Infection of endotheliotropic human cytomegalovirus of trabecular meshwork cells

Roles played by IL-8 in altering dynamics of trabecular meshwork cells after human cytomegalovirus infection

Open-angle glaucoma (OAG) is the leading cause of blindness worldwide. Human cytomegalovirus (HCMV) is known to infect the trabecular meshwork cells (HTMCs) and corneal endothelial cells leading to chronic and recurrent elevations of the intraocular pressure (IOP) as secondary glaucoma. To investigate how HCMV affects the function of HTMCs, we analyzed the effects of HCMV infection on cultured HTMCs infected with the endothelial-adapted strain, TB40/E, of HCMV. We studied the induced molecular mechanisms focusing on the OAG-associated chemokines, IL-8 and CCL2. The HTMCs were analyzed for transcriptome changes using RNAseq analysis. Our results showed that HCMV infection activated interferon signaling and significantly increased the expression of IL-8 and CCL2. The IL-8-responsive transcriptional pathway was analyzed by using a CXCR2 antagonist which is associated with cellular movement and development of the hematological system. In contrast, the CCL2-sensitive pathway, assessed using a CCR2 antagonist, was linked to olfactory receptor signaling and keratinization. HCMV infection activated cell motility with the formation of lamellipodia and filopodia. The infection-induced activation of cell motility was dependent on both CXCR2 and CCR2, and IL-8 stimulated filopodia-mediated cell motility. HCMV infection also induced cell contraction that was dependent on CXCR2, but not on CCR2, and it involved the activation of Rac1/Cdc42. These results suggest that HCMV infection altered the cytoskeletal dynamics and contraction of the HTMCs in a CCR2- and CXCR2-dependent manner. These changes have the potential of causing an increase in the resistance to aqueous humor outflow in HCMV-associated anterior uveitis and corneal endotheliitis.

Efficacy and safety of ROH-101 (0.15% ganciclovir gel) for cytomegalovirus corneal endotheliitis: an open-label, uncontrolled, phase 3 study in Japan

PURPOSE

Cytomegalovirus (CMV) corneal endotheliitis often causes severe visual impairment owing to irreversible corneal endothelial dysfunction. Given the side effects of systemic antiviral therapy, development of an approved topical antiviral agent for CMV corneal endotheliitis is desirable. This study evaluated the efficacy and safety of topical 0.15% GCV gel, ROH-101, in the treatment of CMV corneal endotheliitis in Japanese patients.

STUDY DESIGN

Open-label, multicenter, uncontrolled, phase 3 study (jRCT2051210064).

METHODS

The study was conducted from August 2021 to December 2022, with a 2-week run-in period with 0.1% fluorometholone eye drops alone, a 12-week treatment period with additional ROH-101, and a 24-week post-treatment observation period after discontinuation of ROH-101. The primary endpoint was the proportion of patients achieving a CMV DNA copy number in the aqueous humor of less than 103 copies/mL at week 12. The clinical findings and safety were assessed over the treatment and post-treatment observation periods.

RESULTS

Twelve eyes of 12 patients with PCR-proven CMV corneal endotheliitis were enrolled. Treatment was discontinued in 1 eye owing to an adverse event. The other 11 eyes completed 12 weeks of treatment with 63.6% achieving the primary endpoint. The clinical findings, such as corneal edema, coin-shaped lesions, and anterior chamber inflammation, improved in all 11 eyes and did not worsen in 8 eyes that completed the post-treatment observation period. Endothelial cell density was well maintained, and none of the 11 eyes showed corneal endothelial dysfunction. Mild adverse drug reactions were reported in 3 eyes (8.3%).

CONCLUSION

ROH-101 was a safe and efficacious treatment in Japanese patients diagnosed with CMV corneal endotheliitis.

