Suppurative corneal ulceration following herpetic keratitis

Predisposing factors, microbiological features and outcomes of patients with clinical presumed concomitant microbial and herpes simplex keratitis

BACKGROUND/OBJECTIVES

To describe the predisposing factors, pathogens and outcomes in patients with clinical presumed concomitant microbial and herpes simplex keratitis (HSK) at Sydney Eye Hospital, Australia over a 5-year period.

SUBJECTS/METHODS

A retrospective case review was conducted. Patients with clinical presumed concomitant microbial and HSK from 2012 to 2016 were identified from pathology and hospital coding databases. Data were extracted from the medical records. VA was converted to the logarithm of the minimum angle of resolution (logMAR). 'Poor' outcome was defined as final VA worse than 6/60, or decrease in VA during treatment, or presence of complication, or needed surgical intervention.

RESULTS

126 episodes in 121 patients were included; median age 70 years (range 18-96); 56% male. Predisposing factors included blepharitis 20/126 (16%) cases, and corneal transplantation 19 (15%). Forty-six (37%) cases had prior HSK. Coagulase-negative staphylococci 51/116 (44%), Staphylococcus aureus 11 (9%), and Pseudomonas aeruginosa 11 (9%) were the most common isolates. The median VA at initial visit was 1.7 logMAR (range 0.04-2.7) and at final visit, 0.98 logMAR (range 0-2.7) (P < 0.05). Complications occurred in 70 episodes: persistent epithelial defect in 38 (30%); intraocular pressure elevation in 15 (12%), and corneal perforation in 12 (10%). 'Poor' outcome was recorded in 46/75 (61%) episodes.

CONCLUSIONS

Patients with clinical presumed concomitant microbial and HSK face significant ocular morbidity and poor visual outcome. In our setting, previous HSK, corneal and ocular surface disease, were common predisposing factors and Gram-positive bacteria were the most commonly associated organisms.

Antiviral treatment and other therapeutic interventions for herpes simplex virus epithelial keratitis

BACKGROUND

Eye disease due to herpes simplex virus (HSV) commonly presents as epithelial keratitis which, though usually self-limiting, may persist or progress without treatment.

OBJECTIVES

To compare the relative effectiveness of antiviral agents, interferon, and corneal debridement in the treatment of HSV epithelial keratitis.

SEARCH METHODS

We searched CENTRAL (which contains the Cochrane Eyes and Vision Group Trials Register) (2014, Issue 12), PubMed (January 1946 to 31 December 2014), EMBASE (January 1980 to 31 December 2014), Latin American and Caribbean Health Sciences Literature Database (LILACS) (January 1982 to 31 December 2014), System for Information on Grey Literature in Europe (OpenGrey) (January 1995 to 31 December 2014), BIOSIS (January 1926 to 5 May 2014), Scopus (January 1966 to 31 December 2014), Japan Science and Technology Institute (J-Global) (January 1975 to 31 December 2014), China National Knowledge Infrastructure (CNKI) (January 1979 to 31 December 2014), British Library's Electronic Table of Contents (Zetoc) (January 1993 to 7 May 2014). We looked for trials listed on the the metaRegister of Controlled Trials (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), the World Health Organization (WHO) International Clinical Trials Registry Platform (ICTRP) (www.who.int/ictrp/search/en), Chinese Clinical Trial Registry, the U.S. Food and Drug Administration (FDA) (www.fda.gov/), National Institute for Health and Clinical Excellence (NICE) (www.

EVIDENCE

nhs.uk) and the European Medicines Agency (EMA) (www.ema.europa.eu/ema/) as of 31 December 2014. There were no language or date restrictions in the search for trials. We also culled literature digests and conference proceedings as of 15 April 2014. There were no language or date restrictions in the search for trials.

SELECTION CRITERIA

Randomised and quasi-randomised trials of HSV dendritic or geographic epithelial keratitis were included that reported the proportion of eyes healed at one week, two weeks, or both after enrolment.

DATA COLLECTION AND ANALYSIS

We tabulated data on study characteristics, risk of bias, and outcomes and used direct comparisons to estimate a risk ratio (RR) and, when feasible, a hazard ratio (HR) with a 95% confidence interval (CI). Heterogeneity was assessed by an inconsistency index. A multiple treatment comparison meta-analysis consolidated direct and indirect comparisons of relative healing at 14 days.

MAIN RESULTS

One hundred thirty-seven studies involving 8333 eyes met the inclusion criteria. Placebo-controlled studies were heterogeneous in comparison with idoxuridine (RR 1.74; 95% CI 1.03 to 2.91) and few in number for vidarabine (RR 1.81; 95% CI 1.09 to 3.01), interferon (RR 1.32; 95% CI 1.06 to 1.64), and debridement. Vidarabine (RR 1.13; 95% CI 1.02 to 1.25), trifluridine (RR 1.30; 95% CI 1.18 to 1.43), acyclovir (RR 1.23; 95% CI 1.14 to 1.34), and brivudine (RR 1.34; 95% CI 1.18 to 1.51) were more effective than idoxuridine. Trifluridine (RR 1.17; 95% CI 1.03 to 1.32) and acyclovir (RR 1.11; 95% CI 1.03 to 1.19) were more effective than vidarabine. No significant differences in healing emerged among trifluridine, acyclovir, brivudine, and foscarnet although few studies compared brivudine or foscarnet with other antivirals. Any potential advantage of ganciclovir compared to acyclovir was mitigated by study heterogeneity and possible publication bias. Only one study evaluated the joint use of two topical antivirals. In a limited number of studies, oral acyclovir (RR 0.92; 95% CI 0.79 to 1.07) or the combination of oral acyclovir with a topical antiviral (RR 1.36; 95% CI 0.68 to 2.74) appeared as effective as a single topical antiviral agent. Compared to topical antiviral monotherapy, the combination of an antiviral with either interferon or debridement had inconsistent effects on expediting healing and improving outcome.

