Treatment of HSV-1 stromal keratitis with topical cyclosporin A: a pilot study

Clinical strategies to prevent recurrence of Herpes simplex and Herpes zoster following ocular surgery: A comprehensive review with practical guidelines

Recurrences of herpetic infections following intraocular surgeries pose a threat to optimal surgical outcomes. The high prevalence of herpetic diseases require ophthalmologists to be familiar with the special measures in the surgery of these patients. A thorough preoperative assessment and meticulous postoperative surveillance should be tailored for each patient, depending on the surgery and the risk of virus reactivation. We compile the relevant evidence in the literature and provide a comprehensive review of the preoperative assessment and postoperative diagnostic clues and management of the herpetic infections following different types of intraocular surgeries, including cataract surgery, keratoplasty, corneal crosslinking, glaucoma, and refractive surgeries.

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

PURPOSE

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).

METHODS

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.

FINDINGS

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.

IMPLICATIONS

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.

CLINICAL TRIAL REGISTRATION

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.

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.

Antiviral and Anti-Inflammatory Therapeutic Interventions for Treating Herpes Stromal Keratitis: A Systematic Review

PURPOSE

Herpes stromal keratitis (HSK) is an immune-mediated corneal inflammation that occurs after a herpes simplex virus infection. This paper aims to systematically identify and compare interventions for treating HSK and their patient outcomes.

METHODS

This systematic review followed the PRISMA methodology. Online databases were searched to obtain all relevant papers. Two independent reviewers screened through 168 records. Seven papers were included and used for data extraction. A qualitative analysis was conducted.

RESULTS

HSK patients receiving prednisolone phosphate and acyclovir showed a higher treatment success rate and significantly longer time to failure compared to patients receiving only acyclovir (P < .001). No difference in resolution time was found between oral and topical acyclovir. Between groups receiving dexamethasone and flurbiprofen, resolution occurred in 93% and 67% of patients, and BCVA (LogMAR) improved from 1.0 to 0.30 and 0.48, respectively. BCVA improved in both cyclosporine-A (P < .001) and its control (prednisolone) groups (P = .002). A tacrolimus treatment group showed greater improvement in BCVA compared to its control (prednisolone) group (P < .001).

CONCLUSION

Corticosteroids and antivirals managed HSK most effectively only when used concurrently. Oral acyclovir showed similar effectiveness to its ointment counterpart, a preferable alternative for easier administration. Corticosteroid use could induce greater therapeutic benefits when tapered in concentration and frequency and administrated for at least 10 weeks. Anti-inflammatory drugs including flurbiprofen, cyclosporine-A, and tacrolimus could be safe and effective for treating HSK. Future long-term follow-up and RCTs could provide insights on the therapeutic benefits of these potential alternatives.

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

PURPOSE

To report our experience with the 2% cyclosporin A (CsA) in a series of challenging inflammatory ocular surface diseases due to different etiologies.

METHODS

The records of patients who received topical 2% CsA for different indications were reviewed retrospectively. Demographic characteristics, indications for treatment, patient symptoms and clinical findings were recorded.

RESULTS

Fifty-two eyes of 52 patients were included. Mean age was 43.2 ± 14.3 (11-66) years with a F/M ratio of 34/18. Indications included pediatric acne rosacea (n = 4), adenoviral corneal subepithelial infiltrates (n = 12), filamentary keratitis (n = 14), pterygium recurrence (n = 15), herpetic marginal keratitis (n = 2) and graft versus host disease (n = 5 patients). Mean duration of treatment was 7.3 ± 2.8 (3-10) months. Forty-three (83%) patients reported favorable outcome with improvement in symptoms after a mean time of 4.4 ± 2.7 (2-6) months.

CONCLUSIONS

Topical 2% CsA may address the needs of different cases with ocular surface inflammation, as a safe option for long-term therapy.

Role of Innate Interferon Responses at the Ocular Surface in Herpes Simplex Virus-1-Induced Herpetic Stromal Keratitis

Herpes simplex virus type 1 (HSV-1) is a highly successful pathogen that primarily infects epithelial cells of the orofacial mucosa. After initial lytic replication, HSV-1 enters sensory neurons and undergoes lifelong latency in the trigeminal ganglion (TG). Reactivation from latency occurs throughout the host's life and is more common in people with a compromised immune system. HSV-1 causes various diseases depending on the site of lytic HSV-1 replication. These include herpes labialis, herpetic stromal keratitis (HSK), meningitis, and herpes simplex encephalitis (HSE). HSK is an immunopathological condition and is usually the consequence of HSV-1 reactivation, anterograde transport to the corneal surface, lytic replication in the epithelial cells, and activation of the host's innate and adaptive immune responses in the cornea. HSV-1 is recognized by cell surface, endosomal, and cytoplasmic pattern recognition receptors (PRRs) and activates innate immune responses that include interferons (IFNs), chemokine and cytokine production, as well as the recruitment of inflammatory cells to the site of replication. In the cornea, HSV-1 replication promotes type I (IFN-α/β) and type III (IFN-λ) IFN production. This review summarizes our current understanding of HSV-1 recognition by PRRs and innate IFN-mediated antiviral immunity during HSV-1 infection of the cornea. We also discuss the immunopathogenesis of HSK, current HSK therapeutics and challenges, proposed experimental approaches, and benefits of promoting local IFN-λ responses.

