Misdiagnosed as Fungal Keratitis: Herpes Simplex Virus-1 Keratitis Confirmed by Next-Generation Sequencing.

Objective: The purpose of this study was to report a case of herpes simplex virus-1 (HSV-1) keratitis misdiagnosed as fungal keratitis due to its clinical presentation being similar to that of fungal keratitis, ultimately diagnosed by NGS. Patients and Methods: A 59-year-old male presented with reduced vision in the right eye, combined with a history of trauma with vegetative matter. The corneal ulcer was accompanied with feathery infiltration, satellite lesion, and endothelial plaques. In vivo confocal microscopy (IVCM) showed hyper-reflective linear, thin, and branching interlocking structures. Fungal keratitis was diagnosed. Voriconazole 100 mg orally daily, topical tobramycin and 1% voriconazole were initiated empirically right away. The condition was aggravated and penetrating keratoplasty was performed. Anterior segment optical coherence tomography (AS-OCT) demonstrated the presence of plaques with a clear boundary between plaques and endothelium, resembling the AS-OCT images observed in cases of viral keratitis. Next-generation sequencing (NGS) further detected HSV-1 deoxyribonucleic acid, and no fungal component was found. Antifungal agents were discontinued and antiviral treatments were added. Results: We successfully treated a patient with HSV-1 keratitis who was misdiagnosed due to clinical features and IVCM findings similar to fungal keratitis. The patient's infection was controlled. At 2 years after surgery, the cornea recovered well. Conclusions: HSV-1 keratitis with atypical clinical presentation can be easily misdiagnosed. This case report emphasizes the importance of NGS in diagnosing the pathogens of keratitis.

The Topical Novel Formulations of Interferon α-2в Effectively Inhibit HSV-1 Keratitis in the Rabbit Eye Model and HSV-2 Genital Herpes in Mice.

Herpes simplex viruses type 1 (HSV-1) and type 2 (HSV-2) are widespread human pathogens that establish chronic latent infections leading to recurrent episodes. Current treatments are limited, necessitating the development of novel antiviral strategies. This study aimed to assess the antiviral efficacy of novel topical formulations containing interferon alpha-2b (IFN α-2b) against HSV-1 and HSV-2. The formulations, Oftalmoferon® forte (eye drops) and Interferon Vaginal Tablets, demonstrated potent antiviral effects against HSV-1 and HSV-2 in Vero cells, respectively, with concentration-dependent inhibition of viral replication. Subsequently, their efficacy was tested in animal models: HSV-1 keratitis in the rabbit eye model and HSV-2 genital herpes in mice. Oftalmoferon® forte effectively treated HSV-1 keratitis, reducing clinical symptoms and ulcerations compared to virus control. Interferon Vaginal Tablets showed promising results in controlling HSV-2 genital herpes in mice, improving survival rates, reducing clinical signs, weight loss and viral replication. The novel IFN α-2b formulations exhibited significant antiviral activity against HSV infections in cell culture and animal models. These findings suggest the potential of these formulations as alternative treatments for HSV infections, particularly in cases resistant to current therapies. Further studies are warranted to optimize treatment regimens and assess clinical efficacy in humans.

Harmol used for the treatment of herpes simplex virus induced keratitis.

Herpes simplex virus type 1 (HSV-1) infection of the eyes results in herpes simplex keratitis (HSK), which has led to vision loss and even blindness in patients. However, the rate of drug resistance in HSV is on the rise; therefore, new antiviral agents with sufficient safety profiles must be developed. At present, we assessed the anti-HSV-1 activity of 502 natural compounds and their ability to reduce the HSV-1-induced cytopathic effect. We chose harmol for further studies because it exhibited the highest antiviral activity. We found that harmol inhibited both HSV-1 F and HSV-1/153 (a clinical drug-resistant strain) replication, with an EC50 of 9.34 µM and 5.84 µM, respectively. Moreover, harmol reduced HSV-1 replication in corneal tissues and viral progeny production in tears, and also alleviated early corneal surface lesions related to HSK. For example, harmol treatment preserved corneal thickness and nerve density in HSK mice. Interestingly, harmol also showed a promising antiviral effect on HSV-1/153 induced HSK in mouse model. Furthermore, harmol combined with acyclovir (ACV) treatment showed a greater antiviral effect than either one alone in vitro. Therefore, harmol may be a promising therapeutic agent for managing HSK.

Commercial human 3D corneal epithelial equivalents for modeling epithelial infection in herpes keratitis.