AUTHORS' CONCLUSIONS

Placebo-controlled studies of HSV epithelial keratitis are limited to superseded interventions. Trifluridine and acyclovir are more effective than idoxuridine or vidarabine and similar in therapeutic effectiveness. Brivudine and foscarnet do not substantially differ in effectiveness from trifluridine or acyclovir. Ganciclovir is at least as effective as acyclovir. The addition of interferon to a nucleoside antiviral agent and the combination of debridement with antiviral treatment need to be further assessed to substantiate any possible advantage in healing.

Antiviral treatment and other therapeutic interventions for herpes simplex virus epithelial keratitis

BACKGROUND

Eye disease due to herpes simplex virus (HSV) commonly presents as epithelial keratitis.

OBJECTIVES

To compare the relative effectiveness of antiviral agents, interferon, and corneal débridement in the treatment of acute HSV epithelial keratitis.

SEARCH STRATEGY

We searched CENTRAL (The Cochrane Library 2010, Issue 4), MEDLINE (January 1950 to October 2010), EMBASE (January 1980 to October 2010), Latin American and Caribbean Literature on Health Sciences (LILACS) (January 1982 to October 2010), Zetoc (British Library's Electronic Table of Contents), System for Information on Grey Literature in Europe (openSIGLE), Biosciences Information Service (BIOSIS), the metaRegister of Controlled Trials (mRCT) (www.controlled-trials.com), ClinicalTrials.gov (www.clinicaltrials.gov), Japan Information Center of Science and Technology (JICST-EPlus), and China Academic Journals database (CAJ) via China National Knowledge Infrastructure (CNKI) with citations confirmed using China/Asia On Demand (COAD). There were no language or date restrictions in the search for trials. All databases except CNKI and COAD were last searched on 27 October 2010, CNKI and COAD were searched on 1 April 2010. We also searched literature digests, conference proceedings and reference lists.

SELECTION CRITERIA

Of 152 eligible studies,106 comparative treatment trials involving 5872 eyes with dendritic or geographic epithelial keratitis were analysed for corneal healing over two weeks.

DATA COLLECTION AND ANALYSIS

Interventions were compared at 14 days after trial enrolment by calculating a risk ratio (RR) that was adjusted with indirect RR, assessed by an inconsistency index (I(2) ) and supplemented by a seven-day RR and a hazard ratio (HR).

MAIN RESULTS

Idoxuridine, though uncertainly better in healing outcome than control because of few trials with 14-day follow up, allowed earlier corneal re-epithelialisation. Vidarabine resulted in a significantly better outcome than placebo in one trial (RR 1.96; 95% CI 1.10 to 3.49). Compared to idoxuridine, in combined direct and indirect analyses, vidarabine (RR 1.11; 95% CI 1.03 to 1.19), trifluridine (RR 1.31; 95% CI 1.20 to 1.42), acyclovir (RR 1.23; 95% CI 1.16 to 1.31), brivudine (RR 1.38; 95% CI 1.18 to 1.61), and ganciclovir (RR 1.40; 95% CI 1.25 to 1.57) were significantly more effective. Trifluridine (RR 1.12; 95% CI 1.04 to 1.21) and acyclovir (RR 1.11; 95% CI 1.05 to 1.19) appeared more effective than vidarabine. No significant differences were found in comparisons between acyclovir, trifluridine and brivudine. The comparison of ganciclovir to acyclovir was limited by heterogeneity and possible publication bias. The joint use of two topical antivirals (RR 1.00; 95% CI 0.89 to 1.12) and the use of oral acyclovir alone (RR 0.92; 95% CI 0.79 to 1.07) or combined with a topical antiviral (RR 1.08; 95% CI 0.99 to 1.17) appeared as effective as topical antiviral therapy. Compared to antiviral monotherapy, the combination of an antiviral with interferon (RR 1.03; 95% CI 0.99 to 1.07) or with débridement (RR 1.04; 95% CI 0.95 to 1.14) did not yield significantly better outcomes but may have accelerated healing. The corneal epithelial healing outcome was improved when antiviral therapy was added to débridement (RR 1.21; 95% CI 1.04 to 1.42).

AUTHORS' CONCLUSIONS

Trifluridine and acyclovir are more effective than idoxuridine or vidarabine, and similar in therapeutic effectiveness. Brivudine and ganciclovir are at least as effective as acyclovir. While not improving outcome, the combination of interferon and an antiviral agent may speed healing. The effectiveness of corneal epithelial débridement is improved by an antiviral agent.

Preliminary Data Suggest a Role for Bacterial Superinfection of a Viral Keratitis after Zosteriform Spread of Herpes Simplex virus to the Eye of the Mouse

After inoculation of herpes simplex virus (HSV) on the snout of the mouse, spread to the eye occurs via neural pathways. The keratitis which ensued was clinically atypical for a pure herpetic keratitis, leading to a search for other causative agents. Preliminary data suggests that bacteriological superinfection of the viral keratitis occurs frequently, producing a unique experimental model.

Neural spread of herpes simplex virus to the eye of the mouse: microbiological aspects and effect on the blink reflex

This paper reports the microbiological aspects of zosteriform spread of herpes simplex virus (HSV) to the eye in the NIH strain of inbred mouse. Microbiological data support the concept of true zosteriform spread of herpes simplex virus from the inoculation site on the snout to the trigeminal ganglion, and thence to the eye. Following zosteriform spread of HSV to the eye, there is a frequent bacterial superinfection and this is associated with a typical clinical picture. Treatment of the mice with intensive systemic and topical antibiotics is able to alter the frequency with which this type of keratitis is seen.