HERPES ZOSTER OPHTHALMICUS

The 56-year-old male whose eye and adnexae appear in this photo presented with a history of recent onset ocular pain, sectoral injection, and photophobia in his left eye. He denied any reduced vision in the affected eye. Additional history-taking revealed that in the past, he had experienced signs and/or symptoms commonly associated with chicken pox. The patient described his health as good and denied any current illness.

Best-corrected vison was 20/20 in the non-affected (right) eye and was 20/25 in the left eye. Biomicroscopy of the right eye was unremarkable, but examination of the affected eye revealed sectoral grade 3+ injection and edema in the temporal conjunctiva and underlying episclera. The left temporal sector of his cornea showed superficial fluorescein staining limited to the epithelial layer. Corneal sensation was intact in the right eye but was significantly reduced in the left eye.

We diagnosed this patient with herpes zoster ophthalmicus (HZO), a condition that occurs when there is reactivation of the varicella-zoster virus in the ophthalmic division of the trigeminal nerve.¹ HZO is caused by the same virus that causes chicken pox and represents approximately 10% to 20% of all herpes zoster presentations.² The dermatologic presentation of herpes zoster, often referred to as shingles, affects approximately one million Americans each year. Although it can occur at any age, it is more common in older individuals.²

Herpes zoster typically occurs in three stages. The pre-eruptive phase is characterized by unilateral burning, tingling, or pain along a dermatome.³ Other symptoms may include fever, headache, and photophobia. The eruptive phase is characterized by dermal changes including a rash that eventually becomes pustular and is typically unilateral, although bilateral lesions have been reported. During this phase, ocular involvement may include the conjunctiva, cornea, uvea, and retina.³ The corneal lesions in HZO differ from true epithelial defects seen in herpes simplex keratitis; they consist of heaped up epithelial tissue. These pseudodendrites lack terminal bulbs and true branching, and unlike H. simplex lesions, they stain poorly with both fluorescein and rose bengal.²

The most common complication of herpes zoster is post herpetic neuralgia (PHN), in which the individual develops chronic pain after the dermal lesions resolve.³ Approximately 20% of people aged 60 to 65 years old who have had acute herpes zoster will develop PHN.⁴ It may persist for months or even years.

Much of the misery caused by HZO can be prevented by the use of vaccines.⁵ There are currently two types of vaccine available in the United States. Zostavax (Merck), a single-dose agent, was approved in 2006. In 2017, Shingrix (GlaxoSmithKline), a two-dose agent, was approved. Both have a proven track record for reducing the incidence of H zoster infections.⁵

Topical ophthalmic antiviral agents have poor efficacy against the herpes zoster virus.⁶ Our patient‘s HZO was successfully treated with topical steroids and systemic acyclovir, and it resolved with minimal sequelae. Corneal sensation is unlikely to return, but in some cases, partial restoration of corneal sensation occurs after resolution of the active disease.⁵

References

1. Shaikh S, Ta CN. Evaluation and Management of Herpes Zoster Ophthalmicus. Am Fam Physician. 2002 Nov 1;66:1723-1730.
2. Vrcek I, Choudhury E, Durairaj V. Herpes Zoster Ophthalmicus: A Review for the Internist. Am J Med. 2017 Jan;130:21-26.
3. Ting DSJ, Ghosh N, Ghosh S. Herpes zoster ophthalmicus. BMJ. 2019 Jan 17;364:k5234.
4. Han LSM, Lam LYW. Herpes zoster ophthalmicus pseudodendrites: For topical antivirals or not? Clin Exp Ophthalmol. 2019 Mar 8. [Epub ahead of print]
5. Levin MJ, Weinberg A. Immune responses to zoster vaccines. Hum Vaccin Immunother. 2019 Jan 24:1-6.
6. Cruzat A, Hamrah P, Cavalcanti BM, Zheng L, Colby K, Pavan-Langston D. Corneal Reinnervation and Sensation Recovery in Patients With Herpes Zoster Ophthalmicus: An In Vivo and Ex Vivo Study of Corneal Nerves. Cornea. 2016 May;35:619-625.