To investigate the characteristics of fundus lesions of patients with neurosyphilis and optic nerve atrophy.

Clinical data of 8 patients with neurosyphilis and optic nerve atrophy admitted in Beijing Ditan Hospital, Capital Medical University from August 2013 to May 2019 were analyzed. All patients underwent serological, cerebrospinal fluid examination and ophthalmic examination which included visual acuity, slit lamp, optical coherence tomography (OCT) measurement of retinal nerve fiber layer (RNFL) thickness around the optic disc, standard color fundus photography, dynamic visual field and fundus characteristics analysis. Visual acuity was converted to the logarithm of the minimum angle of resolution (logMar) for statistical analysis, the syphilis toluidine red non-heated serum assay (TRUST) titers were converted as logarithmic at base 2. The correlation of visual acuity and TRUST titers of blood and CSF were explored by Spearman correlation analysis.

All eight patients were male, with an average age of (46.00 ± 8.79) years old (ranging from 34 to 59 years old). The visual acuity ranged from light sense to 0.6, the course of disease ranged from 3 months to 2 years. The thickness of RNFL decreased significantly in 8 patients (16 eyes), ranging from 28.5 μm to 70.33 μm, with a decrease rate of 33.39%-73.01%, among which, RNFL thickness decreased 30%-50% in 4 eyes and higher than 50% in 12 eyes. Nasal RNFL average thickness decreased the most, following by infratemporal, supranasal, inferonasal, supratemporal and temporal, with the decrease rates of 60.24%, 58.30%, 54.48%, 51.76%, 51.26% and 50%, respectively. Among the 8 patients (16 eyes), 2 patients (4 eyes) showed light optic disc, while the other 6 patients (12 eyes) showed pale optic disc in both eyes. All patients presented retinal vascular thinning. Only 3 patients underwent visual field examination, who had different degrees of visual field defect in 6 eyes. The TRUST titer were 1︰4-1︰256 in 8 patients, while the CSF TRUST titer were 1︰1-1︰4. Serum and CSF treponema pallidus gelatin agglutination test (TPPA) were positive in all 8 patients. Spearman’s rank correlation analysis showed that the degree of visual impairment in neurosyphilis patients were not positively correlated with TRUST titer in serum (r = 0.075, P = 0.86) and CSF (r = 0.183, P = 0.66), without significant differences.

The fundus of patients with neurosyphilis and optic nerve atrophy showed light or pale optic disk and shrinked retinal blood vessels. The thickness of RNFL around optic nerve decreased, and the visual field lacked, which could be manifested as the annular relative dark point or the absolute dark point, and only the superior or inferior temporal optic islands were left with severe visual field loss. Without timely treatment, it would eventually lead to optic nerve atrophy.