Delayed herpes zoster pseudodendrites. Polymerase chain reaction detection of viral DNA and a role for antiviral therapy.

BACKGROUND: The late-onset pseudodendrites, delayed corneal mucous plaques, of herpes zoster ophthalmicus are reported to be of mechanical or immune origin and to be worsened by antiviral therapy.

OBJECTIVE: To study pseudodendrites to ascertain a viral presence in the lesions and their response to antiviral therapy.

DESIGN: Prospective clinical study.

SETTING: Outpatient and inpatient hospital-based corneal specialty referral practice; molecular virology laboratory.

PATIENTS: Six patients, aged 33 to 89 years, four with delayed herpes zoster ophthalmicus pseudodendrites and two with herpes zoster ophthalmicus neurotrophic ulceration. One patient was immunosuppressed.

MAIN OUTCOME MEASURES: Findings from clinical evaluation; polymerase chain reaction assays of lesions and tear film of six patients; polymerase chain reaction and light and electron microscopy of the corneal button from one patient; and the clinical response of four patients to various antiviral drugs.

RESULTS: In contrast to reports in the current literature, delayed pseudodendrites may also be infectious, as they are positive for zoster DNA by polymerase chain reaction and appear responsive to certain antiviral therapy. The corneal button from an immunosuppressed patient had mature and immature viral particles in the basal cells within 2 weeks of transplantation.

CONCLUSIONS: To our knowledge, this is the first report of viral DNA in delayed zoster pseudodendrites. Recurrent viral infection may play a role in this form of zoster keratopathy and warrant antiviral therapy.