Persistent and Severe Mpox Keratitis Despite Systemic and Topical Treatment.

PURPOSE: The purpose of this study was to report a case of peripheral ulcerative keratitis in a patient diagnosed with corneal polymerase chain reaction (PCR) and a positive mpox culture. METHODS: This is a case report. RESULTS: An immunocompetent 54-year-old man was diagnosed with conjunctivitis in his left eye 15 days after being diagnosed with mucocutaneous monkeypox. He received treatment with dexamethasone 0.1% and tobramycin 0.3% eye drops for 2 weeks. Two weeks after discontinuing this treatment, he developed peripheral ulcerative keratitis and a paracentral epithelial defect. Mpox keratitis was diagnosed by corneal culture and PCR. Corneal inflammation persisted for more than 6 months, manifested as corneal epithelial defect, limbitis, endotheliitis, neurotrophic changes, and trabeculitis. This persistence was observed alongside positive corneal PCR results, despite undergoing 2 courses of trifluorothymidine, 2 courses of oral tecovirimat, and intravenous cidofovir. An amniotic membrane transplantation was then performed. CONCLUSIONS: Persistent corneal pain and replication are possible with the mpox virus, even in immunocompetent patients. Having received treatment with topical corticosteroids before antiviral treatment for the pox virus may have contributed to the severity and persistence of the clinical condition. Cycle threshold PCR values can be used to support the diagnosis and monitor treatment effectiveness.

Viral Keratitis, Surgical Intervention in Viral Keratitis, Challenges in Diagnosis and Treatment of Viral Keratitis, HSV, HZV.

Viral keratitis is a significant cause of ocular morbidity and visual impairment worldwide. In recent years, there has been a growing understanding of the pathogenesis, clinical manifestations, and diagnostic modalities for viral keratitis. The most common viral pathogens associated with this condition are adenovirus, herpes simplex (HSV), and varicella-zoster virus (VZV). However, emerging viruses such as cytomegalovirus (CMV), Epstein-Barr virus (EBV), and Vaccinia virus can also cause keratitis. Non-surgical interventions are the mainstay of treatment for viral keratitis. Antiviral agents such as Acyclovir, Ganciclovir, and trifluridine have effectively reduced viral replication and improved clinical outcomes. Additionally, adjunctive measures such as lubrication, corticosteroids, and immunomodulatory agents have alleviated symptoms by reducing inflammation and facilitating tissue repair. Despite these conservative approaches, some cases of viral keratitis may progress to severe forms, leading to corneal scarring, thinning, or perforation. In such instances, surgical intervention becomes necessary to restore corneal integrity and visual function. This review article aims to provide an overview of the current perspectives and surgical interventions in managing viral keratitis. The choice of surgical technique depends on the extent and severity of corneal involvement. As highlighted in this article, on-going research and advancements in surgical interventions hold promise for further improving outcomes in patients with viral keratitis.

OUTCOMES OF INFECTIOUS PANUVEITIS ASSOCIATED WITH SIMULTANEOUS MULTI-POSITIVE OCULAR FLUID POLYMERASE CHAIN REACTION.

