Detection of Atrial Fibrillation After Central Retinal Artery Occlusion.

Background: Central retinal artery occlusion (CRAO) causes sudden, irreversible blindness and is a form of acute ischemic stroke. In this study, we sought to determine the proportion of patients in whom atrial fibrillation (AF) is detected by extended cardiac monitoring after CRAO. Methods: We performed a retrospective, observational cohort study using data from the Optum deidentified electronic health record of 30.8 million people cross-referenced with the Medtronic CareLink database of 2.7 million people with cardiac monitoring devices in situ. We enrolled patients in 3 groups: (1) CRAO, (2) cerebral ischemic stroke, and (3) age-, sex-, and comorbidity-matched controls. The primary end point was the detection of new AF (defined as ≥2 minutes of AF detected on a cardiac monitoring device). Results: We reviewed 884 431 patient records in common between the two databases to identify 100 patients with CRAO, 6559 with ischemic stroke, and 1000 matched controls. After CRAO, the cumulative incidence of new AF at 2 years was 49.6% (95% CI, 37.4%­61.7%). Patients with CRAO had a higher rate of AF than controls (hazard ratio, 1.64 [95% CI, 1.17­2.31]) and a comparable rate to patients with stroke (hazard ratio, 1.01 [95% CI, 0.75­1.36]). CRAO was associated with a higher incidence of new stroke compared with matched controls (hazard ratio, 2.85 [95% CI, 1.29­6.29]). Conclusions: The rate of AF detection after CRAO is higher than that seen in age-, sex-, and comorbidity-matched controls and comparable to that seen after ischemic cerebral stroke. Paroxysmal AF should be considered as part of the differential etiology of CRAO, and those patients may benefit from long-term cardiac monitoring.

Structural and Functional Imaging of the Retina in Central Retinal Artery Occlusion - Current Approaches and Future Directions.

Central retinal artery occlusion (CRAO) is a form of acute ischemic stroke which affects the retina. Intravenous thrombolysis is emerging as a compelling therapeutic approach. However, it is not known which patients may benefit from this therapy because there are no imaging modalities that adequately distinguish viable retina from irreversibly infarcted retina. The inner retina receives arterial supply from the central retinal artery and there is robust collateralization between this circulation and the outer retinal circulation, provided by the posterior ciliary circulation. Fundus photography can show canonical changes associated with CRAO including a cherry-red spot, arteriolar boxcarring and retinal pallor. Fluorescein angiography provides 2-dimensional imaging of the retinal circulation and can distinguish a complete from a partial CRAO as well as central versus peripheral retinal non-perfusion. Transorbital ultrasonography may assay flow through the central retinal artery and is useful in the exclusion of other orbital pathology that can mimic CRAO. Optical coherence tomography provides structural information on the different layers of the retina and exploratory work has described its utility in determining the time since onset of ischemia. Two experimental techniques are discussed. 1) Retinal functional imaging permits generation of capillary perfusion maps and can assay retinal oxygenation and blood flow velocity. 2) Photoacoustic imaging combines the principles of optical excitation and ultrasonic detection and - in animal studies - has been used to determine the retinal oxygen metabolic rate. Future techniques to determine retinal viability in clinical practice will require rapid, easily used, and reproducible methods that can be deployed in the emergency setting.

Management of Central Retinal Artery Occlusion: A Scientific Statement From the American Heart Association.

PURPOSE: Central retinal artery occlusion (CRAO) is a form of acute ischemic stroke that causes severe visual loss and is a harbinger of further cerebrovascular and cardiovascular events. There is a paucity of scientific information on the appropriate management of CRAO, with most strategies based on observational literature and expert opinion. In this scientific statement, we critically appraise the literature on CRAO and provide a framework within which to consider acute treatment and secondary prevention. METHODS: We performed a literature review of randomized controlled clinical trials, prospective and retrospective cohort studies, case-control studies, case reports, clinical guidelines, review articles, basic science articles, and editorials concerning the management of CRAO. We assembled a panel comprising experts in the fields of vascular neurology, neuro-ophthalmology, vitreo-retinal surgery, immunology, endovascular neurosurgery, and cardiology, and document sections were divided among the writing group members. Each member received an assignment to perform a literature review, synthesize the data, and offer considerations for practice. Multiple drafts were circulated among the group until consensus was achieved. RESULTS: Acute CRAO is a medical emergency. Systems of care should evolve to prioritize early recognition and triage of CRAO to emergency medical attention. There is considerable variability in management patterns among practitioners, institutions, and subspecialty groups. The current literature suggests that treatment with intravenous tissue plasminogen activator may be effective. Patients should undergo urgent screening and treatment of vascular risk factors. There is a need for high-quality, randomized clinical trials in this field.

