Herpes simplex virus keratitis: an update of the pathogenesis and current treatment with oral and topical antiviral agents

Ophthalmic herpes simplex viral keratitis is responsible for a range of ocular manifestations from superficial epithelial disease to stromal keratitis and endotheliitis. The Herpetic Eye Disease Study has guided the management of herpetic eye disease for almost twenty years, but newer medications such as valacyclovir are now available and are considered to have better bioavailability than acyclovir. In this review, we examine the existing evidence on the pathogenesis of different ophthalmic herpes simplex viral keratitis disease modalities and the role of oral and topically administered antiviral drugs in the treatment of herpes simplex viral keratitis.

Clinical correlates of common corneal neovascular diseases: a literature review

A large subset of corneal pathologies involves the formation of new blood and lymph vessels (neovascularization), leading to compromised visual acuity. This article aims to review the clinical causes and presentations of corneal neovascularization (CNV) by examining the mechanisms behind common CNV-related corneal pathologies, with a particular focus on herpes simplex stromal keratitis, contact lenses-induced keratitis and CNV secondary to keratoplasty. Moreover, we reviewed CNV in the context of different types of corneal transplantation and keratoprosthesis, and summarized the most relevant treatments available so far.

Nonthermal Dielectric Barrier Discharge (DBD) Plasma Suppresses Herpes Simplex Virus Type 1 (HSV-1) Replication in Corneal Epithelium

PURPOSE

Herpes keratitis (HK) is the leading cause of cornea-derived and infection-associated blindness in the developed world. Despite the availability of effective antivirals, some patients develop refractory disease, drug-resistant infection, and topical toxicity. A nonpharmaceutical treatment modality may offer a unique advantage in the management of such cases. This study investigated the antiviral effect of nonthermal dielectric barrier discharge (DBD) plasma, a partially ionized gas that can be applied to organic substances to produce various biological effects.

METHODS

Human corneal epithelial cells and explanted corneas were infected with herpes simplex virus type 1 (HSV-1) and exposed to culture medium treated with nonthermal DBD plasma. The extent of infection was measured by plaque assay, quantitative PCR, and Western blot. Corneal toxicity assessment was performed with fluorescein staining, histologic examination, and 8-OHdG detection.

RESULTS

Application of DBD plasma-treated medium to human corneal epithelial cells and explanted corneas produced a dose-dependent reduction of the cytopathic effect, viral genome replication, and the overall production of infectious viral progeny. Toxicity studies showed lack of detrimental effects in explanted human corneas.

CONCLUSIONS

Nonthermal DBD plasma substantially suppresses corneal HSV-1 infection in vitro and ex vivo without causing pronounced toxicity.

TRANSLATIONAL RELEVANCE

Nonthermal plasma is a versatile tool that holds great biomedical potential for ophthalmology, where it is being investigated for wound healing and sterilization and is already in use for ocular microsurgery. The anti-HSV-1 activity of DBD plasma demonstrated here could be directly translated to the clinic for use against drug-resistant herpes keratitis.

An investigative peptide-acyclovir combination to control herpes simplex virus type 1 ocular infection

PURPOSE

To investigate the efficacy of a combination treatment composed of the cationic, membrane-penetrating peptide G2, and acyclovir (ACV) in both in vitro and ex vivo models of herpes simplex virus 1 (HSV-1) ocular infection.

METHODS

The antiviral activity of a combined G2 peptide and ACV therapy (G2-ACV) was assessed in various treatment models. Viral entry, spread, and plaque assays were performed in vitro to assess the prophylactic efficacy of G2, G2-ACV, and ACV treatments. In the ex vivo model of HSV-1 infection, the level of viral inhibition was also compared among the three treatment groups via Western blot analysis and immunohistochemistry. The potential change in expression of the target receptor for G2 was also assessed using immunohistochemistry and RT-PCR.

