OCT retinal nerve fiber layer thickness differentiates acute optic neuritis from MOG antibody-associated disease and Multiple Sclerosis: RNFL thickening in acute optic neuritis from MOGAD vs MS.

BACKGROUND: Optic neuritis (ON) is the most common manifestation of myelin oligodendrocyte glycoprotein antibody associated disorder (MOGAD) and multiple sclerosis (MS). Acute ON in MOGAD is thought to be associated with more severe optic disk edema than in other demyelinating diseases, but this has not been quantitatively confirmed. The goal of this study was to determine whether optical coherence tomography (OCT) can distinguish acute ON in MOGAD from MS, and establish the sensitivity of OCT as a confirmatory biomarker of ON in these entities. METHODS: This was a multicenter cross-sectional study of MOGAD and MS patients with peripapillary retinal nerve fiber layer (pRNFL) thickness measured with OCT within two weeks of acute ON symptom. Cirrus HD-OCT (Carl Zeiss Meditec, Inc. Dublin, CA, USA) was used to measure the pRNFL during acute ON. Eyes with prior ON or disk pallor were excluded. A receiver operating characteristic (ROC) curve analysis was performed to assess the ability of pRNFL thickness to distinguish MOGAD from MS. RESULTS: Sixty-four MOGAD and 50 MS patients met study inclusion criteria. Median age was 46.5 years (interquartile range [IQR]: 34.3-57.0) for the MOGAD group and 30.4 years (IQR: 25.7-38.4) for the MS group (p<0.001). Thirty-nine (61%) of MOGAD patients were female compared to 42 (84%) for MS (p = 0.007). The median pRNFL thickness was 164 µm (IQR: 116-212) in 96 acute MOGAD ON eyes compared to 103 µm (IQR: 93-113) in 51 acute MS ON eyes (p<0.001). The ROC area under the curve for pRNFL thickness was 0.81 (95% confidence interval 0.74-0.88) to discriminate MOGAD from MS. The pRNFL cutoff that maximized Youden's index was 118 µm, which provided a sensitivity of 74% and specificity of 82% for MOGAD. Among 31 MOGAD and 48 MS eyes with an unaffected contralateral eye or a prior baseline, the symptomatic eye had a median estimated pRNFL thickening of 45 µm (IQR: 17-105) and 7.5 µm (IQR: 1-18), respectively (p<0.001). All MOGAD affected eyes had a ≥ 5 µm pRNFL thickening, whereas 26 (54%) MS affected eyes had a ≥ 5 µm thickening. CONCLUSION: OCT-derived pRNFL thickness in acute ON can help differentiate MOGAD from MS. This can aid with early diagnosis and guide disease-specific therapy in the acute setting before antibody testing returns, and help differentiate borderline cases. In addition, pRNFL thickening is a sensitive biomarker for confirming acute ON in MOGAD, which is clinically helpful and could be used for adjudication of attacks in future MOGAD clinical trials.

Mismatch in Supply and Demand for Neuro-Ophthalmic Care.

BACKGROUND: Previous research suggests the number of neuro-ophthalmologists in the United States may be below a level that provides sufficient access to neuro-ophthalmic care in much of the United States. However, national estimates of the amount of clinical time spent on neuro-ophthalmology are lacking. METHODS: The North American Neuro-Ophthalmology Society administered a survey on professional time allocation to its active members. Survey response was 95%. The survey characterized the hours each week each respondent allocated to overall work, clinical work, clinical work in ophthalmology/neurology, and clinical work in neuro-ophthalmology specifically. The survey additionally collected information regarding demographics, current wait times to be seen for new patients, and the difference in clinical time spent in neuro-ophthalmology spent between the current day compared with that shortly after completing clinical training. Linear regression was used to identify potential relationships between the above and average wait time. RESULTS: On average, responding physicians spent 70% of their clinical time on neuro-ophthalmology. In 6 states, there were no reported practicing neuro-ophthalmologists, and in only 8 states was the clinical full-time equivalent to population ratio below the suggested threshold of 1 for every 1.2 million. The median wait time for a new patient was 6 weeks. This wait time was associated with the fraction of clinical time spent in neuro-ophthalmology (0.2 weeks longer wait for a 10 percentage point increase in the fraction of time spent in neuro-ophthalmology; P = 0.02), and suggestively associated with training (training in ophthalmology was associated with 1.0 week shorter wait time; P = 0.06). CONCLUSION: The survey suggests that neuro-ophthalmologists are unable to see patients in a timely manner and a decreasing number of clinicians are entering the field. Future interventions should be considered to incentivize neuro-ophthalmology training in ophthalmology and neurology residents such that the United States population is able to appropriately access neuro-ophthalmic care.