Herpes stromal keratitis is the leading cause of infectious blindness in the western world. Infection by HSV1 is most common, but VZV and hCMV also infect the cornea. Multiple models of HSV1 corneal infection exist, but none for VZV and hCMV because of their host specificity. Here, we used commercially available 3D human corneal epithelial equivalents (HCEE) to study infection by these herpesviruses. HCEE was infected by HSV-1 and hCMV without requiring scarification and resulted in spreading infections. Spread of HSV-1 infection was rapid, while that of hCMV was slow. In contrast, infections with VZV required damage to the HCEE and did not spread. Acyclovir dramatically reduced replication of HSV-1 in this model. We conclude that highly quality-controlled, readily available HCEE is a useful model to study human-restricted herpesvirus infection of the human corneal epithelium and for screening of antiviral drugs for treating HSK in an 3D model system.

Emerging drugs for the treatment of herpetic keratitis.

INTRODUCTION: Herpes simplex keratitis stands as a prominent factor contributing to infectious blindness among developed nations. On a global scale, over 60% of the population tests positive for herpes simplex virus type-1 (HSV-1). Despite these statistics, there is currently no vaccine available for the virus. Moreover, the conventional nucleoside drugs prescribed to patients are proving ineffective in addressing issues related to drug resistance, recurrence, latency, and the escalating risk of vision loss. Hence, it is imperative to continually explore all potential avenues to restrict the virus. This review article centers on the present treatment methods for HSV-1 keratitis (HSK), highlighting the ongoing clinical trials. It delves into the emerging drugs, their mode-of-action and future therapeutics. AREAS COVERED: The review focuses on the significance of a variety of small molecules targeting HSV-1 lifecycle at multiple steps. Peer-reviewed articles and abstracts were searched in MEDLINE, PubMed, Embase, and clinical trial websites. EXPERT OPINION: The exploration of small molecules that target specific pathways within the herpes lifecycle holds the potential for substantial impact on the antiviral pharmaceutical market. Simultaneously, the pursuit of disease-specific biomarkers has the capacity to usher in a transformative era in diagnostics within the field.

Herpes Simplex Keratitis as a Complication of Pterygium Surgery.

BACKGROUND Infectious keratitis after pterygium surgery is a rare but potentially devastating complication. The present study presents 5 cases of herpes simplex keratitis (HSK) after pterygium surgery. CASE REPORT This study was conducted in our clinic in a 5-year period from February 2017 to September 2021. The 5 patients were men, aged between 42 and 73 years, with no prior history of herpes simplex virus (HSV) infections. Symptoms appeared near 1 month (median 30 days, range 10 to 70 days) after primary pterygium surgery. Diagnosis was based on clinical symptoms and laboratory test results, such as tear HSV-sIgA, corneal tissue polymerase chain reaction, and next-generation sequencing of metagenomics. The epithelial (1/5) and stromal (4/5) subtypes of HSK were identified. The patients received topical ganciclovir gel, immunosuppressive eyedrops, and oral acyclovir tablets, along with additional surgical interventions if necessary. Three were healed with conservative therapy, 1 eye required amniotic membrane transplantation due to corneal melt, and 1 was perforated and followed by corneal grafting. Finally, a literature review of previous publications on HSK after ocular surgeries was conducted. CONCLUSIONS HSK is a rare but serious complication that can arise after uneventful pterygium surgery. It is worthy of attention that both epithelial and stromal forms can occur. Timely diagnosis and treatment are crucial to prevent unfavorable outcomes. Consequently, routine corneal fluorescein staining, tear sIgA examination, and corneal scraping for polymerase chain reaction or next-generation sequencing of metagenomics should be performed in any suspected cases.

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.

Targeted delivery of herpes simplex virus glycoprotein D to CD169+ macrophages using ganglioside liposomes alleviates herpes simplex keratitis in mice.

Herpes simplex keratitis (HSK) is a common blinding corneal disease caused by herpes simplex virus type 1 (HSV-1) infection. Antiviral drugs and corticosteroids haven't shown adequate therapeutic efficacy. During the early stage of HSV-1 infection, macrophages serve as the first line of defense. In particular, CD169+ macrophages play an important role in phagocytosis and antigen presentation. Therefore, we constructed GM-gD-lip, a ganglioside GM1 liposome vaccine encapsulating HSV-1 glycoprotein D and targeting CD169+ macrophages. After subconjunctival injection of the vaccine, we evaluated the survival rate and ocular surface lesions of the HSK mice, as well as the virus levels in the tear fluid, corneas, and trigeminal ganglia. We discovered that GM-gD-lip reduced HSV-1 viral load and alleviated the clinical severity of HSK. The GM-gD-lip also increased the number of corneal infiltrating macrophages, especially CD169+ macrophages, and polarized them toward M1. Furthermore, the number of dendritic cells (DCs) and CD8+ T cells in the ocular draining lymph nodes was significantly increased. These findings demonstrated that GM-gD-lip polarized CD169+ macrophages toward M1 to eliminate the virus while cross-presenting antigens to CD8+ T cells via DCs to activate adaptive immunity, ultimately attenuating the severity of HSK. The use of GM-gD-lip as an immunotherapeutic method for the treatment of HSK has significant implications.