RESULTS

Statistically significant effects against HSV-1 infection were seen in all treatment groups in the viral entry, spread, and plaque assays. The greatest effects against HSV-1 infection in vitro were seen in the G2-ACV group. In the ex vivo model, statistically significant anti-HSV-1 effects were also noted in all control groups. At 24 hours, the greatest inhibitory effect against HSV-1 infection was seen in the ACV group. At 48 hours, however, the G2-ACV-treated group demonstrated the greatest antiviral activity. Syndecan-1, a target of G2, was found to be upregulated at 12-hours postinfection.

CONCLUSIONS

This study shows that G2-ACV may be an effective antiviral against HSV-1 (KOS) strain when applied as single prophylactic applications with or without continuous doses postinfection.

Inhibition of ataxia telangiectasia mutated (ATM) kinase suppresses herpes simplex virus type 1 (HSV-1) keratitis

PURPOSE

Herpes keratitis (HK) remains the leading cause of cornea-derived blindness in the developed world, despite the availability of effective antiviral drugs. Treatment toxicity and the emergence of drug resistance highlight the need for additional therapeutic approaches. This study examined ataxia telangiectasia mutated (ATM), an apical kinase in the host DNA damage response, as a potential new target for the treatment of HK.

METHODS

Small molecule inhibitor of ATM (KU-55933) was used to treat herpes simplex virus type 1 (HSV-1) infection in three experimental models: (1) in vitro--cultured human corneal epithelial cells, hTCEpi, (2) ex vivo--organotypically explanted human and rabbit corneas, and (3) in vivo--corneal infection in young C57BL/6J mice. Infection productivity was assayed by plaque assay, real-time PCR, Western blot, and disease scoring.

RESULTS

Robust ATM activation was detected in HSV-1-infected human corneal epithelial cells. Inhibition of ATM greatly suppressed viral replication in cultured cells and in explanted human and rabbit corneas, and reduced the severity of stromal keratitis in mice. The antiviral effect of KU-55933 in combination with acyclovir was additive, and KU-55933 suppressed replication of a drug-resistant HSV-1 strain. KU-55933 caused minimal toxicity, as monitored by clonogenic survival assay and fluorescein staining.

CONCLUSIONS

This study identifies ATM as a potential target for the treatment of HK. ATM inhibition by KU-55933 reduces epithelial infection and stromal disease severity without producing appreciable toxicity. These findings warrant further investigations into the DNA damage response as an area for therapeutic intervention in herpetic ocular diseases.

Herpes Simplex Keratitis in Patients with SARS-CoV-2 Infection: A Series of Five Cases

Herpes simplex virus type 1 (HSV-1) is a leading cause of infectious blindness worldwide. Most of the initial infection cases manifest as acute epithelial keratitis. Reactivation of herpesviruses is common in critically ill patients, including patients with severe Coronavirus disease (COVID-19). However, the data on COVID-19-related ocular infections is sparse, despite recent observations that more than 30% of COVID-19-infected patients had ocular manifestations. We report five cases of HSV-1 keratitis in COVID-19 patients. In total, five COVID-19 patients underwent ophthalmic examination, showing similar symptoms, including photophobia, tearing, decreased vision, eye redness, and pain. After initial assessment, tests of visual acuity and corneal sensitivity, a fluorescein staining test, and complete anterior and posterior segment examinations were performed. A diagnosis of HSV-1 keratitis was confirmed in all cases. Therapy was initiated using a local and systemic antiviral approach together with local antibiotic and mydriatic therapy. The complete reduction of keratitis symptoms and a clear cornea was achieved in all patients within 2 weeks. SARS-CoV-2 infection may be a risk factor for developing HSV-1 keratitis, or it may act as a potential activator of this ocular disease.

Bilateral herpes simplex keratitis reactivation after lacrimal gland botulinum toxin injection

Botulinum toxin A (BTA) injections into lacrimal gland are being used for refractory epiphora due to intractable lacrimal disorders with success rates reported from 18% to 86%. Most common side effects are transient ptosis and diplopia. We report a case of a 59-year-old female injected with 2.5 units of BTA injection in each lacrimal gland for functional epiphora. The patient had a history of herpes simplex viral keratitis that was quiescent for more than 2 years. After 3 weeks, she developed reactivation of viral keratitis bilaterally, which was successfully managed with antivirals and topical steroids. Reactivation of quiescent herpes simplex keratitis is a possibility after lacrimal gland BTA and caution should be exercised in such cases.