Intravenous Fibrinolysis for Central Retinal Artery Occlusion: A Cohort Study and Updated Patient-Level Meta-Analysis.

BACKGROUND AND PURPOSE: Central retinal artery occlusion results in sudden, painless, usually permanent loss of vision in the affected eye. There is no proven, effective treatment to salvage visual acuity and a clear, unmet need for an effective therapy. In this work, we evaluated the efficacy of intravenous tissue-type plasminogen activator (IV alteplase) in a prospective cohort study and an updated systematic review and meta-analysis. METHODS: We enrolled consecutive patients with acute central retinal artery occlusion within 48 hours of symptoms onset and with a visual acuity of <20/200 from January 2009 until May 2019. The primary outcomes were safety and functional visual acuity recovery. We compared rates of visual recovery between those treated with alteplase within 4.5 hours of symptom onset to those who did not receive alteplase (including an analysis restricted to untreated patients presenting within the window for treatment). We incorporated these results into an updated systematic review and patient-level meta-analysis. RESULTS: We enrolled 112 patients, of whom 25 (22.3% of the cohort) were treated with IV alteplase. One patient had an asymptomatic intracerebral hemorrhage after IV alteplase treatment. Forty-four percent of alteplase-treated patients had recovery of visual acuity when treated within 4.5 hours versus 13.1% of those not treated with alteplase (P=0.003) and 11.6% of those presenting within 4 hours who did not receive alteplase (P=0.03). Our updated patient-level meta-analysis of 238 patients included 67 patients treated with alteplase within 4.5 hours since time last known well with a recovery rate of 37.3%. This favorably compares with a 17.7% recovery rate in those without treatment. In linear regression, earlier treatment correlated with a higher rate of visual recovery (P=0.01). CONCLUSIONS: This study showed that the administration of intravenous alteplase within 4.5 hours of symptom onset is associated with a higher likelihood of a favorable visual outcome for acute central retinal artery occlusion. Our results strongly support proceeding to a randomized, placebo-controlled clinical trial.

Myasthenia Gravis Presenting as Lutz Posterior Internuclear Ophthalmoplegia.

Myasthenia gravis can mimic central neurological disorders and should be considered in the differential diagnosis of any form of pupil-sparing ophthalmoplegia. We report an unusual manifestation of myasthenia gravis presenting as bilateral internuclear ophthalmoplegia (INO) of abduction, sometimes referred to as Lutz posterior INO (or reverse INO).

Oculomotor Synkinesis (Aberrant Reinnervation of the Third Cranial Nerve) Associated with Atypical Tolosa-Hunt Syndrome.

A 70-year-old woman with systemic lupus erythematosus developed a painful pupil-involving right third nerve palsy, ipsilateral fourth nerve palsy, and periorbital paraesthesia. Magnetic resonance imaging demonstrated enhancement and thickening of the right third nerve, and she was diagnosed with presumed Tolosa-Hunt syndrome. Repeated imaging seven months later showed resolution of the enhancing thickened oculomotor nerve, but the patient developed signs of oculomotor synkinesis. This presentation demonstrates a rare case of oculomotor synkinesis secondary to inflammation.

Stroke Risk and Risk Factors in Patients With Central Retinal Artery Occlusion.

