Case Series: Pediatric Herpes Simplex Keratitis

Herpes simplex keratitis: A brief clinical overview

The aim of our minireview is to provide a brief overview of the diagnosis, clinical aspects, treatment options, management, and current literature available regarding herpes simplex keratitis (HSK). This type of corneal viral infection is caused by the herpes simplex virus (HSV), which can affect several tissues, including the cornea. One significant aspect of HSK is its potential to cause recurrent episodes of inflammation and damage to the cornea. After the initial infection, the HSV can establish a latent infection in the trigeminal ganglion, a nerve cluster near the eye. The virus may remain dormant for extended periods. Periodic reactivation of the virus can occur, leading to recurrent episodes of HSK. Factors triggering reactivation include stress, illness, immunosuppression, or trauma. Recurrent episodes can manifest in different clinical patterns, ranging from mild epithelial involvement to more severe stromal or endothelial disease. The severity and frequency of recurrences vary among individuals. Severe cases of HSK, especially those involving the stroma and leading to scarring, can result in vision impairment or even blindness in extreme cases. The cornea's clarity is crucial for good vision, and scarring can compromise this, potentially leading to visual impairment. The management of HSK involves not only treating acute episodes but also implementing long-term strategies to prevent recurrences and attempt repairs of corneal nerve endings via neurotization. Antiviral medications, such as oral Acyclovir or topical Ganciclovir, may be prescribed for prophylaxis. The immune response to the virus can contribute to corneal damage. Inflammation, caused by the body's attempt to control the infection, may inadvertently harm the corneal tissues. Clinicians should be informed about triggers and advised on measures to minimize the risk of reactivation. In summary, the recurrent nature of HSK underscores the importance of both acute and long-term management strategies to preserve corneal health and maintain optimal visual function.

Incidence and Risk Factors of Bilateral Herpetic Keratitis: 2022 Update

Simultaneously occurring bilateral herpetic keratitis is a rare clinical manifestation of ocular herpes. Immunocompromised patients are more susceptible to develop bilateral disease. The purpose of this study is to review recent literature on the topic and to highlight latest updates, regarding risk factors and possible correlations to the disease, as well as new therapeutic options.

Impact of Adherence (Compliance) to Oral Acyclovir Prophylaxis in the Recurrence of Herpetic Keratitis: Long-Term Results From a Pediatric Cohort

PURPOSE

To evaluate the long-term role of adherence to oral acyclovir prophylaxis in reducing the risk for recurrent herpes simplex virus keratitis (HSK) in children.

METHODS

A retrospective cohort study was performed including all pediatric patients 16 years or younger) with their first HSK diagnosis and treatment at our center. Children were started on a standardized oral acyclovir prophylactic regimen after the acute phase. Adherence to prophylaxis was assessed monthly through parent interviews. The possible association between any recurrence (not only the first) and exposure to acyclovir prophylaxis was evaluated using random-effects multivariate logistic regression.

RESULTS

A total of 20 eyes of 17 patients (8 boys and 9 girls) were included. The mean follow-up time was 3.5 years. Adherence to acyclovir prophylaxis was registered in 100% of patients with no recurrences and in 36.4% of patients with 1 or more recurrences (P = 0.035). All other tested variables (time of follow-up, sex, age, infectious diseases, underlying hematological diseases, eye, and HSK type) did not differ between the 2 groups. The multivariate model confirmed the lower risk for recurrence in patients who were compliant to therapy (adjusted odds ratio 0.04, 95% confidence intervals 0.00-0.42, P = 0.008). No adverse effects were recorded during follow-up.

CONCLUSIONS

Oral acyclovir prophylaxis is a safe and an effective medical treatment for recurrent HSK and its long-term efficacy is associated with compliance to the therapy.

Ocular manifestations of herpes simplex virus

PURPOSE OF REVIEW

To review ocular manifestations and complications of herpes simplex virus (HSV) and discuss recent advancements in diagnostic and treatment strategy.

RECENT FINDINGS

In-vivo confocal microscopy has expanded our understanding of corneal nerve degeneration, corneal dendritic cell activity, and changes in biomechanical properties in HSV keratitis. Although currently available only as a research tool, metagenomic deep sequencing has the potential to improve diagnostic accuracy beyond the well established PCR technology, especially in atypical cases. Development of an HSV vaccine has shown some encouraging results in a murine model. New treatment options for neurotrophic cornea offer promise, specifically cenegermin nerve growth factor.

SUMMARY

Ocular herpes simplex infection and its complications continue to cause significant visual burden and decreased quality of life. Familiarity with its clinical features, wider adoption of viral PCR diagnostic technology, and recognition of the need for long-term maintenance medications for recurrent or chronic cases form the basis for effective management. Metagenomic deep sequencing, the development of a herpes vaccine, and cenegermin nerve growth factor offer promise as diagnostic, preventive, and therapeutic options, respectively.