Authors: Anna Kabanovski, Laura Donaldson, Trishal Jeeva-Patel, Edward Margolin.

Disclosure Block: A. Kabanovski: None. L. Donaldson: None. T. Jeeva-Patel: None. E. Margolin: None.

Abstract Body:

Purpose: Syphilis is an uncommon cause of optic nerve head edema, however, differentiating syphilis from other etiologies of optic nerve head swelling may be challenging. We describe four cases of ocular syphilis presenting with swollen optic nerve head(s) without overt signs of intraocular inflammation in order to better define the phenotypic presentation of this condition to allow its early recognition and treatment and discuss potential pathophysiologic mechanisms of syphilitic optic neuropathy.
Study Design: Retrospective case series.
Methods: Patients who presented to a tertiary neuro-ophthalmology practice with swollen optic nerve head(s) but no overt signs of intraocular inflammation, which was eventually determined to be secondary to syphilis, were included. Results of neuro-ophthalmic examination including formal visual fields, optical coherence tomography, fundus autofluorescence, as well as brain and orbital MRI findings and lumbar puncture results were reviewed.
Results: Four patients were included in the study. The mean age was 43, two were female and two had bilateral involvement. Two patients had a recent history of skin rash and one was investigated for abdominal pain and elevated liver enzymes. Two patients presented with photopsias and preserved visual function while two presented with vision loss. While chorioretinitis was present in all cases, it was very subtle in all and was only appreciated on fundus autofluorescence in 3 out of 4 cases. All patients demonstrated evidence of optic perineuritis on MRI of the orbits. All patients were treated with a course of intravenous penicillin with variable degrees of visual recovery.
Conclusions: Systemic symptoms are common in patients with syphilic optic neuropathy. Optic disc edema as a manifestation of syphilis is usually accompanied by subtle chorioretinitis which is best appreciated on fundus autofluorescence. Optic perineuritis is common in patients with syphilitic optic neuropathy, its pathophysiology likely similar to meningitis seen in neurosyphilis.