Multimodal Imaging Enhanced by Indocyanine Green Angiography in Syphilitic Uveitis

Area of Science:

• Ophthalmology
• Infectious Diseases
• Medical Imaging

Background:

• Syphilitic uveitis (SU) is an ocular manifestation of syphilis that can lead to significant vision impairment.
• Accurate characterization of fundus changes in SU is crucial for timely diagnosis and effective management.
• Multimodal imaging (MMI) offers comprehensive visualization of ocular structures, but its role in SU requires further elucidation.

Purpose of the Study:

• To systematically characterize fundus changes in syphilitic uveitis (SU) using multimodal imaging (MMI).
• To evaluate the added value of indocyanine green angiography (ICGA) in enhancing MMI for SU diagnosis.
• To identify imaging biomarkers predictive of visual outcomes in SU.

Main Methods:

• A prospective study included 24 patients with SU from 2018-2019, plus 8 from a prior pilot study.
• MMI included ICGA, fluorescein angiography (FA), fundus autofluorescence (FAF), and spectral domain optical coherence tomography (SD-OCT).
• Imaging was performed at admission, discharge, and during follow-up visits.

Main Results:

• MMI identified subclinical inflammation in 15.6% of eyes and posterior segment inflammation not detected by standard examination in 17.8% of eyes.
• ICGA revealed characteristic choroidal findings: geographical hypofluorescence (47%), hypofluorescent dark dots (72%), and speckled hypofluorescence (93%).
• External limiting membrane (ELM) disruption on SD-OCT correlated with worse best-corrected visual acuity (BCVA) at presentation and after treatment.

Conclusions:

• ICGA-enhanced MMI plays a critical role in detecting and localizing intraocular inflammation in SU, highlighting the choroid as the primary site.
• Choroidal hypofluorescence is the most frequent abnormality observed.
• ELM disruption is a significant indicator of poor visual prognosis in syphilitic uveitis.