Loss of TRPM8 Exacerbate Herpes Simplex Keratitis Infection in Mice by Promoting the Infiltration of CD11b+ Ly6G+ Cells and Increasing the Viral Load in the Cornea.

Purpose: To reveal the role of transient receptor potential cation subfamily M member 8 (TRPM8) channels in herpes simplex keratitis (HSK). Methods: HSK models were established using TRPM8 knockout (TRPM8-/-) mice and their wild-type (WT) littermates. The infected corneas were graded and harvested to evaluate the mRNA levels of inflammatory factors through quantitative real-time polymerase chain reaction (RT-PCR), as well as the infiltration of inflammatory cells through immunofluorescence staining and flow cytometry. Viral titers were determined by plaque assay and absolute quantitative method. RNA-sequencing was conducted to elucidate the transcriptome of corneal epithelium in response to TRPM8 knockout after infection. The anti-inflammatory effect of TRPM8 agonist menthol was documented via subconjunctival administration. Results: Compared to their wild-type counterparts, TRPM8-deficient mice exhibited exacerbated infection symptoms and thicker corneas in HSK models. Infection in TRPM8-deficient mice resulted in significant lymphocyte infiltration, primarily consisting of Ly6G+ CD11b+ cells. Additionally, TRPM8-deficient mice displayed increased levels of corneal viral titers after infection, along with decreased expression of interferon-stimulated genes (ISGs). Subconjunctival administration of menthol effectively alleviated infection-induced symptoms and Ly6G+ CD11b+ cell infiltration in herpes simplex virus type 1 (HSV-1)-treated mice. Conclusions: TRPM8 promoted host resistance to HSV-1 infection by suppressing the accumulation of Ly6G+ CD11b+ cells and virus replication. These findings suggest that targeting TRPM8 could be valuable for therapeutic interventions against HSV-1 infections.

Steroids in the Management of Infectious Keratitis.

PURPOSE: To summarize the evidence base on the use of topical corticosteroids for infectious keratitis. METHODS: Narrative review. RESULTS: Infectious keratitis is a painful condition that often results in visually significant corneal stromal scarring, even when antimicrobial therapy is successful. Corticosteroids may reduce inflammation and subsequent scar formation and while relieving the acute ocular pain associated with a corneal ulcer. However, corticosteroids also reduce the host immune response, which could hinder the ability to clear infection. The safety and effectiveness of corticosteroids depends to a large part on the efficacy of the antimicrobials being used to treat the underlying infection. Randomized trials have found that corticosteroids are safe and effective for herpetic keratitis when used with appropriate antiviral therapy, and are safe for bacterial keratitis when used with broad spectrum topical antibiotics. The effectiveness of corticosteroids for bacterial keratitis has not been shown conclusively, although more advanced bacterial corneal ulcers may do better with corticosteroids. No randomized trials have assessed the safety and effectiveness of steroids for fungal or acanthamoeba keratitis. Animal studies suggest corticosteroids may be harmful in fungal keratitis, and observational human studies have found that steroids are harmful for fungal and acanthamoeba keratitis when started prior to anti-amoebics. CONCLUSIONS: Topical corticosteroids, when used as an adjunct to antimicrobial therapy, may be beneficial if the antimicrobial being used can effectively clear or suppress the infection, such as in bacterial and herpetic keratitis. Randomized trials would be helpful to further delineate the role of corticosteroids for infectious keratitis.

New-Onset of Herpes Simplex Keratitis After Blepharoplasty, Case Series and Review of the Literature.