Clinical Management of Herpes Simplex Virus Keratitis

Herpes simplex virus (HSV) keratitis is one of the leading causes of blindness worldwide. Additionally, up to 90% of the population in some countries is seropositive for HSV. HSV can cause a wide spectrum of ocular disease ranging from blepharitis to retinitis. Although the initial clinical expressions of HSV-1 and HSV-2 are similar, HSV-2 has been reported more frequently in association with recurrent HSV disease. Besides irreversible vision loss from keratitis, HSV also causes encephalitis and genital forms of the disease. Despite these statistics, there remains no vaccine against HSV. Current treatment therapies for related ocular diseases include the use of oral and topical antivirals and topical corticosteroids. While effective in many cases, they fail to address the latency and elimination of the virus, making it ineffective in addressing recurrences, a factor which increases the risk of vision loss. As such, there is a need for continued research of other potential therapeutic targets. This review utilized several published articles regarding the manifestations of HSV keratitis, antiviral immune responses to HSV infection, and clinical management of HSV keratitis. This review will summarize the current knowledge on the host–virus interaction in HSV infections, as well as highlighting the current and potential antiviral therapeutics.

Update on Herpes simplex keratitis management

Herpes simplex keratitis (HSK) is a common, potentially blinding condition characterised by recurrent infections of the cornea, seen by both general ophthalmologists and corneal specialists. Successful treatment of recurrences reduces disease duration, prevents progressive corneal scaring leading to vision loss and reduces risk of further recurrences. In this review we discuss the relative advantages of the diagnostic laboratory investigations including polymerase chain reaction, viral culture and fluorescence-based immunohistochemistry. We review treatment strategies in selected aspects of HSK and discuss the management options in cases not responding to treatment.

Topical Tacrolimus as an adjunct to Conventional Therapy for Stromal Herpetic Keratitis: a Randomized Clinical Trial

Purpose

This study investigates the effects of 0.05% topical tacrolimus as an adjunct therapy for patients with non-necrotizing herpetic stromal keratitis (HSK).

Methods

Patients with non-necrotizing HSK, referred to the Cornea Clinic at Hospital in Rasht, Iran, between September 2016 and February 2018, were randomly assigned to two groups. The case group (N = 25) and the control group (N = 25) received conventional treatment with systemic acyclovir and topical prednisolone. The case group (N = 25) additionally received 0.05% tacrolimus eye drops four times a day for one month. Complete ocular examinations, including best-corrected visual acuity (BCVA) assessment, intraocular pressure (IOP) measurement, slit lamp biomicroscopy, and photo slit lamp imaging, were performed before treatment, and 3, 7, 14, 21, and 28 days after the intervention.

Results

The mean age of the patients was 46.2 ± 12.9 years, and 70% of the patients were male. There was no difference between the groups in terms of age, sex, and baseline ocular measurements (P> 0.05). The case group had a lower mean logarithm of the minimum angle of resolution (LogMAR) for BCVA, lower grading scores, and steeper decreasing trends for corneal haziness, edema, neovascularization, and epitheliopathy compared to the control group after the second week (P< 0.05), while IOP remained unchanged between groups (P> 0.05).

Conclusion

The addition of 0.05% topical tacrolimus enhances visual acuity and reduces corneal inflammation, neovascularization, and scarring; thus, it can used as an appropriate adjunct treatment for patients with HSK.

Risk of Corneal Graft Rejection After High-risk Keratoplasty Following Fine-needle Vessel Coagulation of Corneal Neovascularization Combined With Bevacizumab: A Pilot Study

Background

Corneal neovascularization is considered an important risk factor for allograft rejection after corneal transplantation (keratoplasty). Therefore, the aim of this study was to determine whether preoperative reduction of corneal neovascularization by fine-needle thermal cauterization combined with bevacizumab reduces the incidence of allograft rejection after subsequent high-risk keratoplasty.

Methods

In this interventional uncontrolled clinical pilot study, 31 eyes of 31 patients with corneal neovascularization in at least one corneal quadrant were included. All eyes were treated by fine-needle thermal cauterization of corneal vessels and subconjunctival injection of bevacizumab. Both treatments were repeated in the cases of visible reperfusion of occluded vessels. Afterward, penetrating keratoplasty was performed. When corneal neovascularization was present on the day of keratoplasty, additional vessel cauterization and injection of bevacizumab was performed. Patients were then followed to determine the incidence of allograft rejection.

Results

In 18 eyes, vessel cauterization with bevacizumab injection was performed once before keratoplasty, whereas 13 eyes required retreatment before keratoplasty. No complications were observed. In 23 eyes, corneal neovascularization was present on the day of keratoplasty due to reperfusion of previously occluded vessels and simultaneous vessel cauterization with bevacizumab injection was performed. During follow-up (mean: 560 days; range: 59-1095 days), 4 graft rejection episodes in 4 eyes were observed. Estimated probabilities of corneal graft survival were 92.9% after 1 year (number at risk: 23), 78.4% after 2 years (number at risk: 9), and 78.4% after 3 years (number at risk: 3).

Conclusions

Our initial results indicate that angioregressive treatment of pathological corneal vessels by fine-needle thermal cauterization combined with subconjunctival injection of bevacizumab before high-risk keratoplasty seems to result in graft survival rates comparable to survival rates seen in normal-risk keratoplasty. The findings of our pilot study warrant further controlled clinical trials with longer follow-up in a larger patient cohort.

Topical cyclosporine-A versus prednisolone for herpetic stromal keratitis: a randomized controlled trial

PURPOSE

To compare topical cyclosporine-A 2% eye drop (Cs-A) with prednisolone acetate 1% eye drop for treatment of herpetic stromal keratitis (HSK).

METHODS

In this randomized clinical trial, 38 eyes of 33 patients with HSK were randomly assigned to receive either 2% Cs-A or 1% prednisolone acetate eye drops. All subjects received oral acyclovir 400 mg twice a day. Slit-lamp examination, Scheimpflug tomography corneal optical densitometry (Pentacam®, Oculus Inc., Wetzlar, Germany), best-corrected visual acuity (BCVA), and intra-ocular pressure (IOP) were evaluated at the first visit, and 14 and 30 days after the treatment.

