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Nasopharyngeal carcinoma is very rarely associated with bilateral vision loss, and only in advanced disease. We report a case of bilateral severe compressive optic neuropathy as a first presentation from massive nasopharyngeal carcinoma with poor visual outcome despite corticosteroid, chemotherapy and radiotherapy. Red flag symptoms and signs of mass lesions in the posterior nasal space should be investigated and treated promptly to prevent devastating visual and prognostic consequences.

Background Obesity is a chronic condition, affecting central and peripheral nervous system. Studies on cranial nerve conduction in obesity are scarce and unclear; therefore, we planned this study. The aim of this study was to evaluate optic and auditory nerve conductions in obesity. Methods It was a case-control study, with inclusion of 40 young males (20 obese and 20 controls) in age group of 18–30 years. We recorded pattern reversal visual evoked potential (PRVEP) and brainstem auditory evoked potential (BAEP). The PRVEP P100 latency and BAEP absolute and interpeak latencies were analyzed. Results In obese individuals, BAEP absolute latencies of wave V were significantly prolonged in both the ears and wave I in left ear. In addition, significant prolongation of interpeak latency III–V was observed in both the ears and I–V latency, in right ear among obese cases. A positive correlation was seen between body mass index and interpeak latency I–V. In PRVEP recordings, P100 latency did not show any significant difference in both the groups. Conclusion Therefore, we can conclude that obesity does not affect optic nerve conduction, but auditory nerve conduction is affected. BAEP I–V interpeak latency may be an indicator of subclinical auditory conduction defects in young obese males.

Traumatic optic neuropathy can have varying presentations. Blunt focal trauma can lead to optic nerve avulsion with underlying retinal findings. A case of partial optic nerve avulsion after finger poke injury leading to focal retinal ischemia is reported.Visual acuity, fundus photography with fluorescein angiography, and spectral-domain optical coherence tomography were performed to document the findings in a 16-year-old man who presented after a finger poke injury to the left orbit during a water polo match.On initial presentation, examination revealed decreased visual acuity with a fixed left pupil and afferent pupillary defect by reverse. On slit-lamp examination of the left eye, a hyphema was present. Dilated fundus examination revealed layering vitreous hemorrhage over the posterior pole and an avulsed vitreous base. On follow-up, a gap temporal to the optic nerve head consistent with a partial optic nerve avulsion was noted once the vitreous hemorrhage cleared. Multimodal imaging revealed retinal ischemia temporal to the disc on fluorescein angiography with corresponding changes in the inner retinal layers and retinal nerve fiber layer using spectral-domain optical coherence tomography.Clinicians should have a high suspicion for optic nerve avulsion if a patient presents with new vitreous hemorrhage and afferent pupillary defect after a finger-poke injury. Optic nerve avulsion injury can cause retinal ischemia, likely because of interruption of retinal blood flow as a result of nerve shearing injury. Multimodal imaging can reveal focal retinal injury and aid in proper diagnosis and follow-up.

Management of patients with thyroid-associated orbitopathy (also called Graves' disease) is dependent on the assessment of the disease activity. Evaluation of disease activity is based on ophthalmological examination. Magnetic resonance imaging (MRI) is an auxiliary method that may help quantify the activity and is also helpful in obtaining anatomical information concerning muscle thickness, exophthalmos, or optic neuropathy. We present a review of MRI techniques of the orbits with emphasis on the evaluation of disease activity. The most convincing seems to be the group of T2-weighted techniques such as conventional T2 weighting, T2 relaxometry, and T2 mapping. Dynamic contrast-enhanced MRI is another promising method.

Over the past decade, ocular imaging strategies have greatly advanced the diagnosis and follow-up of patients with optic neuropathies. Developments in optic nerve imaging have specifically improved the care of patients with papilloedema and idiopathic intracranial hypertension, inflammatory optic neuropathies, and compressive optic neuropathies. For example, optic nerve imaging with optical coherence tomography (OCT) is now widely used as an outcome measure in clinical trials of neurological disorders (eg, demyelinating diseases), and OCT findings could be informative of disease progression in patients with various neurodegenerative disorders (eg, Alzheimer's disease or Parkinson's disease). In the past 5 years, multimodality optic nerve imaging has expanded to systematically include focused and wide-field colour and autofluorescence fundus photographs; various types of optic nerve, macular, and vascular OCT; and specific MRI techniques. Such multimodality imaging makes the diagnosis of optic neuropathies easier and provides objective information on optic nerve damage, which is useful for prognosis. Non-mydriatic ocular fundus cameras and OCT have become readily available in non-ophthalmic settings and could easily be implemented in neurological clinics and emergency departments, allowing for direct access to optic nerve imaging and enabling teleconsultations. In the future, these imaging studies could be used in association with artificial intelligence deep-learning systems, which are already transforming the field of ocular imaging.

An 81-year-old woman developed painful vision loss to hand motions in the right eye over a several-day period. Dilated fundus examination revealed no acute pathology, but automated perimetry showed a superotemporal visual field defect in the asymptomatic left eye, suggestive of a junctional scotoma. Magnetic resonance imaging demonstrated enhancement of the right optic nerve extending to its junction with the optic chiasm. The patient's vision failed to improve with intravenous corticosteroids, but demonstrated significant improvement with therapeutic plasma exchange. She was subsequently found to be seropositive for aquaporin-4 autoantibodies, confirming the diagnosis of neuromyelitis optic spectrum disorder.

Glaucoma is a neurodegenerative disease that causes irreversible blindness due to loss of retinal ganglion cells (RGCs) and their axons. We previously identified a G661R mutation of ADAMTS10 (A Disintegrin And Metalloproteinase with ThromboSpondin type 1 motif 10) as the disease-causing mutation in a beagle model of glaucoma. ADAMTS10 is a secreted matrix metalloproteinase that belongs to the ADAMTS family which is involved in extracellular matrix (ECM) turnover. Previous studies have shown that ADAMTS10 binds fibrillin microfibrils, promotes their formation, and influences their fibrillin isoform composition. Here, we established a mouse model carrying the G661R mutation of ADAMTS10 (ADAMTS10

The optic nerve is the second cranial nerve but is not a true cranial nerve. Instead, it's an extension of the brain parenchyma. The optic nerve transmits electrical impulses from the retina to the brain, which will be processed in visual information. Often, the clinical definition of a lesion in the optic nerves is not clear, and magnetic resonance imaging (MRI) plays a crucial role. In addition, the optic nerves can be affected by several diseases, such as congenital malformations, inflammatory, vascular, and neoplastic diseases. This article aims to review the optic nerve anatomy, discuss the best MRI techniques to evaluate each nerve segment, and demonstrate the imaging aspect of the diseases that most commonly affect it.

