Herpetic Keratitis Research Articles

The herpes simplex virus alkaline nuclease is required to maintain replication fork progression.

Herpes simplex virus 1 (HSV-1) is a near-ubiquitous pathogen within the global population, causing a lifelong latent infection with sporadic reactivation throughout the life of the host. Within at-risk and immunocompromised communities, HSV-1 infection can cause serious morbidities including herpes keratitis and encephalitis. With the possibility of herpesviruses to evade established antiviral therapies and there being no approved HSV-1 vaccine, there comes a need to investigate potential targets for intervention against infection and subsequent disease. UL12 is the viral 5'-3' exonuclease, which is required for the production of infectious progeny. In this study, we show that in the absence of UL12, viral replication fork progression is abrogated. These data point to UL12 as an attractive target for intervention, which could lead to better clinical outcomes of HSV-1-associated disease in the future.

Foscarnet eyedrops for the treatment of refractory herpetic keratitis

PurposeThe purpose of this case series is to describe the clinical course of patients receiving foscarnet eyedrops for the treatment of refractory herpetic keratitis.ObservationsSix patients diagnosed with herpetic keratitis were treated with foscarnet 24 mg/mL (2.4%) eyedrops with resulting improvement in keratitis.ConclusionTopical foscarnet may be a safe and effective treatment for herpetic keratitis in conjunction with, or as an alternative to, conventional antiviral therapy. This is an off-label use of foscarnet.

Peculiarities of the regional hemodynamics in patients with mono- and bilateral herpes simplex virus stromal keratitis

Background. Herpes simplex virus keratitis (HSVK) is the main cause of blindness in the world resulted from corneal pathology. The blood circulation system of the eye plays an important role in the effective implementation of the immune response. The purpose of the study: to determine the influence of the factor of laterality of the stromal HSVK on the ocular hemodynamics and the frequency of complications. Material and methods. Primary stromal HSVK (was registered for the first time and lasted no more than 3 months) was diagnosed in 32 people (35 eyes), 205 patients (226 eyes) had recurrent stromal HSVK. Among these patients, stromal HSVK was detected both in one eye — unilateral, and in two eyes — bilateral. Complications of stromal HSVK includes: the presence of a transparent graft — in 23 eyes and its opacity — in 10 eyes, secondary glaucoma — in 6 eyes, condition after corneal ulcer — in 16 eyes. The average age of the patients (M ± SD) is 42.2 ± 15.0 years. The control group consisted of 16 healthy volunteers (32 eyes) of similar age. The standard technique of rheoophthalmogram on the ReoCom computer rheograph (Kharkiv, Ukraine) was used. The following indicators were analyzed: rheographic quotient (RQ, ‰) (pulse volumetric blood filling); α1/T (%) — the tone of the large vessels of the eye; velocity of blood filling V (Ohm/s). Results. Patients with stromal HSVK had mainly monolateral eye lesion — 89.8 %, and bilateral lesion was present in 10.2 % of cases. There were no significant differences in the frequency of laterality between primary and recurrent stromal HSVK. In case of recurrence of complicated unilateral and bilateral stromal HSVK, the volumetric pulse blood filling was 17.6 and 30.3 % lower, respectively, than in uncomplicated course, which determines the insufficiency of blood supply to the eye. The rate of blood filling in complicated stromal HSVK was lower than in uncomplicated one by 23 %. At the recurrence of bilateral stromal HSVK, the RQ was higher by 26.4 %, and the rate of blood filling was higher by 36.3 % compared to unilateral one. There were no differences in remission. The tone of the large vessels of the eye with bilateral stromal HSVK is 14 % lower than with unilateral course. Conclusions. In case of recurrent stromal HSVK, the volume pulse blood filling of the eye and its velocity are higher, and the vascular tone is lower than in case of unilateral one, both uncomplicated and complicated. It is assumed that such a significant activation of the ocular hemodynamics is compensatory and contributes to a greater local immune response and improvement of trophism.

Trigeminal Trophic Syndrome With Herpetic Keratitis.