PURPOSE: To report 3 cases of new-onset herpes simplex keratitis (HSK) after uncomplicated extraocular plastic surgery and discuss potential risk factors. METHODS: This case series includes 3 patients who underwent uncomplicated blepharoplastic surgery. Within 2 weeks postoperatively, all patients reported ocular discomfort, and their ophthalmic examinations revealed corneal lesions suspicious of HSK. One case was confirmed as an active herpes infection, and the other 2 cases were clinically diagnosed with HSK. The patients were treated with oral acyclovir and followed up for up to 6 weeks. RESULTS: All patients demonstrated improvement without sequelae at follow-up visits from 5 days to 4 weeks after initiating acyclovir treatment. CONCLUSIONS: Risk factors for new-onset HSK after uncomplicated extraocular surgeries may be related to an immunocompromised state, postoperative administration of topical or periocular corticosteroids, or environmental factors such as psychological stress. Ophthalmologists, particularly plastic surgeons, should be vigilant for ocular discomfort following eyelid surgeries and consider the possibility of herpes infection. This report highlights the importance of recognizing and managing HSK in the context of extraocular plastic surgery.

In vivo CRISPR gene editing in patients with herpetic stromal keratitis.

In vivo CRISPR gene therapy holds large clinical potential, but the safety and efficacy remain largely unknown. Here, we injected a single dose of herpes simplex virus 1 (HSV-1)-targeting CRISPR formulation in the cornea of three patients with severe refractory herpetic stromal keratitis (HSK) during corneal transplantation. Our study is an investigator-initiated, open-label, single-arm, non-randomized interventional trial at a single center (NCT04560790). We found neither detectable CRISPR-induced off-target cleavages by GUIDE-seq nor systemic adverse events for 18 months on average in all three patients. The HSV-1 remained undetectable during the study. Our preliminary clinical results suggest that in vivo gene editing targeting the HSV-1 genome holds acceptable safety as a potential therapy for HSK.

Application of topical 2% cyclosporine A in inflammatory ocular surface diseases.

PURPOSE: To report our experience with the 2% cyclosporin A (CsA) in a series of challenging inflammatory ocular surface diseases due to different etiologies. METHODS: The records of patients who received topical 2% CsA for different indications were reviewed retrospectively. Demographic characteristics, indications for treatment, patient symptoms and clinical findings were recorded. RESULTS: Fifty-two eyes of 52 patients were included. Mean age was 43.2 ± 14.3 (11-66) years with a F/M ratio of 34/18. Indications included pediatric acne rosacea (n = 4), adenoviral corneal subepithelial infiltrates (n = 12), filamentary keratitis (n = 14), pterygium recurrence (n = 15), herpetic marginal keratitis (n = 2) and graft versus host disease (n = 5 patients). Mean duration of treatment was 7.3 ± 2.8 (3-10) months. Forty-three (83%) patients reported favorable outcome with improvement in symptoms after a mean time of 4.4 ± 2.7 (2-6) months. CONCLUSIONS: Topical 2% CsA may address the needs of different cases with ocular surface inflammation, as a safe option for long-term therapy.

Double Trouble: An Unusual Keratitis Case of Herpes Simplex Virus and Varicella-Zoster Virus Co-infection.

PURPOSE: The aim of this study was to describe a case of herpes simplex virus (HSV) and varicella-zoster virus (VZV) corneal co-infection in a patient with systemic immunosuppression. METHODS: A 77-year-old White man who was recently administered pembrolizumab present with reduction in visual acuity in his left eye from 20/25 to 20/50. There was a known history of ocular HSV keratitis. Slit-lamp examination showed superficial dendritic lesions suggestive of VZV. RESULTS: Viral polymerase chain reaction testing was positive for both HSV and VZV, confirming clinical diagnosis of VZV keratitis in the setting of recurrent HSV keratitis. The infection responded to treatment with topical trifluridine. Two months later, he had another episode of keratitis based on his symptoms reported through telephone encounter which resolved with trifluridine. Unfortunately, the patient committed suicide 4 months after onset. CONCLUSIONS: This is the first case of keratitis with HSV and VZV co-infection likely related to systemic immunosuppression. Clinicians should have a high suspicion for viral co-infections in the setting of systemic immunosuppression.

Clinical Features of Pediatric Age Herpes Simplex Virus Keratitis.

