Herpes Zoster Ophthalmicus
BY WILLIAM L. MILLER, OD, PHD, FAAO
Herpes zoster ophthalmicus (HZO) affects those who have had a primary infection in their childhood as a result of the varicella zoster virus (chickenpox). The virus lies dormant in the trigeminal sensory ganglion and is reactivated to cause ocular disease. More than 90% of adults demonstrate antibody titers for the disease, and nearly 30% of those develop herpes zoster in their lifetime. Two recent retrospective studies show most patients between the ages of 50 and 59 affected (Edell and Cohen, 2013; Ghaznawi et al, 2011), while another study found a mean age of 62.6, with an increased risk rate of 23% per decade (Yawn et al, 2013).
The zoster vaccine (Zostavax [Merck & Co.]), which can prevent a zoster reactivation, is also reported to be underused (Edell and Cohen, 2013). Therefore, it is important as a public health issue to educate our patients on the benefit of herpes zoster vaccinations (Yawn et al, 2013; Jung et al, 2013). The Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices (ACIP) recommends its administration to patients over the age of 60. Caution must be exercised in patients who have experienced previous episodes of HZO, as viral reactivations within the cornea have been reported (Hwang et al, 2013).
Signs and Treatment
Clinical signs of HZO are varied and can affect the ocular surface, adnexa, and face. The ensuing signs are typically preceded by prodromal symptoms for up to five days that may include fever, malaise, headache (all non-specific) as well as burning, hyperesthesia, and pain along the affected dermatome. Without treatment, patients have a 50% to 70% chance of developing ophthalmic signs, which range from dermatitis, respecting the midline, or inflammation on the ocular surface (conjunctivitis, keratitis, episcleritis, scleritis, and anterior uveitis). The risk of ophthalmic involvement is heightened if patients present with Hutchinson’s sign (vesicles on the tip of the nose). Corneal pseudodendrites, if present, can be confused with herpes simplex. A prudent diagnosis includes combining symptoms and often non-specific signs with a systemic case history.
Treatment and management strategies are aimed at quelling the inflammation and sequelae, which may include glaucoma. Aggarwal et al (2014) demonstrated that a topical antiviral (0.15% ganciclovir, Zirgan [Bausch + Lomb]) used five times per day may be useful in treating the corneal pseudodendrites in HZO patients. Others recommend 3% acyclovir ointment instead (Sanjay et al, 2011). Overall, treatment will include prescribing of antiviral medications such as acyclovir, famciclovir, and valacyclovir to prevent and/or reduce the risk for serious ocular morbidity. They should be prescribed within 48 to 72 hours of the dermatological rash and continued for at least seven days. The increased efficacy and reduced frequency of administration favors both famciclovir and valacyclovir (McDonald et al, 2012).
Oral steroids are useful in patients who have serious and debilitating symptoms. However, their use should be concomitant with oral antivirals and are accompanied by serious side effects that may include adrenal suppression, gastritis, and hypertension.
Other medications that can suppress the inflammatory effects of HZO include topical steroids, used in episcleritis, disciform immune keratitis, and anterior uveitis.
They could also be helpful with glaucoma, depending on the etiology, and used concomitantly with antiglaucoma medications for managing the intraocular pressure increases due to inflammation. CLS
For references, please visit www.clspectrum.com/references.asp and click on document #220.
Dr. Miller is an associate professor and chair of the Clinical Sciences Department at the University of Houston College of Optometry. He is a consultant or advisor to Alcon and Vistakon and has received research funding from Alcon and CooperVision, and lecture or authorship honoraria from Alcon and B+L. You can reach him at firstname.lastname@example.org.