Ocular findings in neurosyphilis: a retrospective study from 2012 to 2022

Abstract

Purpose: This study aimed to investigate ocular manifestations in patients with neurosyphilis and their association with general indexes.

Methods: This retrospective study was conducted among patients who were hospitalized for neurosyphilis from 2012 to 2022. Clinical manifestations, laboratory tests, brain MRI, and ocular examinations were reviewed and analyzed.

Results: A total of 106 neurosyphilis patients were included, of which 10 patients presented with ocular signs as their initial symptoms. The most common main complaint was reduced vision (6/10), followed by diplopia (2/10) and ptosis (2/10). The causes of vision loss included optic neuropathy (4/6) and posterior uveitis (2/6), with all six patients showing optic nerve involvement. A total of 29 (27.4%) patients exhibited pupil abnormalities. A lumbar puncture was performed on all 106 patients, and abnormal cerebrospinal fluid (CSF) findings were revealed in 101 (95.3%) patients, indicating central nervous involvement. The median white blood cell count in the CSF of the patients with pupil abnormalities was significantly higher than that of those without pupil abnormalities (14.0 vs. 6.0 cells/μl, p = 0.037). In addition, the patients with abnormal pupillary light reflex (PLR) were more likely to have multiple brain lesions compared to those with normal PLR (77.3% vs. 29.2%, p < 0.001).

Conclusion: Optic nerve involvement is the main cause of vision loss in neurosyphilis. Patients with optic neuropathy or posterior uveitis should undergo prompt diagnostic evaluation for syphilis. Pupil abnormalities can serve as indicators of more severe CSF and MRI findings.

Keywords: neurosyphilis; ocular syphilis; optic neuropathy; pupil abnormalities; pupil light reflex (PLR).

Figure 1

Visual field (VF), MRI, and optical coherence tomography (OCT) results of a neurosyphilis patient presented with posterior optic neuritis. (A) The VF result showed a dense inferior altitudinal defect in the left eye. The MD improved from severe damage (−7.28 dB) to moderate damage (−3.73 dB) in the left eye after standard penicillin treatment; (B) The MRI result revealed increased signaling of the optic nerve and optic chiasm on the right side, bilateral optic tract lesions, minor degeneration of the right frontal lobe and left parietal lobe upon hospitalization; (C) The fundoscopy showed the optic disk with normal morphology in the left eye. Temporal and inferior peripapillary retinal nerve fiber layer atrophy in the left eye persisted over a 7-year follow-up period.

Figure 2

Significant differences in cerebrospinal fluid (CSF) white blood cell counts in relation to pupil abnormalities in neurosyphilis patients. (A) The patients with abnormal pupils had higher CSF white blood cell counts than those with normal pupils (p = 0.037); (B) The patients with abnormal pupil light reflex (PLR) had higher CSF white blood cell counts than those with normal PLR (p = 0.034).