PURPOSE: To evaluate features of infectious panuveitis associated with multiple pathogens detected by ocular fluid sampling. METHODS: Single-center, retrospective, consecutive case series of patients with aqueous/vitreous polymerase chain reaction testing with >1 positive result in a single sample from 2001 to 2021. RESULTS: Of 1,588 polymerase chain reaction samples, 28 (1.76%) were positive for two pathogens. Most common pathogens were cytomegalovirus (n = 16, 57.1%) and Epstein-Barr virus (n = 13, 46.4%), followed by varicella zoster virus (n = 8, 28.6%), Toxoplasma gondii (n = 6, 21.4%), herpes simplex virus 2 (n = 6, 21.4%), herpes simplex virus 1 (n = 6, 21.4%), and Toxocara (n = 1, 3.6%). Mean initial and final visual acuity (logarithm of the minimum angle of resolution) were 1.3 ± 0.9 (Snellen ∼20/400) and 1.3 ± 1.1 (Snellen ∼20/400), respectively. Cytomegalovirus-positive eyes (n = 16, 61.5%) had a mean final visual acuity of 0.94 ± 1.1 (Snellen ∼20/175), whereas cytomegalovirus-negative eyes (n = 10, 38%) had a final visual acuity of 1.82 ± 1.0 (Snellen ∼20/1,320) ( P < 0.05). Main clinical features included intraocular inflammation (100%), retinal whitening (84.6%), immunosuppression (65.4%), retinal hemorrhage (38.5%), and retinal detachment (34.6%). CONCLUSION: Cytomegalovirus or Epstein-Barr virus were common unique pathogens identified in multi-PCR-positive samples. Most patients with co-infection were immunosuppressed with a high rate of retinal detachment and poor final visual acuity. Cytomegalovirus-positive eyes had better visual outcomes compared with cytomegalovirus-negative eyes.

Molecular imaging on ACE2-dependent transocular infection of coronavirus.

A transocular infection has been proved as one of the main approaches that severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) invades the body, and angiotensin-converting enzyme 2 (ACE2) plays a key role in this procedure. Dynamic and quantitative details on virus distribution are lacking for virus prevention and drug design. In this study, a radiotraceable pseudovirus packed with an enhanced green fluorescent protein (EGFP) gene, 125 I-CoV, was prepared and inoculated in the unilateral eye of humanized ACE2 (hACE2) mice or ACE2-knockout (ACE2-KO) mice. Single-photon emission computed tomography/computed tomography images were acquired at multiple time points to exhibit ACE2-dependent procedures from invasion to clearance. Positron emission tomography (PET) and western blot were performed to quantify ACE2 expression and verify the factors affecting transocular infection. For the transocular infection of coronavirus (CoV), the renin-angiotensin-aldosterone system (RAAS), lungs, intestines, and genital glands were the main targeted organs. Due to the specific anchor to ACE2-expressed host cells, virus concentrations in genital glands, liver, and lungs ranked the top three most and stabilized at 3.75 ± 0.55, 3.30 ± 0.25, and 2.10 ± 0.55% inoculated dose (ID)/mL at 48 h post treatment. Meanwhile, ACE2-KO mice had already completed the in vivo clearance. In consideration of organ volumes, lungs (14.50 ± 3.75%ID) and liver (10.94 ± 0.71%ID) were the main in-store reservoirs of CoV. However, the inoculated eye (5.52 ± 1.85%ID for hACE2, 5.24 ± 1.45%ID for ACE2-KO, p > 0.05) and the adjacent brain exhibited ACE2-independent virus infection at the end of 72 h observation, and absolute amount of virus played a key role in host cell infection. These observations on CoV infection were further manifested by infection-driven intracellular EGFP expression. ACE2 PET revealed an infection-related systematic upregulation of ACE2 expression in the organs involved in RAAS (e.g., brain, lung, heart, liver, and kidney) and the organ that was of own local renin-angiotensin system (e.g., eye). Transocular infection of CoV is ACE2-dependent and constitutes the cause of disturbed ACE2 expression in the host. The brain, genital glands, and intestines were of the highest unit uptake, potentially accounting for the sequelae. Lungs and liver were of the highest absolute amount, closely related to the respiratory diffusion and in vivo duplication. ACE2 expression was upregulated in the short term after infection with CoV. These visual and quantitative results are helpful to fully understanding the transocular path of SARS-CoV-2 and other CoVs.

Exploration of the ocular surface infection by SARS-CoV-2 and implications for corneal donation: An ex vivo study.

