From the Guidelines
Herpes zoster ophthalmicus (HZO) is the type of herpes zoster infection that necessitates an emergency ophthalmology consultation, particularly when there is ocular involvement, as it can lead to serious complications such as keratitis, uveitis, and vision loss. This condition occurs when the varicella-zoster virus reactivates in the ophthalmic division of the trigeminal nerve (V1) 1. The diagnosis of HZO is primarily clinical, based on the presence of a zoster rash in the V1 distribution, and may be supported by Hutchinson's sign, which indicates nasociliary nerve involvement 1.
Key considerations for emergency consultation include:
- Presence of zoster rash in the V1 distribution
- Positive Hutchinson's sign
- Ocular symptoms such as eye pain, redness, decreased vision, or light sensitivity
- High risk of complications including keratitis, uveitis, scleritis, retinitis, optic neuritis, and vision loss
Treatment should begin immediately with oral antiviral therapy, such as acyclovir 800mg five times daily, valacyclovir 1g three times daily, or famciclovir 500mg three times daily for 7-10 days, as these medications have been shown to be effective in reducing the severity and duration of HZO when started within 72 hours of rash onset 1. Topical steroids may be needed for certain ocular complications but should only be prescribed by an ophthalmologist due to the potential risks of worsening the infection or causing other adverse effects 1.
The urgency of treatment stems from the fact that antiviral therapy is most effective when started early, and prompt intervention can significantly reduce the risk of permanent ocular damage and post-herpetic neuralgia, thereby improving patient outcomes in terms of morbidity, mortality, and quality of life 1.
From the Research
Herpes Zoster Infection Types Requiring Ophthalmologist Emergency Consult
- Herpes zoster ophthalmicus (HZO) is a subset of herpes zoster that involves the ophthalmic division of the fifth cranial trigeminal nerve and requires urgent ophthalmic consultation due to the potential for vision impairment 2.
- HZO can lead to substantial visual disability if not promptly detected and treated, making it an ophthalmic emergency 3, 4.
- The disease is characterized by a wide range of associated ocular symptoms, including severe chronic pain and vision loss, and is typically a clinical diagnosis due to its classic presentation of a unilateral vesicular eruption in the dermatomes corresponding to the ophthalmic division of the fifth cranial nerve 4.
Ocular Complications of Herpes Zoster Infection
- Ocular complications of HZO include conjunctivitis, keratitis, uveitis, optic neuropathy, and retinitis, with up to 25% of patients developing chronic or recurrent disease 2.
- Uveitis is a common complication of HZO, occurring in approximately half of individuals with the disease, and is most frequently diagnosed during the second week following rash onset 5.
- Eyes with uveitis are more likely to have other ocular complications, including moderate or severe vision loss, corneal scarring, neurotrophic keratitis, band keratopathy, corneal melt, elevated intraocular pressure, glaucoma, and cataract 5.
Treatment and Prevention of Herpes Zoster Infection
- Early recognition and timely treatment with antivirals may prevent ocular complications of HZO, and prompt antiviral therapy is associated with a lower rate of moderate vision loss among eyes with uveitis 5.
- HZO is preventable by vaccination against herpes zoster, with both the recombinant adjuvanted vaccine (RZV) and live-attenuated vaccine (ZVL) significantly reducing the incidence of HZ and HZO in older adults 2.