The aim of this study was to report a rare observation of trigeminal trophic syndrome presenting with concurrent herpetic keratitis. This study was a case report. A 42-year-old male with a remote history of a motor vehicle accident, traumatic brain injury, extensive facial reconstructive surgery, and traumatic optic neuropathy presented with left periorbital swelling. He was found to have extensive periorbital and total hypoesthesia in the cranial nerve V1 distribution and partial hypoesthesia in the V2 distribution. Corneal findings were highly suspicious for herpes simplex keratitis or zoster ophthalmicus. The patient was diagnosed with herpetic epithelial and stromal keratitis with periorbital ulceration secondary to Trigeminal trophic syndrome. The patient was treated broad spectrum intravenous antibiotics, intravenous acyclovir, and topical antibiotics. He was treated with topical steroids upon closure of epithelial defect. Upon discharge, the patient's vision improved from hand-motion to 20/30 at near. The patient was later fit with a custom thermoplastic facial mask to minimize further selfinjurious behavior. To our knowledge, this is the first report of trigeminal trophic syndrome presenting with concurrent herpetic keratitis. Successful treatment requires a multidisciplinary approach to provide the patient insight and create protective equipment.

Topical Application of 0.05% Cyclosporine for the Treatment of Neurotrophic Keratopathy Secondary to Herpes Simplex Keratitis

The purpose of this study was to assess the effectiveness and tolerability of 0.05% cyclosporine A (CsA) eye drops for neurotrophic keratopathy (NK) secondary to herpes simplex keratitis (HSK). Fifteen patients (15 eyes) with prior HSK and secondary NK, classified as stage 2 or 3 on the basis of the Mackie classification, were enrolled. All patients received a combined treatment regimen of 0.05% CsA eye drops (1 drop 4 times daily), a silicone hydrogel bandage contact lens, and 0.15% ganciclovir ophthalmic gel (1 drop 3 times daily). For patients achieving corneal healing, CsA was continued at a reduced dosage of twice daily for an additional 2 months and other treatments were discontinued. Follow-ups were scheduled at weeks 1, 2, 3, and 4 and at months 2 and 3 after treatment initiation, followed by a 3-month follow-up period. Key outcomes, including best-corrected visual acuity, Schirmer I test, and corneal sensitivity, were assessed at each visit before and after treatment. Significant reductions were observed in the area of corneal defects, expressed as proportion of total corneal area, throughout follow-up period. Complete corneal healing was achieved by 13.3% of patients by week 2, 60.0% by week 3, 86.7% by week 4, and 100.0% by week 8, with the mean (SD) time to healing being 3.8 (1.8) weeks (range, 2-8 weeks). Additionally, significant improvements were noted in diseased eyes for best-corrected visual acuity, tear secretion (Schirmer I test values), and corneal sensitivity after treatment. CsA eye drops, with bandage lenses and ganciclovir, effectively resolve NK from HSK, without adverse effects. This combination therapy shows promise for future clinical use and research. Our study is a retrospective observational study because it involves the analysis of previously collected data, so the study was not registered prior to its commencement. However, if it is necessary for publication, we are willing to proceed with retrospective registration.

Preventing and treating neurotrophic keratopathy by a single intrastromal injection of AAV-mediated gene therapy

PurposeNeurotrophic keratopathy (NK) is a degenerative corneal condition resulting from corneal nerve injury. Current therapies, including the recombinant human nerve growth factor (rhNGF) therapy, requires continuous administration. This study aims to develop a novel and highly effective gene therapy strategy for the prevention and treatment of NK. MethodsAdeno-associated virus (AAV) was transduced into corneal stromal cells by intrastromal injection. Three dimensional corneal wholemount imaging with co-immunostaining of ZO-1 and tubulin was utilized to assess the transduction of AAV.rh10. The efficacy of prevention and treatment of NK by a single intrastromal injection of AAV-Ngf was tested using capsaicin mouse model, herpes simplex keratitis (HSK) model, type Ⅱ diabetes model and alkali burn model. rhNGF eye drops served as the positive control. ResultsIntrastromal injection of AAV.rh10 efficiently transduced the subepithelial nerve plexus and retrogradely transported to the trigeminal ganglion (TG). A single injection of AAV.rh10-Ngf can significantly promote corneal nerve repair, accelerate corneal epithelial repair, reduce corneal stromal edema, and improve corneal sensitivity across the four NK models. The therapeutic effects were consistent with those achieved by continuous administration of rhNGF drops by 6 times daily. ConclusionsThis proof-of-concept study demonstrates that AAV.rh10-Ngf gene therapy is a promising method for preventing and treating of NK. Our results underline the potential for developing clinical trials to further explore the safety and efficacy of such gene therapy.

