quadrants of the superficial capillary plexus and in all quadrants of the deep capillary plexus compared with controls (p < 0.05 for all). The study group had significantly higher choriocapillaris flow area values compared with controls (p = 0.042). CONCLUSION: Reduced vessel density of the retinal capillary plexus was detected in COVID-19 patients who may be at risk for retinal vascular complications.

Optical coherence tomography angiography analysis of the retina in patients recovered from COVID-19: a case-control study.

OBJECTIVE: To quantify the density of the macular microvasculature and the area of the foveal avascular zone (FAZ) in patients recovered from coronavirus disease 2019 (COVID-19) using optical coherence tomography angiography (OCTA) analysis. METHODS: In a comparative cross-sectional, observational study, patients recovered from COVID-19 were included in this study. All included subjects exhibited a reverse transcription-polymerase chain reaction-confirmed diagnosis of COVID-19. Spectral domain macular OCTA was performed at least 2 weeks after recovery from systemic COVID-19. Vessel density (VD) of the superficial (SCP) and deep retinal capillary plexus (DCP) and the area of the FAZ were measured in COVID-19 recovered patients versus age-matched normal controls. RESULTS: Thirty-one recovered COVID-19 patients and 23 healthy normal controls were studied. Mean quality scan index was 7.64 ± 0.66 in the COVID cases and 8.34 ± 0.71 in the normal controls (p = 0.001). Mean SCP VD and DCP VD of the COVID cohort were significantly lower than the SCP VD and DCP VD of the control group in the foveal and parafoveal regions. FAZ area was greater in the COVID cohort, but this difference was not statistically significant. In addition, in the COVID cohort, VD of the SCP was lower in patients with a history of COVID-19 hospitalization versus those without such a history, but this did not reach statistical significance. CONCLUSIONS: Patients recovered from COVID-19 displayed alterations in the retinal microvasculature, including a significantly lower VD in the SCP and DCP. Patients with coronavirus infection may be at risk of retinal vascular complications.

The Expanded Clinical Spectrum of Coxsackie Retinopathy.

The authors present two cases of coxsackie retinopathy that presented with the classic findings of acute outer retinal disruption that evolved to an outer retinal scar. In these two cases, the classic lesions displayed an extramacular distribution. The authors provide detailed multimodal imaging in both cases highlighting the nature of the lesions. It is important to consider coxsackie virus infection in the differential diagnosis of extramacular lesions with outer retinal disruption. The term "unilateral acute idiopathic maculopathy" should be replaced with "coxsackie retinopathy" to better align with the expanded clinical spectrum and the known etiology of this disorder. [Ophthalmic Surg Lasers Imaging Retina. 2020;51:529-532.].

Investigation of routes of entry and dispersal pattern of RGNNV in tissues of European sea bass, Dicentrarchus labrax.

Viral encephalopathy and retinopathy (VER) is a serious neuropathological fish disease affecting in the Mediterranean aquaculture mainly European sea bass, Dicentrarchus labrax. It is well known that betanodaviruses are neurotropic viruses that replicate in nerve tissues, preferentially brain and retina. However, routes of entry and progression of the virus in the central nervous system (CNS) remain unclear. The role of four tissues-eye, oesophagus, gills and skin-as possible gateways of a betanodavirus, the redspotted grouper nervous necrosis virus (RGNNV), was investigated after experimental challenges performed on European seabass juveniles. The dispersal pattern of Betanodavirus at primarily stages of the disease was also assessed, using a real-time qPCR assay. The development of typical clinical signs of VER, the presence of characteristic histopathological lesions in the brain and retina and the detection of viral RNA in the tissues of all experimental groups ascertained that successful invasion of RGNNV under all experimental routes was achieved. Transneuronal spread along pathways known to be connected to the initial site of entry seems to be the predominant scenario of viral progression in the CNS. Furthermore, viraemia appeared only after the installation of the infection in the brain.

Long-term multimodal imaging in acute posterior multifocal placoid pigment epitheliopathy and association with coxsackievirus exposure.

The purpose of this study was to evaluate potential insights into the pathogenesis of acute posterior multifocal placoid pigment epitheliopathy (APMPPE) using multimodal diagnostic imaging and laboratory evaluation in long-term follow-up. A retrospective, single-center case series was conducted on seven consecutive patients (14 eyes) who were given a diagnosis of APMPPE from March 1, 2011, through June 30, 2019 with at least three months of follow-up. Clinical characteristics (age, symptoms, visual acuity [VA]), laboratory testing including coxsackievirus titers, and multimodal imaging from fundus photography, spectral-domain optical coherence tomography (SD-OCT), fundus autofluorescence (FAF), fluorescein angiography (FA), and indocyanine green angiography (ICG) were analyzed for each patient. The initial median VA was 20/71 and final median VA was 20/22. Coxsackievirus B (CVB) titers were elevated (≥ 1:80) in six of seven patients, with a four-fold increase in convalescent titers seen in two patients suggestive of recent infection. All patients were treated with oral corticosteroids, and five patients underwent corticosteroid-sparing immunomodulatory therapy. Initially, multifocal deep choroidal lesions were observed in the posterior pole corresponding to patches of hypocyanescence on ICG. Overlying retinal pigment epithelium (RPE) disease was observed on FAF, although this finding was not universally observed, suggesting that RPE disease may occur as a sequelae to unchecked choroidal inflammation. SD-OCT architectural changes confirmed outer retina and ellipsoid zone disruption. FA of active lesions showed early hypofluorescence and late hyperfluorescence with surrounding leakage while inactive disease showed areas of staining. Long-term follow-up of multimodal diagnostic imaging in APMPPE revealed that choroidal inflammation likely precedes RPE change and photoreceptor damage. Elevation of coxsackievirus titers with seroconversion may be associated with an infectious trigger in concert with immune-mediated disease in this posterior uveitis syndrome.