Nutritional deficiency is an under-recognized cause of optic neuropathy. The purpose of this review is to discuss how to identify, diagnose, and appropriately manage patients with nutritional optic neuropathy.Nutritional deficiencies have long been thought to be more prevalent in the developing countries. However, with the advent of bariatric surgery, restrictive/selective diets, and the increase in alcohol dependence, it is not uncommon to see nutritional optic neuropathies in the developed world.Although nutritional optic neuropathy can cause severe and debilitating vision loss, it is often reversible when it is diagnosed and treated in a timely manner.

The purpose of this study is to provide an overview of the replacements used in lost vision in the form of the bionic eye, to show their deficiencies and outline other possibilities for non-invasive stimulation of functional areas of the visual cortex. The review highlights the damage not only to the primary altered cellular structures, but also to all other horizontally and vertically localised structures. Based on the results of a large number of functional magnetic resonance imaging and electrophysiological methods, the authors focus on the pathology of the entire visual pathway in pigmentary retinopathy (PR) and age-related macular degeneration (AMD). This study provides a recent overview of the possible systems used to replace lost vision. These range from stimulation with intraocular implants, through stimulation of the optic nerve and lateral geniculate nucleus to the visual cortex. The second part deals with the design of image processing technology and its transformation into the form of transcranial stimulation of undamaged parts of the brain, which is protected by a patent. This is comprehensive overview of the current possibilities of replacement of lost vision and a proposal for a new non-invasive methods of stimulation of functional neurons of the visual cortex.

Optic neuropathy associated with Sjögren syndrome is rare and usually has an acute onset.This study aimed to report a case of asymmetric optic nerve atrophy attributed to Sjögren syndrome.A 37-year-old woman was referred to neuro-ophthalmology service because of right optic nerve atrophy of unknown etiology. The patient was asymptomatic. Best-corrected visual acuity was 20/200 Snellen equivalent in the right eye and 20/20 Snellen equivalent in the left eye. The right eye had a relative afferent pupillary defect. Visual field demonstrated dense temporal loss, superior arcuate involvement, and an inferior paracentral defect in the right eye. Slit-lamp examination showed mild fluorescein staining of the cornea, moderate lissamine green staining of the conjunctiva, and abnormal tear breakup time in both eyes. Fundus examination revealed diffuse pallor of the right optic disc and a normal left optic disc. Optical coherence tomography showed inferior and superior retinal nerve fiber layer atrophy in the right eye and inferior retinal nerve fiber layer atrophy in the left eye. A diagnosis of right optic nerve atrophy was made. Immunologic studies were significant for positive anti-Ro and anti-La antibodies. MRI of the brain and orbit ruled out any intracranial or white-matter pathology. A diagnosis of optic nerve atrophy secondary to Sjögren syndrome was suspected, so corticosteroid treatment was started.Optic nerve atrophy may be the initial manifestation of Sjögren syndrome. Therefore, optic neuropathy associated with Sjögren syndrome remains a diagnostic challenge. In these cases, specific antibodies such as anti-Ro and anti-La facilitate early diagnosis and can prevent vision-threatening complications.

(1) Background: The normal A1 segment of the anterior cerebral artery (ACA) has a supraoptic course. The proximal infraoptic course of an A1 segment leaving the internal carotid artery (ICA) near the origin of the ophthalmic artery is a rare possibility. This study aimed to determine the prevalence and detailed anatomy of infraoptic A1 segments. (2) Methods: We retrospectively studied 145 computed tomography angiograms from 92 male and 53 female cases, with ages varying from 61 to 78 y.o. (3) Results: In 21/145 cases, infraoptic or infrachiasmatic horizontal-medial courses of A1 segments that emerged distally from the ICA were found. Distal infraoptic A1 segments were bilateral in 16/145 cases and unilateral in 3/145 cases. Infrachiasmatic A1 segments were found bilaterally in 2/145 male cases. All the infraoptic/infrachiasmatic A1 segments left long ICAs with low bifurcations. In 7/34 sides with distal infraoptic or infrachiasmatic A1 segments, supracarotid courses were present. In one female, the right A1 segment had an anterior supraclinoid, supracarotid and infraoptic course. In two female cases with a bilateral distal infraoptic A1, the segment was almost contacting the respective posterior cerebral artery. (4) Conclusions: In cases with dolicho(ectatic) ICAs, the A1 segments could have infraoptic and supracarotid courses the neurosurgeons should be aware of.

Glaucoma is currently leading retinal disease, which damages the eye because of the Intraocular pressure (IOP) on the eye. If glaucoma is left untreated it will lead to vision loss by damaging the Optic Nerve Head (ONH). The progression of glaucoma is examined on the retinal part of the eye by an experienced ophthalmologist. This approach is very tedious, and it consumes more time to do it manually. Hence this issue is right problem that can be solved by automatically diagnosing glaucoma with the help of the deep learning approaches. Convolutional Neural Networks (CNN's) are appropriate to find the solution for this type of issue as they can extract various levels of data from the input image, and which encourages to differentiate among non-glaucomic and glaucomic images. This proposed paper introduces an efficient glaucoma master framework to segment the optic cup and optic disc to find the Cup-to-Disc-Ratio (CDR). Here the diagnosis of glaucoma is achieved by using deep learning with novel CNN. The proposed system uses two individual CNN architecture to segment the Optic Cup (OC) and Optic Disc (OD) to get more accurate result. This model is trained and tested on DRISHTI – GS database, which is publicly available and an accuracy of 98% for optic disc and 97% for optic cup segmentation is achieved.

To report a case of nonarteritic anterior ischemic optic neuropathy (NAION) after intravitreal injection in a patient with a history of fellow-eye NAION.Observational case report.An 82-year-old woman with a history of fellow eye NAION developed an inferior visual field defect 1 day after an intravitreal aflibercept injection for neovascular age-related macular degeneration. She was found to have optic disk edema and an inferior altitudinal defect, consistent with NAION. The mechanism may have involved compromised perfusion to the optic nerve head related to elevated intraocular pressure or vasoconstriction because of antivascular endothelial growth factor activity.Nonarteritic anterior ischemic optic neuropathy is a rare complication of intravitreal injection and may be related to postinjection elevation in intraocular pressure. Monitoring of intraocular pressure postinjection with low-threshold for preinjection aqueous suppression or postinjection anterior chamber paracentesis for persistently elevated intraocular pressure is recommended in patients with a history of NAION.