Clinical and Magnetic Resonance Imaging Characteristics of Postfenestration Optic Nerve Sheath Pseudomeningoceles.

PURPOSE: The clinical significance of postoperative pseudomeningocele formation following optic nerve sheath fenestration (ONSF) has not been fully characterized. A literature review identifies 9 previously published cases the authors believe demonstrate pseudomeningocele formation and approximately 19 other similar findings that were either transient or less defined blebs. This study was undertaken to more clearly define the clinical, radiographic, and histopathologic features associated with this entity. METHODS: Sixteen-year, single-center, retrospective chart review of all ONSF cases performed by 2 surgeons. Clinical data, intracranial pressure, radiographic imaging, and histopathology of clinically detected pseudomeningoceles after ONSF were reviewed. RESULTS: Eighty-six eyes in 57 patients underwent ONSF (28 unilateral, 12 bilateral sequential, 17 bilateral simultaneous). Forty-nine of 57 patients had elevated intracranial pressure preoperatively (41 idiopathic intracranial hypertension, 4 venous thrombosis, 2 meningitis, 1 arteriovenous malformation, and 1 sarcoid). In 32 patients undergoing postoperative imaging, 4 eyes (4.7%) in 4 patients developed well-defined pseudomeningoceles, of which 3 were symptomatic and 2 required surgical revision. Each pseudomeningocele developed in the setting of elevated preoperative intracranial pressure (350, 360, 430, 500 mm H20). Magnetic resonance imaging and/or computed tomography revealed sharply demarcated fluid-filled sacs adjacent to the optic nerve. The contents of these sacs were hypointense on T1-weighted imaging, hyperintense on T2-weighting, variably enhanced with contrast, and hypointense on fluid attenuated inversion recovery, and were thus consistent with cerebrospinal fluid. Histopathologic analysis of one of these outpouchings demonstrated an acellular, fibrocollagenized lining consistent with pseudomeningocele. Three eyes in 3 additional patients had less well-defined findings on imaging interpreted as bleb-like or cyst-like change. CONCLUSIONS: Pseudomeningoceles following ONSF may be asymptomatic or may cause symptomatic orbital mass effect and rarely visual loss, amendable to surgical excision. Post-ONSF pseudomeningoceles are identified on computed tomography or magnetic resonance imaging to occur at the locations of fenestration sites and contain cerebrospinal fluid communicating with the subdural space that may act as a "filtration" bleb in some cases. Imaging findings may represent a spectrum spanning intraorbital cerebrospinal fluid leakage, partial walling off of bleb, or fully developed cysts. Resection of optic nerve pseudomeningoceles is considered in symptomatic cysts or eyes with papilledema that fails to improve.

A Profile of Neuro-Ophthalmic Practice Around the World.