PURPOSE: The objective of this study is to evaluate the clinical features of pediatric herpes simplex virus keratitis, its recurrence rates, and its effects on visual acuity. METHODS: In this retrospective case series, records of pediatric patients (0-16 years) who presented with herpes simplex virus keratitis between January 2012 and September 2021 were evaluated. Data including age, gender, additional systemic diseases, the number of recurrences, recurrence time, treatment protocol, follow-up period, and presence of amblyopia were reviewed. RESULTS: Twenty-four patients (16 females and 8 males) with a mean age of 6.6 ± 4 (1.1-15) years were included in the study. The mean follow-up time was 21 ± 19.9 (7-94) months. Four patients (16.6%) had bilateral keratitis. Including all 4 patients with bilateral involvement, a total of 10 (41.6%) patients had additional systemic diseases that cause immunodeficiency. After prophylactic antiviral treatment for at least 6 months (except for isolated epithelial keratitis), recurrence was detected in 5 (22.7%) patients, who were all immunodeficient. Among immunodeficient individuals, the recurrence rate was found to be 50%. Keratitis recurrence was significantly associated with immunodeficiency ( P = 0.03). However, type of keratitis ( P = 0.42), gender ( P = 0.47), and bilaterality ( P = 0.54) were not related with recurrence. 66.7% of the patients younger than 10 years developed amblyopia during follow-up. CONCLUSIONS: In childhood, the most frequent corneal manifestation of herpes simplex virus is stromal keratitis that mostly progresses with corneal scarring, residual astigmatism, and amblyopia. The recurrence rate increases in the presence of immunosuppression. Close follow-up, rapid diagnosis, and treatment are critical for battling against amblyopia and achieving good visual prognosis.

Bilateral Thygeson's Superficial Punctate Keratitis with Dendritic Corneal Lesion: A Case Report.

Thygeson's superficial punctate keratitis (TSPK) is a recurrent bilateral corneal epithelial disease. Typically, small, multiple discrete epithelial lesions occur in the central cornea. However, dendritic corneal lesions are rare. Herein, we report a rare case of TSPK in both eyes after a unilateral dendritic corneal lesion. A 42-year-old woman presented with decreased vision and foreign body sensation in her right eye that persisted for 1 month. Her uncorrected visual acuity and best-corrected visual acuity (BCVA) were 20/160 in the right eye. Slit-lamp microscopy revealed a dendritic lesion in the central cornea of the right eye. No abnormalities were observed in her left eye. Herpetic keratitis in the right eye was diagnosed and systemic acyclovir was prescribed, along with topical acyclovir ointment and steroids. After one week, most of the corneal lesions had disappeared, and the BCVA in the right eye had improved to 20/25. The corneal epithelium completely recovered after 2 weeks. However, 2 weeks later, the patient visited the hospital with decreased visual acuity in the right eye, and the BCVA decreased to 20/40. Multiple fine corneal lesions were observed under a slit-lamp microscope. The patient was diagnosed with TSPK of the right eye. Topical steroids were started, and after 7 days, the corneal condition improved. However, after 6 weeks, visual acuity decreased in the left eye, and a corneal lesion similar to that in the right eye was observed; therefore, the patient was diagnosed with bilateral TSPK. Short-term topical steroids and long-term topical cyclosporine A 0.1% were used in both eyes, and the disease was maintained without recurrence for 3 months. TSPK can appear as a unilateral dendritic corneal lesion similar to herpetic keratitis. Therefore, in case of unilateral dendritic corneal lesions, it should be considered that TSPK may develop later.

The Impact of Antiviral Resistance on Herpetic Keratitis.

ABSTRACT: Herpes simplex keratitis resistance to antiviral treatment presents a growing concern. The herpes simplex virus has many different mechanisms of resistance to antiviral treatment, which have been well described. Resistance to acyclovir occurs because of mutations in the viral thymidylate kinase and DNA polymerase that decrease this enzyme's affinity for its substrate. This article discusses factors that explain the prevalence of this resistance, the ability for recurrences in immunocompromised populations, current treatments for acyclovir-resistant herpes simplex keratitis, and novel therapies for this growing concern.

Bilateral Severe Herpes Simplex Endotheliitis with a Possible Association with Latanoprost.

PURPOSE: To report bilateral Herpes Simplex virus (HSV) keratitis in a patient on latanoprost for primi]k=8ary open angle glaucoma (POAG). METHODS: Case report. RESULTS: A 76-year-old healthy male on latanoprost monotherapy for POAG polresented with sudden bilateral decreased vision. Examination showed bilateral dense corneal edema with loose epithelium. Aqueous fluid was positive for HSV-1 DNA on polymerase chain reaction (PCR). Latanoprost was discontinued, topical prednisolone acetate 1% eye, acyclovir 400 mg 5 times a day and combination of dorzolamide hydrochloride 2% and timolol maleate 0.5% twice daily were prescribed. The vision rapidly improved to 20/25 along with complete resolution of corneal edema within four weeks, with no recurrences over the next one year. CONCLUSION: Bilateral simultaneous HSV endotheliitis is a rare condition and positive PCR test can help rule in the diagnosis. HSV keratitis is a known adverse event with Latanoprost use and can present atypically.