Management of inter- and intra-fraction movements of target volumes and organs at risk (OARs) during radiotherapy is essential. While there is little OAR or target volume movement, the movements and orientation of the eyes can be significant during radiotherapy and they can affect the position of the optic nerve. The objective of the present study was to assess the variations of the optic nerve position due to gaze direction and to discuss their clinical consequences on the radiation treatment of intraorbital tumors.Three patients without a history of oculomotor nerve palsy underwent six CT acquisitions with a thermoplastic mask: eyes open with different gaze directions (straight ahead, left, right, up, down) and eyes closed. The acquisition with the straight-ahead gaze was chosen as the reference position. Left and right optic nerves were segmented on the six acquisitions, and total volumes and maximum amplitude motions were calculated in three dimensions.Maximum differences were observed while looking left and up, with a median maximum amplitude of 5 and 6mm [range: 2-7mm], respectively. These motions induced a position variation of more than 50% of the volume of the optic nerve (compared to the reference position). Greater variations of motion were observed for the anterior portion of the nerve. The gaze position with the fewest variations compared to the reference position was eyes closed.Optic nerve positions vary significantly due to the gaze direction, especially for the anterior portion of the nerve. These variations should be taken into account for the treatment of small intraorbital tumors involving the anterior third of the optic nerve.

A 52-year-old male patient with polyarthritis nodosa (PAN) was referred to our neurology outpatient clinic. His main symptom was paroxysmal alternating bilateral blindness. Subsequently, he developed retro-orbital pain. Neurological examination including funduscopy was normal and laboratory tests showed no relevant abnormalities. MRI orbits showed remarkable perineural thickening and contrast enhancement of the optic nerve sheaths with sparing of the central optic nerve. These findings are pathognomonic for the clinical-radiological diagnosis of optic perineuritis (OPN). The patient was treated with high-dose immunosuppressants and had a good clinical outcome. Rapid diagnosis of OPN is important because early treatment is associated with a better outcome.

Hemodialysis (HD) is known to affect ocular blood flow. This case-control study aims to evaluate macular and peripapillary vasculature in patients with end-stage renal disease (ESRD) receiving HD in comparison to matched controls. A total of 24 eyes of 24 ESRD patients receiving HD and 24 eyes of 24 healthy, age- and gender-matched control subjects were prospectively included in this study. Optical coherence tomography angiography was used to image the superficial (SCP), deep (DCP), and choriocapillary (CC) macular vascular plexus, as well as the radial peripapillary capillaries (RPC) of the optic disc. In addition, retinal thickness (RT) and retinal volume (RV) were compared between both groups. Flow density (FD) values of each retinal layer and data of parameters related to the foveal avascular zone (FAZ), as well as RT and RV, were analyzed using Mann–Whitney U tests. There was no significant difference in FAZ parameters between the two groups. Whole en face FD of the SCP and CC was noticeably reduced in the HD group in comparison to the control group. FD was negatively correlated with the duration of HD treatment. RT and RV were significantly smaller in the study group than in controls. Retinal microcirculation appears altered in patients with ESRD undergoing HD. Concurrently, the DCP appears more resilient towards hemodynamic changes in comparison to the other microvascular retinal layers. OCTA is a useful, non-invasive tool to investigate retinal microcirculation in ESRD patients.

Asymptomatic optic nerve lesions are frequent in multiple sclerosis (MS) and their impact on cognition and/or brain volume has never been taken into account.We used the data from the cross-sectional Visual Ways in MS (VWIMS) study including relapsing remitting MS. All patients underwent brain and optic nerve Magnetic Resonance Imaging (MRI) including Double Inversion Recuperation (DIR) sequence, retinal OCT, and cognitive evaluation with the Brief International Cognitive Assessment in MS (BICAMS). We measured the association between OCT findings (thickness/volume of retinal layers) and extra-visual parameters (cerebral volumes and BICAMS scores) in optic nerves with and/or without the presence of DIR asymptomatic optic nerve hypersignal.Between March and December 2017, we included 98 patients. Two patients were excluded. Over the 192 eyes, 73 had at least one clinical history of optic neuritis (ON-eyes) whereas 119 were asymptomatic (NON-eyes). Among the 119 NON-eyes, 58 had 3D-DIR optic nerve hypersignal (48.7%). We confirmed significant associations between some retinal OCT measures and some extra-visual parameters (cerebral volumes, cognitive scores) in NON-eyes. Unexpectedly, these associations were found when an asymptomatic optic nerve DIR-hypersignal was present on MRI, but not when it was absent.Our study showed a relation between OCT measures and extra-visual parameters in NON-eyes MS patients. As a confusion factor, asymptomatic optic nerve lesions may be the explanation of the relation between OCT measures and extra-visual parameters. Retinal OCT seems to be far more a "window over the optic nerve" than a "window over the brain".

The pathological basis of optic nerve crush (ONC) is the apoptosis of retinal ganglion cells (RGCs), which leads to an irreversible impairment of visual function. When stimulated by external stimuli, microglia polarize into different types and play different roles in repairing retinal injury. In this study, gadolinium chloride (GdCl

Juvenile-onset open-angle glaucoma (JOAG) is a subset of primary open-angle glaucoma that is diagnosed before 40 years of age. The disease may be familial or non-familial, with proportions varying among different populations. Myocilin mutations are the most commonly associated. JOAG is characterized by high intraocular pressures (IOP), with many patients needing surgery. The mean age at diagnosis is in the 3(rd) decade, with a male preponderance. Myopia is a common association. The pathophysiology underlying the disease is immaturity of the conventional outflow pathways, which may or may not be observed on gonioscopy and anterior segment optical coherence tomography. The unique optic nerve head features include large discs with deep, steep cupping associated with high IOP-induced damage. Progression rates among JOAG patients are comparable to adult primary glaucomas, but as the disease affects younger patients, the projected disability from this disease is higher. Early diagnosis, prompt management, and life-long monitoring play an important role in preventing disease progression. Gene-based therapies currently under investigation offer future hope.

Doubling of the optic disc is rare in clinic, which appears as true doubling or pseudo-doubling. Bilateral doubling of the optic discs is even more less seen in clinic. Here, we report the case of a 35-year-old woman who presented to the clinic for a physical examination. The patient's best-corrected visual acuity was 0.6 OD with +2.25 DS/3.50 DC×175°, and 0.9 OS with -3.00 DS/0.50 DC×145°. The intraocular pressure of each eye was normal. Fundoscopy examination revealed an enlarged suspected optic disc in both eyes. Visual field examination revealed an additional blind spot in each eye. Optical coherence tomography (OCT) analysis showed a normal macular thickness and profile. B-scan ultrasound revealed a single optic nerve shadow in each eye. Cranial computed tomography (CT) showed only 1 optic foramen and 1 optic nerve in each eye. Although double-blind spots were demonstrated by visual field examination, and pits in both optic disc regions for both eyes were shown by OCT, it was not enough to support the diagnosis of true doubling of the optic disc. Consequently, the diagnosis of bilateral pseudo-doubling of optic discs was made based on the clinical evidence, leading to the consideration of possible causality of other ophthalmic diseases.