Host immune cellular reactions in corneal neovascularization

Corneal neovascularization (CNV) is a global important cause of visual impairment. The immune mechanisms leading to corneal heme- and lymphangiogenesis have been extensively studied over the past years as more attempts were made to develop better prophylactic and therapeutic measures. This article aims to discuss immune cells of particular relevance to CNV, with a focus on macrophages, Th17 cells, dendritic cells and the underlying immunology of common pathologies involving neovascularization of the cornea. Hopefully, a thorough understanding of these topics would propel the efforts to halt the detrimental effects of CNV.

Clinical Pattern And Visual Impairment Associated With Herpes Simplex Keratitis

Purpose

Herpes simplex keratitis (HSK) has varied presenting patterns, and is one of the leading causes of corneal scarring and subsequent visual disability. This study was carried out to determine the incidence and patterns of HSK presenting at a tertiary eye center in eastern Nepal and to assess the associated visual impairment.

Methods

This was a descriptive, cross-sectional study at a tertiary eye-care center that included 302 cases of clinically diagnosed HSK over a period of 1 year. Detailed ocular examination was done in all patients. Clinical manifestations and visual acuity at presentation and on subsequent visits in cases that followed up were recorded. Findings were noted in structured format and later assessed.

Results

Of 302 cases of HSK, 53 presented with epithelial keratitis, 156 with stromal keratitis without ulceration, 22 with stromal keratitis with ulceration, 66 with endothelitis, and five with neurotrophic ulcers. Presenting visual acuity in 108 patients (35.7%) was <3/60. Of 175 patients who followed up, 36 patients continued to have vision <3/60.

Conclusion

This study shows that HSK has diverse presentation and can cause significant vision impairment. Stromal keratitis without ulceration was the most common presentation in our study. In developing nations, due to higher incidence of fungal and bacterial keratitis, HSK is not studied much. Few epidemiological data are available on the subject, and since the disease is notorious for recurrence, long-term study is paramount to estimate the burden of visual morbidity caused by the disease.

Reactivation of Herpes Simplex Keratitis on a Corneal Graft Following SARS-CoV-2 mRNA Vaccination

Background

Ocular herpes simplex is usually caused by herpes simplex virus type 1 (HSV-1) and less commonly by the type 2 virus (HSV-2). Ocular manifestations of HSV include blepharitis, conjunctivitis, lacrimal system obstruction, corneal involvement, and uveitis. Corneal involvement is one of the causes of loss of vision and can be epithelial herpetic keratitis or stromal herpetic keratitis.

Objective

A significant population has a colonization of herpes viruses. Under certain circumstances, these viruses can reactivate with a significant ocular morbidity. Globally, COVID-19 vaccines are recommended; however, the vaccine safety data are limited.

Case report

Herein, we reported a case of herpetic keratitis reactivation that occurred 2 days after receiving SARS-CoV-2 mRNA vaccine. The patient is a 50-year-old man who underwent penetrating keratoplasty (PKP) in 2020 for corneal opacity caused by a previous herpes simplex keratitis in 2013. Herpetic keratitis was treated successfully with topical antiviral acyclovir along with topical moxifloxacin and artificial tears. After treatment, prophylactic oral acyclovir was started.

Conclusion

Both ophthalmologist and patients should be aware of this phenomenon. Long-term prophylactic antiviral treatment may be recommended for those patients.

Patient priorities in herpes simplex keratitis

Objective

Herpes simplex keratitis (HSK) is a sight-threatening disease and a leading cause of infectious corneal blindness. Involving patients in setting the research agenda maximises patient benefit and minimises research waste. With no published patient involvement exercises, patients' priorities in HSK are unclear. The objective of this study is to explore patients' priorities for research in HSK.

