Bilateral Acute Retinal Necrosis from Ocular Syphilis in a Nonimmunocompromised Patient: A Case Report and Review of the Literature

Acute retinal necrosis (ARN) is an inflammatory condition of the eye usually caused by viral infection, predominantly herpes simplex virus or varicella-zoster virus. More rarely, noninfectious conditions or infection with other viral and nonviral pathogens can lead to ARN. Onset of disease, which may occur unilaterally or bilaterally, is usually rapid and characterized by a range of symptoms, including pain of eye movement, eye redness, light sensitivity, impaired vision, and narrowing of the visual field. While infectious ARN may develop in otherwise healthy individuals, those who are immunocompromised may be more susceptible to this eye pathology, especially patients who are infected with HIV. Left untreated, ARN can lead to permanent vision loss; thus, rapid identification of the specific etiology of ARN is crucial for implementing appropriate therapies. However, infection with rare pathogens in patients who are at risk for common causes of ARN can complicate diagnosis and treatment, highlighting the need for physicians to know the full range of possible etiologies for the differential diagnosis. We present a case of bilateral ARN in an immunocompetent woman who was infected with genital herpes simplex virus 2, and therefore at high risk of viral infection, but whose ARN was an example of ocular syphilis caused by the bacterial pathogen Treponema pallidum. A review of the literature on ocular syphilis is also discussed.