Herpes Simplex Epithelial Keratitis and Contact lens: A Case Report

Herpes simplex virus keratitis is an ocular infection arising from the reactivation of HSV; if not promptly addressed, it can lead to diminished visual acuity and potential blindness in the affected eye. The sight-threatening aspects of this infection are primarily associated with the development of scarring and opacity. A 22-year-old woman, an otherwise healthy contact lens wearer, sought medical attention with complaints of painful, red, and photophobic eyes. Upon examination, a dendritic ulcer was observed on the right eye, accompanied by toxic keratopathy in both eyes. The treatment regimen that was implemented consisted of valacyclovir and ocular lubrication. The disruption of the host's natural immunological barriers, exacerbated by suboptimal contact lens handling, paved the way for subsequent dendritic ulceration. This occurrence was instigated by the reactivation of the herpes simplex virus, underscoring the critical importance of timely intervention.

Current Formulation Strategies to Design Novel Carriers for Targeted Drug Delivery and Management of Infectious Keratitis: A Comprehensive Review on the Present State of the Art

Objective: Infectious keratitis is a pernicious disease that affects the anterior segment of the eye and is one the leading causes of blindness worldwide. This disease may cause severe visual impairment or permanent vision damage if left untreated. Discussion: No doubt there are many conventional drug delivery systems to treat ocular keratitis, yet it is the fifth leading cause of blindness globally. This is the result of the eye's complex anatomy and barrier system, which restricts the total ocular contact time of the conventional formulations resulting in underdosing. The widely used traditional formulations to treat keratitis, like antibiotic eye drops and ointments, are rendered useless due to less ocular contact time and low therapeutic drug levels at the target ocular site. The main requirement of the present time is to develop novel drug delivery-backed stratagems to overcome the shortcomings of conventional formulations, which will reduce the morbidity associated with infectious keratitis and improve clinical outcomes. It is worth mentioning that there are documented incidents of Herpetic keratitis of the cornea followed by COVID-19 infection and vaccination. Conclusion: This paper is a rigorous review of all the novel drug delivery strategies to combat ocular keratitis. These future drug delivery strategies will pave the way for the present time researcher and formulation chemists to develop multi-dimensional novel formulations that are safe, patient-compliant, and surpass the ocular barriers to maintain therapeutic drug levels in ocular tissues.

Non-Contact-Lens-Related Acanthamoeba Keratitis Caused by Acanthamoeba sp. Group T4D/T4e

Acanthamoeba keratitis (AK) is a rare but serious infection of the cornea, typically associated with contact lens wear. Here, we present a case of AK caused by the Acanthamoeba genotype T4D/T4e in a patient without identifiable risk factors: a 34-year-old woman who initially presented with signs and symptoms suggestive of herpetic keratitis, and who did not respond to conventional treatment. Corneal culture and targeted metagenomic analysis (18S rRNA, 16S-like rRNA) revealed the presence of an Acanthamoeba species closely related to the ‘Nagington’ strain. Despite intensive anti-Acanthamoeba therapy, complications arose necessitating penetrating keratoplasty. In conclusion, this case underscores the importance of considering Acanthamoeba as a causal agent of keratitis in non-contact-lens wearers. The identification of Acanthamoeba genotype T4D/T4e challenges the previous understanding of its pathogenic potential. Furthermore, it emphasizes the need for ongoing research into the pathogenicity of different Acanthamoeba subtypes. Early diagnosis and treatment are essential for preventing vision-threatening complications associated with AK.

Outcomes of Corneal Transplantation for Herpetic Keratitis: A Narrative Review.

Herpes simplex virus (HSV) is one of the most common etiologic agents of corneal disease and a significant cause of corneal blindness worldwide. Although most cases can be successfully managed with medical therapy, HSV keratitis associated with visually significant stromal scarring often requires corneal transplantation for visual rehabilitation. While penetrating keratoplasty (PK) represented the traditional keratoplasty technique, the past few decades have seen a shift towards lamellar keratoplasty procedures, including deep anterior lamellar keratoplasty and mushroom keratoplasty. This paper describes the current surgical techniques and perioperative antiviral prophylaxis regimen for herpetic keratitis and reviews their postoperative clinical outcomes.