RESULTS

Within-group analysis revealed significant improvement of total cornea optical density after 30 days of treatment in both groups (30.3 ± 10.5 to 28.3 ± 9.8, p < 0.001 for prednisolone group, and 30.5 ± 8.8 to 28.8 ± 8.3 p < 0.001 for Cs-A group, mean ± SD). We were not able to disclose any significant difference between the two groups regarding the improvement of cornea optical density (p = 0.66). Best-corrected visual acuity (BCVA) logMAR significantly improved in both groups after 30 days of treatment (0.20 ± 0.52, p = 0.002 in prednisolone group, and 0.24 ± 0.31, p < 0.001 in Cs-A group, mean ± SD). Analysis between groups did not show a significant difference of BCVA improvement (p = 0.45). We did not observe any severe side effect attributable to drugs.

CONCLUSIONS

Cs-A 2% and prednisolone acetate 1% topical eye drops are effective for treatment of HSK.

Practice patterns for herpes simplex keratitis: A survey of ophthalmologists in Gulf Coast countries

Purpose

Herpes simplex is a common cause of visual disability, and there are published evidence-based guidelines for therapy. This survey aims to determine the preferred practice patterns of ophthalmologists in Gulf Coast Countries regarding herpetic eye disease, as well as identify areas of controversy or barriers to acceptance of evidence-based protocols.

Methods

Anonymous web-based survey of ophthalmologists in Saudi Arabia, Bahrain, the United Arab Emirates, and Oman.

Results

There were 48 responses to the survey. For a first episode of epithelial dendritic keratitis, 28.2% reported “observation” rather than specific therapy. The majority of respondents utilize oral or topical antiviral for epithelial keratitis, with oral antiviral being the most popular (43.6%). The majority also included a corticosteroid with antiviral for stromal keratitis (83.9%) or iritis (70.3%). Over 90% prescribe a prophylactic antiviral after keratoplasty for herpetic eye disease, although the length of therapy ranged widely from <6 months to indefinite. The perceived risk of recurrent disease was ranked as the most important factor when considering antiviral prophylaxis, followed by risk of adverse effects. Topical cyclosporine was utilized “never or almost never” by 76.9% of respondents.

Conclusions

Most respondents report following evidence-based guidelines. There was less consensus in areas where there are remaining knowledge gaps, such as the length of antiviral prophylaxis after keratoplasty and the potential role for topical cyclosporine.

Challenges of corneal infections

INTRODUCTION

Ocular infections remain an important cause of blindness worldwide and represent a challenging public health concern. In this regard, microbial keratitis due to fungal, bacterial, or viral infection can result in significant vision loss secondary to corneal scarring or surface irregularity. Left untreated corneal perforation and endophthalmitis can result, leading to loss of the eye. Rigorously studied animal models of disease pathogenesis have provided novel information that suggests new modes of treatment that may be efficacious clinically and emerging clinical data is supportive of some of these discoveries.

AREAS COVERED

This review focuses on advances in our understanding of disease pathogenesis in animal models and clinical studies and how these relate to improved clinical treatment. We also discuss a novel approach to treatment of microbial keratitis due to infection with these bacterial pathogens using PACK-CXL and recommend increased basic and clinical studies to address and refine the efficacy of this procedure.

EXPERT COMMENTARY

Because resistance to antibiotics has developed over time to these bacterial pathogens, caution must be exercised in treatment. Attractive novel modes of treatment that hold new promise for further investigation include lipid based therapy, as well as use of small molecules that bind deleterious specific host responsive molecules and use of microRNA based therapies.

Confocal Microscopic Analysis of a Rabbit Eye Model of High-Incidence Recurrent Herpes Stromal Keratitis

PURPOSE

Using CJLAT, a chimeric herpes simplex virus (HSV-1) that produces a high incidence of herpes stromal keratitis (HSK) in latently infected rabbits, and in vivo confocal microscopy (CM), we characterized the cellular events that precede the development of HSK.

METHODS

Thirty days after infection, in vivo CM was performed daily for 10 days and then weekly for up to 80 days after infection.

RESULTS

We detected 3 types of subclinical corneal lesions before HSK was clinically apparent: (1) small epithelial erosions; (2) regenerating epithelium overlying small cell infiltrates within the basal epithelial cell layer; and (3) dendritic-like cells within the basal epithelial layer overlying stromal foci containing infiltrating cells. Sequential in vivo CM observations suggested that subclinical foci resolved over time but were larger and more abundant with CJLAT than with wild-type HSV-1 McKrae. Active HSK was observed only with CJLAT and was initially associated with a large epithelial lesion overlying stromal immune cell infiltrates.

CONCLUSIONS

These results suggest that replication in the cornea of reactivated virus from the trigeminal ganglia produces epithelial lesions, which recruit immune cell infiltrates into the basal epithelial layer and anterior stroma. The virus is usually cleared rapidly eliminating viral antigens before the arrival of the immune cells, which disperse. However, if the virus is not cleared rapidly, or if an additional reactivation results in an additional round of virus at the same site before the immune cells disperse, then the immune cells are stimulated and may induce an immunopathological response leading to the development of HSK.

Therapeutic Effect of 0.1% Topical Tacrolimus for Childhood Interstitial Keratitis Refractory to Cyclosporine

PURPOSE

To report our findings in a case of childhood refractory interstitial keratitis successfully treated with 0.1% topical tacrolimus.

METHODS

A 12-year-old boy presented with a 3-year history of interstitial keratitis. For the recurrent interstitial keratitis he had been treated with topical and systemic acyclovir, steroids, and topical cyclosporine for 3 years. Our examinations revealed severe stromal infiltrates and neovascularization. Treatment was changed from topical 0.5% cyclosporine to topical 0.1% tacrolimus combined with topical acyclovir and betamethasone.