BACKGROUND: The risk of Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) transmission through corneal graft is an ongoing debate and leads to strict restrictions in corneas procurement, leading to a major decrease in eye banking activity. The aims of this study are to specifically assess the capacity of human cornea to be infected by SARS-CoV-2 and promote its replication ex vivo, and to evaluate the real-life risk of corneal contamination by detecting SARS-CoV-2 RNA in corneas retrieved in donors diagnosed with Coronavirus Disease 2019 (COVID-19) and nonaffected donors. METHODS AND FINDINGS: To assess the capacity of human cornea to be infected by SARS-CoV-2, the expression pattern of SARS-CoV-2 receptor angiotensin-converting enzyme 2 (ACE-2) and activators TMPRSS2 and Cathepsins B and L in ocular surface tissues from nonaffected donors was explored by immunohistochemistry (n = 10 corneas, 78 ± 11 years, 40% female) and qPCR (n = 5 corneas, 80 ± 12 years, 40% female). Additionally, 5 freshly excised corneas (80 ± 12 years, 40% female) were infected ex vivo with highly concentrated SARS-CoV-2 solution (106 median tissue culture infectious dose (TCID50)/mL). Viral RNA was extracted from tissues and culture media and quantified by reverse transcription quantitative PCR (RT-qPCR) (viral RNA copies) 30 minutes (H0) and 24 hours (H24) after infection. To assess the risk of corneal contamination by SARS-CoV-2, viral RNA was tested by RT-qPCR (Ct value) in both corneas and organ culture media from 14 donors diagnosed with COVID-19 (74 ± 10 years, 29% female) and 26 healthy donors (79 ± 13 years, 57% female), and in organ culture media only from 133 consecutive nonaffected donors from 2 eye banks (73 ± 13 years, 29% female). The expression of receptor and activators was variable among samples at both protein and mRNA level. Based on immunohistochemistry findings, ACE-2 was localized mainly in the most superficial epithelial cells of peripheral cornea, limbus, and conjunctiva, whereas TMPRSS2 was mostly expressed in all layers of bulbar conjunctiva. A significant increase in total and positive strands of IP4 RNA sequence (RdRp viral gene) was observed from 30 minutes to 24 hours postinfection in central cornea (1.1 × 108 [95% CI: 6.4 × 107 to 2.4 × 108] to 3.0 × 109 [1.4 × 109 to 5.3 × 109], p = 0.0039 and 2.2 × 107 [1.4 × 107 to 3.6 × 107] to 5.1 × 107 [2.9 × 107 to 7.5 × 107], p = 0.0117, respectively) and in corneoscleral rim (4.5 × 109 [2.7 × 109 to 9.6 × 109] to 3.9 × 1010 [2.6 × 1010 to 4.4 × 1010], p = 0.0039 and 3.1 × 108 [1.2 × 108 to 5.3 × 108] to 7.8 × 108 [3.9 × 108 to 9.9 × 108], p = 0.0391, respectively). Viral RNA copies in ex vivo corneas were highly variable from one donor to another. Finally, viral RNA was detected in 3 out of 28 corneas (11%) from donors diagnosed with COVID-19. All samples from the 159 nonaffected donors were negative for SARS-CoV-2 RNA. The main limitation of this study relates to the limited sample size, due to limited access to donors diagnosed with COVID-19 and concomitant decrease in the procurement corneas from nonaffected donors. CONCLUSIONS: In this study, we observed the expression of SARS-CoV-2 receptors and activators at the human ocular surface and a variable increase in viral RNA copies 24 hours after experimental infection of freshly excised human corneas. We also found viral RNA only in a very limited percentage of donors with positive nasopharyngeal PCR. The low rate of positivity in donors diagnosed with COVID-19 calls into question the utility of donor selection algorithms. TRIAL REGISTRATION: Agence de la Biomédecine, PFS-20-011 https://www.agence-biomedecine.fr/.

Sensory Nerve Retraction and Sympathetic Nerve Innervation Contribute to Immunopathology of Murine Recurrent Herpes Stromal Keratitis.

