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Current Opinion in Ophthalmology Sep 2019Optic pathway gliomas are low-grade neoplasms that affect the precortical visual pathway of children and adolescents. They can affect the optic nerve, optic chiasm,... (Review)
Review
PURPOSE OF REVIEW
Optic pathway gliomas are low-grade neoplasms that affect the precortical visual pathway of children and adolescents. They can affect the optic nerve, optic chiasm, optic tracts and radiations and can either be sporadic or associated with neurofibromatosis type one. Gliomas isolated to the optic nerve (ONG) represent a subgroup of optic pathway gliomas, and their treatment remains controversial. New developments in ONG treatment have emerged in recent years, and it is necessary for clinicians to have a current understanding of available therapies.
RECENT FINDINGS
The current review of the literature covers the background of and recent developments in ONG treatment, with a focus on standard chemotherapy, new molecularly targeted therapies, radiation therapy and surgical resection and debulking.
SUMMARY
Although standard chemotherapy remains the mainstay of ONG treatment, newer molecularly targeted therapies such as mitogen-activated protein kinase kinase inhibitors and bevacizumab represent a promising new treatment modality, and clinical studies are ongoing.
Topics: Adolescent; Antineoplastic Agents; Child; Female; Humans; Male; Molecular Targeted Therapy; Ophthalmologic Surgical Procedures; Optic Chiasm; Optic Nerve Glioma; Optic Nerve Neoplasms; Optic Tract; Radiotherapy
PubMed: 31246635
DOI: 10.1097/ICU.0000000000000587 -
Child's Nervous System : ChNS :... Nov 2017The optic chiasm is an essential structure located at the skull base that stirred over time the curiosity of anatomists, who became more and more interested in its... (Review)
Review
PURPOSE
The optic chiasm is an essential structure located at the skull base that stirred over time the curiosity of anatomists, who became more and more interested in its structure and function. Through centuries, the optic chiasm was viewed as a vessel crossing, a way of transporting tears secreted by the brain to the eye, integrating images, or responsible for coordinated eye movements. The paper aims to overview the history of understanding the optic chiasm from the beginnings of antiquity to the twentieth century.
METHODS
We reviewed the literature and studied all the historical sources on optic chiasm and eyes in the works of ancient, medieval, Renaissance authors, and the seventeenth to nineteenth century works.
RESULTS
The optic chiasm is a structure that fascinated ancient anatomists and made them develop various theories on its function. In terms of function, the optic chiasm had a history based more on speculation, the seventeenth century bringing its first understanding and reaching the peak in the nineteenth century with the understanding of the anatomical structure of the chiasm and its role in the visual process.
CONCLUSION
The history of the optic chiasm is a fascinating time travel displaying the conceptual transformations that have been made in anatomy and medicine by our forerunners.
Topics: History, 15th Century; History, 16th Century; History, 17th Century; History, 18th Century; History, 19th Century; History, 20th Century; History, Ancient; History, Medieval; Humans; Ophthalmology; Optic Chiasm
PubMed: 28808784
DOI: 10.1007/s00381-017-3564-1 -
Neurology India 2022
Topics: Antitubercular Agents; Ethambutol; Humans; Optic Chiasm; Optic Nerve; Optic Nerve Diseases
PubMed: 36076719
DOI: 10.4103/0028-3886.355154 -
Journal of Neurology, Neurosurgery, and... Oct 1973Three patients with nasal visual field defects are described. In each case it is believed that compression of the lateral fibres of the optic nerve by the anterior...
Three patients with nasal visual field defects are described. In each case it is believed that compression of the lateral fibres of the optic nerve by the anterior cerebral or internal carotid artery was the cause. Binasal hemianopia can thus be produced by a single lesion and is as much a true hemianopia as the common bitemporal one. The value of careful neuroradiological investigation to display the relationships of a tumour to the chiasma, optic nerves, and related vessels and thus explain the field defects is demonstrated.
Topics: Adenoma, Chromophobe; Brain Neoplasms; Carotid Artery, Internal; Cerebral Angiography; Cerebral Arteries; Female; Hemianopsia; Humans; Male; Meningioma; Middle Aged; Optic Chiasm; Optic Nerve; Pituitary Neoplasms; Pneumoencephalography; Visual Fields
PubMed: 4753868
DOI: 10.1136/jnnp.36.5.697 -
The British Journal of Ophthalmology Sep 2006Implications for our understanding of the mechanisms of early development of the visual pathway
Implications for our understanding of the mechanisms of early development of the visual pathway
Topics: Albinism, Ocular; Fovea Centralis; Humans; Optic Chiasm; Visual Pathways
PubMed: 16929052
DOI: 10.1136/bjo.2006.097618 -
Multiple Sclerosis (Houndmills,... Jan 2022Optic neuritis (ON) is often the presenting symptom in inflammatory central nervous system demyelinating disorders.
