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EW NEWS & OPINION 18 The lowdown on HSV and VZV T he herpes simplex virus (HSV) can be a great masquerader, according to Francis Mah, MD, director of cornea and external disease, and co-director of refractive surgery, Scripps Clinic, La Jolla, Calif. HSV can manifest itself in myriad ways in the eye, from blepharitis to iritis to keratitis. "Almost anything funny or strange in the external eye that happens to pop up can be HSV," Dr. Mah said. In addition, HSV's close cousin varicella-zoster virus (VZV), which results in shingles, can also have significant periocular implica- tions. "If you have ocular complica- tions with shingles, those can be worse (than HSV)," Dr. Mah said. So what can be done here? Here is the latest for treating both of these conditions. Handling HSV With HSV epithelial keratitis, the most common sign is the dendrite, Dr. Mah said. For such cases of ep- ithelial keratitis, treatment has been limited. "For decades all we had was trifluorothymidine [Viroptic, Pfizer, New York]," Dr. Mah said, adding that while it is effective, there are downsides, such as cost, with a relatively high price even for the generic. He finds that toxicity is also a major issue here. "Not only does it have the traditional preservative BAK, but it also has thimerosal, which is a pretty toxic preservative that has been all but eliminated from topical medications," Dr. Mah said. In addition, he said that the drug must be given 9 times a day. "Because of those issues, although it's very effective, I personally don't use trifluridine," Dr. Mah said. Instead he tends to prescribe oral antivirals such as acyclovir, valacy- clovir (Valtrex, GlaxoSmithKline, Middlesex, U.K.), or famciclovir (Famvir, Novartis Pharmaceuticals, Basel, Switzerland). These have been shown to be as effective as the topi- cal medication, without the toxicity risk. "I'll use acyclovir at 800 milligrams 2 or 3 times a day," Dr. Mah said. Bennie Jeng, MD, professor and chair, Department of Ophthalmol- ogy and Visual Sciences, University of Maryland School of Medicine, Baltimore, also opts for oral medica- tions because of toxicity concerns. "Some people, including myself, will use oral acyclovir or some derivative of it because we know it penetrates into the tear film pretty well and that decreases the toxicity because it's an (oral) drug," Dr. Jeng said. He will also lighten the viral load with epithelial debridement along the dendrite. Another possibility might be to add interferon, he said. There have been studies that have shown a synergistic effect to including this with oral medication. Some people will also add topi- cal steroids after starting antivirals to decrease what they may perceive as inflammation underneath the area of infection, he said. Dr. Mah said that the newest treatment for HSV is use of the topical agent Zirgan (ganciclovir, Bausch + Lomb, Bridgewater, N.J.). This gel only needs to be dosed 5 times a day compared to trifluridine at 9 times a day. "Obviously, it's much less dos- ing," he said. "It's also much less toxic in general." So far there are no studies comparing the effectiveness of this to oral medication, he noted. However, expense may be a consid- eration. "If you have a sample, I would definitely give this to pa- tients." Outside of the U.S., acyclovir ointment is another option. "It's effective and well tolerated," he said. "We just don't have it here in the U.S." Patients can develop stromal keratitis after the viral infection has been treated, Dr. Mah said. "These dead viral particles that are left be- hind in the cornea cause the body to react as if there was a live viral infec- tion. You get an immune response in the stroma and it causes scarring and edema." Dr. Jeng described the tradi- tional infectious stromal keratitis as "necrotizing" and this immune reaction as "non-necrotizing." "I think the mainstay of treat- ment for immune keratitis is topical steroids," he said. Dr. Jeng also puts patients on oral antiviral medication for a time. "I will use the orals to treat any possible virus that is sitting around," he said. "Then I will keep them on prophylactic dosing for some period of time because the Herpetic Eye Disease Study (HEDS) has shown that using acyclovir prophylaxis prevents recurrence." With the herpes virus, iritis can also commonly occur. "The herpes viruses are the one type of virus class that is associated with elevated in- traocular pressure from active infec- tion," Dr. Jeng said. "The thought is there is inflammation at the trabecu- lar meshwork that clogs it up and causes the pressure to go up." The treatment for this is topical steroids, which will decrease inflammation and lower the pressure. In addition, he uses oral antiviral medications as a prophylaxis against recurrence. Treating VZV The related VZV virus, which lurks in the body after chicken pox and can cause shingles, may also result in ocular problems. Dr. Mah said this could cause conditions such as neurotrophic keratopathy, glau- coma, and iritis. He finds that these can be much more difficult to man- age than similar conditions caused by HSV. A significant prognostic in- dicator of possible ocular problems is Hutchinson's sign. This is marked by pustules on the side of the nose and indicate that the nasociliary branch of the fifth cranial nerve has been affected by the VZV virus, Dr. Mah explained. "If I see the little pustules down the nose, a positive Hutchinson's sign, I'll watch these patients more carefully because I July 2014 by Maxine Lipner EyeWorld Senior Contributing Writer Getting hip to treating ocular herpes Pharmaceutical focus HSV keratitis affects thousands of people in the U.S. each year. Source: Edward J. Holland, MD 12-29 News_EW July 2014-DL_Layout 1 6/30/14 8:38 AM Page 18

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