Mitomycin Intravascular Chemoembolization for Corneal Neovascularization.

The purpose of the study was to evaluate the efficacy of mitomycin C intravascular chemoembolization (MICE) for corneal neovascularization (CNV). This is a prospective, nonrandomized, interventional study. Patients with stable CNV irrespective of the underlying etiology were enrolled in the study. 0.1% mitomycin C was injected intravascularly in CNV at the slit lamp under topical anesthesia. To evaluate the regression of vessels, the ImageJ software was used to trace and quantify vasculature by a pixel count in standardized clinical slit-lamp photographs. Eight eyes from 8 patients with corneal neovascularization and lipid keratopathy were studied. The mean age at treatment was 37 ± 12.75 (range 17-64) years. The median follow-up was 419.5 days (74-1166 days). Herpes simplex keratitis was the main underlying etiology (75%). The visual axis was compromised in 75%, and 100% had stromal scarring. The mean pixel count before MICE was 5983.41 ± 5004.96 pixels. After the treatment, the mean pixel count was 2060.38 ± 3142.96 pixels (delta: 3923.03, P = 0.029). No complications were recorded during the follow-up period. No recurrence of the CNV was observed at the last follow-up. Two eyes (25%) underwent a successful keratoplasty 4 months after MICE. MICE effectively reduced neovascularization with no immediate safety concerns, though its impact on vision and long-term safety requires further investigation with larger, longer term studies.

The immunobiology of corneal HSV-1 infection and herpetic stromal keratitis.

SUMMARYHuman alphaherpesvirus 1 (HSV-1) is a highly successful neurotropic pathogen that primarily infects the epithelial cells lining the orofacial mucosa. After primary lytic replication in the oral, ocular, and nasal mucosal epithelial cells, HSV-1 establishes life-long latency in neurons within the trigeminal ganglion. Patients with compromised immune systems experience frequent reactivation of HSV-1 from latency, leading to virus entry in the sensory neurons, followed by anterograde transport and lytic replication at the innervated mucosal epithelial surface. Although recurrent infection of the corneal mucosal surface is rare, it can result in a chronic immuno-inflammatory condition called herpetic stromal keratitis (HSK). HSK leads to gradual vision loss and can cause permanent blindness in severe untreated cases. Currently, there is no cure or successful vaccine to prevent latent or recurrent HSV-1 infections, posing a significant clinical challenge to managing HSK and preventing vision loss. The conventional clinical management of HSK primarily relies on anti-virals to suppress HSV-1 replication, anti-inflammatory drugs (such as corticosteroids) to provide symptomatic relief from pain and inflammation, and surgical interventions in more severe cases to replace damaged cornea. However, each clinical treatment strategy has limitations, such as local and systemic drug toxicities and the emergence of anti-viral-resistant HSV-1 strains. In this review, we summarize the factors and immune cells involved in HSK pathogenesis and highlight alternate therapeutic strategies for successful clinical management of HSK. We also discuss the therapeutic potential of immunoregulatory cytokines and immunometabolism modulators as promising HSK therapies against emerging anti-viral-resistant HSV-1 strains.

Etiological analysis of ocular herpes virus infection.

To do the etiological analysis of ocular herps virus infection, revealing the pathogen species and the distribution of different virus types within the eye. Samples were collected from 2017 to 2021 at the Department of Ophthalmology, Peking University Third Hospital and tested using real-time PCR for common ocular viruses: herpes simplex virus 1 (HSV-1), cytomegalovirus (CMV), varicella-zoster virus (VZV) and Epstein-Barr virus (EBV). The pathogenesis of the different viruses was classified and analyzed according to the site of infection. Viral PCR detections were performed on 3627 samples collected over the 5-years and 649 (17.89%) samples contained one or more of the viruses tested. The overall detection rate of CMV was highest at 9.93%. Of all sample types, aqueous humor was the most common (1752 cases), of which 340 were positive (19.41% positive rate). Corneal samples were the next most common, with 1481 cases and 250 positive results (16.88% positive rate). CMV positivity was higher in aqueous humor and corneal samples than other viruses; vitreous body had the highest positive rate at 36.36% (20/55), among which 18 cases were VZV positive. Distribution of virus types differed among infection sites, with CMV the most common virus type detected in the cornea and aqueous humor, while VZV was the most common virus detected in the vitreous body.