Pharmacokinetics of ganciclovir eye drops: a comparative study of solutions prepared from ganciclovir for intravenous infusion and ganciclovir gel

PURPOSE

To evaluate the pharmacokinetics of ganciclovir eye drops by comparing solutions prepared from ganciclovir for intravenous infusion and ganciclovir gel and to assess the impact of systemic administration on drug levels in ocular tissues and serum.

STUDY DESIGN

Experimental study design.

METHODS

Ganciclovir solutions (0.5% and 1.0%) prepared by diluting DENOSINE ® IV Infusion in saline and 0.15% ganciclovir gel (Virgan®) were topically administered in rabbit eyes, with and without concomitant systemic administration of ganciclovir. The concentrations of ganciclovir in the corneal epithelium, stroma, and endothelium, aqueous humor; and blood plasma were analyzed by high-performance liquid chromatography (HPLC).

RESULTS

The ganciclovir solutions (0.5% and 1.0%) maintained therapeutic ganciclovir levels in the corneal endothelium above the effective dose required for 50% inhibition (ED50) up to 6 h, albeit with a swift decline thereafter. The 0.15% ganciclovir gel maintained higher therapeutic concentrations in the corneal endothelium for up to 12 h, exceeding the ED50. Serum concentrations of ganciclovir were significantly elevated in the groups receiving combined systemic administration.

CONCLUSION

Topical application of 0.15% ganciclovir gel maintained high endothelial concentrations, well above the therapeutic threshold, with or without systemic administration. Furthermore, the observed increase in ganciclovir levels within the plasma and aqueous humor following systemic administration posits it as a viable strategy for severe cases of cytomegalovirus corneal endotheliitis or those inadequately managed by local treatments alone.

Clinical Differences between Posner-Schlossman Syndrome Patients with Intermittent Intraocular Pressure Elevation and Glaucomatous Damage

INTRODUCTION

Although there is abundant evidence that Posner-Schlossman syndrome (PSS) can lead to secondary glaucoma, data on the clinical differences between PSS patients with secondary glaucoma and those with intermittent intraocular pressure (IOP) elevation are sparse.

METHODS

This retrospective observational study included 52 patients (52 eyes) diagnosed with PSS and admitted to Zhongnan Hospital of Wuhan University between January 2019 and February 2022. Demographic characteristics and clinical features were gathered from admission records. Patients were divided into two groups: 27 cases with intermittent IOP elevation (group A) and 25 cases with secondary glaucoma (group B and C). Of the secondary glaucoma cases, 18 were further divided into the topical IOP-lowering medications group (group B) and 7 into the glaucoma surgery group (group C). Clinical characteristics of different groups were compared.

RESULTS

Compared to the intermittent IOP elevation group, PSS patients with secondary glaucoma had a longer course of disease, a higher incidence of iris depigmentation, lower best corrected visual acuity, lower endothelial cell density, and higher interferon-γ (IFN-γ) concentration and cytomegalovirus (CMV) deoxyribonucleic acid (DNA) copy number in the aqueous humor (all p < 0.05). Group C presented a higher CMV DNA copy number in the aqueous humor than groups A and B (p < 0.05). Compound trabeculectomy proved effective in group C, with a functional filter bleb and well-controlled IOP without disease progression after 1 year of follow-up.

CONCLUSION

Distinctive characteristics existed between PSS patients with secondary glaucoma and those with intermittent IOP elevation. Compound trabeculectomy appears to be an effective treatment option when IOP cannot be controlled through topical medications.

