Eyes As the Window to Syphilis: A Rare Case of Ocular Syphilis As the Initial Presentation of Syphilis

In the pre-antibiotic era, neurosyphilis (NS) was common, occurring in 34% of patients with syphilis. Currently, there has been a rising trend in syphilis with HIV-infected patients being more prone to develop NS. Ocular involvement is very rare in NS and accounts for only 1%-5% of the cases in the United States. We report the case of a 53-year-old male with a past medical history of gastroesophageal reflux disease and hyperlipidemia who presented to his ophthalmologist for blurred vision in both eyes. He had been noticing a black spot in the visual field of his left eye for two weeks. He had also noticed a rash on his forearms. His past and social history was significant for treated Lyme disease, having pet cats. He identified as a heterosexual male, married, and with five children. However, on further history taking, he reported a homosexual exposure about five years prior. He denied any history of genital ulcer or penile discharge. On examination at the ophthalmology clinic, he was found to have a visual acuity of 20/20 right eye and 20/100 left eye. Posterior segment examination of the both eyes showed subtle neuritis and vasculitis. Fundus photography revealed subtle neuroretinitis bilaterally. Work up was initiated for inflammatory and infectious causes. His rapid plasma reagin and fluorescent treponemal antibody absorption showed positive titers for syphilis. His presentation was most consistent with ocular syphilis. A lumbar puncture (LP) was done with Venereal Disease Research Laboratory (VDRL) positivity in the spinal fluid. He was therefore initiated on intravenous (IV) penicillin four million units every four hours for 14 days. His ophthalmology follow-up after one month showed both subjective and objective improvement in his visual symptoms. He also followed with the infectious disease team and a repeat LP done three months later showed nonreactive VDRL in cerebrospinal fluid (CSF). Ocular syphilis is increasing in incidence. Clinical presentation is variable, and a high index of suspicion with a low threshold for serological testing are important as early treatment can reverse retinal changes and restore visual acuity. There is a recommendation for CSF examination in all patients with ocular syphilis including HIV-negative cases. There have been studies showing a high CSF abnormal rate in HIV-negative patients with ocular syphilis. The recommended treatment for NS is aqueous crystalline penicillin G (18 to 24 million units per day, administered as three to four million units IV every four hours, or 24 million units daily as a continuous infusion) for 10 to 14 days. Follow-up is a key component of management with neurological examination and LP for CSF VDRL performed three months after treatment and every six months after, until the CSF is nonreactive for VDRL with normal white blood cell count. It is important to be cognizant of the rising trend of ocular syphilis, even in HIV-negative individuals. Early treatment is time sensitive to preventing permanent vision loss. Our case also emphasizes on thorough history taking, even for patients who appear to be at a low risk for sexually transmitted infections.