RESULTS

After 2 weeks of treatment with topical tacrolimus, the degree of stromal infiltrates decreased. Although the improvements were slow, the stromal infiltrates resolved somewhat, and neovascularization and topical acyclovir and betamethasone were tapered and stopped in 18 months. Since then, the patient has not shown any recurrence for 9 months without medication.

CONCLUSION

Our findings indicate that topical tacrolimus should be considered for treating refractory interstitial keratitis in children.

Evaluation of Effect of Topical Tacrolimus Treatment on Herpetic Stromal Keratitis in a Rat Model

OBJECTIVES

To investigate the effectiveness of topical tacrolimus treatment on herpetic stromal keratitis (HSK) in a rat model.

METHODS

The development of HSK was monitored for 14 days after the inoculation of rats with herpes simplex type 1 virus. Rats that developed HSK were divided into four groups as follows: (1) topical antiviral treatment (control), (2) topical antiviral and 1% prednisolone acetate, (3) topical antiviral and 0.03% tacrolimus ointment, and (4) topical antiviral plus 0.1% tacrolimus ointment. After 14 days of treatment, the severity levels of HSK were scored and compared with the levels before the treatment. The expression of CD3, CD4, and CD8 was evaluated by flow cytometry. The development of the disease was evaluated clinically and histologically.

RESULTS

Significant improvement in vascularization was observed in the groups with the drug treatment in addition to the antiviral agent (P<0.05), but there was no obvious difference within groups 2, 3, and 4 in the vascularization severity. The regression of corneal edema was 8.05%±6% in group 1, 25.17%±14.55% in group 2 (P=0.01), 36.40%±21.69% in group 3 (P=0.03), and 46.39%±14.96% in group 4 (P=0.00). A significant decrease in the number of inflammatory cells in the groups with the drug treatment was evaluated by immunohistochemical staining and confirmed by flow cytometry analysis.

CONCLUSIONS

Topical tacrolimus treatment caused a significant decrease in corneal vascularization accompanied by a lower number of inflammatory cells in the experimental HSK corneal edema model. Therefore, topical tacrolimus has the potential to be used in the treatment of HSK.

Emerging treatment options for meibomian gland dysfunction

Meibomian gland dysfunction (MGD) is one of the most common diseases observed in clinics; it influences a great number of people, and is the leading cause of evaporative dry eye. Given the increased recognition of the importance of MGD, a great amount of attention has been paid to therapies targeting this condition. The traditional treatments of MGD consist of warm compresses and lid hygiene for removing an obstructed meibum, as well as antibiotics and anti-inflammatory agents to improve the quality of the meibum. However, each of these treatments has a different shortcoming and the treatment of MGD remains challenging. Despite the numerous possible treatment options for MGD, it is still difficult to obtain complete relief of signs and symptoms. This review focuses on current emerging treatment options for MGD including intraductal meibomian gland probing, emulsion eye drops containing lipids, the LipiFlow® thermal pulsation system, N-acetyl-cysteine, azithromycin, oral supplementation with omega-3 essential fatty acids, and cyclosporine A.

Cyclosporine a 0.05% eye drops for the treatment of subepithelial infiltrates after epidemic keratoconjunctivitis

BACKGROUND

To evaluate the treatment with topical 0.05% cyclosporine A (CsA) in patients with subepithelial corneal infiltrates (SEI).

METHODS

We reviewed 16 patients (22 eyes) before and after the treatment with 0.05% CsA eye drops. All patients had been treated previously with topical corticosteroids without any improvement and also they had to stop the medication secondary to intraocular pressure elevation. The objective data recorded included best-corrected visual acuity (BCVA), evaluation of corneal subepithelial infiltrate scores (CSIS), intraocular pressure (IOP) prior to treatment and the last follow-up visit.

RESULTS

Six males (37.5%) and 10 females (62.5%), mean age of 35.2 ± 16.6 years, were included. The patients' average topical CsA use duration was 5.1 ± 3.5 months (1 - 13 months). The average follow up time of the patients was 9.2 ± 4.7 months (4 - 22 months). One patient, although he didn't have a 0 scale of SCIS, did not show up for follow up examinations after six months. The mean BCVA (logarithm of the minimum angle of resolution) before and after the treatment were 0.15 ± 0.15 and 0.07 ± 0.07 respectively, CSIS 1.68 ± 0.89 and 0.23 ± 0.53 respectively, IOP 18.50 ± 3.82 and 16.86 ± 2.76 mmHg respectively. There were statistically significant improvements in BCVA (p=0.002), reduction of CSIS (p=0.002) and reduction of IOP (p<0.001) prior to treatment and the last follow-up visit. 18 eyes (81.9%) showed clinical improvement and 4 (18.1%) had decreased SEI which did not fully disappear during the treatment period. The eyes which reached CSIS score 0 (18 eyes) were treated with CsA for 1 - 13 months; while the eyes which had clinical improvement but had not CSIS score 0 (4 eyes) were decided to discontinue of CsA treatment in last follow-up visit. There were recurrences in 2 eyes 3 months after the treatment. Patients reported reduction in the severity of symptoms after the treatment. Most of the patients reported no foreign body sensation, glare, or other side effects with topical CsA treatment. Overall, patients noted an improvement in vision and satisfaction with topical 0.05% CsA treatment.

CONCLUSIONS

Topical 0.05% CsA is a safe and effective alternative treatment in patients with SEI who do not respond to other treatment modalities or have undesired side effects from topical steroids.