BACKGROUND: To compare contrast neuro-ophthalmic practice in various countries, an 18-question survey was sent to the international North American Neuro-Ophthalmology Society (NANOS) members in the spring of 2016. METHODS: At least 1 NANOS member was contacted for each non-US nation in the NANOS membership roster. If there were multiple NANOS members from 1 country, multiple were contacted. If responses were received from more than 1 person from a single country, the first response received was used as the source data. The survey (in English) was emailed to 47 NANOS members from 31 countries. Twenty responses were received representing members from 15 nations. RESULTS: In all 15 nations, at least half of the neuro-ophthalmologists were trained as ophthalmologists. In 60% of nations, at least half of the neuro-ophthalmologists were trained internally, whereas in 33% of countries, at least half were trained in the United States. The number of physicians who practiced a significant amount of neuro-ophthalmology ranged from low (0.08/million, India) to high (3.10/million, Israel). Countries having the highest percentage of neuro-ophthalmologists exclusively practicing neuro-ophthalmology also were those with better patient access to neuro-ophthalmic care. Requirement of approval to see a neuro-ophthalmologist or for imaging studies requested by neuro-ophthalmologists was not typical. In most nations, academic neuro-ophthalmologists were paid a straight salary. In no nation were neuro-ophthalmologists paid more than another ophthalmic subspecialty. CONCLUSIONS: Individual national health care system designs and compensation models have had a profound influence on the rewards and challenges that face neuro-ophthalmologists. There seems to have been a connection between recognition of the discipline, financial rewards of neuro-ophthalmic practice, conditions that permit full-time neuro-ophthalmic practice, and patient access to care. A higher percentage of gross national product for health care did not seem to insure an adequate supply of neuro-ophthalmologists.

Neuro-Ophthalmology: Transitioning From Old to New Models of Health Care Delivery.

In contradiction to fundamental laws of supply and demand, 2 decades of payment policies have led to some medical specialties experiencing declines in both manpower and reimbursement. This paradox has resulted in increasingly long wait times to see some specialists, some specialties becoming less attractive to potential trainees, and a dearth of new trainees entering these fields. Evolving models of health care delivery hold the promise of increasing patient access to most providers and may diminish costs and improve outcomes for most patients/conditions. However, patients who need care in understaffed fields may, in the future, be unable to quickly access a specialist with the requisite expertise. Impeding the sickest and most complex patients from seeing physicians with appropriate expertise may lead to increased costs and deleterious outcomes-consequences contrary to the goals of health care reform. To ensure appropriate access for these patients requires 2 conditions: 1. Compensation models that do not discourage trainees from pursuing nonprocedural specialties, and 2. A care delivery model that expediently identifies and routes these patients to the appropriate specialist.

Takayasu arteritis-related photic and postprandial amaurosis.

We report the case of a 66-year-old man with Takayasu arteritis who developed photic and postprandial amaurosis occurring at a corticosteroid dose <40 mg per day, despite concurrent methotrexate. The amaurosis resolved with correction of anemia by packed red blood cell transfusion. Marginal retinal perfusion in Takayasu arteritis may precipitate symptomatic hypoxia as a result of eating a meal or exposing the eye to bright lights. Correction of anemia improves oxygen delivery to the hypoxic retina and relieves recurrent amaurosis.

18F-FDG Uptake in Neurosarcoid Dural Plaque on PET/CT.

While the imaging modality of choice to diagnose neurosarcoidosis is gadolinium-enhanced MRI, F-FDG PET/CT maybe used to stage the disease or target the optimal biopsy site. Few cases have described intense F-FDG uptake at the sites of active neurosarcoidosis in the midbrain and pituitary gland, cerebellar hemispheres, and temporal lobes. Here, we present a case of neurosarcoidosis whose PET/CT examination demonstrated F-FDG avidity in a dural plaque.

Reversal of Visual Impairment Associated with Vasospasm After Resection of Sphenoclinoidocavernous Meningioma with Intra-Arterial Verapamil.