Methods

A literature review of publications in the year preceding recruitment of patients identified nine domains of research interest. A questionnaire was sent to participants asking them to rank these in order of priority. The ranking results were given a weighted-average score, and a thematic analysis was undertaken for the narrative data.

Results

Thirty-seven patients participated in the survey. Top priorities for patients were risk factors for recurrence of infection, diagnostic tests and treatment failure. The narrative data revealed three key clinical needs: difficulties in long-term symptom control, the need for rapid access care in acute infection and the desire for more accessible information.

Conclusion

This study highlighted three major issues in our current approach to HSK. First, there may be a misalignment between research efforts and patient priorities. Second, high-quality patient information is not widely available. This may hamper patients' abilities to make informed decisions and contribute towards research. Third, clinical service priorities are of equal importance to patients as research. Researchers and clinicians are encouraged to address both needs in parallel.

Systemic IL-1β production as a consequence of corneal HSV-1 infection-contribution to the development of herpes simplex keratitis

This study sought to identify potential therapeutic targets in herpes simplex keratitis (HSK) patients with active and inactive infection by investigating peripheral cytokine production. Peripheral blood mononuclear cells (PBMCs) and serum were prepared from healthy controls and HSK patients during active infection or following treatment (inactive infection). Serum antibody titres were determined by ELISA. Protein expression levels were analysed by Western blot. Cytokine levels were determined by multiplex ELISA. Active corneal herpes simplex virus type 1 (HSV-1) infection resulted in significantly elevated peripheral levels of IL-1β in HSK patients compared to healthy controls, and remained significantly increased following treatment. Elevated production of IL-1β in inactive patients was associated with significantly increased levels of IRF3 and STAT1, key proteins involved in promoting anti-viral immune responses. Our data suggest that inflammation persists beyond the period that it is clinically evident and that enhanced peripheral production of IL-1β may have implications for HSV-1 viral clearance in active and inactive HSK patients.

[Postoperative therapy after penetrating keratoplasty in herpes simplex keratitis]

INTRODUCTION

Keratitis due to herpes simplex infection is a common cause of corneal damage resulting in impaired vision.

AIM

The aim of this study was to assess the outcome of penetrating keratoplasties in patients treated with systemic antiviral and immunosuppressive drugs.

METHOD

The authors retrospectively analysed data of 12 patients who underwent penetrating keratoplasty. The average age at onset of the first keratitis preceding surgery was 18 years (between 5 and 40 years). The indication for surgery in 9 cases was to improve vision and in 3 patient to prevent corneal perforation. Nine patients were given both acyclovir and mycophenolate mofetil, as anti-viral agent and immunosuppressive treatment, respectively. Two patients were treated with anti-viral agent only while one patient received no systemic therapy. The average follow-up time was 53.1 months (between 16 and 84 months).

RESULTS

Of the 9 patients who underwent surgery for improving vision, 8 patients had transparent grafts during follow up without vascularization. All eight patients had been treated with acyclovir and mycophenolate mofetil. In one patient who had no systemic treatment recurrence and graft rejection was observed. Only one of the surgeries performed in acute stage of inflammation resulted in a properly healed transparent graft without recurrence and rejection. In this patient acyclivir and mycophenolate mofetil therapy had been given previously. In two cases the preventive - full or partial - systemic treatment had no effect. The visual acuity improved in all cases. In three patients visual acuity was influenced by some other factors as well.

CONCLUSIONS

The systemic acyclovir and mycophenolat mofetil therapy is fairly successful in perforating keratoplasty due to herpes simplex infection. Acyclovir decreases the risk of recurrence, while mycophenolate mofetil may prevent graft rejection. The timing of surgery is decisive; it leads to better results when performed in a scarred, noninflammatory state.