Visual dysfunction due to sellar and suprasellar lesions is thought to be caused by chiasmatic compression and bending of the optic nerve at the entrance of the optic canal. We examined the relationship between visual field impairment and magnetic resonance (MR) imaging.This study reviewed 122 consecutive patients with sellar and suprasellar tumors. We have newly devised a simple visual field impairment score (SVFIS) that was divided into 12 areas. SVFIS is classified into four grades as mild (0-3 points), moderate (4-6 points), severe (7-9 points), and most severe (10-12 points) for each eye. We investigated the relationship between SVFIS grades and MR imaging, including the recently reported optic nerve-canal bending angle (ONCBA) and visual acuity.Ipsilateral visual acuity tended to deteriorate with increased SVFIS grade. Larger ONCBA was associated with increased SVFIS grades. Bitemporal hemianopia occurred in the early stage (mild case), but the central visual field within 30° was particularly likely to be impaired. The visual field disturbance progressed clockwise (counterclockwise on the left side) from the upper temporal side. Disorders of the central visual field within 5° were associated with ipsilateral large ONCBA.The newly developed SVFIS grades are closely associated with indicators of visual pathway impairment on MR imaging, and are useful as indicators of the severity and progression of visual field impairment due to sellar and suprasellar lesions. Disorders of the central visual field within 5° were found to be associated with ipsilateral large ONCBA.

With the development of imaging, the etiology of ocular lesions caused by lung cancer was not found only intraocular. Neuro-ophthalmological imaging has been found to be useful for the diagnosis of meningeal carcinomatosis, although few studies have previously been published. Our study used magnetic resonance imaging (MRI) to determine if there was a the relationship between ocular symptoms and lung cancer metastasis.We carried out a retrospective analysis which included patients with ocular lesions and lung cancer on which orbit MRI was performed together with ocular examination during January 2014 to January 2022. Here, we describe the characteristics of intraocular metastasis and optic nerve sheath lesions.A total of 21 lung cancer patients had ocular lesions, of which eight cases had choroidal metastasis; a further eight patients had optic nerve sheath lesions. There was one case (12.5%) of choroidal metastasis with brain or meningeal metastasis, and eight cases (100%) with optic nerve sheath lesions with brain or meningeal metastasis. A total of 75.0% patients with choroidal metastasis did not have any history of known lung cancer, and 25.0% of optic nerve sheath lesions in patients were found before a meningeal metastasis diagnosis. The features of optic nerve sheath lesions included thickening and strengthening of the long segment of the orbital optic nerve sheath with a clear boundary.The pathway of choroidal and optic nerve sheath lesions was different. Optic nerve sheath lesions were associated with brain and meningeal metastasis. When lung cancer-induced meningeal metastasis is suspected, orbital MRI is recommended to assist in the diagnosis.

To determine whether patients with biopsy-confirmed optic nerve glioma differ in clinical features and outcomes from those diagnosed by neuroradiologic imaging alone.Retrospective comparative analysis. Pilocytic astrocytomas (PAs) and gliomas of the optic nerve were identified through ICD-O codes in the Surveillance, Epidemiology, and End Results (SEER) cancer registry from 1975 through 2017. Demographics, clinical features, and outcomes were compared according to the method of diagnosis (biopsy-confirmed and radiologic only) and by age (birth through 19 years and 20 years of age and older). Differences in proportions were tested with the chi-square test. Associations with tumor-related death were evaluated with logistic regression. Statistical significance: α0.01.Over 42 years, 313 PAs and 720 gliomas of the optic nerve were identified. The young age distributions were similar between the 2 groups. PAs were biopsied more often than gliomas (54% vs 13.2% [ P0.001]). Tumor-attributable death occurred more often among PAs and gliomas that were biopsied than those that were not (7.1% vs 0.7% [ P0.01]; 7.4% vs 1.1% [ P0.01], respectively). Roughly 15% of both PAs and gliomas were diagnosed in persons 20 years and older.Biopsy-confirmed cases of PA and glioma of the optic nerve were associated with more therapeutic interventions and worse outcomes compared with patients who were diagnosed radiologically. Clinical variables relevant to clinical decision-making not captured by SEER likely explain the inability to meaningfully interpret outcome from the registry database. Cancer registries should avoid coding specific histopathologic diagnoses when tissue is not obtained.

Charcot-Marie-Tooth disease (CMT) is a common hereditary peripheral polyneuropathy encompassing distinct monogenetic disorders. Pathogenic mutations in mitofusin 2 (MFN2) are the most frequent cause of its axonal type, CMT type 2A, with diverse phenotypes. We herein report a Japanese patient with a novel heterozygous MFN2 pathogenic variant (c.740 G>C, p.R247P) and severe CMT phenotypes, including progressive muscle weakness, optic atrophy, urinary inconsistency, and restrictive pulmonary dysfunction with eventration of the diaphragm that developed over her 60-year disease course. Our case expands the clinico-genetic features of MFN2-related CMT and highlights the need to evaluate infrequent manifestations during long-term care of CMT patients.

INTRODUCTION: Neuro-ophthalmic findings collectively defined as Spaceflight-Associated Neuro-ocular Syndrome (SANS) are one of the leading health priorities in astronauts engaging in long duration spaceflight or prolonged microgravity exposure. Though multifactorial in etiology, similarities to terrestrial idiopathic intracranial hypertension (IIH) suggest these changes may result from an increase or impairing in intracranial pressure (ICP). Finding a portable, accessible, and reliable method of monitoring ICP is, therefore, crucial in long duration spaceflight. A review of recent literature was conducted on the biomedical literature search engine PubMed using the search term “non-invasive intracranial pressure”. Studies investigating accuracy of noninvasive and portable methods were assessed. The search retrieved different methods that were subsequently grouped by approach and technique. The majority of publications included the use of ultrasound-based methods with variable accuracies. One of which, noninvasive ICP estimation by optical nerve sheath diameter measurement (nICP_ONSD), presented the highest statistical correlation and prediction values to invasive ICP, with area under the curve (AUC) ranging from 0.75 to 0.964. One study even considers a combination of ONSD with transcranial Doppler (TCD) for an even higher performance. Other methods, such as near-infrared spectroscopy (NIRS), show positive and promising results [good statistical correlation with invasive techniques when measuring cerebral perfusion pressure (CPP): r = 0.83]. However, for its accessibility, portability, and accuracy, ONSD seems to present itself as the up to date, most reliable, noninvasive ICP surrogate and a valuable spaceflight asset.Félix H, Santos Oliveira E. Non-invasive intracranial pressure monitoring and its applicability in spaceflight. Aerosp Med Hum Perform. 2022; 93(6):517–531.

A 48-year-old woman with untreated hypothyroidism initially presented with tinnitus and hearing loss, followed by blurred vision and eye pain months later. Ophthalmic evaluation revealed no optic disc oedema. Visual field defects in both eyes suggested retrobulbar optic neuropathy. MRI of the brain and orbits demonstrated enhancement of both optic nerve sheaths and diffuse pachymeningeal enhancement. Audiologic evaluation revealed hearing loss in both ears, and frequent square wave jerks were seen on videonystagmography. Fine needle aspiration from one pulmonary lymph node showed non-necrotising granulomatous inflammation, confirming the diagnosis of neurosarcoidosis. The visual fields improved significantly on prednisone, and she is maintained on prednisone, infliximab and methotrexate. Though common, multiple cranial neuropathies in neurosarcoidosis are poorly represented in the literature. Clinicians should be aware of the symptoms that may herald a diagnosis of neurosarcoidosis, so that treatment may be implemented sooner, and further cranial neuropathies may be prevented.