Purpose: Herpes stromal keratitis (HSK) represents a spectrum of pathologies which is caused by herpes simplex virus type 1 (HSV-1) infection and is considered a leading cause of infectious blindness. HSV-1 infects corneal sensory nerves and establishes latency in the trigeminal ganglion (TG). Recently, retraction of sensory nerves and replacement with "unsensing" sympathetic nerves was identified as a critical contributor of HSK in a mouse model where corneal pathology is caused by primary infection. This resulted in the loss of blink reflex, corneal desiccation, and exacerbation of inflammation leading to corneal opacity. Despite this, it was unclear whether inflammation associated with viral reactivation was sufficient to initiate this cascade of events. Methods: We examined viral reactivation and corneal pathology in a mouse model with recurrent HSK by infecting the cornea with HSV-1 (McKrae) and transferring (intravenous [IV]) human sera to establish primary infection without discernible disease and then exposed the cornea to UV-B light to induce viral reactivation. Results: UV-B light induced viral reactivation from latency in 100% of mice as measured by HSV-1 antigen deposition in the cornea. Further, unlike conventional HSK models, viral reactivation resulted in focal retraction of sensory nerves and corneal opacity. Dependent on CD4+ T cells, inflammation foci were innervated by sympathetic nerves. Conclusions: Collectively, our data reveal that sectoral corneal sensory nerve retraction and replacement of sympathetic nerves were involved in the progressive pathology that is dependent on CD4+ T cells after viral reactivation from HSV-1 latency in the UV-B induced recurrent HSK mouse model.

LOW VULNERABILITY OF THE POSTERIOR EYE SEGMENT TO SARS-COV-2 INFECTION: Chorioretinal SARS-CoV-2 Vulnerability.

PURPOSE: Retinal manifestations have been described in COVID-19 patients, but it is unknown whether SARS-CoV-2, the causal agent in COVID-19, can directly infect posterior ocular tissues. Here, we investigate SARS-CoV-2 host factor gene expression levels and their distribution across retinal and choroidal cell types. METHODS: Query of single-cell RNA sequencing data from human retina and choroid. RESULTS: We find no relevant expression of two key genes involved in SARS-CoV-2 entry, ACE2 and TMPRSS2, in retinal cell types. By contrast, scarce expression levels could be detected in choroidal vascular cells. CONCLUSION: Given the current understanding of viral host cell entry, these findings suggest a low vulnerability of the posterior eye segment to SARS-CoV-2 with a potential weak spot in the vasculature, which could play a putative causative role in ocular lesions in COVID-19 patients. This may qualify the vasculature of the human posterior eye segment as an in vivo biomarker for life-threatening vascular occlusions in COVID-19 patients.

Ocular transmissibility of COVID-19: possibilities and perspectives.

Since the initial outbreak of coronavirus disease 2019 (COVID-19), extensive research has emerged from across the globe to understand the pathophysiology of this novel coronavirus. Transmission of this virus is a subject of particular interest as researchers work to understand which protective and preventative measures are most effective. Despite the well understood model of aerosol-respiratory mediated transmission, the exact mechanism underlying the inoculation, infection and spread of COVID-19 is currently unknown. Given anatomical positioning and near constant exposure to aerosolized pathogens, the eye may be a possible gateway for COVID-19 infection. This critical review explores the possibility of an ocular-systemic or ocular-nasal-pulmonic pathway of COVID-19 infection and includes novel insights into the possible immunological mechanisms leading to cytokine surge.

Retinal findings in hospitalised patients with severe COVID-19.