PURPOSE: Central retinal artery occlusion (CRAO) is mechanistically similar to a stroke. Current guidelines recommend a standardized and systematic evaluation of risk factors for patients who have had a stroke. This study evaluates the yield of this evaluation in patients with CRAO and frequency of stroke in this population. DESIGN: Cohort study. METHODS: We evaluated the diagnostic yield of an expedited inpatient evaluation of cerebrovascular risk factors in a cohort of patients presenting with an acute CRAO within the period from 2009 to 2017 at an academic hospital. Vital signs and laboratory parameters, including low-density lipoprotein level, hemoglobin A1c fraction, erythrocyte sedimentation rate, C-reactive protein level, platelet count, and troponin level, were collected. Echocardiography, cardiac telemetry, magnetic resonance imaging (MRI), and cerebrovascular imaging were obtained to screen for strokes and vascular risk factors. All new diagnoses and clinical treatments stemming from the inpatient evaluation were documented. Outcomes included the frequency of stroke on MRI, hypertensive emergency, critical carotid disease, or critical cardiac disease, including high-grade valvular lesions, new myocardial infarction, or arrhythmias. We documented the frequency of a change in medication, acute surgical intervention, or new diagnosis of systemic disease as a result of the inpatient evaluation. Finally, we evaluated the rate of symptomatic stroke, myocardial infarct, and death risk in the 24 months after CRAO. RESULTS: In this cohort of 103 patients with CRAO and systematic risk factor screening, 36.7% of patients had critical carotid disease, 37.3% had coincident acute stroke, 33.0% presented with hypertensive emergency, 20.0% had a myocardial infarction or critical structural cardiac disease, 25% underwent an urgent surgical intervention, and 93% had a change in medication as a result of the inpatient evaluation. Patients with CRAO had similar risk of subsequent stroke, myocardial infarction, and death as patients with high-risk transient ischemic attack. CONCLUSIONS: Patients with CRAO are at significant risk of future cardiovascular and cerebrovascular events and often have undiagnosed risk factors that may be modifiable.

Current treatment of central retinal artery occlusion: a national survey.

BACKGROUND: Central retinal artery occlusion (CRAO) is an ophthalmological emergency, the retinal analog of a stroke. To date there is no consensus or national guidelines on how this disorder should be managed. As academic neurologists and ophthalmologists treat CRAO frequently, we set out to understand how these clinicians approach patients with CRAO with a national survey. METHODS: We identified university-associated teaching hospitals offering vascular neurology, neuro-ophthalmology and/or retina fellowships in the US and asked the directors of the programs to respond to questions in an open response format to profile the acute management of CRAO at their institution. RESULTS: We found remarkable heterogeneity in the approach to acute treatment of patients with CRAO among the 45 institutions that responded to the survey. Only 20% had a formal policy, guideline or white paper to standardize the approach to treatment. The primary treating physician was an ophthalmologist, neurologist, or neuro-ophthalmologist 44, 27, and 4% of the time, respectively; 24% were co-managed acutely by neurology and ophthalmology. Intravenous fibrinolysis was offered to selected patients in 53% of institutions, and was the preferred initial treatment in 36%. When the acute treatment team involved a vascular neurologist, fibrinolysis was more likely to be considered a first-line treatment (p < 0.05). Anterior chamber paracentesis, ocular massage and hyperbaric oxygen therapy were offered 42, 66 and 7% of the time, respectively, while 9% of institutions offered no treatment. Anterior chamber paracentesis was more likely to be offered at programs where neurologists were not involved in treating CRAOs (p < 0.001). At 35% of institutions, patients with acute CRAO were not routinely referred to a general emergency room for initial evaluation and treatment. Carotid imaging was routinely obtained by 89% of programs, magnetic resonance imaging of the brain by 69%, echocardiogram by 62%, laboratory screening for an inflammatory state by 27% and retinal angiography by 30%. The thoroughness of vascular risk factors' screening was greater in programs that routinely referred acute CRAO cases to the emergency department. CONCLUSIONS: This survey shows that there is significant variability in treatment practices for acute CRAO in the US. Because of the high cerebrovascular and cardiovascular risk reported in this population of patients, it is notable that the approach to risk factor screening is also highly variable and many programs do not routinely refer patients to an emergency department for urgent evaluation. Finally, there appears to be equipoise among treatment teams regarding the efficacy of systemic fibrinolysis, as 53% of programs report a willingness to treat at least some patients with this modality.

Nutritional Optic Neuropathy Caused by Copper Deficiency After Bariatric Surgery.

A 47-year-old woman developed severe bilateral visual loss 4 years after a Roux-en-Y gastric bypass and 24 years after vertical banded gastroplasty. Her serum copper level was 35 µg/dL (normal, 80-155 µg/dL). She was prescribed elemental copper tablets. Because her methylmalonic acid was slightly elevated, she received vitamin B12 injections as well. Five weeks later, she reported that her vision had improved and, at 10 months, her vision had recovered from 20/400 bilaterally to 20/25 in each eye. This case highlights the importance of checking copper levels in addition to the "more routine" vitamin levels, such as B1, B6, B12, E, and serum folate in patients with suspected nutritional optic neuropathy after bariatric surgery, particularly if it involved a bypass procedure.