To assess the validity of neurosonological parameters (transorbital sonography (TOS)) for detection and monitoring of patients with idiopathic intracranial hypertension (IIH).Prospective, single-center, case-controlled study in 25 patients with IIH and 19 controls. Visual parameters of papilledema, visual acuity, computerized static threshold perimetry, fundus examination, and neurosonological parameters of papilledema/optic disc elevation (ODE), optic nerve sheath diameter (ONSD) and optic nerve diameter (OND) were recorded at baseline and only for patients with IIH again within 6 months.ONSD was significantly enlarged among individuals with IIH (6.2 ± 0.73 mm) compared to controls (4.99 ± 0.54 mm; p 0.001). Bilateral ODE was found in 36/50 eyes in patients at their initial visit and in none of the controls. Re-evaluation 6 months later showed a significant reduction of ONSD (6.0 ± 0.7 mm; p = 0.024) and ODE (0.2 (0-1) mm; p ≤0.001). Best corrected visual acuity (BCVA) and square root of lost variance (sLV) remained stable. Headache intensity (Numeric rating scale, NRS) improved significantly p 0.001. When compared to patients with first diagnosed IIH (n = 18), the subset of patients with preexisting IIH with acute relapse (n = 7) showed persistent but reduced levels of ICP increase. They also presented significant decrease of BVCA (p = 0.01) and mean defect (MD) (p = 0.012). Re-evaluation 6 months later showed significant change in ODE in both groups.Our study confirmed that TOS and ophthalmological parameters are a valuable and non-invasive method to detect and monitor elevated ICP in IIH.

Retinal ganglion cell (RGC) axons of the African clawed frog, Xenopus laevis, unlike those of mammals, are capable of regeneration and functional reinnervation of central brain targets following injury. Here, we describe a tadpole optic nerve crush (ONC) procedure and assessments of brain reinnervation based on live imaging of RGC-specific transgenes which, when paired with CRISPR/Cas9 injections at the one-cell stage, can be used to assess the function of regeneration-associated genes in vivo in F0 animals. Using this assay, we find that map3k12, also known as dual leucine zipper kinase (Dlk), is necessary for RGC axonal regeneration and acts in a dose-dependent manner. Loss of Dlk does not affect RGC innervation of the brain during development or visually driven behavior but does block both axonal regeneration and functional vision restoration after ONC. Dlk loss does not alter the acute changes in mitochondrial movement that occur within RGC axons hours after ONC but does completely block the phosphorylation and nuclear translocation of the transcription factor Jun within RGCs days after ONC; yet, Jun is dispensable for reinnervation. These results demonstrate that in a species fully capable of regenerating its RGC axons, Dlk is essential for the axonal injury signal to reach the nucleus but may affect regeneration through a different pathway than by which it signals in mammalian RGCs.

Background The meninges, formed by dura, arachnoid and pia mater, cover the central nervous system and provide important barrier functions. Located between arachnoid and pia mater, the cerebrospinal fluid (CSF)-filled subarachnoid space (SAS) features a variety of trabeculae, septae and pillars. Like the arachnoid and the pia mater, these structures are covered with leptomeningeal or meningothelial cells (MECs) that form a barrier between CSF and the parenchyma of the optic nerve (ON). MECs contribute to the CSF proteome through extensive protein secretion. In vitro, they were shown to phagocytose potentially toxic proteins, such as α-synuclein and amyloid beta, as well as apoptotic cell bodies. They therefore may contribute to CSF homeostasis in the SAS as a functional exchange surface. Determining the total area of the SAS covered by these cells that are in direct contact with CSF is thus important for estimating their potential contribution to CSF homeostasis. Methods Using synchrotron radiation-based micro-computed tomography (SRµCT), two 0.75 mm-thick sections of a human optic nerve were acquired at a resolution of 0.325 µm/pixel, producing images of multiple terabytes capturing the geometrical details of the CSF space. Special-purpose supercomputing techniques were employed to obtain a pixel-accurate morphometric description of the trabeculae and estimate internal volume and surface area of the ON SAS. Results In the bulbar segment, the ON SAS microstructure is shown to amplify the MECs surface area up to 4.85-fold compared to an “empty” ON SAS, while just occupying 35% of the volume. In the intraorbital segment, the microstructure occupies 35% of the volume and amplifies the ON SAS area 3.24-fold. Conclusions We provided for the first time an estimation of the interface area between CSF and MECs. This area is of importance for estimating a potential contribution of MECs on CSF homeostasis.

BACKGROUND Optical coherence tomography angiography (OCTA) is a new noninvasive imaging modality that provides high resolution images of the optic nerve head and peripapillary retinal capillary vasculature which can be affected by optic nerve or retinal pathologies. High repeatability of peripapillary capillary density measurement using OCTA has been demonstrated in normal eyes and eyes with glaucoma. The purpose of our study was to quantify the repeatability of peripapillary capillary density measurement using OCTA in both normal eyes and eyes with optic atrophy, optic disc edema, and retinal vasculopathy. METHODS This prospective cross-sectional study enrolled 31 patients (59 eyes) including 16 eyes with optic nerve pathology (7 with disc edema from papilledema and 9 with optic atrophy), 35 eyes with retinal vascular disease, and 8 normal eyes. All eyes were imaged twice (30 minutes apart) with the Optovue AngioVue OCTA instrument to obtain 4.5 × 4.5 mm peripapillary scans. Scans were considered good quality if signal strength was 6 or greater. The OCTA parameters obtained include the radial peripapillary capillary (RPC) density of the whole disc, inside the disc, peripapillary region, and the 4 quadrants of the disc (superior, nasal, inferior, and temporal). A Student's t test was used to compare means. Intraclass correlation coefficient (ICC) was calculated to measure repeatability. RESULTS Repeatability of RPC density measurements for all regions analyzed demonstrated good to excellent repeatability for the whole cohort {ICC for the whole image was 0.915 (95% confidence interval [CI] = 0.855-0.951)}; ICC for the peripapillary region was 0.945 (95% CI = 0.905-0.969). In the subset of eyes with good image quality (i.e., signal strength ≥ 6), ICC was slightly higher for all regions, with excellent repeatability of the peripapillary region (ICC was 0.971 [95% CI = 0.943-0.986]). Conversely, for eyes with poor image quality scans (i.e., signal strength < 6), ICC was lower, corresponding to moderate to good repeatability for most parameters. For the subset of eyes with optic atrophy, disc edema from papilledema or retinal vasculopathy, all had good to excellent repeatability of the vessel density of the entire disc (ICC values were 0.954 [95% CI = 0.804-0.990], 0.921 [95% CI = 0.711-0.982], and 0.895 [95% CI = 0.788-0.951, respectively]) and of the peripapillary region (ICC values were 0.980 [95% CI = 0.904-0.996], 0.966 [95% CI = 0.854-0.993], and 0.916 [95% CI = 0.827-0.961], respectively). CONCLUSIONS The peripapillary capillary density measurement obtained using a commercial OCTA instrument is highly repeatable in eyes with optic nerve atrophy, disc edema from papilledema, or retinal vasculopathy.

