HZO MANAGEMENT

Timely diagnosis of herpes zoster ophthalmicus (HZO) and prompt initiation of proper treatment with a combination of antiviral therapy and a corticosteroid can reduce acute and long-term morbidity for affected patients. However, prevention is the best intervention for HZO, and ophthalmologists can play an important role in this area by counselling patients about the live attenuated varicellazoster virus vaccine (“HZ vaccine”; Zostavax, Sanofi Pasteur MSD), according to Elisabeth M Messmer MD.

Dr Messmer, professor, Department of Ophthalmology, Ludwig Maximilians University, Munich, Germany discussed the management of HZO at a symposium during the 4th EuCornea Congress in Amsterdam. She noted that HZO accounts for about 10 per cent to 20 per cent of cases of zoster. It can involve the entire eye, become chronic, particularly in older persons, and be associated with severe complications and debilitating pain during the acute episode, but particularly with the development of post-herpetic neuralgia.

Antiviral treatment can reduce the severity of HZO, shorten its duration and reduce the risk of ocular complications. However, it does not reliably prevent HZO post-herpetic neuralgia. On the other hand, as documented in the Shingles Prevention Study, the herpes zoster vaccine is safe, well-tolerated and reduces the risk of herpes zoster, the burden of illness from herpes zoster and the risk of HZO post-herpetic neuralgia. In 2006, the European Medicines Agency (EMA) issued marketing authorisation for routine use of the herpes zoster vaccine in persons aged 60 and over, excluding those with a few contraindications, and the EMA expanded the authorisation to individuals 50 years and older in 2007. Although there are no data available on herpes zoster vaccination rates in Europe, in the US, recent data show coverage is falling well below the target.

More awareness needed

Cost appears to be one of the causes for the low uptake, but other explanations include low awareness of national recommendations issued by the US Centers for Disease Control and Prevention’s Advisory Committee on Immunization Practices along with lack of recommendation by primary care physicians. “According to one study in the US, only 66 per cent of primary care physicians thought the vaccine for preventing herpes zoster is important. Corneal specialists and other ophthalmologists should be aware of the vaccine and recommending it to their patients,” Dr Messmer said.

Although it is recommended that antiviral treatment for HZO be started within 72 hours of disease onset, there is evidence that patients can also benefit if the medication is started up to seven days after the appearance of skin lesions. Standard antiviral treatment for HZO involves a course of at least 10 days, although it is better to continue the medication until all ocular manifestations are healed, Dr Messmer said. “In collaborating with dermatologists or other physicians managing patients with HZO, it is the ophthalmologist who should be deciding when treatment can be discontinued,” she commented.

Antiviral treatment options for immunocompetent patients with HZO include oral acyclovir, valacyclovir, famcyclovir and brivudin. However, immunosuppressed patients should be treated only with intravenous acyclovir and using a higher dose than that used for immunocompetent persons. Even with this more aggressive treatment, immunosuppressed patients may show resistance, and in that situation, intravenous foscarnet is indicated. Corticosteroids should be given only in combination with an antiviral. Systemic steroid treatment will hasten improvement of keratitis, uveitis and secondary glaucoma and also decreases the intensity of HZO post-herpetic neuralgia. A topical corticosteroid is indicated for treatment of mucous plaque keratitis, stromal keratitis, endotheliitis and uveitis.

Patients who develop neurotrophic keratopathy should be treated with the same modalities used for neurotrophic keratopathy of any aetiology, including ocular lubricants and a bandage contact lens. They may be candidates for amniotic membrane transplantation, tarsorrhaphy, and use of cyanoacrylate glue for sealing corneal perforation. “Neurotrophic growth factor is now in clinical studies as a treatment for neurotrophic keratopathy secondary to herpes zoster ophthalmicus, and so I think there may be some light at the end of the tunnel for management of this condition,” Dr Messmer said.

Oral NSAIDs can be tried for alleviating pain in patients with HZO and HZO post-herpetic neuralgia, but clinicians should recognise that more aggressive therapy may be needed. Options for pain control include oral morphine derivatives, tricyclic antidepressant medications (eg, amitriptyline), or anticonvulsants (eg, gabapentin) and topical capsaicin ointment. HZO-related disease is an uncommon indication for keratoplasty. However, if a graft procedure is necessary, the surgery should be performed only when the eye is quiet.

“According to reports in the literature, there is a low rate of recurrence after keratoplasty for herpes zoster ophthalmicus, and so there are no clear guidelines on the need for prophylaxis with systemic antiviral medication. However, attention should be given to the proper management of ocular surface complications that are often encountered postoperatively,” Dr Messmer emphasised.