Topiramate-induced palinopsia: a case series and review of the literature.

BACKGROUND: To report palinopsia as a possible side effect of topiramate. METHODS: Case series and review of the literature. RESULTS: Nine patients in our series, and 4 previously reported patients, who developed palinopsia while on topiramate, are reviewed. All patients were women, and comorbidities included migraine, idiopathic intracranial hypertension, and bulimia nervosa. Palinopsia resolved in 8 patients after stopping or decreasing the dose of topiramate. The lowest dose of topiramate causing palinopsia was 25 mg twice a day. More than half of our patients reported exacerbation of visual disturbance in early morning or late evening. CONCLUSIONS: Topiramate-induced palinopsia may be underdiagnosed because physicians do not inquire about such visual symptoms.

Improved diffusion tensor imaging of the optic nerve using multishot two-dimensional navigated acquisitions.

PURPOSE: A diffusion-weighted multishot echo-planar imaging approach combined with SENSE and a two-dimensional (2D) navigated motion correction was investigated as an alternative to conventional single-shot counterpart to obtain optic nerve images at higher spatial resolution with reduced artifacts. METHODS: Fifteen healthy subjects were enrolled in the study. Six of these subjects underwent a repeated acquisition at least 2 weeks after the initial scan session to address reproducibility. Both single-shot and multishot diffusion tensor imaging studies of the human optic nerve were performed with matched scan time. Effect of subject motions were corrected using 2D phase navigator during multishot image reconstruction. Tensor-derived indices from proposed multishot were compared against conventional single-shot approach. Image resolution difference, right-left optic nerve asymmetry, and test-retest reproducibility were also assessed. RESULTS: In vivo results of acquired multishot images and quantitative maps of diffusion properties of the optic nerve showed significantly reduced image artifacts (e.g., distortions and blurring), and the derived diffusion indices were comparable to those from other studies. Single-shot scans presented larger variability between right and left optic nerves than multishot scans. Multishot scans also presented smaller variations across scans at different time points when compared with single-shot counterparts. CONCLUSION: The multishot technique has considerable potential for providing improved information on optic nerve pathology and may also be translated to higher fields.

Homonymous hemianopia in nonketotic hyperglycemia is an ictal phenomenon.

Extended video-EEG or 18F-fluorodeoxyglucose PET (FDG-PET) was obtained in 3 adult patients with hemianopia secondary to nonketotic hyperglycemia. Two male patients presented with left hemianopia and episodic left gaze deviation and one male patient presented with right hemianopia and visual hallucinations. None of the 3 patients had a history of seizures or known epilepsy risk factors. All 3 patients were found to have elevated serum glucose (267 mg/dL, 320 mg/dL, and 487 mg/dL) without acidosis or urine ketones. In all 3 patients, video-EEG recorded recurrent ictal discharges originating from the posterior quadrant contralateral to their hemianopia. In 2 patients, FDG-PET demonstrated corresponding focal areas of hypermetabolism. Resolution of visual symptoms was achieved with antiepileptic drugs, hydration, and tight glycemic control.

Circumscribed outer foveolar defects in spinocerebellar ataxia type 7.

PURPOSE: To report circumscribed outer foveolar defects in a 40-year-old man with a history of spinocerebellar ataxia type 7. METHODS: A 40-year-old man with genetically confirmed spinocerebellar ataxia type 7 presented with progressive vision loss and decreased color perception for 3 years. He underwent a full ocular examination, fundus photography, autofluorescence, spectral-domain optical coherence tomography imaging, and a full-field electroretinogram. RESULTS: The patient's ocular examination and fundus autofluorescence were both normal except for mild temporal pallor of both optic discs. Spectral-domain optical coherence tomographic imaging showed foveal thinning with an outer foveolar defect because of focal loss of photoreceptors, disruption of the inner segment-outer segment junction but preservation of the external limiting membrane, and thinning of the outer plexiform layer in both eyes. Electroretinography showed severely reduced cone function with mildly reduced rod function. CONCLUSION: Spinocerebellar ataxia type 7 should be included in the differential diagnosis for "outer retinal holes" or "foveal cavitation," which also includes solar retinopathy, juxtafoveal telangiectasia, Welder maculopathy, tamoxifen retinopathy, Stargardt disease, amyl nitrate abuse, and cone or cone-rod degeneration syndromes.