Keep Viruses From “Going Viral”

Viruses don’t discriminate. With a few exceptions, they’re happy to set up camp in an eye of any patient, regardless of age, sex, or socioeconomic status. All they need is opportunity. Under the right conditions, a virus can thrive and potentially cause long-term damage to ocular structures. But, with proper oversight, clinicians in optometry can offer guidance and medical treatments that can assure the eye outlives the virus. Nathan Lighthizer, OD, of Northeastern State University’s Oklahoma College of Optometry reviewed the strategies an optometrist can utilize in his presentation, “Going Viral: HSV, HZO, EKC” at the Southeastern Educational Congress of Optometry (SECO) 2021 meeting, held April 28 to May 2 in Atlanta.

Dr Lighthizer’s instruction was based on the cases of 3 patients. The first appeared with a unilateral red eye. Dr Lighthizer said he learned early in his career “for any unilateral red eye, herpes simplex has to be in your differential somewhere.” According to an in-class digital poll, most clinicians attending the presentation put this diagnosis on the top of their list of suspects, too. 

But 2 days later, the patient, a 74-year-old woman, reappeared with worsening vision, redness, and pain. She also indicated temporal pain and vesicles on the side of the nose, known as Hutchinson’s sign. Her diagnosis was herpes zoster.

For shingles patients, “the earlier you can get them on oral antivirals, the better, Dr Lighthizer said. In particular Dr Lighthizer recommended valacyclovir due to its reduced dosing schedule and because it’s capable of treating even outside the 72-hour window of onset.

The second patient presented with extreme light sensitivity, watery discharge, and close to a dozen corneal infiltrates. The epidemic keratoconjunctivitis diagnosis was clear — even before the highly contagious virus spread through the office and to the next 5 patients who used the same sign-in pen. 

This infection also presents with foreign body sensation, itching, or burning, and often on the heels of a cold or flu. Dr Lighthizer said almost all the cases he sees appear in October or November. “It’s unlikely to appear in your chair in July,” he explained. Approximately “80% of EKC patients will have corneal involvement.” 

To understand the course of the virus, Dr Lighthizer advised, remember the “rule of 8s.” He explained, “The average course of EKC is 18 to 24 days. They call it the rule of 8s because it’s adenovirus 8 (strain 8); it’s 8 days of a red eye — an infectious red eye — and then 7 to 8 days of an immune response, and 7 to 8 days of resolution.”

“Because the subepithelial corneal infiltrates can scar the cornea, these patients will require treatment with steroids and an antiseptic,” Dr Lighthizer said. 

The last example showcased a 34-year-old woman who wore contact lenses but was experiencing sudden onset irritation, so much so that she could not put her lenses in. An examination revealed a round corneal infiltrate. Although Dr Lighthizer first suspected contact lens involvement, further testing uncovered an acute mild uveitis and intraocular pressure in the affected eye that was significantly higher than the unaffected eye. She also demonstrated reduced corneal sensitivity during a test Dr Lighthizer conducts using dental floss. These signs all pointed her to Herpes simplex virus diagnosis. According to Dr Lighthizer, these patients are usually treated with ganciclovir. 

Viruses have to run their course. But distinguishing these patients from one another, especially early in its course, can help clinicians guide treatment and assure preserved ocular health long after it has gone.  

Reference

Lighthizer N. Going viral: HSV, HZO, EKC. Presented at: Southeastern Educational Congress of Optometry (SECO) 2021 Annual Meeting; April 28-May 2, 2021; Atlanta, GA. Course V116.