Evaluating the Incidence and Neuro-Ophthalmic Manifestations of Carotid-Cavernous Fistulas.

BACKGROUND: To determine the incidence of carotid-cavernous fistula (CCF) and describe the neuro-ophthalmic manifestations and eventual clinical outcomes. METHODS: This was a population-based, retrospective cohort study using the Rochester Epidemiology Project to identify patients aged 18 years or older residing in Olmsted County, MN, diagnosed with CCF from 1997 to 2019. The medical records were reviewed for ophthalmic signs and symptoms, including conjunctival chemosis, proptosis, orbital bruit, diplopia, ophthalmoplegia, orbital pain, ocular hypertension, and blurred vision. Also determined was the number of patients with CCF found incidentally on neuroimaging, without clinical manifestations. RESULTS: Ten patients were diagnosed with a CCF between 1997 and 2019 with an overall incidence rate of 0.37 per 100,000 per year (95% CI 0.20-0.68). The median age was 50.5 years (range 23-74 years), 6 (60%) were female, and 9 were White and 1 patient was Korean. Three patients (30%) were asymptomatic and found incidentally on imaging that was obtained for unrelated reasons, and one patient's ocular details were unavailable because she passed away from severe head trauma. The following neuro-ophthalmologic or ocular manifestations were identified in the remaining 6 patients: chemosis/conjunctival injection (n = 6), cranial nerve (CN) VI palsy (n = 6), CN III palsy (n = 2), proptosis (n = 4), ocular/orbital pain (n = 3), audible orbital bruit (n = 2), ocular hypertension (n = 1), and blurred vision (n = 1). Of those patients with symptomatic CCFs, all underwent treatment except for one that spontaneously resolved. None of the patients suffered a stroke or cerebral hemorrhage. The 3 patients with incidentally discovered CCFs were asymptomatic and did not require treatment. CONCLUSIONS: This is the first population-based study to show a low incidence rate of CCFs, supporting the notion that it is an uncommon condition. Neuro-ophthalmic manifestations are common, especially chemosis/conjunctival injection and CN VI palsy. Up to a third of patients with CCF can be asymptomatic and may be found incidentally on neuroimaging during the evaluation for unrelated symptoms.

Transient Bilateral Central Scotoma on Awakening: A Distinct Phenomenon.

BACKGROUND: Transient vision loss can be an alarming symptom owing to potentially serious etiologies such as thromboembolism or giant cell arteritis. Transient monocular vision loss (TVML) on awakening has been recently described as a benign phenomenon (Bouffard et al, 2017). Our objective was to describe the unique phenomenon of transient binocular vision loss (TBVL) on awakening. METHODS: Retrospective observational case series of 5 patients who experienced TBVL on awakening seen in the neuro-ophthalmology clinic at the Mayo Clinic between 2016 and 2020. Patients who described generalized blurred vision and those with monocular transient vision loss were excluded. RESULTS: The median age was 81.4 years (range, 68-92 years), and all were male. Every patient described a stereotyped transient bilateral central scotoma on awakening with slightly irregular borders and mild asymmetry between the 2 eyes lasting between 15 and 90 minutes. Frequency ranged from 3 to 7 times per week, and there was a median of 319 episodes (range, 126-728 episodes) before evaluation in the neuro-ophthalmology clinic. All patients had normal optic nerves, and no plaques were noted in the retinal vessels. All 5 had macular drusen, which were predominantly extrafoveal and mild. Two patients underwent electrophysiology testing, which were both normal on full-field electroretinogram (ERG), but there was blunted central wave forms on multifocal ERG. Two patients underwent dark adaptation testing, which showed both prolong and diminished dark adaptation. Neuroimaging and thromboembolic workup were unrevealing. CONCLUSIONS: TBVL is a distinct phenomenon from TMVL on awakening, which has a different demographic and symptomology. The etiology is unclear but seems to be a focal macular process in conjunction with an autoregulatory failure resulting in a supply-demand mismatch during low-light conditions.

Proceedings of the 42nd Annual and First Virtual Upper Midwest Neuro-Ophthalmology Group Meeting, 24 July 2020.

The 42nd meeting of the Upper Midwest Neuro-Ophthalmology Group (UMNOG) took place on 24 July 2020 in an inaugural virtual format due to COVID-19 precautions. Eighty-seven people attended virtually, including 25 trainees, which marked the highest UMNOG meeting attendance on record. We present a synopsis of the meeting presentations.