To describe ocular findings in infants with signs of congenital Zika virus syndrome (CZS) in Paraíba, Brazil, as well as to conduct a literature review and report correlations with published clinical cases.In the Paraíba sample, infants with microcephaly suggestive of CZS were classified as Z (confirmed), PZ (probable), or SZ (suspected) according to serological testing and/or clinical findings of CZS. The patients underwent a clinical eye examination, and the results were correlated with published clinical cases.Ocular findings were present in 24 (42.9%) of 56 patients, consisting of gross retinal pigmentation in 11 (45.8%), macular chorioretinal atrophy in 11 (45.8%), optic nerve hypoplasia in 1 (4.2%), optic nerve pallor in 14 (58.3%), and increased cup-to-disk ratio in 2 (8.3%). The study revealed retina and optic nerve findings consistent with previous reports of ophthalmic involvement in CZS. However, external ocular changes observed in other studies were not detected.Ocular findings similar and consistent with the literature on CZS were observed with considerable frequency and severity, regardless of the patients' serological confirmation or classification. Infants with signs of CZS should undergo ocular examination.

A 63-year-old white man with hypertension, hyperlipidemia, adrenal insufficiency, and history of metastatic spindle cell melanoma previously treated with ipilimumab, presented with unilateral papillitis in the left eye. The disc edema evolved to neuroretinitis with additional MRI findings of perineuritis. Broad laboratory evaluation confirmed active B. henselae infection, and he confirmed exposure to a newly adopted kitten. His vision improved following a course of antibiotics and oral steroids with resolution of clinical findings. To the best of our knowledge, this is the first reported case of cat-scratch neuroretinitis with MRI findings of optic nerve and optic nerve sheath enhancement.

Given the rising number of patients with blindness from macular, optic nerve, and visual pathway disease, there is considerable interest in the potential of electrical stimulation devices to restore vision. Electrical devices for restoration of visual function can be grouped into three categories: (1) visual prostheses whose goal is to bypass damaged areas and directly activate downstream intact portions of the visual pathway; (2) electric field stimulation whose goal is to activate endogenous transcriptional and molecular signaling pathways to promote neuroprotection and neuro-regeneration; and (3) neuromodulation whose stimulation would resuscitate neural circuits vital to coordinating responses to visual input. In this review, we discuss these three approaches, describe advances made in the different fields, and comment on limitations and potential future directions.

Retinal ganglion cells generate a pattern of action potentials to communicate visual information from the retina to cortical areas. Myelin, an insulating sheath, wraps axonal segments to facilitate signal propagation and when deficient, can impair visual function. Optic nerve development and initial myelination has largely been considered completed by the fifth postnatal week. However, the relationship between the extent of myelination and axonal signaling in the maturing optic nerve is not well characterized. Here, we examine the relationship between axon conduction and elements of myelination using extracellular nerve recordings, immunohistochemistry, western blot analysis, scanning electron microscopy, and simulations of nerve responses. Comparing compound action potentials from mice aged 4–12 weeks revealed five functional distinct axonal populations, an increase in the number of functional axons, and shifts toward fast-conducting axon populations at 5 and 8 weeks postnatal. At these ages, our analysis revealed increased myelin thickness, lower g-ratios and changes in the 14 kDa MBP isoform, while the density of axons and nodes of Ranvier remained constant. At 5 postnatal weeks, axon diameter increased, while at 8 weeks, increased expression of a mature sodium ion channel subtype, Na(v) 1.6, was observed at nodes of Ranvier. A simulation model of nerve conduction suggests that ion channel subtype, axon diameter, and myelin thickness are more likely to be key regulators of nerve function than g-ratio. Such refinement of axonal function and myelin rearrangement identified an extended period of maturation in the normal optic nerve that may facilitate the development of visual signaling patterns.

Vision disorders are associated with traumatic brain injury (TBI) in 20%–40% of clinical cases and involve a diverse set of potential symptoms that can present acutely or chronically. Due to its structure and position, the optic nerve is vulnerable to multiple forms of primary injury, which can result in traumatic optic neuropathy (TON). Multiple studies have shown that the optic tract may also be injured during TBI, though data regarding the temporospatial resolution of injury to the optic nerve are sparse. We evaluated the time course of optic nerve injury and visual impairments in our closed head impact acceleration mouse model of mild TBI (mTBI) designed to mimic repetitive injuries experienced in the context of sport. Our results show that inflammation and gliosis occur acutely in response to injury. Additionally, indications of optic nerve degeneration and functional loss of vision beginning at 1-month postinjury, and retinal ganglion cell loss at 7 months, revealed that the degeneration is continuous and permanent. Together, this study demonstrated that the optic nerve is vulnerable to damage during mTBI, which can cause TON and vision loss. These findings will be important for clinicians to consider to determine whether optic nerve is injured in the TBI patients with vision problems.

This study evaluates the effectiveness of a multidisciplinary protocol for management of patients with papilledema and vision loss secondary to increased intracranial pressure.Retrospective record review of all adult patients who presented with vision-threatening papilledema (VTPE) and were treated under this protocol. Patients are admitted for lumbar drain placement and diuretics and followed daily to determine if they may be managed medically or require surgery (optic nerve sheath fenestration [ONSF] and/or cerebrospinal fluid [CSF] shunting).Nineteen patients were included. Twelve had body mass index in the obese range and 6 were morbidly obese. Fourteen had idiopathic intracranial hypertension. Five had secondary pseudotumor cerebri syndrome related to medication use, dural venous sinus thrombosis, hypothyroidism, end-stage renal disease, pulmonary disease, and diastolic heart failure. Three patients did not require surgery and were discharged on oral diuretics; 3 patients underwent unilateral ONSF, 9 underwent bilateral ONSF, and 4 underwent bilateral ONSF followed by ventriculoperitoneal shunt placement. The average follow-up was 10.1 months. The visual acuity improved bilaterally in 12 patients and unilaterally in 4 patients. The remaining 3 patients had worsened vision in both eyes. Fifteen patients had bilateral improvement in their visual fields. Five eyes in 3 patients showed further constriction of the visual field at follow-up.We demonstrate how a multidisciplinary complex care protocol for treating VTPE can expedite and streamline treatment and restore vision. We found that most patients had improved symptoms and signs, including visual acuity, visual fields, and papilledema. We encourage institutions that manage VTPE to adopt similar institutional protocols.