Effect of undernourishment on Herpes Simplex Virus Type 1 ocular infection in the Wistar rat model

We have studied the susceptibility to Herpes Simplex Virus Type 1 (HSV-1) infection in malnourished rats. Groups of 10 rats were undernourished during suckling by offspring duplication. The animals were put on commercial diet and at 1, 2, 3, 5 and 8 weeks after weaning, infected in the eye by scarification with HSV-1, strain F. Significant differences in morbidity and mortality were observed between malnourished and control groups infected three weeks after weaning. Viral titres were higher in ocular washings and brains obtained from the malnourished group. This group showed a diminution in antigen dependent lymphocyte proliferation compared to control, and significantly lower delayed type hypersensitivity reaction against inactivated virus (malnourished = 0.16 +/- 0.02 mm, control = 0.26 +/- 0.03 mm, p < 0.05). Neutralizing antibodies in serum were lower in the malnourished group and lower levels of interferon were obtained in the malnourished group 24 h post-infection. We conclude that malnutrition during suckling induces a delay in the capability to overcome HSV infection.

Bilateral meibomian gland morphological alterations in unilateral herpes simplex keratitis based on artificial intelligence analysis

AIM

To explore whether unilateral herpes simplex keratitis (HSK) can cause morphological changes of bilateral meibomian glands (MGs) based on artificial intelligence (AI) analytical system.

METHODS

In the retrospective study, 29 patients with unilateral HSK and 29 participants matched in terms of age and sex were included as control group. Meibographic images of the upper eyelid using Keratograph 5M and assessed ocular surface parameters including tear meniscus height and tear break-up time. MG density and vagueness values were automatically analyzed and calculated using an AI analytical system. We compared the differences between the affected and the contralateral unaffected eyes in HSK patients, and the normal control eyes. We employed either the paired t-test or the Wilcoxon signed-rank test to compare significant difference between the affected and unaffected eyes in HSK patients or between the HSK group and control group.

RESULTS

The MG density was 0.19±0.09 in the HSK-affected eye and 0.18±0.07 in contralateral unaffected eye, which had no significant difference (P=0.616). The MG density between the affected eye with HSK and the normal control group was statistically significant (P=0.028). There was a significant difference in MG density between the contralateral unaffected eye and the normal control group (P=0.012). However, no significant difference in vagueness value was observed between the eye with HSK and the control group or between HSK eye and contralateral eye.

CONCLUSION

The MG density between the HSK-affected eye and the contralateral unaffected eye don't significantly differ, whereas there is a significant decrease in the HSK group compared to that of the normal participants. Unilateral HSV keratitis may suffer from bilateral changes of MG morphology indicating bilateral dry eye. Therefore, the fellow eye of patients with unilateral HSK should be considered a potential case of MG dysfunction, necessitating early treatment for bilateral dry eye in the clinic.

Clinical and Demographic Characteristics of Herpetic Keratitis Patients-Tertiary Centre Experience

Background and Objectives: Herpes simplex keratitis (HSK) is the leading infectious cause of corneal damage and associated loss of visual acuity. Because of its frequent recurrence, it represents a major health problem; thus, timely and accurate diagnosis is the key to successful treatment. To enable this, we aimed to determine HSK patients' demographic and clinical features. Materials and Methods: This prospective study included 55 patients diagnosed with HSK between March 2019 and August 2022 at the Department of Ophthalmology, Clinical Hospital Rijeka. Results: We found that HSK is most prevalent in the elderly, with 72.73% of patients older than 60. The most common HSK types were dendritic (HSK-D; 43.64%) and stromal with epithelial ulceration (HSK-SEU 23.64%). HSK recurrences occurred in 65.45% of patients, with most having two to five recurrences (55.56%). Visual acuity at presentation (65.5%) and after treatment (50.9%) was mostly in the 20/50 range. The longest period until the disease symptoms were resolved was in the group with stromal HSK without epithelial ulceration (HSK-SnEU), for which symptoms lasted more than 11 weeks in 87.5% of patients. The overall incidence of HSK-related complications was high (85.45%), with 76.4% of patients having corneal scarring. The average time from symptom to treatment was 15.78 days. Interestingly, we observed a strong seasonality in the incidence of HSK, which was most prevalent in the colder months, with 63.6% of cases occurring between October and March. Conclusions: To the best of our knowledge, this is the first prospective study in Croatia, and one of the few in Europe, to describe the demographic and clinical features of HSK patients. We found that HSK is most common in the elderly population, with its dendritic form as a clinical presentation. We have shown that HSK is prone to recurrence and secondary complications, with a worryingly long time between symptom and treatment, indicating the need for diagnostic testing in routine practice.