BACKGROUND: Visual loss can be encountered in the immediate, early, or even delayed postoperative period after resection of skull base meningiomas involving the optic apparatus. Various mechanisms for visual loss can include mechanical injury, vascular insult, optic nerve and chiasm edema, and vasospasm of the blood supply to the visual apparatus. CASE DESCRIPTION: In this article, we describe a patient who developed unilateral visual worsening in the early postoperative period after skull base resection of a sphenoclinoidocavernous meningioma that was compressing the ipsilateral optic nerve. After implementing hyperdynamic therapy and high-dose corticosteroids, catheter angiography showed severe vasospasm of the ipsilateral ophthalmic artery with delayed filling of the choroidal blush. Intra-arterial chemical angioplasty with verapamil was administered that resulted in angiographic improvement and clinical restoration of vision back to preoperative baseline. Vision remained stable in the postoperative course and continued to improve after discharge from the hospital. CONCLUSIONS: To our knowledge, this is the first report of successful reversal of postoperative unilateral visual loss related to vasospasm after resection of a skull base sphenoclinoidocavernous meningioma. This may be a useful strategy to diagnose and treat possible vasospasm-induced visual loss after resection of skull base meningiomas involving the optic apparatus.

Saturday Night Retinopathy with Ophthalmoplegia: A Case Series.

The purpose of this study was to present three cases of Saturday night retinopathy. The study design was observational case series. We described three cases who presented to our centre with acute visual loss following intravenous drug abuse and stupor leading to continuous pressure on the orbit while asleep. All cases presented with acute vision loss and had funduscopic evidence of ophthalmic or central retinal artery occlusion. Two of the cases presented with ophthalmoplegia and proptosis. One of the cases had significantly increased intraocular pressure with corneal oedema. All cases had fixed and non-reactive pupils with significant relative afferent pupillary defect. One case also had accompanying peroneal nerve damage. All three cases had poor visual outcomes. Saturday night retinopathy is a blinding condition with either central retinal or ophthalmic artery occlusion, which may present with transient orbital congestion and ophthalmoplegia. It may be accompanied by other nerve damage from compression in other parts of the body and is caused by prolonged positional pressure on the orbit.

Treatment of neuro-ophthalmic sarcoidosis.

BACKGROUND: Because of the rarity of neuro-ophthalmic sarcoidosis, there are no therapeutic guidelines based on evidence-based medicine for this disorder. EVIDENCE ACQUISITION: Review of literature combined with personal experience. RESULTS: Corticosteroids are the preferred initial therapy for neuro-ophthalmic sarcoidosis. If patients cannot tolerate the requisite dose of corticosteroid needed to control their disease, or if corticosteroids fail to adequately control the disease process, the choices of a second agent are based on the consideration of rapidity of clinical response and the safety profile. CONCLUSIONS: Although methotrexate and mycophenolate mofetil are the medications that are often selected after corticosteroid failure, more rapidly acting agents that have been used are infliximab and intravenous cyclophosphamide.

Postirradiation periocular granuloma faciale associated with uveitis.

Granuloma faciale is a rare dermatopathologic condition that presents as brown-red plaques, nodules, or papules primarily on the face, with the potential for extrafacial and mucous membrane involvement. A case of an 83-year-old woman with periocular granuloma faciale accompanied by a marked anterior uveitis is presented; an association of periocular granuloma faciale with anterior uveitis has not been previously reported.

Papilledema due to a permanent catheter for renal dialysis and an arteriovenous fistula: a "two hit" hypothesis.

Elevated intracranial pressure in patients with chronic renal failure has several potential causes. Its rare occurrence secondary to the hemodynamic effects of hemodialysis is described and the findings support a multifactorial etiology ("two hits").

Miller Fisher variant of Guillain-Barré syndrome masquerading as acute sphenoid sinusitis with orbital apex syndrome.

Miller Fisher syndrome (MFS), a variant of Guillain-Barré syndrome, is a rare disorder typically characterized by a triad of ataxia, areflexia, and ophthalmoplegia, which may have a highly variable clinical presentation. We report a case of MFS in a 45-year-old female presenting with sphenoid sinusitis and sixth nerve palsy. She underwent endoscopic sphenoid sinusotomy without improvement, had postoperative deterioration, was diagnosed with MFS, and was treated with intravenous immunoglobulin with complete response. Because of the potential severity of Guillain-Barré syndrome, great vigilance should be taken when examining sixth nerve palsies to prevent misdiagnosis and delay in treatment of the MFS variant of this disease.