Eyeworld

EW FEATURE January 2011 57 Determining best treatment not always easy "C hallenging" is an apt term to describe treat- ment for pa- tients with ocular herpes simplex virus (HSV). Determining the type of HSV pres- ent in the eye and then treating that specific disease appropriately while avoiding additional flares and visual damage can be perplexing, said Ed- ward J. Holland, M.D., professor of ophthalmology, University of Cincinnati, and director, Cornea Service, Cincinnati Eye Institute, Cincinnati. "It's important to understand that HSV is a great masquerader and can be present in a variety of differ- ent ways," he said. HSV also has been reported as the leading global cause of unilateral blindness. Although the treatment algo- rithm for HSV has remained the same for quite some time, clinicians continue to debate certain treatment aspects, such as when or if to use steroids for certain kinds of HSV, Dr. Holland said. Drugs to treat HSV that are new to the market or that are on the horizon give clinicians additional reasons to reflect on cur- rent treatment regimens. HSV epithelial disease One common form of HSV is epithe- lial disease, for which about 60,000 cases occur each year in the United States, said Francis S. Mah, M.D., co-medical director, Charles T. Campbell Ophthalmic Microbiology Laboratory, University of Pittsburgh School of Medicine, Pittsburgh. These cases are often accompanied by changes in vision, a foreign body sensation, and possible nerve dam- age, Dr. Mah explained. Live virus is present. In addition to removal of the viral load, the typical treatment for this form of HSV has been topical trifluridine (Viroptic, GlaxoSmithK- line, Middlesex, United Kingdom) nine times a day for the first few days and then a decreasing dose. However, this particular medication and its frequent dosing have come with a few problems. "Burning and stinging are side effects. There is also the compliance issue and cost," Dr. Mah said. Additionally, trifluridine is not viral-specific and has led to signifi- cant toxicity and a risk for repeated infections, Dr. Holland said. For these reason, clinicians moved to the use of oral antivirals such as acyclovir (various manufacturers) or valcyclovir (Valtrex, GlaxoSmithK- line, Middlesex, England) to replace or supplement topical treatment. "Straight oral therapy was a huge breakthrough in HSV keratitis because it's given patients more ef- fective treatment," Dr. Holland said. Dr. Mah has observed that general ophthalmologists are more likely to prescribe topical treatment, while cornea specialists tend to favor oral medications. Studies have shown that both are equally efficacious, he said. Ganciclovir (Zirgan, Bausch & Lomb, Rochester, N.Y.), an anti-viral topical treatment that has been available in Europe for about a decade under the name Virgan, be- came available in the United States in 2010. "This is DNA specific, has greater efficacy, and most impor- tantly, has minimal toxicity," Dr. Holland said. Dosing is only five times a day versus nine times a day. Additionally, it does not have the same preservatives as trifluridine. The introduction of Zirgan into the U.S. market has turned the tide back to the use of more topical therapy, Dr. Holland said. The introduction of Zirgan has been a big advance in the U.S. market, Dr. Mah said. Dr. Holland said he typically treats this kind of HSV with Zirgan for 14 days but will also use oral anti-viral medications. HSV stromal keratitis Another form of HSV that requires a slightly different treatment is stro- mal keratitis, Dr. Mah said. A patient with stromal keratitis typically has a post-infectious reaction shortly after a lesion has occurred. Although the keratitis may clear up on its own, treatment aims to prevent further progression to the stroma and to prevent vision- or eye-threatening conditions, Dr. Mah said. Steroids are used to quiet the eye, and anti-viral medications—oral or topical—are used to prevent the recurrence that steroids can trigger, Dr. Mah said. However, the use of steroids in these patients is a big controversial in HSV treatment, Dr. Holland said. "Some clinicians say they just let the eye heal. I've had too many patients have scarring," he said. So, once the virus is no longer live, he will often initiate steroids during the second week and con- tinue use of an oral anti-viral agent for prophylaxis. Dr. Holland believes that oph- thalmologists should not rush to taper steroids too quickly. "They can taper too rapidly, and patients get re- current infections and the risk of scarring or loss of vision. I prefer to quiet the stroma with aggressive top- ical steroids and then do an ex- tremely slow tapering. The enemy is not topical steroids, the enemy is re- bound inflammation," he said. Dr. Holland compares the side effects from steroids—including higher IOP or secondary cataract— against the side effects of visual damage—including the possible need for a keratoplasty—and would rather risk the former than the latter. Because of the risk for visual damage, Dr. Holland usually starts by Vanessa Caceres EyeWorld Contributing Editor Expanding options for HSV treatment patients with a stronger steroid dose and will taper to a lower dose as nec- essary. Then, he will taper just one drop at a time over several weeks or months. "Over the long term, this slow dose of steroids is worth the risk over the alternative, which is AT A GLANCE • HSV treatment is often challenging; ocular HSV infections are the lead- ing global cause of unilateral blind- ness • On initial exam, clinicians should determine if the HSV presents with live virus or not • Cases with live virus require oral and/or topical anti-viral medica- tions. Cases that occur after the presence of live virus typically re- quire steroids and oral or topical anti-viral medications • The use of steroids and the dosage amount when treating certain forms of HSV is controversial • Some new medications have given clinicians more treatment options for HSV. Other treatment options are under investigation Dendritic ulcer due to HSV Source: Henry Muller, M.D. continued on page 58

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