A propósito de 3 casos con retinopatía posterior a fase aguda de fiebre por chikungunya / About 3 cases of post-acute retinopathy of chikungunya fever

Este es un estudio descriptivo de serie de casos de 3 pacientes con diagnóstico por serología IgM e IgG de chikungunya y en quienes se descartaron otras enfermedades metabólicas autoinmunes e infecciosas que presentaron manifestaciones oculares con alteraciones vasculares y características inflamatorias. Fueron atendidos en las clínicas de Retinovascular y Retina y Vitreo del Hospital «Dr. Rodolfo Robles Valverde», del Benemérito Comité Pro-Ciegos y Sordos de la ciudad de Guatemala en el transcurso del año 2019. Guatemala es un país con una alta prevalencia de enfermedades transmitidas por vectores, dentro de las cuales se encuentra la chikungunya1,2, la cual presenta aumento en la incidencia los últimos años. Dentro de las complicaciones oculares se han reportado casos de neuritis óptica, iridociclitis, epiescleritis, retinitis y uveítis; además de discrasias sanguíneas que pueden afectar la retina3. Es importante considerarlos como un diagnóstico diferencial importante de alteraciones vasculares oculares

A descriptive study is presented on a case series of 3 patients, with IgM an IgG serology diagnosis of Chikungunya in whom other metabolic, autoimmune and infectious diseases were ruled out. They presented with other ocular manifestations with vascular changes and inflammatory characteristics. They were treated at the Retinovascular and Retinal and Vitreous clinics at the "Dr. Rodolfo Robles Valverde Hospital" and "Benemérito Comité Pro-ciegos y Sordos" in Guatemala City during 2019. Guatemala is a country with a high prevalence of vector-borne diseases, including chikungunya. In recent years cases of this disease has increased in recent years, and complications are currently seen more frequently. Within these complications, there have been reports of cases of optic neuritis, iridocyclitis, episcleritis, retinitis, uveitis, and blood dyscrasia that can affect the retina. It is important to consider these as an important differential diagnosis of ocular vascular alterations

About 3 cases of post-acute retinopathy of chikungunya fever. / A propósito de 3 casos con retinopatía posterior a fase aguda de fiebre por chikungunya.

A descriptive study is presented on a case series of 3 patients, with IgM an IgG serology diagnosis of Chikungunya in whom other metabolic, autoimmune and infectious diseases were ruled out. They presented with other ocular manifestations with vascular changes and inflammatory characteristics. They were treated at the Retinovascular and Retinal and Vitreous clinics at the "Dr. Rodolfo Robles Valverde Hospital" and "Benemérito Comité Pro-ciegos y Sordos" in Guatemala City during 2019. Guatemala is a country with a high prevalence of vector-borne diseases, including chikungunya. In recent years cases of this disease has increased in recent years, and complications are currently seen more frequently. Within these complications, there have been reports of cases of optic neuritis, iridocyclitis, episcleritis, retinitis, uveitis, and blood dyscrasia that can affect the retina. It is important to consider these as an important differential diagnosis of ocular vascular alterations.

Detection of SARS-CoV-2 in Human Retinal Biopsies of Deceased COVID-19 Patients.

PURPOSE: To report the presence of viral ribonucleic acid (RNA) of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in human retina in deceased patients with confirmed novel coronavirus disease 2019 (COVID-19). PATIENTS AND METHODS: Fourteen eyes of 14 deceased patients with confirmed COVID-19 disease were enucleated during autopsy. A sample of human retina was secured and fixed in RNAlater™. Real-time reverse transcriptase-polymerase chain reaction (RT-PCR) was performed to detect three different viral RNA sequences (RdRp-gene, E-gene and Orf1 gene) of SARS-CoV-2. RESULTS: In three out of 14 eyes SARS-CoV-2 viral RNA was detected in the retina of deceased COVID-19 patients. As analysis for three different sequences (RdRp-gene, E-gene and Orf1 gene) revealed positive results in RT-PCR, the existence of SARS-CoV-2 viral RNA in human retina is proven according to the standards of the World-Health-Organization. CONCLUSION: Viral RNA of SARS-CoV-2 is detectable in the retina of COVID-19 patients.

Viral encephalopathy and retinopathy is endemic in wild groupers (genus Epinephelus spp.) of the Algerian coast.

This work describes betanodavirus infection in two species of groupers (family Serranidae) from the Algerian coast: the dusky grouper Epinephelus marginatus and the golden grouper Epinephelus costae. At necropsy, characteristic clinical signs, external injuries, clouded eyes and brain congestion, generally associated with viral encephalopathy and retinopathy (VER) infection were observed. The partial sequences of RNA1 and RNA2 from two viral strains were obtained, and the phylogenetic analysis revealed the presence of the red-spotted grouper nervous necrosis virus (RGNNV) genotype closely related to strains previously detected in groupers in the same geographic area. Results obtained in this study support the hypothesis that VER disease is endemic in the Algerian grouper population.