AIM: To identify retinal findings using dilated eye examination, which are possibly related to SARS-CoV-2 infection in hospitalised patients with confirmed severe COVID-19. METHODS: In this cross-sectional study, hospitalised patients with confirmed severe COVID-19 in a single referral centre for the treatment of COVID-19, in Santo André, São Paulo Metropolitan Area, Brazil, underwent dilated eye examination of both eyes performed by a retina specialist. Findings were recorded using a portable digital fundus camera. Retinographies were analysed by two retina specialists. Medical records were reviewed for assessment of patient demographics, baseline comorbidities and clinical data. RESULTS: There were a total of 18 patients, nine (50%) male, median IQR age of 62.5 (12) years. Ten of the 18 patients (55.6%; 95% CI 33.7 to 75.4) had abnormalities on dilated eye examination. The main findings were flame-shaped haemorrhages (N=4; 22.2%; 95% CI 9.0 to 45.2) and ischaemic pattern lesions (cotton wool spots and retinal sectorial pallor) (N=4; 22.2%; 95% CI 9.0 to 45.2), with one patient having both cotton wool spots and flame-shaped haemorrhages. CONCLUSION: These findings suggest that patients with severe COVID-19 have acute vascular lesions of the inner retina including flame-shaped haemorrhages and cotton wool spots. Further studies controlling for confounding factors are necessary to properly assess these findings so as to increase the understanding of COVID-19 pathophysiology and to identify new therapies.

Herpes simplex virus PCR in 2230 explanted corneal buttons.

PURPOSE: To determine herpes simplex virus (HSV) DNA prevalence and mean cycle threshold of polymerase chain reaction (PCR) in corneal tissue of patients with penetrating keratoplasty (PKP), with (HSK+) and without (HSK-) previous clinical herpetic keratitis history. METHODS: Retrospective review of recipient corneal buttons which were explanted through PKP between March 2010 and September 2018 at the Department of Ophthalmology, Saarland University Medical Center in Homburg/Saar, Germany. Corneal tissue samples were analysed by real-time PCR for the presence of HSV DNA. For each subject, clinical data, including patients' demographics and clinical diagnoses, were collected. RESULTS: In total, 2230 corneal samples (age at the time of the surgery 57.3 ± 19.2 years) of 1860 patients were analysed. HSV PCR was positive in 137 (6.1%) corneal samples, with a 30.57 ± 6.01 (range 14-39) mean cycle threshold (Ct) value. Two hundred ninety-eight (13.4%) corneas of 266 patients were clinically HSK+, and 1932 (86.6%) corneas of 1600 patients were clinically HSK-. HSV DNA was detected significantly more frequently (p < 0.0001) in HSK+ corneal samples (108 corneal samples; 36.2%), than in HSK- corneal samples (29 corneal samples; 1.5%). Ct value was significantly lower in HSK+ than in HSK- corneal samples (29.8 ± 5.8 versus 32.6 ± 5.9; p = 0.008). CONCLUSION: Our data demonstrate that a positive clinical history of HSK is related to HSV PCR positivity in about every 2.8th patient. In addition, about every 66th explanted corneal tissue is HSV PCR-positive despite the lack of clinical suspicion. These patients may need additional local/systemic antiviral treatment to avoid newly acquired HSK following penetrating keratoplasty.

CHARACTERIZING COVID-19-RELATED RETINAL VASCULAR OCCLUSIONS: A Case Series and Review of the Literature.

PURPOSE: To describe clinical and ophthalmologic features and outcomes of patients with coronavirus disease-19 with retinal vascular occlusions. METHODS: Retrospective multicenter case series and PubMed review of cases reported from March 2020 to September 2021. Outcome measures are as follows: type of occlusion, treatments, best-corrected visual acuity, and central macular thickness on optical coherence tomography. RESULTS: Thirty-nine patients were identified. Fifteen patients with a median age of 39 (30-67) years were included in the multicenter study. Vascular occlusions included central retinal vein occlusion (12 eyes), branch retinal vein occlusion (4 eyes), and central retinal artery occlusion (2 eyes). Three cases were bilateral. Baseline best-corrected visual acuity was 20/45 (no light perception-20/20). Baseline central macular thickness was 348.64 (±83) µm. Nine eyes received anti-vascular endothelial growth factor agents, dexamethasone intravitreal implant, or both. Final best-corrected visual acuity was 20/25 (no light perception-20/20), and central macular thickness was 273.7 ± 68 µm (follow-up of 19.6 ± 6 weeks). Among the 24 cases from the literature review, retinal vein occlusion was the predominant lesion. Clinical characteristics and outcomes were similar to those found in our series. CONCLUSION: Coronavirus disease-19-associated retinal vascular occlusions tend to occur in individuals younger than 60 years. Retinal vein occlusion is the most frequent occlusive event, and outcomes are favorable in most cases.