Corneal Graft Success Rates in HSV Keratitis: A Systematic Review

Herpes Simplex Virus (HSV) has worldwide prevalence. The primary objective of this systematic review was to compare penetrating keratoplasty (PK) and deep anterior lamellar keratoplasty (DALK) regarding the efficacy and complications of the treatment of corneal scarring caused by herpes simplex keratitis. Out of the 469 articles identified during the combined search of the literature based on the PubMed and Cochrane libraries, 10 retrospective and 2 prospective studies published from January 2010 to December 2019 were included. The study outcomes indicated that both surgical approaches resulted in a comparable improvement of visual acuity (VA). However, DALK demonstrated fewer complications in the majority of studies. Higher graft survival rates were associated with higher acyclovir (ACV) doses (above 800 mg/day), topical steroid and antibiotic drops. In conclusion, in terms of postoperative VA, both PK and DALK demonstrate comparable efficacy. However, DALK, which is applied in less severe HSK cases, is associated with fewer complications and better graft survival rates. High dosages of ACV, topical steroids and antibiotics contribute significantly to improved postoperative outcomes.

[Scientific legacy of Professor A.A. Kasparov. Inductor of endogenous interferon Poludan in the treatment of ocular herpes and other corneal diseases]

This article presents a retrospective analysis of the research findings by professor A.A. Kasparov, who developed and implemented a novel approach to treating ocular herpes. The treatment system is fundamentally different from the conventional chemotherapeutic approach and revolves around non-specific immunotherapy using an endogenous interferon inducer - a biosynthetic complex of polyriboadenylic and polyribouridylic acids, known as Poludan. This approach also incorporates personalized cell therapy based on Poludan, along with herpes vaccine aimed at preventing recurrence. The regenerative and antiviral properties of this approach have proven successful in treating other corneal conditions such as adenovirus infections, early postoperative bullous keratopathy, as well as in stimulation of epithelialization after refractive surgeries (photorefractive keratectomy, phototherapeutic keratectomy).

Combined versus sequential penetrating keratoplasty and cataract surgery for herpes simplex keratitis: a retrospective study

Purpose

To compare the surgical outcomes of combined penetrating keratoplasty (PK) and cataract surgery with those of sequential surgery (cataract surgery after PK) for herpes simplex keratitis (HSK).

Methods

The medical records of consecutive patients diagnosed with HSK who underwent combined or sequential PK and cataract surgery in active and stable stages between June 2015 and June 2022 were reviewed retrospectively. Complications, graft survival, endothelial cell density (ECD), and final BCVA were compared and analyzed between both surgical methods in each stage.

Results

A total of 171 eyes of 171 patients were enrolled, including active stage (69 combined, 46 sequential) and stable stage (34 combined, 22 sequential). The average follow up was 24.2 ± 15.8 months (range, 3 months - 48 months). The final BCVA had obvious improvement and the postoperative ECD was not different in combined and sequential groups of each stage. In sequential group of active stage, 66.7% of persistent epithelial defects and 50% of HSK recurrence occurred within 3 months after cataract surgery; nevertheless, compared to that in sequential group, capsular rupture (p = 0.021), persistent epithelial defects (p = 0.027), and HSK recurrence (p = 0.035) occurred more frequently in combined group, leading to a lower graft survival rate (p = 0.045); at the last visit, 46.4 and 67.4% of grafts remained clear in combined and sequential groups, respectively. By contrary, 82.4 and 50.0% of grafts remained clear in stable stages of combined and sequential groups at the last visit, respectively, and a higher graft survival rate was observed in combined group (p = 0.030).

