ACUTE BILATERAL RETINAL NECROSIS - HEALING OF THE 2ND AFFECTED EYE

Background The acute retinal necrosis syndrome (ARN) is caused by the Varicella zoster virus or the Herpes simplex virus. However the dosage and duration of the antiviral therapy for prevention of an infection in the second eye or treatment of an infection on an affected fellow eye is still not known. We discuss the timing of a possible steroid treatment and demonstrate in a case report how an acute retinal necrosis syndrome in a fellow eye was successfully treated. Patient First eye. A 27-year-old not immunocompromised patient (HIV-negative) showed 2 months after a febril state an acute iritis in the right eye. 14 days later an acute retinal necrosis syndrome was observed. The patient received Acyclovir 3 x 750 mg i.v. for 6 days, and afterwards 5 x 200 mg orally for 5 days. The patient developed an inoperable retinal detachment despite therapy. Second eye. Eight days later the fellow eye developed a localized retinal necrosis. Varizella zoster DNA was found in the aqueous humor using the polymerase chain reaction (PCR). The antiviral therapy with Acyclovir was increased from 1.1 g q 12 h (2 x 15 mg/kg/d) to 1.0 g q 8 h (3 x 12.5 mg/kg/d). After 4 weeks the i.v. therapy was followed by an oral therapy of 5 x 800 mg for 12 weeks. This dosage was reduced to 5 x 400 mg for another 12 weeks. The oral therapy with corticosteroids started on the 11th day with 100 mg Prednisone, in slowly reducing dosage during 18 weeks. The fellow eye recovered fully with a visual acuity of 20/20 after 6 months. Conclusion The disease started in the fellow eye with an acute iritis and a secundary glaucoma. These symptoms can be a characteristic prodroma of an acute retinal necrosis syndrome caused by a varizella zoster- or Herpes simplex virus infection, which was not recognized first. Whether a long-term therapy (as described above) is necessary or not is unclear on the basis of a single case report, but we currently recommend the high-dose treatment regimen until further data emerge.