Treatments for corneal neovascularization: a review

Corneal neovascularization (CNV) may be a physiological response to various stimuli, but a chronic and persistent upregulation of neoangiogenesis can result in pathological CNV. Pathological blood vessels are immature and lack structural integrity, predisposing the cornea to lipid exudation, inflammation, and scarring. CNV can therefore become a potentially blinding condition. In this review, we frame CNV in an epidemiological perspective, consider risk factors for CNV, provide an overview of CNV pathogenesis, and consider the impact of CNV on corneal transplantation. We consider treatments that are of largely historical interest, before reviewing contemporary medical and surgical treatments. Within medical treatments, we report on steroids, nonsteroidal anti-inflammatory agents, antivascular endothelial growth factor agents, and cyclosporine. Within surgical treatments, we report on the use of lasers, photodynamic therapy, superficial keratectomy, and diathermy/cautery-based treatments.

Cyclosporine A 1% eye drops for the treatment of subepithelial infiltrates after adenoviral keratoconjunctivitis

PURPOSE

To describe the use of cyclosporine A (CSA) 1% eye drops for the treatment of symptomatic corneal subepithelial infiltrates (SEI) occurring as a sequelae of adenoviral keratoconjunctivitis (AK) that are resistant to tapering of corticosteroid eye drops.

METHODS

This is a retrospective case series of patients seen at 2 institutions who had symptomatic corneal SEI occurring after AK that was resistant to tapering of corticosteroid eye drops and who were subsequently treated with CSA 1%. Information gathered included basic demographic information (age and sex), involved eye(s), duration of symptoms, initial best spectacle-corrected visual acuity (BSCVA), type of corticosteroid used, clinical course, and best spectacle-corrected visual acuity at the last follow-up visit.

RESULTS

Twelve eyes of 7 patients had symptomatic SEI develop after AK that were responsive to corticosteroid eye drops but were resistant to tapering. After the initiation of CSA eye drops, the corticosteroid eye drops could be tapered, and all eyes could be maintained on CSA eye drops once per day or less. Mean follow-up time was 13.0 months (range, 4-28 months).

CONCLUSIONS

CSA eye drops may be an effective corticosteroid-sparing agent for the treatment of SEI after AK. The use of CSA in this setting warrants further study.

Clinical review: topical ophthalmic use of cyclosporin A

Cyclosporine A (CsA) is an immunomodulatory agent that primarily inhibits the proliferation and action of T cells. Systemic CsA has been used successfully in solid organ transplantation and noninfectious uveitis. Topical CsA with various formulations has been used in the field of ocular surface diseases since early 1980s. An ophthalmic emulsion 0.05% (Restasis, Allergan, Irvine, CA), was approved by the United States Food and Drug Administration in 2003 to treat dry eye syndrome. This article aims to evaluate the peer-reviewed published scientific literature and to define well-established uses of CsA eyedrops in the field of ocular surface diseases.

Topical ophthalmic cyclosporine: pharmacology and clinical uses

Cyclosporine has been used successfully as a systemic immunomodulator for more than two decades, and numerous studies have investigated its mechanisms of action. In 2003 an ophthalmic formulation, cyclosporine 0.05% ophthalmic emulsion, was approved by the FDA to treat dry eye disease. Topical cyclosporine emulsion has also been investigated for treatment of other ocular surface disorders that may have an immune-based inflammatory component. In these trials, cyclosporine 0.05% ophthalmic emulsion has shown efficacy for management of posterior blepharitis, ocular rosacea, post-LASIK dry eye, contact lens intolerance, atopic keratoconjunctivitis, graft-versus-host disease, and herpetic stromal keratitis. As these disorders are often refractory to other available treatments, ophthalmic cyclosporine is a welcome nontoxic adjunct or replacement to potentially toxic topical or systemic immunosuppressive therapies.

The role of infections in autoimmune disease

Autoimmunity occurs when the immune system recognizes and attacks host tissue. In addition to genetic factors, environmental triggers (in particular viruses, bacteria and other infectious pathogens) are thought to play a major role in the development of autoimmune diseases. In this review, we (i) describe the ways in which an infectious agent can initiate or exacerbate autoimmunity; (ii) discuss the evidence linking certain infectious agents to autoimmune diseases in humans; and (iii) describe the animal models used to study the link between infection and autoimmunity.

Regression of severe corneal stromal neovascularization with topical cyclosporine 0.05% after penetrating keratoplasty for fungal corneal ulcer

PURPOSE

To report regression of corneal stromal neovascularizations with the use of topical cyclosporine 0.05% in a corneal transplant patient performed for fungal corneal ulcer.

DESIGN

Case report.

METHODS

A 14-year-old boy treated for fungal corneal ulceration developed 360 degrees corneal stromal neovascularization peroperatively. Topical cyclosporine 0.05% was used to decrease the risk of rejection.

RESULTS

The neovascularizations regressed totally within 2 months and no signs of graft rejection were present at 6 months follow up.

CONCLUSION

Topical cyclosporine 0.05% may result in regression of stromal corneal neovascularizations and help to reduce the risk of graft rejection in selected cases.

Evidence-based treatment of herpes simplex virus keratitis: a systematic review

Herpes simplex virus (HSV) keratitis is a common cause of ocular and visual morbidity. In this article, we systematically review published randomized clinical trials (RCTs) for HSV epithelial and stromal keratitis in order to establish a rational evidence-based foundation for treatment of these disorders. Articles for review were identified in the MEDLINE database from January 1, 1966, to May 30, 2006. Our review criteria stipulated that each study be performed in prospective, randomized, and double-blinded fashion, that it be controlled, and that it rely on specific clinical criteria for diagnosis and outcome. Of articles thus identified in the English language press, 38 articles met our review criteria, 30 for HSV epithelial keratitis and 8 (comprising 7 RCTs) for HSV stromal keratitis. From these studies, we concluded that the best evidence from treatment trials on HSV epithelial keratitis supports the use of topical trifluridine and topical or oral acyclovir, and suggests a possible additional benefit for topical interferon. The best evidence from RCTs for HSV stromal keratitis supports the use of topical corticosteroids given together with a prophylactic antiviral to shorten the duration of active HSV stromal keratitis, and the use of long-term suppressive oral acyclovir therapy to reduce the incidence of recurrent HSV keratitis.