Conclusion

Although the postoperative ECD is not different between two surgical groups in each stage, sequential surgery in active stage of HSK seems to have advantages in less complications and higher graft survival rate, whereas combined surgery in stable stage has a better outcome than that in sequential surgery.

Prevalence of HSV Genomic Signatures Among Acanthamoeba Hosts and Contaminated Lens Cases: A Molecular and Clinical Study

Purpose

To document the presence of herpes simplex virus (HSV) genomic signatures among Acanthamoeba hosts recovered from patients with Acanthamoeba keratitis (AK) and in contaminated lens cases.

Methods

We used a combination of PCR sequencing and shotgun metagenomics to detect and confirm the presence of HSV genomic signatures in Acanthamoeba hosts and lens cases. Clinical outcomes were correlated with the prevalence of host HSV signatures.

Results

HSV genomic signatures were detected in 26% (n = 6) of Acanthamoeba hosts recovered from patients with culture confirmed AK. HSV-1 and HSV-2 or both were identified in 33%, 50%, and 17% of isolates, respectively. Fifty-two percent of patients (12/23) were misdiagnosed initially as presenting with HSV keratitis. Patients with HSV-positive Acanthamoeba isolates had a mean best-corrected visual acuity of 1.43 LogMAR at diagnosis and 0.53 LogMAR at follow-up, compared with 1.85 and 0.92 LogMAR, respectively, in HSV-negative cases. Contact lens use was identified as a risk factor in 83% of 18 patients. We detected 46,597 viral signatures in 5 of 14 contaminated lens cases (35.7%). Distribution included 33% bacteriophages, 8.2% giant viruses, 4.1% nonhuman Herpesviridae, and 0.39% human Herpesviridae. Among the 184 human Herpesviridae genomic signatures, HSV types 1 or 2 or both were documented in 5.7%, VZV in 39.7%, HHV7 in 38.6%, HHV6 in 15.0%, and Epstein-Barr virus in 0.5%.

Conclusions

This study is the first to identify HSV-positive genomic signatures in clinical AK isolates and/or contact lens cases. Taken together, the high prevalence of HSV genomic signatures in both amebic hosts and lens cases, might signal an unrecognized Acanthamoeba-HSV association and the need for reassessing current management.

Rapid NETosis Is an Effector Mechanism to Combat Ocular Herpes Infection

Purpose

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.

Methods

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.

Results

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.

Conclusions

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.

[Therapeutic effect of acupoint injection as adjuvant treatment on dry eyes of convalescent herpes simplex keratitis]

OBJECTIVE

To evaluate the clinical effect of acupoint injection of houttuynia cordata as the accessory treatment on dry eyes of convalescent herpes simplex keratitis (HSK).

METHODS

A total of 60 patients with dry eyes of convalescent HSK were randomized into an observation group and a control group, 30 cases in each one. In the control group, the artificial tears and anti-inflammatory drugs were combined in treatment. In the observation group, on the base of the treatment as the control group, the acupoint injection of houttuynia cordata at Neiqiuhou (Extra) was combined, 3 mL each time, once a day. After consecutive 3 injections, the injection was adjusted to be once every two days, consecutively for 3 times. The treatment for 6 times was as one course and one course of treatment was required. Separately, before treatment and in 7, 15 and 30 days after treatment, the changes of the scores of visual analogue scale (VAS), theresults of SchirmerⅠtest (SⅠT), the tear break-up time (BUT) and the score of corneal fluorescein staining (CFS) were observed and analyzed in the patients of the two groups.

RESULTS

In 7, 15 and 30 days after treatment, VAS scores and CFS scores were all reduced as compared with those before treatment in the patients of the two groups (P<0.05), and the scores of VAS and CFS in the observation group were lower than those in the control group (P<0.05). In 7, 15 and 30 days after treatment, the values of SⅠT and BUT were all increased as compared with those before treatment in the patients of the two groups (P<0.05), and the values in the observation group were higher than the control group in 15 and 30 days after treatment (P<0.05).

