Man presents with unilateral new blind spot
The right eye had atrophy of the RPE as well as pigmentary changes extending temporally from the optic nerve into the macula.
A 61-year-old man presented to the Lahey Clinic Emergency Department with a 4-day history of sudden onset painless blurred vision in the right eye. More specifically, he described a new “blind spot” just temporal to central vision.
The patient denied eye pain, redness, flashes or floaters and had no symptoms in the left eye. A detailed review of systems revealed vertigo and disequilibrium starting 3 weeks before presentation. His medical history was notable for hyperlipidemia, obesity, chronic kidney disease, hematuria, microscopic colitis and benign prostatic hyperplasia. His ocular history was notable for high myopia (–13 D in each eye) for which he underwent phakic IOL implantation bilaterally several years prior. He had no known drug allergies and did not use alcohol, tobacco or recreational drugs. His social history was notable for having protected sex with men, and he stated he was monogamous. Medications included aspirin, atorvastatin, bupropion, eszopiclone, gabapentin and emtricitabine/tenofovir.
Examination
The patient’s best corrected visual acuity was 20/60 in the right eye and 20/20 in the left eye. IOP was within normal limits in each eye. Pupils were symmetric, round and briskly reactive with no afferent pupillary defect. On confrontation visual field testing, the patient identified an area of vision loss appearing as a black spot just temporal to central vision in the right eye. Motility was full and painless. Color vision testing was normal in each eye. Slit lamp examination revealed the absence of anterior chamber inflammation and a well-positioned phakic IOL in each eye.
Upon dilated fundus examination, there was no vitreous inflammation or debris in either eye. The optic nerve in each eye appeared pink and sharp with no abnormality. In the right eye, there was atrophy of the retinal pigment epithelium (RPE) as well as pigmentary changes extending temporally from the optic nerve into the macula (Figure 1). The left eye fundus examination was unremarkable (Figure 2).
Source: Nisha S. Dhawlikar, MD, MPH, and Tara Bryant, MD
Imaging
The patient was sent for 30-2 Humphrey visual field testing, which revealed a central scotoma in the right eye and nonspecific superonasal changes in the left eye (Figure 3). Fundus autofluorescence of the right eye demonstrated peripapillary hyperautofluorescence extending temporally from the disc to the fovea (Figure 4). In the left eye, fundus autofluorescence showed trace peripapillary hyper- and hypoautofluorescence and a small region of hypoautofluorescence superotemporally (Figure 5). OCT of the macula revealed outer retinal atrophy in the right eye with disruption of the photoreceptor layer and irregularity of the RPE (Figure 6). OCT of the macula of the left eye was within normal limits (Figure 7). Fluorescein angiography in the right eye revealed early hyperfluorescence in the area of RPE atrophy (Figure 8). Fluorescein angiography of the left eye was remarkable only for a focal area of hyperfluorescence superotemporally (Figure 9).
What is your diagnosis?
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Unilateral scotoma
The differential diagnosis for acute onset painless unilateral scotoma with retinal findings is broad and includes a number of infectious and inflammatory etiologies. Given our patient’s history of new neurologic symptoms and findings of outer retinal disruption on OCT, ocular syphilis was considered the most likely diagnosis in this case. Other diagnostic considerations included acute posterior multifocal placoid pigment epitheliopathy, which can present with unilateral paracentral scotoma and systemic symptoms but is typically seen in a younger age demographic. Multiple evanescent white dot syndrome is another inflammatory chorioretinopathy and may present with outer retinal disturbance on OCT but is generally associated with multiple discrete retinal lesions and is more common in young women. Atypical central serous chorioretinopathy was also considered in this case, although the OCT findings were not consistent with this diagnosis.
Workup and management
Due to his acute neurologic symptoms, the patient had been sent for neuroimaging at the time of his presentation to the emergency department, and the testing was unremarkable. Given the concern for ocular syphilis, laboratory testing was obtained, including rapid plasma reagin (RPR) and fluorescent treponemal antibody absorption testing. A complete blood count, basic metabolic panel and HIV testing were also performed.
Laboratory results were significant for a positive syphilis antibody with an RPR titer of 1:256. This clinical picture was felt to be consistent with a diagnosis of syphilitic posterior placoid chorioretinitis. The patient was admitted to Lahey Medical Center for treatment with intravenous penicillin at a dose of 4 million units every 4 hours for 2 weeks. During admission, the patient underwent lumbar puncture, which was notable for elevated protein and nonreactive Venereal Disease Research Laboratory test.
Upon completion of his treatment course, the patient’s visual acuity improved from 20/50 to 20/30 in the right eye. Repeat OCT macula of the right eye revealed partial recovery of the photoreceptor and RPE layers (Figure 10).
Discussion
Syphilis is a sexually transmitted disease caused by the spirochete Treponema pallidum with a total disease burden in the United States of about 115,000 cases in 2018. Ocular syphilis, a form of tertiary syphilis, may be the first presentation of syphilitic infection. The most common ocular complication of syphilis is syphilitic uveitis, and the most frequent posterior segment manifestation is chorioretinitis. Additional ocular presentations include interstitial keratitis, iritis, vitritis, serous retinal detachments and papillitis.
Acute syphilitic posterior placoid chorioretinitis is characterized by a large, solitary yellow-white placoid macular lesion at the level of the outer retina. It is believed that T. pallidum organisms enter through the choroidal circulation to gain access to the outer retina, leading to an inflammatory reaction at the level of the choriocapillaris-RPE-retinal photoreceptor complex. OCT findings include disruption of the photoreceptor inner segment/outer segment junction and nodular hyperreflectivity of the RPE.
Treatment for ocular syphilis is the same as neurosyphilis: 4 million units of intravenous penicillin G every 4 hours for 2 weeks. If there is a penicillin allergy, 2 g of intravenous ceftriaxone could be given daily for 2 weeks. With adequate treatment, there is often complete visual recovery with reconstitution of the outer retinal anatomy on OCT.
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- Syphilis. www.cdc.gov/std/stats18/syphilis.htm. Accessed June 7, 2020.
- For more information:
- Nisha S. Dhawlikar, MD, MPH, and Tara Bryant, MD, can be reached at New England Eye Center, Tufts University School of Medicine. 800 Washington Street, Box 450, Boston, MA 02111; website: www.neec.com.
- Edited by Alison J. Lauter, MD, and Sarah E. Thornton, MD. They can be reached at the New England Eye Center, Tufts University School of Medicine, 800 Washington St., Box 450, Boston, MA 02111; website: www.neec.com.