Clinical outcomes of ocular syphilis within the Great Plains region: potential syndemic impact of methamphetamine use.

BACKGROUND/

OBJECTIVES

To characterise the clinical spectrum of ocular syphilis and its visual acuity impact in patients with and without methamphetamine use.

SUBJECTS/

METHODS

This retrospective observational case series of patients with ocular syphilis was conducted at a tertiary referral centre within the Midwest United States. Patients diagnosed with ocular syphilis between 2021 and 2023 at the University of Nebraska Medical Center were included in the study. Patients were stratified into methamphetamine use and non-methamphetamine use groups. Paired, non-parametric comparisons of visual characteristics and visual outcomes at baseline, month-3, and month-6 were performed between the two groups.

RESULTS

A total of 34 eyes of 21 patients were included in the analysis. The median age was 44 years (39- 53), and fifteen patients (71%) were male. The median baseline visual acuity (VA) was 6/60 (6/45.7-LP) in the methamphetamine group (11 eyes, n = 7), which was significantly worse than the non-methamphetamine group (23 eyes, n = 14) with the median VA of 6/18 (6/7.5-6/45.7), p = 0.0136. While the non-methamphetamine group exhibited a significant VA improvement from baseline to month-3 follow-up (6/18-6/7.5, p = 0.001) and from baseline to month-6 follow-up (6/21-6/6, p = 0.002), this was not seen in the methamphetamine group (6/120-6/24, p = 0.225). Duration from symptom onset to presentation was shorter within the methamphetamine group compared to the non-methamphetamine group (7 days vs 36 days, p = 0.024).

CONCLUSIONS

Methamphetamine use was associated with worse visual acuity at presentation and follow-up despite patients presenting sooner for evaluation.