Clinical Features of Glaucoma Associated with Cytomegalovirus Corneal Endotheliitis

Purpose

Methods

Results

Conclusion

Antiviral cytotoxic T lymphocyte responses for long term prognosis of corneal infection by cytomegalovirus in immunocompetent subjects

Ocular cytomegalovirus (CMV) infections in immunocompetent individuals are rare, but its activation can cause chronic and relapsing inflammation in anterior segment of the eye resulting in loss of corneal clarity and glaucoma. Fifty five patients with anterior segment CMV infection were assessed for their clinical characteristics, and CMV corneal endotheliitis was found to cause significant loss of corneal endothelial cells. The disease duration with recurrences was significantly correlated with the maximum intraocular level of CMV DNA. To examine why CMV is activated in healthy immunocompetent individuals and causing corneal endothelial cell damage, assays of cytotoxic T cells (CTLs) which directly target infected corneal endothelial cells were performed for 9 HLA-matched CMV corneal endotheliitis patients (HLA-A*2402). When the cell loss was analyzed for associations with CTL responses, CMV-induced endothelial cell damage was mitigated by pp65-specific CTL induction. The recurrence-free time was also prolonged by pp65-specific CTL induction (hazard ratio (HR): 0.93, P = 0.01). In contrast, IE1-specific CTL was associated with endothelial cell damage and reduced the time for corneal transplantation (HR: 1.6, P = 0.003) and glaucoma surgery (HR: 1.5, P = 0.001). Collectively, induction of pp65-specific CTL was associated with improved visual prognosis. However, IE1-specific CTL without proper induction of pp65-specific CTL can cause pathological damage leading to the need of surgical interventions.

The beneficial impact of filtration surgery on antiviral therapy cessation in patients with cytomegalovirus-related secondary glaucoma

Purpose

Cytomegalovirus (CMV)-related keratouveitis elevates intraocular pressure (IOP). Antiviral therapy does not always control IOP and some patients do not tolerate systemic antiviral therapy because of the side effects. The purpose of this study is to evaluate the clinical characteristics of patients with CMV-related keratouveitis and determine the impact of glaucoma surgeries on the postoperative antiviral therapy regimen.

Methods

We enrolled twenty-two patients with CMV-DNA-positive keratouveitis between June 2012 and July 2019 in Kobe University Hospital. The following clinical parameters were collected: gender, age, history of previous intraocular surgery, antiviral medications, visual acuity, IOP, glaucoma drug score, corneal endothelial cells density, and the mean deviation of a Humphrey visual field test at the first visit and before and 1 year after glaucoma surgery.

Results

All twenty-two patients started on oral and/or topical antiviral therapy. Eighteen patients needed glaucoma surgery despite their antiviral medications. Nine patients underwent trabeculotomy (TLO) and nine underwent trabeculectomy (TLE) as the first surgical intervention. Six of patients who initially underwent TLO and two of the patients who initially underwent TLE required additional TLE within 1 year. Each of the 15 patients who underwent at least 1 TLE showed a reduction in the magnitude and variation of IOP and glaucoma drug scores and 13 patients were able to discontinue antiviral therapy. For the remaining 4 patients, IOP and inflammation were controlled but with antiviral medications.

Conclusions

In patients with CMV-related keratouveitis, TLE decreases and stabilizes IOP and contributes to withdrawal from antiviral medications.

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

PURPOSE

We report 3 cases of patients with chronic ocular surface inflammatory disease who developed cytomegalovirus (CMV) corneal endotheliitis during immunosuppressant and steroid treatment.

PATIENTS AND METHODS

This is a retrospective observational study analyzing the clinical characteristics and outcomes of 3 patients with ocular surface inflammatory diseases (2 with Mooren ulcer and 1 with idiopathic scleritis) who developed CMV corneal endotheliitis. All patients developed CMV corneal endotheliitis between 8 and 14 months of starting steroid and immunosuppressant treatment, including topical 0.1% tacrolimus. Decimal visual acuity, endothelial counts, and intraocular pressure were analyzed.

RESULTS

All patients received topical 0.5% ganciclovir after the diagnosis of CMV corneal endotheliitis, which improved endothelial inflammation. However, all patients developed irreversible mydriasis and required additional surgeries, including endothelial keratoplasty, cataract surgery, and glaucoma surgery. At the final follow-up (14-46 months post-CMV corneal endotheliitis onset), fair outcomes were achieved, as demonstrated by a mean decimal best-corrected visual acuity of 0.3 and a well-controlled intraocular pressure.