High silent prevalence of human herpesvirus 1 (HSV-1) infection affecting the indigenous reservation of the municipality of Dourados, Central-West Brazil

BackgroundThe indigenous population located in the central region of Brazil, is the second largest in terms of population size in the country. The Indigenous Reserve of Dourados has risk factors that increase the vulnerability of the indigenous population to infectious diseases, especially Human alphaherpesvirus (HSV-1), a neglected disease with high prevalence in priority populations in developing countries. The virus can also cause many more severe diseases, including widespread neonatal infections, herpetic keratitis, and herpes encephalitis, which can be fatal if left untreated. We estimated the prevalence of anti-HSV-1 antibodies and correlated it with the demographic and behavioral characteristics of the Indigenous population of the Jaguapirú and Bororó villages (Dourados, Mato Grosso do Sul (MS), Brazil).MethodsOur approach was cross-sectional. From March 2017 to November 2018. Using anti-HSV-1 (Gg1) IgM and anti-HSV-1 (gG1) IgG Euroimmun and the detection and quantification of HSV-1 viral load in plasma samples, through real-time PCR. The maps were constructed using QGIS and the statistical analyses using R Studio software.ResultsA total of 1138 individuals (> 18 years old) were enrolled. The prevalence of anti-HSV-1 IgM and IgG were 20% and 97.5%, respectively. The prevalence of anti-HSV-1 antibodies for IgG was higher in both sexes. Anti-HSV-1 IgM antibodies were present in 17.1%, 21.2%, 12.5%, and 22% of the participants with urinary problems, genital wounds, genital warts, and urethral discharge, respectively. Real-time PCR was used for confirmatory testing; HSV-1 DNA was detected in 25.6% (54/211) of anti-HSV1 IgM-positive samples. Viral loads ranged from 5.99E + 02 to 3.36E + 13.ConclusionsThe seroprevalence of HSV-1 IgM and detection of HSV-1 DNA in the Indigenous population confirmed high silent prevalence. Furthermore, the seroprevalence of HSV-1 in the Indigenous population was higher than that reported in the general adult Brazilian population. Various socioeconomic factors, drug use, and health and sexual behaviors could contribute to the facilitation of HSV-1 transmission in the Indigenous population. Our results may help develop culturally appropriate intervention programs that eliminate health access barriers and improve the implementation of public health policies aimed at promoting information regarding the prevention, treatment, and control of HSV-1 infection in Brazilian Indigenous populations.

Keratorefractive lenticule extraction in eyes with post-herpetic scars

Correcting refractive errors by remodeling the corneal curvature with an excimer laser (which emits ultraviolet radiation) may reactivate a latent Herpes Simplex Virus (HSV), resulting in keratitis. New techniques using infrared sources, such as femtosecond-assisted Keratorefractive Lenticule Extraction (KLEx), may thus provide a safer approach to eyes with previous HSV keratitis; however, no cases of KLEx in such cases have been reported. As a result, we present three cases in which KLEx successfully corrected myopia. Three myopic eyes from three patients with a known history of healed HSV keratitis that occurred more than 12 months before surgery underwent KLEx. All patients received oral antiviral prophylaxis before and after surgery. In case 1, the post-HSV scar was semiperipheral, involving only a portion of the treated area; surgery went smoothly, with the intrastromal lenticule well delineated and dissected even through the scar. In cases 2 and 3, the healed scar was peripheral and did not interfere with surgery. After 6 months, all three cases had good visual acuity without complications. Finally, KLEx combined with antiviral prophylaxis can effectively correct myopia in eyes with healed HSV. The femtosecond laser can penetrate non-dense, peripheral corneal scars.

Pistacia vera L. as natural source against antimicrobial and antiviral resistance.

