Unilateral recurrent acute retinal necrosis syndrome caused by cytomegalovirus in an immune-competent adult.

PURPOSE: To report an immune-competent patient with unilateral recurrent acute retinal necrosis syndrome caused by cytomegalovirus, and to highlight the importance of diagnostic vitreous biopsy and specific antiviral therapy in this condition. METHODS: Case report. RESULTS: A 75-year-old man with good general health had two episodes of acute retinal necrosis syndrome affecting his left eye. Vitreous biopsy was performed in each episode, and polymerase chain reaction analysis on the vitreous specimen was positive for cytomegalovirus and negative for varicella zoster virus and herpes simplex virus 1 and 2. On each occasion, investigations indicated past cytomegalovirus infection but no evidence of a systemic re-activation. No indication of immunodeficiency was found over a 2-year follow-up period. His management, which included systemic and intravitreal antiviral therapy, is discussed. CONCLUSIONS: To the authors' knowledge, only two other cases of acute retinal necrosis syndrome caused by cytomegalovirus have been reported previously in immune-competent patients. This case illustrates the importance of vitreous biopsy for viral polymerase chain re-action studies in cases of acute retinal necrosis syndrome, in order to direct appropriate antiviral treatment. It also illustrates the role of an intravitreal antiviral drug that is effective against all three herpetic viruses.