CONCLUSIONS

Topical steroids and immunosuppressants can induce fulminant CMV corneal endotheliitis with cataract progression and irreversible mydriasis. In these cases, early diagnosis and treatment, including topical 0.5% ganciclovir, glaucoma surgery, cataract surgery, and endothelial keratoplasty, are necessary for preserving the patient's vision.

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

Purpose

Considering the difficulty of obtaining adequate biological tissue in clinical practice, we established an animal model of cytomegalovirus (CMV) keratouveitis in rats and investigated the viral infection sites and corresponding imaging and histopathological features.

Methods

Subconjunctival injection and topical use of dexamethasone were used to induce ocular immunosuppression in rats followed by intracameral inoculation of murine cytomegalovirus (MCMV). The clinical manifestations, intraocular pressure (IOP) and imaging changes were observed. Infected eyes were further examined by immunofluorescence, light microscopy, and electron microscopy. MCMV RNA was detected by reverse transcription-polymerase chain reaction.

Results

Typical keratouveitis occurred in the experimental rats and was characterized by corneal edema, keratic precipitates, and iridocyclitis with increased IOP. Corneal endothelial lesions displayed as “black holes,” enlarged intercellular gaps, and high-intensity cellular infiltration by confocal microscopy, consistent with the pathological changes of “ballooning degeneration,” endothelial cell detachment, and inflammatory cell infiltration. Mitochondrial edema was the most prominent organelle lesion in endothelial cells. Trabeculitis, mechanical obstruction of Schlemm's canal, and anterior chamber angle stenosis accounted for elevated IOP. Inflammation of the iris and ciliary body tended to transform into a chronic form. Immunofluorescence revealed that corneal endothelial cells, iris cells, trabecular meshwork cells, and monocytes could be infected by MCMV. MCMV RNA was found in the anterior segments after infection.

Conclusions

CMV can widely infect anterior segment tissue, including the corneal endothelium, iris, and trabecular meshwork, in vivo, inducing the corresponding clinical manifestations. Corneal endotheliitis and hypertensive anterior uveitis could be the specific stage of anterior segment infection of CMV.

Distinguishing Features of Anterior Uveitis Caused by Herpes Simplex Virus, Varicella-Zoster Virus, and Cytomegalovirus

PURPOSE

To determine distinguishing features of the clinical characteristics of anterior uveitis (AU) caused by herpes simplex virus (HSV), varicella-zoster virus (VZV), and cytomegalovirus (CMV).

DESIGN

Retrospective, multicenter case series.

METHODS

Consecutive patients with herpetic AU examined at 11 tertiary centers in Japan between January 2012 and December 2017 and who were followed for ≥3 months were evaluated. Diagnosis was made by polymerase chain reaction (PCR) for HSV, VZV, or CMV in the aqueous humor, or classical signs of herpes zoster ophthalmicus.

RESULTS

This study enrolled 259 herpetic AU patients, including PCR-proven HSV-AU (30 patients), VZV-AU (50), and CMV-AU (147), and herpes zoster ophthalmicus (32). All HSV-AU and VZV-AU patients were unilateral, while 3% of CMV-AU patients were bilateral. Most HSV-AU and VZV-AU patients were sudden onset with an acute clinical course, while CMV-AU had a more insidious onset and chronic course. There were no significant differences for all surveyed symptoms, signs, and complications between HSV-AU and VZV-AU. However, significant differences were detected for many items between CMV-AU and the other two herpetic AU types. Ocular hyperemia and pain, blurring of vision, ciliary injection, medium-to-large keratic precipitates (KPs), cells and flare in the anterior chamber, and posterior synechia significantly more often occurred in HSV-AU and VZV-AU vs CMV-AU. In contrast, small KPs, coin-shaped KPs, diffuse iris atrophy, elevated intraocular pressure, and glaucoma surgery were significantly more frequent in CMV-AU vs HSV-AU and VZV-AU.