Therapeutic options for the management of early neurotrophic keratopathy: A case report and review

BACKGROUND

Neurotrophic keratopathy is caused by the loss of corneal sensation secondary to impaired trigeminal nerve function. Timely and appropriate action is required in the management of this condition to prevent serious complications such as corneal ulceration, perforation, and loss of vision. The role of immunomodulating agents such as cyclosporine as a therapeutic option and a review of several future treatment modalities are discussed.

CASE REPORT

A 46-year-old black woman with a noted history of recurrent herpes simplex virus-1 keratitis and secondary neurotrophic keratopathy in the left eye was examined. She reported that another physician had treated her for this condition over the last 6 months. Her treatment regimen consisted of a bandage contact lens, antibiotic solution, and artificial tears. Best-corrected visual acuities were 20/20 in the right eye and 20/25 in the left eye. Biomicroscopy evaluation found punctate keratitis in both eyes and neurotrophic keratopathy with an area of pinpoint epithelial defect in the left eye. Restasis (0.05% cyclosporine ophthalmic emulsion; Allergan, Irvine, California) bid was added to her medical regimen. Within 4 weeks of starting Restasis therapy, the epithelial defect had resolved, and she was advised to discontinue both the bandage lens and antibiotic solution. She was ultimately discharged on a continued regimen of Restasis twice a day and lubricating drops as needed with scheduled follow-up every 3 months.

CONCLUSION

Management of neurotrophic keratopathy requires decisive action. Early treatment intervention is important to help avoid severe complications. The use of immunomodulating agents (topical cyclosporine) in the early stage of management should be considered.

Efficacy of Commercially Available Topical Cyclosporine A 0.05% in the Treatment of Meibomian Gland Dysfunction

OBJECTIVE

To investigate the efficacy of topical cyclosporine A 0.05% (tCsA) (Restasis, Allergan Pharmaceuticals) in the treatment of meibomian gland dysfunction (posterior blepharitis).

METHODS

Thirty-three patients with symptomatic meibomian gland dysfunction were randomized in a prospective study to either tCsA or placebo (Refresh Plus preservative-free artificial tears), 2 times daily for 3 months. They were evaluated at baseline and at 1, 2, and 3 months for subjective symptoms and objective signs including meibomian gland inclusions, lid margin vascular injection, tarsal telangiectasis, fluorescein staining, tear breakup time, and Schirmer scores.

RESULTS

Twenty-six patients completed the study. All patients were tested for ocular symptoms, lid margin vascularity, tarsal telangiectasis, meibomian gland inclusions, tear breakup time, and fluorescein staining. At the 3-month visit, the tCsA group showed a greater improvement in ocular symptoms than the placebo group, but this difference was not statistically significant. At the 3-month visit, several objective examination findings were statistically significantly (P < 0.05) improved in the tCsA group compared with the placebo group. These differences included lid margin vascular injection, tarsal telangiectasis, and fluorescein staining. The most significant finding (P = 0.001) was the greater decrease in the number of meibomian gland inclusions in the tCsA group compared with the placebo group.

CONCLUSIONS

Topical CsA may be helpful in the treatment of meibomian gland dysfunction (posterior blepharitis). Topical CsA did not induce an improvement in the symptoms, but it did decrease the number of meibomian gland inclusions in patients with meibomian gland dysfunction.

Molecular mimicry versus bystander activation: herpetic stromal keratitis

Herpes stromal keratitis (HSK) is a significant inflammatory disease of the cornea as a result of herpes simplex virus (HSV) infection often progressing to vision loss if left untreated. However, even with immunosuppressive compounds and anti-viral drug treatment, HSV continues to be the leading cause of infectious corneal blindness in the industrialized world. The inflammatory nature of the disease is the root of the pathogenic process characterized by irreversible corneal scarring, neovascularization of the avascular cornea, and infiltration of activated leukocytes. Experimental evidence using mice suggest HSK is the result of either molecular mimicry or a bystander activation phenomenon. This review will revisit the basis of HSK focusing on issues that pertain to the autoimmune component versus collateral damage as a result of non-specific activation as a means to explain the pathologic manifestations of the disease.

Topical Cyclosporine A Inhibits Subepithelial Immune Infiltrates but Also Promotes Viral Shedding in Experimental Adenovirus Models

PURPOSE

To determine the effects of topical cyclosporine A (CsA), an immunomodulating T-cell inhibitor, on the formation of subepithelial immune corneal infiltrates (SEIs) and acute adenovirus replication in the NZW Rabbit Ad5 SEI and Ad5 replication models.

METHODS

In the Ad5 SEI model, eyes were treated topically with either 2% CsA in corn oil, 0.5% CsA in artificial tears, or their respective control vehicles 4 times daily for 14 days and then twice daily for 4 days. SEIs were graded on day 23 by masked slit-lamp examination. Using the same treatment protocol in the Ad5 replication model, rabbit eyes were cultured on days 0, 1, 3, 4, 5, 7, 9, 11, 14, 16, 18, and 21 postinoculation, and their tear film viral titers were determined on A549 cells.

RESULTS

The formation of SEIs was significantly reduced following treatment with either 2.0% or 0.5% CsA. However, 2% and 0.5% CsA significantly increased viral titers on several days, prolonged the duration of Ad5 shedding, and increased the number of Ad5-positive cultures per total during the late phase of infection (days 7-21) compared with their respective controls. The 0.5% CsA was equipotent to 2% CsA for most outcome parameters tested.

