Clinical features of neurosyphilis with optic neuritis as an initial finding

Objective: To study the characteristics of neurosyphilis with optic neuritis as an initial finding. Methods: Retrospective analysis of clinical data and laboratory testing results of 16 cases (27 eyes) with optic neuritis as an initial finding of neurosyphilis from October 2010 to March 2015 in General Hospital of People's Liberation Army was made. Results: Six-teen patients (12 males, 4 females) were collected, the median age of patients was 47 (range 33 to 65) years,the mean age was (49.63±9.05) years. Treponema pallidum particle agglutination assay (TPPA) analysis was positive in all of the patients and rapid plasma reagin (RPR) test was positive in 14 patients (2 patients did not test). Lumbar puncture was requested and performed for all patients. Cerebrospinal fluid (CSF) TPPA analysis was positive in 16 patients and RPR test was positive in 12 patients. The CSF white blood cell counting increased in 9(56.3%) patients and 10(62.5%)patients presented with increased CSF protein level. Both eyes were involved in 11 patients (68.8%). Relative afferent papillary defect was positive in 11 patients. Twenty-seven eyes were affected in 16 patients, and among them 7 eyes' pupil diameter were 2.5 mm or less. Incipient visual acuity was less than 0.1 in 22 eyes. The slit lamp examination showed vitreous opacity in 12 eyes and visible cells in 6 eyes among 27 eyes. Fundus examination found that 6 eyes had papillary edema and 15 eyes had pallor disc among 27eyes. Electro-retinogram (ERG) was tested in 24 eyes, and 18 eyes were abnormal. Visual evoked potential (VEP) were performed in 26 eyes (flash VEP in 22 eyes, pattern VEP in 4 eyes), and all were abnormal. Fourteen eyes were tested by 30-2 perimetry, and 6 eyes had diffuse visual field defect, 2 eyes had peripheral visual field defect, 4 eyes had quadrant defect and 2 eyes had center scotoma. Fundus fluorescence angiography was done in 16 eyes and choroidal hyper-fluorescent dots were found in posterior pole in 4 eyes. All patients were treated with antibiotic medicines, among them 10 cases in the General Hospital, and 6 cases in the other hospitals. During 15 months follow-up after discharge, visual acuity of 17 eyes recovered to 0.5 and above. Conclusion: Syphilitic optic neuritis is a condition that manifests with severe visual loss and tends to involve both eyes, Some patients have a smaller pupil diameter. Due to the particular infective routes of the disease, patients often conceal their sexual history. The manifestations of ocular syphilis are complicated and easy to misdiagnose or undiagnose. Clinical manifestations combining with the detailed history taking, serum and cerebrospinal fluid examination can guide to an accurate diagnosis and prevent from permanent vision loss.