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.

Development of Cytomegalovirus Corneal Endotheliitis During Long-Term Topical Tacrolimus and Steroid Treatment for Chronic Ocular Surface Inflammatory Diseases.

PURPOSE: We report 3 cases of patients with chronic ocular surface inflammatory disease who developed cytomegalovirus (CMV) corneal endotheliitis during immunosuppressant and steroid treatment. PATIENTS AND METHODS: This is a retrospective observational study analyzing the clinical characteristics and outcomes of 3 patients with ocular surface inflammatory diseases (2 with Mooren ulcer and 1 with idiopathic scleritis) who developed CMV corneal endotheliitis. All patients developed CMV corneal endotheliitis between 8 and 14 months of starting steroid and immunosuppressant treatment, including topical 0.1% tacrolimus. Decimal visual acuity, endothelial counts, and intraocular pressure were analyzed. RESULTS: All patients received topical 0.5% ganciclovir after the diagnosis of CMV corneal endotheliitis, which improved endothelial inflammation. However, all patients developed irreversible mydriasis and required additional surgeries, including endothelial keratoplasty, cataract surgery, and glaucoma surgery. At the final follow-up (14-46 months post-CMV corneal endotheliitis onset), fair outcomes were achieved, as demonstrated by a mean decimal best-corrected visual acuity of 0.3 and a well-controlled intraocular pressure. CONCLUSIONS: Topical steroids and immunosuppressants can induce fulminant CMV corneal endotheliitis with cataract progression and irreversible mydriasis. In these cases, early diagnosis and treatment, including topical 0.5% ganciclovir, glaucoma surgery, cataract surgery, and endothelial keratoplasty, are necessary for preserving the patient's vision.

Establishing an Animal Model of Cytomegalovirus Keratouveitis in Rats: Broad Infection of Anterior Segment Tissue by Cytomegalovirus.

Purpose: Considering the difficulty of obtaining adequate biological tissue in clinical practice, we established an animal model of cytomegalovirus (CMV) keratouveitis in rats and investigated the viral infection sites and corresponding imaging and histopathological features. Methods: Subconjunctival injection and topical use of dexamethasone were used to induce ocular immunosuppression in rats followed by intracameral inoculation of murine cytomegalovirus (MCMV). The clinical manifestations, intraocular pressure (IOP) and imaging changes were observed. Infected eyes were further examined by immunofluorescence, light microscopy, and electron microscopy. MCMV RNA was detected by reverse transcription-polymerase chain reaction. Results: Typical keratouveitis occurred in the experimental rats and was characterized by corneal edema, keratic precipitates, and iridocyclitis with increased IOP. Corneal endothelial lesions displayed as "black holes," enlarged intercellular gaps, and high-intensity cellular infiltration by confocal microscopy, consistent with the pathological changes of "ballooning degeneration," endothelial cell detachment, and inflammatory cell infiltration. Mitochondrial edema was the most prominent organelle lesion in endothelial cells. Trabeculitis, mechanical obstruction of Schlemm's canal, and anterior chamber angle stenosis accounted for elevated IOP. Inflammation of the iris and ciliary body tended to transform into a chronic form. Immunofluorescence revealed that corneal endothelial cells, iris cells, trabecular meshwork cells, and monocytes could be infected by MCMV. MCMV RNA was found in the anterior segments after infection. Conclusions: CMV can widely infect anterior segment tissue, including the corneal endothelium, iris, and trabecular meshwork, in vivo, inducing the corresponding clinical manifestations. Corneal endotheliitis and hypertensive anterior uveitis could be the specific stage of anterior segment infection of CMV.