CONCLUSIONS

A role for topical CsA in the treatment of adenovirus ocular infections remains to be defined in large, randomized controlled clinical trials. During acute infection, reducing SEI formation is highly desirable, but enhancing viral replication may inadvertently serve to promote local epidemics. Future trials should address the important issues of optimized formulation and dose regimen and the possibility of prolonging virus shedding.

Cyclosporine A delivery to the eye: a pharmaceutical challenge

Systemic administration of cyclosporine A (CsA) is commonly used in the treatment of local ophthalmic conditions involving cytokines, such as corneal graft rejection, autoimmune uveitis and dry eye syndrome. Local administration is expected to avoid the various side effects associated with systemic delivery. However, the currently available systems using oils to deliver CsA topically are poorly tolerated and provide a low bioavailability. These difficulties may be overcome through formulations aimed at improving CsA water solubility (e.g. cyclodextrins), or those designed to facilitate tissue drug penetration using penetration enhancers. The use of colloidal carriers (micelles, emulsions, liposomes and nanoparticles) as well as the approach using hydrosoluble prodrugs of CsA have shown promising results. Solid devices such as shields and particles of collagen have been investigated to enhance retention time on the eye surface. Some of these topical formulations have shown efficacy in the treatment of extraocular diseases but were inefficient at reaching intraocular targets. Microspheres, implants and liposomes have been developed to be directly administered subconjunctivally or intravitreally in order to enhance CsA concentration in the vitreous. Although progress has been made, there is still room for improvement in CsA ocular application, as none of these formulations is ideal.

[The latest in herpes simplex keratitis therapy]

Herpetic keratitis is characterized by spontaneous recurrences and a risk of vision loss, the latter being more serious when relapses are frequent and severe. Two clinical forms are commonly distinguished: epithelial keratitis, usually quickly resolved with topical antivirals, and stromal keratitis, which has a slower progression, even when both steroids and antivirals are used. Great strides have been made during the last 20 Years in the therapy of herpes keratitis, which is now considered and treated as a chronic disease. Randomized controlled studies definitively showed the decrease in spontaneous herpetic ocular events in patients treated with long-term oral acyclovir. The effectiveness of preventive treatment has also been shown during high-risk periods, especially ocular surgery, in patients with a history of herpes keratitis. However, the optimal duration and dosage of antiviral prevention have yet to be defined. We can also hope that in the future novel antiviral strategies such as vaccination will reduce the place of herpes keratitis as an indication for corneal graft.

Management of acute ulcerative and necrotising herpes simplex and zoster keratitis with amniotic membrane transplantation

AIM

To report promoted healing of acute ulcerative and necrotising herpetic keratitis after amniotic membrane transplantation (AMT).

METHODS

Retrospective, non-comparative case series of seven patients with acute ulcerative and necrotising herpetic stromal keratitis. Single or multilayer AMT with epithelial side facing up was performed. The main outcome measures were wound healing of the corneal ulcers and decrease of stromal inflammation.

RESULTS

The mean follow up was 10.7 (SEM 1.4) months (range 5-15 months). AMT was performed once in five cases, and twice in further two. Improvement of stromal inflammation was noted within 16.4 (2.5) days (range 7-28 days). Epithelial defects healed within a mean of 17 (2.7) days (range 7-28 days). Vision improved in all but two patients. No serious side effects occurred during the follow up.

CONCLUSIONS

Although performed in an uncontrolled and non-randomised series of patients, these findings indicate that the AMT shows promise in selected cases for the restoration of ocular surface integrity, reduction of stromal inflammation, and improvement of vision in acute ulcerative and necrotising herpetic keratitis.

Feline herpesvirus

Feline herpesvirus infection is an extremely common disease and leads to ocular problems in a large percentage of affected cats. Feline herpesvirus-1 is maintained within the feline population by ready transmission from cat to cat, ensuring continued exposure of kittens and adults. The virus is similar in structure and pathogenicity to herpes simplex virus in humans. Both viruses are members of the family Herpes-viridae and subfamily Alphaherpesviridae. The hallmark of this family of herpesviruses is latency that develops after primary infection. This factor is clinically important because disease may recur at later points in life without further exposure to the virus. Conjunctivitis and corneal ulcers are particularly common forms of feline herpesvirus-1 recurrence.

Outcomes of implantation of an artificial cornea, AlphaCor: effects of prior ocular herpes simplex infection

PURPOSE

To review outcomes of AlphaCor artificial cornea implantation in patients with and without a history of ocular herpes simplex virus (HSV) and to determine whether herpetic eye disease is an indication for AlphaCor surgery.

METHODS

Outcomes of the initial 40 implantations were reviewed and stratified by the presence of a history of ocular disease caused by HSV. Outcomes measures (complications, visual acuity gained) were compared.

RESULTS

Eight of the 40 AlphaCor implantations (20%) were in patients with a history of ocular HSV. Six of these eight patients (75%) developed melt-related complications after AlphaCor insertion. Half of the affected patients required removal of the AlphaCor and replacement with a donor corneal graft to restore ocular integrity. In comparison, only six of the 32 (18.8%) patients without HSV developed a melt after AlphaCor insertion. Patients with HSV with devices in situ exhibited a mean loss of 0.3 line of best-corrected visual acuity compared with the preoperative visual acuity, whereas patients without HSV exhibited a mean gain of 1.4 lines of best-corrected visual acuity.

CONCLUSIONS

The extensive lamellar corneal surgery involved in AlphaCor implantation may precipitate reactivation of latent HSV such that reactivation and resultant inflammation reduce device biointegration and facilitate melting of corneal stromal tissue anterior to the device. Although there may be some benefit from systemic antiviral medication, the current series is not large enough to demonstrate such a benefit, and melting can occur despite medication. The statistically significant difference in outcomes between recipients of AlphaCor with and without HSV is evidence that a history of HSV should be an exclusion factor for AlphaCor surgery.

