Spectral-domain optical coherence tomography features of acute syphilitic posterior placoid chorioretinitis: the role of autoimmune response in pathogenesis

Abstract

Purpose: Syphilis is an infectious disease that can cause a wide variety of ocular signs. One of the rarest manifestations of ocular syphilis is acute syphilitic posterior placoid chorioretinitis (ASPPC). We report on the spectral-domain optical coherence tomography (SD-OCT) features of a case diagnosed with unilateral ASPPC.

Methods: A 64-year-old man presented with a sudden loss of visual acuity (VA) in the right eye. His only clinical sign was a large, geographic, yellow-white lesion centered on the right fovea. Our patient was studied with SD-OCT on presentation and during follow-up, as well as with fluorescein and indocyanine green angiography, electrophysiological study, and serologic and autoimmune screening.

Results: Laboratory workup revealed positive serology for active syphilis and elevated anti-beta2 glycoprotein I antibodies. SD-OCT showed a marked distortion of both the choroidal and outer retinal architecture. After treatment, best-corrected VA improved to 20/25. Pattern electroretinography displayed a severe reduction of P50 amplitude, which improved in late follow-up. Six months after presentation, VA was 20/25 and anti-beta2 glycoprotein I antibodies returned to normal levels.

Conclusions: Our findings are compatible with immunologically mediated temporary physiological impairment of the neuroretina, since the changes seen by SD-OCT could not have normalized if they were due to anatomical injury. The results of our study provide clues to understanding the pathogenesis of this disease and allow us to define a characteristic temporal sequence of events in ASPPC.

Keywords: Beta2 glycoprotein; Chorioretinitis; Placoid; Spectral-domain optical coherence tomography; Syphilis.

Fig. 1

Fundus image of the RE showing a typical placoid macular lesion of ASPPC (a). Late-staining hyperfluorescence seen on angiography (b). Normal fundus of the RE, 2 weeks after presentation (c). Normal angiography after completion of treatment (d).

Fig. 2

SD-OCT of the right macula (a) showing absence of the inner/outer photoreceptor segment junction layer as well as an absent external limiting membrane. Choroidal detail reveals irregular, diffuse infiltration of the choroidal vasculature (b). SD-OCT of the left macula showing normal retinal stratification and well-defined, numerous choroidal vascular spaces.

Fig. 3

SD-OCT image comparison before (a) and after treatment completion (b). The inner/outer segment junction is now visible in the full extent of the scan. Choroidal detail reveals slightly improved vascular definition, better noticed in the area temporal to the fovea.