Purpose This study aimed to evaluate the radiation-induced adverse effects on ocular structures in head and neck cancer patients and investigate the radiation dose-volume effects on the cornea, lacrimal gland, retina, optic nerve and chiasm.Materials and Methods A total of 38 eyes of 19 patients were included in this prospective, cohort study. All patients underwent complete ophthalmological examination in addition to contrast sensitivity, visual field and visual evoked potentials (VEP) tests. Ophthalmological examinations and psychophysical tests were performed in 6th, 12th, 18th, 24th months and in the last visit. The relationship between the ophthalmologic findings, and the radiation doses below and above the cut-off values was evaluated.Results Contrast sensitivity decrease and visual field deterioration were observed in 42% of the patients in the last visit (median 26 months) whereas a prolonged latency and decreased amplitude of P100 wave in VEP was observed in 58% and 33% of the eyes, respectively at 24th month. Totally 16 patients (84.2%) developed dry eye disease and eight of them received radiotherapy below tolerance doses and had mild to moderate dry eye findings. Radiation-induced retinopathy was observed in three of the eyes in eight patients who received radiation above tolerance dose.Conclusion Head and neck cancers treated with radiotherapy, resulted in various ophthalmic complications. All patients who are treating with radiotherapy should be evaluated by an ophthalmologist in terms of anterior and posterior segment damage, even if the radiation dose is below the tolerance limit.

Unlike the usual peripheral nerve, the optic nerve accompanies a thick "dural sheath," a thin "sheath of pia mater" (SPM), and multiple "septa," which divides the nerve fibers into fascicles. We collected specimens from 25 adult cadavers and 15 fetuses and revisited the histological architecture of the optic and oculomotor nerves. In the optic chiasma, the meningeal layer of the dura joins the pia to form a thick SPM, and the periosteum of the sphenoid is continuous with the dural sheath at the orbital exit of the bony optic canal. The septa appeared as a cluster of irregularly arrayed fibrous plates in the intracranial course near the chiasma. Thus, the septa were not derived from either the SPM or the dural sheath. In the orbit, the central artery of the retina accompanies collagenous fibers from the dural sheath and the SPM to provide the vascular sheath in the optic nerve. These connective tissue configurations were the same between adult and fetal specimens. At the optic disk, the dural sheath and SPM merged with the sclera, whereas the septa appeared to end at the lamina cribrosa. However, in fetuses without lamina cribrosa, the septa extend into the nerve fiber layer of the retina. The SPM and septa showed strong elastin immunoreactivity, in contrast to the absence of reactivity in the sheaths of the oculomotor nerve. Each S100 protein-positive Schwann sheath of the oculomotor nerve was surrounded by collagenous endoneurium. Glial fibrillary acidic protein-positive astrocytes showed a linear arrangement along the septa.

PURPOSE: Prior studies on compressive optic neuropathy (CON) have come from large tertiary centers, which may contain referral bias toward more severe or atypical disease. To our knowledge, there are no studies to determine the population-based etiologies and clinical outcomes of compressive optic neuropathy (CON). This study aims to bridge that gap using the Rochester Epidemiology Project database. DESIGN: Retrospective, population-based cohort METHODS: Medical records of all residents living in Olmsted County, Minnesota from January 1, 2000 through December 31, 2018 were screened for CON. Demographic and clinical information were collected before and after treatment. RESULTS: 23 patients had a confirmed diagnosis of CON during our study period, which provided an overall incidence of 1.14 per 100,000 per year. Average age at onset of CON was 51 years (SD 24), and 39% were male. The most common etiologies were pituitary adenoma and meningioma. There was significant improvement in visual fields (p < 0.003) but not in visual acuity (p = 0.08) after patients underwent treatment for CON. There was also a significant relationship between the time until treatment and the degree of visual field improvement at follow-up (Pearson correlation rho = −0.58, p < 0.047). CONCLUSION: To our knowledge, this study provides the first population-based incidence of CON. The finding that earlier treatment leads to better visual outcomes stresses the importance of having CON on the differential diagnosis of patients with optic neuropathy.

OBJECTIVE Resection of meningiomas in direct contact with the anterior optic apparatus carries risk of injury to the visual pathway. Stereotactic radiosurgery (SRS) offers a minimally invasive alternative. However, its use is limited owing to the risk of radiation-induced optic neuropathy. Few SRS studies have specifically assessed the risks and benefits of treating meningiomas in direct contact with the optic nerve, chiasm, or optic tract. The authors hypothesized that SRS is safe for select patients with meningiomas in direct contact with the anterior optic apparatus. METHODS The authors performed an international multicenter retrospective analysis of 328 patients across 11 institutions. All patients had meningiomas in direct contract with the optic apparatus. Patients were followed for a median duration of 56 months after SRS. Neurological examinations, including visual function evaluations, were performed at follow-up visits. Clinical and treatment variables were collected at each site according to protocol. Tumor volumes were assessed with serial MR imaging. Variables predictive of visual deficit were identified using univariable and multivariable logistic regression. RESULTS SRS was the initial treatment modality for 64.6% of patients, and 93% of patients received SRS as a single fraction. Visual information was available for 302 patients. Of these patients, visual decline occurred in 29 patients (9.6%), of whom 12 (41.4%) had evidence of tumor progression. Visual decline in the remaining 17 patients (5.6%) was not associated with tumor progression. Pre-SRS Karnofsky Performance Status predicted visual decline in adjusted analysis (adjusted OR 0.9, 95% CI 0.9–1.0, p < 0.01). Follow-up imaging data were available for 322 patients. Of these patients, 294 patients (91.3%) had radiographic evidence of stability or tumor regression at last follow up. Symptom duration was associated with tumor progression in adjusted analysis (adjusted OR 1.01, adjusted 95% CI 1.0–1.02, adjusted p = 0.02). CONCLUSIONS In this international multicenter study, the vast majority of patients exhibited tumor control and preservation of visual function when SRS was used to treat meningioma in direct contact with the anterior optic pathways. SRS is a relatively safe treatment modality for select patients with perioptic meningiomas in direct contact with the optic apparatus.