Corneal ulceration in pediatric patients: a brief overview of progress in topical treatment

Pediatric microbial keratitis is a rare but potentially devastating condition. The condition is similar to adult microbial keratitis, but is often characterized by a more severe inflammatory response. The micro-organisms that cause microbial keratitis in children are similar to the causative agents in adults, with herpes simplex and bacteria being the predominant causative agents, and fungi being less frequent. Of the bacterial pathogens, Pseudomonas aeruginosa, Staphylococcus aureus and alpha-hemolytic streptococci are common. The risk factors for pediatric keratitis include colonization of the eyes during birth and trauma to the cornea. Certain microbial factors involved in microbial keratitis are common to all micro-organisms, including adhesion to the cornea, penetration into the cornea, destruction of the corneal stroma (usually by microbial and/or host proteases), and recruitment of white blood cells to help defend the eye. Specific inflammatory responses that occur during pediatric microbial keratitis are not known in detail, but it is likely that cytokines and polymorphonuclear leucocytes are major factors, as they are in adult microbial keratitis. Treatment for pediatric microbial keratitis is usually the same as treatment for adult microbial keratitis; topical application of antimicrobial agents initially, followed by application of anti-inflammatory agents. With pediatric microbial keratitis, extra care must be taken to ensure nontoxicity due to blood adsorption. New microbial keratitis treatments are being developed and these mainly focus on new antimicrobials, antivirulence agents (such as vaccination against microbial toxins) or specific anti-inflammatory agents. There remains a clear need for increased research into the specific responses during microbial keratitis in children which will help progress new therapies as well as the development of new antimicrobials, especially new antifungal therapies.

Bystander activation involving T lymphocytes in herpetic stromal keratitis

Herpes simplex virus infection of mouse corneas can lead to the development of an immunopathological lesion, termed herpetic stromal keratitis (HSK). Such lesions also occur in TCR-transgenic mice backcrossed to SCID (TgSCID) that are unable to mount detectable HSV-specific immune responses. The present study demonstrates that lesion expression in such mice depends on continuous viral replication, whereas in immunocompetent mice, lesions occurred even if virus replication was terminated at 4 days after infection. The continuous replication in TgSCID mice was considered necessary to produce an activating stimulus to CD4(+) T cells that invade the cornea. Lesions in TgSCID were resistant to control by cyclosporin A, but were inhibited by treatment with rapamycin. This result was interpreted to indicate that T cell activation involved a non-TCR-mediated cytokine-driven bystander mechanism. Bystander activation was also shown to play a role in HSK lesions in immunocompetent mice. Accordingly, in immunocompetent DO11.10 mice, lesions were dominated by KJ1.26(+) OVA-specific CD4(+) T cells that were unreactive with HSV. In addition, KJ1.26(+) HSV nonimmune cells parked in ocularly infected BALB/c mice were demonstrable in HSK lesions. These results provide insight for the choice of new strategies to manage HSK, an important cause of human blindness.

Tegument-specific, virus-reactive CD4 T cells localize to the cornea in herpes simplex virus interstitial keratitis in humans

Herpes stromal keratitis (HSK) is a prevalent and frequently vision-threatening disease associated with herpes simplex virus type 1 (HSV-1) infection. In mice, HSK progression occurs after viral clearance and requires T cells and neutrophils. One model implicates Th1-like CD4 T cells with cross-reactivity between the HSV-1 protein UL6 and a corneal autoantigen. HSK can be prevented by establishing specific immunological tolerance. However, HSK can also occur in T-cell receptor-transgenic X SCID mice lacking HSV-specific T cells. To study the pathogenesis of HSK in the natural host species, we measured local HSV-specific T-cell responses in HSK corneas removed at transplant surgery (n = 5) or control corneas (n = 2). HSV-1 DNA was detected by PCR in two specimens. HSV-specific CD4 T cells were enriched in three of the five HSK specimens and were not detectable in the control specimens. Reactivity with peptide epitopes within the tegument proteins UL21 and UL49 was documented. Responses to HSV-1 UL6 were not detected. Diverse HLA DR and DP alleles restricted these local responses. Most clones secreted gamma interferon, but not interleukin-5, in response to antigen. HSV-specific CD8 cells were also recovered. Some clones had cytotoxic-T-lymphocyte activity. The diverse specificities and HLA-restricting alleles of local virus-specific T cells in HSK are consistent with their contribution to HSK by a proinflammatory effect.

Feline herpesvirus

Feline herpesvirus infection is extremely common and may lead to recurring ocular disease in the adult cat. Recognition of the history and clinical signs that are consistent with FHV-1 infection is critical because diagnostic tests may be negative. Although a variety of treatment options are available, no one therapy is successful in every cat, and a small percentage of cats respond poorly to any treatment.

The evolution of antiviral therapy for external ocular viral infections over twenty-five years

PURPOSE

To review the past 25 years of the evolution of antiviral therapy for the treatment of common external ocular viral infections (herpes simplex virus type 1, varicella-zoster virus, and adenovirus).

METHODS

A broad-based literature review in the fields of virology, antiviral research, and ophthalmology will be carried out. The pathogenesis of the major external ocular viral infections and history of antiviral development will be cited. Important conceptual breakthroughs as well as historical landmarks will be emphasized.

RESULTS

The successful development of effective antivirals to treat the most common external ocular viral infections have dramatically reduced morbidity and sight loss. The immune pathogenesis of herpetic stromal keratitis is better understood.

CONCLUSIONS

Remarkable progress in the development of antiviral therapy has occurred over the past quarter century. Future needs include improved antivirals and immunomodulators and vaccines to prevent and treat herpetic ocular infections and adenovirus keratoconjunctivitis.