CONCLUSION

This multicenter, retrospective study identified distinguishing features of HSV-AU, VZV-AU, and CMV-AU.

Management of cytomegalovirus corneal endotheliitis

Background

Cytomegalovirus (CMV) can manifest as corneal endotheliitis in immunocompetent individuals. Early diagnosis is prudent to prevent endothelial cell loss, which could ultimately lead to corneal decompensation. CMV DNA was first detected in an eye with corneal endotheliitis in 2006; since then, clinical evidence from numerous case reports and case series have accumulated.

Main text

In this narrative review, we identified several drugs, including ganciclovir, valganciclovir, and their combination in oral, intravenous, intravitreal, and topical forms in different concentrations, together with the judicious use of topical steroids, have reported variable success. There has yet to be any prospective comparative study evaluating the efficacy and safety of these assorted forms of treatment; clinical evidence is based on case reports and case series. CMV endotheliitis presenting with corneal edema can masquerade as other corneal diseases and thus poses a great challenge especially in post-keratoplasty eyes. Heightened awareness is needed before and after keratoplasty to start prompt prophylaxis and treatment.

Conclusion

There is no consensus on the management of CMV endotheliitis. Further studies are much needed to elucidate the optimal treatment modality, regime, and duration in the treatment and prophylaxis of CMV endotheliitis.

Relationships between the clinical characteristics and copy numbers of DNA of cytomegalovirus determined by real-time PCR

Purpose

To determine whether there is a correlation between the clinicals characteristics including various types of keratic precipitates and the copy numbers of the DNA of cytomegalovirus (CMV) in eyes with CMV corneal endotheliitis.

Methods

We reviewed the medical charts of four cases of corneal endotheliitis that were CMV-positive. We have classified types of clinical phenomenon into four types: coin-shaped KPs, sectoral corneal edema with or without Khodadoust line-like KPs, mutton-fat KPs, and fine KPs and have graded their severity. We also determined the copy numbers of the DNA of CMV in the aqueous humor by real-time polymerase chain reaction before and during the treatment. We evaluated the correlation between the patterns of clinical characteristics and copy number of the DNA of CMV.

Results

There were clinical improvements in all eyes following topical ganciclovir in conjunction with low dose of topical steroid treatment, with or without oral valganciclovir. The clinical characteristics and the copy numbers of the DNA of CMV varied during the treatment period. The presence of coin-shaped KPs was correlated with high copy numbers (10⁵–10³ copies/ml) of the DNA of CMV. The copy numbers of the DNA of CMV with sectoral corneal edema with or without Khodadoust line-like KPs ranged from 10⁴ to 10² copies/ml, and it was occasionally accompanied by high intraocular pressure. Mutton-fat KPs were observed inferiorly, sometimes together with coin-shaped KPs and sectoral corneal edema, or solely. The copy numbers in eyes with mutton-fat KPs varied and occasionally less than the cutoff level. Fine-pigmented KPs were observed after the resolution of the endotheliitis, and no DNA of CMV was detected in the aqueous humor.

Conclusions

Careful observations of the clinical characteristics such as the KPs and corneal edema might be helpful in estimating the amount of the DNA of CMV in eyes with corneal endotheliitis.

