Secondary Ocular Syphilis Dysfunction Visible With ICGA Protocol

Acute syphilitic posterior placoid chorioretinitis (ASPPC) appears on  late-phase indocyanine green angiography examination as hypofluorescence of the plaque, researchers report in a study published in the American Journal of Ophthalmology. The retrospective, observational case study also found that the retinal pigment epithelium (RPE) impairment it causes is reversible with prompt antibiotic treatment. 

Participants (N=1493) diagnosed with uveitis between 2012 and 2015 were retrospectively reviewed for syphilis infection. A total of 12 patients and 15 eyes were positive for syphilis and had yellowish placoid lesions at the RPE in the posterior pole, according to the publication.

The study population comprised 11 men and a woman, aged mean 50 (range, 34-58) years, 75% had secondary syphilis, and 1 patient was HIV-positive. The average time to ocular diagnosis was 25±25 days.

The deep yellowish placoid lesions were located within the temporal arcades in 8 eyes and five eyes had plaques extending beyond the arcades and/or around the optic disc.

Most plaques were hyperautofluorescent on blue fundus autofluorescence, isofluorescent on early-phase fluorescein angiography, becoming progressively hyperfluorescent during mid and late fluorescein angiography phases. B-scans passing through the placoid lesions revealed multiple attenuation areas or complete disappearance of the ellipsoid zone.

RPE granular irregularities caused shadowing on spectral-domain optical coherence tomography and hyperautofluorescence on fundus autofluorescence, which could indicate lipofuscin.

Patients were given intravenous penicillin. After treatment, one eye had persistent granular RPE irregularities, three eyes persistent ellipsoid zone disruption, two eyes focal hyperautofluorescent dots, and one eye hyperautofluorescent areas.

Best-corrected visual acuity was 0.91±0.76 logMAR before treatment and 0.03±0.10 logMAR after treatment.

Two eyes had a serous retinal detachment at fewer than 10 days after onset, which was resorbed after treatment.

This study was limited by sample size; however, this is expected given the rarity of ASPPC.

“ASPPC is a rare form of ocular syphilis, and its angiographic features and pathophysiology are still debated. Our findings support the hypothesis that ASPPC could primarily involve the RPE, leading to secondary damage to the photoreceptors, suggesting that prompt antibiotic treatment could help to preserve the RPE function and vision,” researchers explain.

Reference

Villaret J, Errera M-H, Sahel J-A, Gaudric A, Mrejen S. Indocyanine green angiography features in acute syphilitic posterior placoid chorioretinitis. Am J Ophthalmol. 2022;S0002-9394(22)00061-7. doi:10.1016/j.ajo.2022.02.008