Purpose: To describe the appearance of acute syphilitic posterior placoid chorioretinitis, a rare ocular manifestation of syphilis, on spectral domain optical coherence tomography (SD OCT) both before and after treatment.
Methods: Ophthalmic examination and imaging studies of 30 eyes of 19 confirmed cases were analyzed both at the time of presentation and at each follow-up visit. Patients with SD OCT and fluorescein angiography at the time of presentation, and at least three documented follow-up visits after initiation of therapy, were included in the study. Standard treatment of neurosyphilis was given to each patient, including 4 million units of penicillin G administered intravenously every 4 hours for 14 days.
Results: Fundus examination and imaging studies were consistent with previous reports and confirmed the diagnosis of acute syphilitic posterior placoid chorioretinitis. In 13 eyes (43.3%), baseline SD OCT scans were performed within 1 to 2 days of presentation and revealed a small amount of subretinal fluid, disruption of the inner segment/outer segment junction, and hyperreflective thickening of the retinal pigment epithelium (RPE). All 30 eyes were again scanned between Days 7 and 9 after presentation and revealed loss of the inner segment/outer segment and OS/RPE bands, and irregular hyperreflectivity of the RPE with prominent nodular elevations but without subretinal fluid. Early disruption of the external limiting membrane and punctate choroidal hyperreflectivity were seen in 1 of the 30 eyes (3.3%) and 14 of the 30 eyes (46.6%), respectively. Vision improved and the outer retinal abnormalities normalized in 28 of the 30 eyes (93.3%) after the treatment of neurosyphilis. The external limiting membrane, inner segment/outer segment band, and/or linear outer segment/RPE junction remained substantially abnormal despite treatment in 2 eyes left with 20/200 vision.
Conclusion: Patients with acute syphilitic posterior placoid chorioretinitis show characteristic outer retinal abnormalities on SD OCT imaging, including disruption of the inner segment/outer segment band, nodular thickening of the RPE with loss of the linear outer segment/RPE junction, and, in some cases, loss of the external limiting membrane, accumulation of subretinal fluid, and punctate hyperreflectivity in the choroid. Vision improved and these abnormalities reversed after treatment of neurosyphilis in most of the patients. Persistently, poor vision despite treatment was associated with long-term loss or disruption of outer retinal anatomy on SD OCT.