Increased global research is focused on the development of novel therapeutics to combat antimicrobial and antiviral resistance. Pistachio nuts represent a good source of protein, fiber, monounsaturated fatty acids, minerals, vitamins, and phytochemicals (carotenoids, phenolic acids, flavonoids and anthocyanins). The phytochemicals found in pistachios are structurally diverse compounds with antimicrobial and antiviral potential, demonstrated as individual compounds, extracts and complexed into nanoparticles. Synergistic effects have also been reported in combination with existing drugs. Here we report an overview of the antimicrobial and antiviral potential of pistachio nuts: studies show that Gram-positive bacterial strains, such as Staphylococcus aureus, are the most susceptible amongst bacteria, whereas antiviral effect has been reported against herpes simplex virus 1 (HSV-1). Amongst the known pistachio compounds, zeaxanthin has been shown to affect both HSV-1 attachment penetration of human cells and viral DNA synthesis. These data suggest that pistachio extracts and derivatives could be used for the topical treatment of S. aureus skin infections and ocular herpes infections.

Rapid NETosis Is an Effector Mechanism to Combat Ocular Herpes Infection.

Neutrophils are known mediators of innate immunity, yet their effector function in herpesvirus infections remains poorly understood. Here, we elucidate the mechanistic action and pivotal role of neutrophil extracellular traps (NETs) during herpes simplex virus type 1 (HSV-1) ocular infection. Neutrophils were collected from mice for HSV-1 infection, fluorescence imaging, and immunoblotting assay. Tear samples from healthy subjects and patients with HSV-1 and mice were collected at L. V. Prasad Eye Institute, India, and at the University of Illinois, USA, respectively. For the in vivo study, C57BL/6 mice as well as diversity outbred mice were infected with HSV-1 (McKrae strain) followed by tear fluid collection at various time points (0-10 days). Samples were used for Flow cytometry, ELISA, and immunofluorescence assay. Human transcriptomic profile of keratitis dataset was used evaluate NETosis signaling pathways. We also performed neutrophil depletion studies. Our data revealed a discernible temporal NET formation (NETosis) predominantly in the infected eye, across normal and diversity outbred murine models and human cases of HSV-1 infection. HSV-1 instigates swift NETosis governed by caspase-1 activation and myeloperoxidase secretion. Distinct accumulations of neutrophils, remaining unengaged in NET release in the contralateral eye post-infection, hinting at a proactive defensive posture in the uninfected eye. Moreover, neutrophil depletion accentuated ocular pathology, augmented viral load, and escalated disease scores, substantiating the protective effects of NETs in curtailing viral replication. Our report uncovers a previously unexplored mechanism of NETosis through pro-inflammatory cell death in response to ocular HSV-1 infection, and HPSE up-regulation, identifying new avenues for future studies.

Overexpression of NLRP12 enhances antiviral immunity and alleviates herpes simplex keratitis via pyroptosis/IL-18/IFN-γ signaling

Herpes simplex keratitis (HSK) is a blinding disease caused by herpes simplex virus type 1 (HSV-1) infection, and rapid eradication of the virus from the affected cornea is imperative. Nod-like receptors (NLRs) are intracellular innate immune sensors closely associated with cell death, inflammation and immune responses. In this study, we investigated the role of NLRP12 in the antiviral immunology in HSK and the underlying mechanisms. We found that NLRP12 expression was significantly decreased in HSV-1-infected human corneal epithelial cells (HCE-Ts) and HSK mouse corneas. Overexpression of NLRP12 significantly reduced viral replication in infected HCE-Ts and functioned through inflammasome-mediated pyroptosis and downstream IL-18-IFN-γ axis. In HSK mouse models, overexpression of NLRP12 reduced viral replication in the cornea and alleviated HSK symptoms. This resulted from enhanced antiviral immune responses including the activation of specific immune cells in both the cornea and the draining lymph nodes. Specifically, the NLRP12-IL-18-IFN-γ axis regulated the interaction between infected corneal epithelial cells and macrophages. In conclusion, our study identified a role of NLRP12 in mediating pyroptosis and regulating antiviral immune responses. This novel finding opens the possibilities of NLRP12 as a viable target in the therapeutic strategies for HSV-1 infection.

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-1F 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.

L-lysine as a Possible Supplement for Treatment of Herpetic Epithelial Keratitis: A Case Report and Literature Review

L-lysine as a Possible Supplement for Treatment of Herpetic Epithelial Keratitis: A Case Report and Literature Review