CONCLUSION

Acupoint injection of houttuynia cordata promotes corneal epithelial recovery, reduces the discomfort symptoms as well as increases tear secretion and the stability of tear film in dry eyes of convalescent herpes simplex keratitis.

Overexpression of NLRP12 enhances macrophage immune response and alleviates herpes simplex keratitis

Introduction

Herpes simplex keratitis (HSK) is a blinding disease caused by corneal infection of Herpes simplex virus type 1 (HSV-1). Effective clearance of HSV-1 from the infected cornea is crucial for HSK management. Macrophages play an important part in the innate immune defense against viral infections. This study investigates the immunomodulatory role of NLRP12 in macrophage immune response during HSV-1 infection.

Methods

NLRP12 expression post-infection was assessed in various macrophage cell lines. Overexpression of NLRP12 was achieved by lentiviral transfection, and its effect on HSV-1 replication and immune responses were examined. Mechanistic insights into the role of NLRP12 were explored using immunofluorescence and Western Blot. For in vivo studies, ocular adoptive transfer of NLRP12-overexpressing bone marrow derived macrophages (BMDMs) was performed. HSV-1 viral loads, HSK symptoms, and macrophage-mediated immune responses were investigated.

Results

A significant decrease in NLRP12 expression post-infection was observed in various macrophage cell lines. Overexpression of NLRP12 in macrophages reduced HSV-1 replication. Mechanistically, overexpression of NLRP12 triggered early and robust pyroptosis in response to HSV-1 infection, inducing interleukin (IL)-18 production and activating downstream antiviral responses through the JAK-STAT signaling pathway. In vivo, ocular adoptive transfer of NLRP12-overexpressing BMDMs to mouse corneas alleviated HSK damage and reduced HSV-1 viral loads. NLRP12-overexpressing BMDMs improved antiviral responses in the cornea and promoted the maturation of corneal-infiltrating macrophages and dendritic cells. Additionally, NLRP12-overexpressing BMDMs amplified the adaptive immune response in the submandibular draining lymph nodes.

Discussion

These findings highlight the role of NLRP12 in macrophage-mediated immune response against HSV-1 infection and suggest its potential for possible immunotherapy for HSK.

Analysis of clinical characteristics and factors influencing herpes simplex virus keratitis

Objective

To investigate the clinical characteristics and factors associated with herpes simplex virus keratitis.

Methods

Patients with herpes simplex virus keratitis who came to our hospital from January 2018 to June 2022 were selected and divided into a good prognosis group and a poor prognosis group according to their prognosis. The clinical data of the two groups were compared, and univariate/multivariate logistic regression was used to analyze the factors influencing the poor prognosis of herpes simplex virus keratitis.

Results

A one-way analysis of variance showed that, compared with the good prognosis group, the poor prognosis group had more elderly patients and a longer course of disease, and the difference was statistically significant (p < 0.05). There were significant differences in the types of patients between the two groups (p < 0.05). Univariate logistic regression analysis also showed that age (≥65 years) (OR: 1.557, 95%CI: 1.081-2.183, p < 0.05), course of disease (> 7 months) (OR: 1.303, 95%CI: 1.003-1.829, p < 0.05), epithelial type (OR: 2.321, 95%CI: 1.198-4.321, p < 0.05), and stromal type (OR: 2.536, 95%CI: 1.672-3.871, p < 0.05) were risk factors for poor prognosis. Multivariate logistic regression analysis showed that age (≥65 years) (OR: 1.656, 95%CI: 1.168-2.357, p < 0.05) and course of disease (> 7 months) (OR: 1.461, 95%CI: 1.031-2.001, p < 0.05) were independent risk factors for the prognosis of herpes simplex keratitis.

Conclusion

The clinical symptoms of herpes simplex virus keratitis include corneal opacity, corneal posterior elastic layer folds, corneal infiltration, posterior corneal mass, corneal edema, and ocular pain. Age and course of disease are important factors in the prognosis of herpes simplex virus keratitis.