In most cases, vestibular schwannomas with papilledema are associated with intracranial hypertension secondary to hydrocephalus (obstructive or communicating). We describe the atypical case of a 39-years-old man who presented with bilateral papilledema revealing a vestibular schwannoma, but without hydrocephalus and with normal intracranial pressure. Ophtalmologic signs were completely resolved after tumor removal. The pathophysiological mechanism generally described to explain bilateral papilledema in such cases is tumor-induced hyperproteinorachia. However, in the absence of hydrocephalus or intracranial hypertension, this case raises the question of the mechanisms involved in the visual impairment related to vestibular schwannoma., Les schwannomes vestibulaires avec œdème papillaire sont en général associés à une hypertension intracrânienne secondaire à une hydrocéphalie (communicante ou obstructive). Nous décrivons ici le cas atypique d’un homme de 39 ans ayant présenté un œdème papillaire révélateur d’un schwannome vestibulaire, mais sans hydrocéphalie et avec une pression intracrânienne normale. L’exérèse tumorale a permis une régression complète des signes ophtalmologiques. En l’absence d’obstruction ventriculaire, le mécanisme physiopathologique généralement décrit pour expliquer l’atteinte visuelle est l’hydrocéphalie secondaire à une hyperprotéinorachie. Cependant, en l’absence d’hydrocéphalie ou d’hypertension intracrânienne, ce cas soulève la question des mécanismes impliqués dans l’atteinte visuelle secondaire à la présence d’un schwannome vestibulaire

Axons of adult neurons in the mammalian central nervous system generally fail to regenerate by themselves, and few if any therapeutic options exist to reverse this situation. Due to a weak intrinsic potential for axon growth and the presence of strong extrinsic inhibitors, retinal ganglion cells (RGCs) cannot regenerate their axons spontaneously after optic nerve injury and eventually undergo apoptosis, resulting in permanent visual dysfunction. Regarding the extracellular environment, research to date has generally focused on glial cells and inflammatory cells, while few studies have discussed the potentially significant role of interneurons that make direct connections with RGCs as part of the complex retinal circuitry. In this study, we provide a novel angle to summarize these extracellular influences following optic nerve injury as “intercellular interactions” with RGCs and classify these interactions as synaptic and non-synaptic. By discussing current knowledge of non-synaptic (glial cells and inflammatory cells) and synaptic (mostly amacrine cells and bipolar cells) interactions, we hope to accentuate the previously neglected but significant effects of pre-synaptic interneurons and bring unique insights into future pursuit of optic nerve regeneration and visual function recovery.

Background: Meta-analyses show a variable relationship between optic nerve sheath diameter (ONSD) and the presence of raised intracranial pressure (ICP). Because optic nerve sheath (ONS) tissue can be deformed, it is possible that ONSD reflects not only the current ICP but also prior deforming biomechanical exposures. In this post hoc analysis of two published data sets, we characterize ONS Young’s modulus (E, mechanical stress per unit of strain) and calculate threshold pressure for plastic deformation. Methods: The authors of two previously published articles contributed primary data for these unique post hoc analyses. Human cadaveric ex vivo measurements of ONSD (n = 10) and luminal distending pressure (range 5 to 65 mm Hg) were used to calculate E and the threshold pressure for plastic deformation. Clinical in vivo measurements of ONSD and ICP during endotracheal tube suction from patients with traumatic brain injury (n = 15) were used to validate the ex vivo cadaveric findings. Results: Ex vivo ONS estimate of E was 140 ± 1.3 mm Hg (mean ± standard error), with evidence of plastic deformation occurring with distending pressure at 45 mm Hg. Similar E (71 ± 10 mm Hg) was estimated in vivo with an average ICP of 34 ± 2 mm Hg. Conclusions: Ex vivo, ONS plastic deformation occurs at levels of pressure commonly seen in patients with raised ICP, leading to distortion of the ICP–ONSD relationship. This evidence of plastic deformation may illustrate why meta-analyses fail to identify a single threshold in ONSD associated with the presence of raised ICP. Future studies characterizing time-dependent viscous characteristics of the ONS will help determine the time course of ONS tissue biomechanical behavior.

Background and purpose T2/FLAIR hyperintensity of the optic nerve/optic nerve head has been described as a sensitive finding in idiopathic intracranial hypertension using post-contrast 3D-T2/FLAIR imaging. The purpose of this study is to assess whether hyperintensity on non-enhanced 2D-T2/FLAIR imaging occurs more likely in diseased patients than controls and to evaluate the relationship between FLAIR signal and visual parameters Materials and methods A retrospective case-control study was performed of patients with idiopathic intracranial hypertension and controls who underwent orbital MRI. Three neuroradiologists reviewed the FLAIR images, subjectively evaluating for hyperintense signal within the optic nerves/optic nerve heads using a 5-point Likert Scale. Quantitative assessment of optic nerve signal using regions of interests was performed. Clinical parameters were extracted. The diagnostic performance was evaluated, and Spearman correlation calculated to assess the relationship between FLAIR signal and visual outcomes. Results The sensitivity of abnormal FLAIR signal within the optic nerves and optic nerve heads in patients with idiopathic intracranial hypertension ranged from 25–54% and 4–29%, respectively, with specificities ranging from 67–92% and 83–100%. Quantitative assessment revealed a significant difference in CNR between cases and controls in the left posterior optic nerve (p=.002). A positive linear relationship existed between abnormal optic nerve head signal and papilledema grade (OD: p=.02, OS: p=.008) but not with other visual parameters. Conclusion T2/FLAIR hyperintensity in the optic nerve/optic nerve head may support the diagnosis of idiopathic intracranial hypertension but its absence should not dissuade it. If present, abnormal signal in the optic nerve head correlates with papilledema.

Background: Optic nerve gliomas (ONGs) are uncommon tumors of the central nervous system in adults. The aim of this study was to define their characteristics, prognostic factors, and the impacts of adjuvant radiotherapy (RT) and chemotherapy on outcomes.Methods: Adult patients (age ≥18 years) with ONGs from the Surveillance, Epidemiology, and End Results (SEER) database were included. Univariate and multivariate Cox regression models were utilized to analyze the factors associated with survival. Kaplan-Meier method was used to evaluate the impacts of adjuvant therapies on overall survival (OS).Results: A total of 179 adult patients diagnosed with ONGs were identified between 1991 and 2016, with a median follow-up period of 64.0 months. The median age at diagnosis was 41.0 years. After excluding 18 patients with unknown information, the remaining patients included 142 (88.2%) low-grade tumors and 19 (11.8%) high-grade tumors. Multivariate analysis showed age at diagnosis, tumor grade, adjuvant chemotherapy were significant factors for OS. The 5-year OS rates for patients with low- and high-grade ONGs were 85.5% and 10.5%, respectively. The employment of adjuvant RT or chemotherapy would significantly shorten OS time in the low-grade group and could not prolong OS time in the high-grade group.Conclusions: This is the largest retrospective study of adult ONGs up to date. The overall prognosis of high-grade ONGs in adult patients is still poor despite multi-modality treatments. Adjuvant RT or chemotherapy might not be considered in adult patients with low-grade ONGs unless the malignant transformation or aggressive progression has been confirmed.

Malignant optic gliomas are an uncommon pathology, with around 67 cases reported worldwide in the literature. We present the case of a 77-year-old-male with a two-month history of progressive vision loss, ultimately leading to bilateral blindness. The initial clinical suspicion was a non-inflammatory ischemic optic neuropathy. Stereotactic biopsy was performed on the optic chiasm, and the histopathological diagnosis was confirmed as Glioblastoma.