Zika Virus Infects Trabecular Meshwork and Causes Trabeculitis and Glaucomatous Pathology in Mouse Eyes

Zika virus (ZIKV) infection during pregnancy leads to devastating fetal outcomes, including neurological (microcephaly) and ocular pathologies such as retinal lesions, optic nerve abnormalities, chorioretinal atrophy, and congenital glaucoma. Only clinical case reports have linked ZIKV infection to causing glaucoma, a major blinding eye disease. In the present study, we have investigated the role of ZIKV in glaucoma pathophysiology using in vitro and in vivo experimental models. We showed that human primary trabecular meshwork (Pr. TM) cells, as well as a human GTM3 cell line, were permissive to ZIKV infection. ZIKV induced the transcription of various genes expressing pattern recognition receptors (TLR2, TLR3, and RIG-I), cytokines/chemokines (TNF-α, IL-1β, CCL5, and CXCL10), interferons (IFN-α2, IFN-β1, and IFN-γ), and interferon-stimulated genes (ISG15 and OAS2) in Pr. TM cells. ZIKV infection in IFNAR1-/- and wild-type (WT) mouse eyes resulted in increased intraocular pressure (IOP) and the development of chorioretinal atrophy. Anterior chamber (AC) inoculation of ZIKV caused infectivity in iridocorneal angle and TM, leading to the death of TM cells in the mouse eyes. Moreover, anterior segment tissue of infected eyes exhibited increased expression of inflammatory mediators and interferons. Furthermore, ZIKV infection in IFNAR1-/- mice resulted in retinal ganglion cell (RGC) death and loss, coinciding with optic nerve infectivity and disruption of anterograde axonal transport. Because of similarity in glaucomatous pathologies in our study and other experimental glaucoma models, ZIKV infection can be used to study infectious triggers of glaucoma, currently an understudied area of investigation.IMPORTANCE Ocular complications due to ZIKV infection remains a major public health concern because of their ability to cause visual impairment or blindness. Most of the previous studies have shown ZIKV-induced ocular pathology in the posterior segment (i.e., retina) of the eye. However, some recent clinical reports from affected countries highlighted the importance of ZIKV in affecting the anterior segment of the eye and causing congenital glaucoma. Because glaucoma is the second leading cause of blindness worldwide, it is imperative to study ZIKV infection in causing glaucoma to identify potential targets for therapeutic intervention. In this study, we discovered that ZIKV permissively infects human TM cells and evokes inflammatory responses causing trabeculitis. Using a mouse model, we demonstrated that ZIKV infection resulted in higher IOP, increased RGC loss, and optic nerve abnormalities, the classical hallmarks of glaucoma. Collectively, our study provides new insights into ocular ZIKV infection resulting in glaucomatous pathology.

Diagnostic efficacy of real-time PCR for ocular cytomegalovirus infections

PURPOSE

The aim of this study is to determine the efficacy of quantitative real-time PCR (qPCR) and clinical characteristics to diagnose ocular cytomegalovirus (CMV) infections.

METHODS

The technical factors were assessed by the outcomes of the qPCR assay at five institutions in Japan using the WHO International Standard of cytomegalovirus. The clinical factors were assessed by examining the aqueous humor samples of 197 eyes of 197 consecutive patients suspected of CMV using the receiver operating characteristics (ROCs).

RESULTS

All of the institutions had excellent detection efficacy, although the copy number ranged from 0.82 to 4.66 copies/IU. In the clinical samples, CMV was detected in 51 eyes, and the amount of CMV DNA was significantly higher for CMV retinitis. In corneal diseases, the amount of CMV DNA was significantly associated with frequency of recurrences and IOP elevations. The sensitivity and specificity of qPCR for the diagnosis was 90.0 and 98.7%, respectively. For the corneal and anterior uveitis types of CMV diseases, the area under the curve (AUC) of qPCR was 0.95 and 0.96, followed by frequency of recurrences with AUC of 0.89 and 0.82, and IOP elevations with AUC of 0.78 and 0.76. Unclassified cytomegalovirus detection, which did not meet diagnostic criteria of CMV corneal endotheliitis, anterior uveitis, or retinitis, was 4.6%, and it was significantly associated with corneal diseases and history of corneal transplantation.

CONCLUSIONS

qPCR with standardization is specific and accurate; however, the inclusion and knowledge of the clinical characteristics improve the diagnostic efficacy.