The progressive outer retinal necrosis syndrome: successful treatment with combination antiviral therapy

To assess a two-drug combination of antiviral therapy for the progressive outer retinal necrosis syndrome (PORN), given the current poor outcome with acyclovir alone.

A retrospective review was performed on six consecutive patients who were diagnosed with PORN and were treated with various combinations of intravenous or oral plus intravenous antiviral therapy. The relative efficacies of these modalities were compared.

Six eyes of six patients showed active retinitis at the time of presentation. Three patients had unilateral retinitis, and the remaining patients had necrotic, end-stage disease in their fellow eye. All the patients were treated with combination therapy, consisting of either ganciclovir and acyclovir (three patients), foscarnet and ganciclovir (two patients), or foscarnet and acyclovir (one patient). Standard induction doses were employed. During the combination therapy, all six eyes showed resolution of the retinitis, manifested by complete fading of the original retinal lesions and an absence of new lesion formation. At the final follow-up, the areas of prior active retinitis had resolved and remained quiescent. A mild recurrence developed in one eye when ganciclovir and foscarnet were both tapered to a single daily dose. This recurrence promptly resolved with reinduction (twice daily) dosing. Two patients maintained a visual acuity of 20/50 or better in their involved eye for the duration of follow-up (38 and 27 weeks, respectively). One patient maintained a visual acuity of 20/40 for 14 weeks. The remaining three patients had macula-off retinal detachments despite resolution of active retinitis. In addition, for the duration of follow-up, one of the three patients with unilateral disease had retinitis in the uninvolved eye; all three uninvolved fellow eyes maintained a visual acuity of 20/20. One patient had progressive optic atrophy.

Prolonged combination antiviral therapy for PORN may successfully arrest the progression of retinitis, maintain remission, and prevent involvement of the fellow eye. Furthermore, if aggressive therapy is begun early, good vision may be preserved.