BACKGROUND
Optic neuritis (ON) is often the presenting symptom in inflammatory central nervous system demyelinating disorders.
OBJECTIVE
To compare the frequency and pattern of optic chiasm involvement in patients with aquaporin-4-immunoglobulin G (AQP4-IgG)-associated ON to patients with myelin oligodendrocyte glycoprotein-immunoglobulin G (MOG-IgG)-associated ON.
METHODS
Retrospective review of all patients evaluated at Mayo Clinic, Stanford University and Ramathibodi Hospital who were found to have: (1) ON, (2) either MOG-IgG or AQP4-IgG by cell-based assay, and (3) magnetic resonance imaging (MRI) at the time of ON. MRI was reviewed for contrast enhancement of the optic chiasm and the pattern of involvement.
RESULTS
One hundred and fifty-four patients (74 AQP4-IgG and 80 MOG-IgG) were included. Among patients with AQP4-IgG-ON, 20% had chiasmal involvement, compared with 16% of patients with MOG-IgG-ON ( = 0.66). In patients with chiasmal involvement, longitudinally extensive optic nerve enhancement (from orbit extending to chiasm) was identified in 54% of MOG-IgG-ON patients, compared with 7% of AQP4-IgG-ON patients ( = 0.01).
CONCLUSION
Chiasmal involvement of MOG-IgG-ON and AQP4-IgG-ON occur at more similar frequencies than previously reported. Furthermore, MOG-IgG-ON chiasmal involvement is more likely to be part of a longitudinally extensive optic nerve lesion.
Topics: Aquaporin 4; Autoantibodies; Humans; Myelin-Oligodendrocyte Glycoprotein; Neuromyelitis Optica; Optic Chiasm; Optic Neuritis; Retrospective Studies
PubMed: 33975499
DOI: 10.1177/13524585211011450 -
Neurology India 2010Arachnoiditis involving optic nerve and the optic chiasm can occur as a complication of tuberculous meningitis (TBM). This study evaluates the clinical features,...
Arachnoiditis involving optic nerve and the optic chiasm can occur as a complication of tuberculous meningitis (TBM). This study evaluates the clinical features, cerebrospinal fluid (CSF) and laboratory parameters and imaging findings of optochiasmatic arachnoiditis (OCA) and also tried to identify any factors which can predict this complication in patients with TBM. Patients admitted with TBM in the neurology wards of a tertiary care teaching hospital over a period of 6 years formed the material for this study. Student's "t" test and univariate analysis were done to identify any predictors for this complication and the variables found to be significant were further analyzed by multivariate logistic regression analysis. One hundred sixty-three patients with TBM, admitted over a 6-year period, were studied. Twenty-three (14%) patients developed OCA. Eighteen out of 23 (78%) developed this complication while on antituberculous treatment (ATT) and 5/23 (22%) were newly diagnosed cases of TBM. Of those already on treatment, 12/23 (52%) were receiving only ATT, the remaining 6/23 (26%) had received steroids along with ATT in varying doses and duration. The average period from diagnosis of TBM to visual symptoms was 6.4 months. On the multivariate logistic regression analysis, female sex (P < 0.037), age less than 27 (P < 0.008) years and protein content in the CSF > 260 mg% (P < 0.021) were the factors predisposing toward this complication. At 6 months follow-up, on treatment with steroids and ATT, 17% had improvement and no further deterioration was noted in visual acuity in 52%. OCA can develop even while on treatment with ATT. Young women with a high CSF protein content seem to be more prone for this complication.
Topics: Adult; Analysis of Variance; Antitubercular Agents; Arachnoiditis; Female; Humans; Logistic Models; Magnetic Resonance Imaging; Male; Optic Chiasm; Spinal Cord Diseases; Tuberculosis, Meningeal; Visual Acuity; Young Adult
PubMed: 21045497
DOI: 10.4103/0028-3886.72194 -
Journal of the Formosan Medical... Jan 2022
Topics: Hemorrhage; Humans; Magnetic Resonance Imaging; Optic Chiasm
PubMed: 34602317
DOI: 10.1016/j.jfma.2021.09.012 -
Physiological Reviews Oct 2001At the optic chiasm the two optic nerves fuse, and fibers from each eye cross the midline or turn back and remain uncrossed. Having adopted their pathways the fibers... (Review)
Review
At the optic chiasm the two optic nerves fuse, and fibers from each eye cross the midline or turn back and remain uncrossed. Having adopted their pathways the fibers separate to form the two optic tracts. Research into the architecture and development of the chiasm has become an area of increasing interest. Many of its mature features are complex and vary between different animal types. It is probable that numerous factors sculpt its development. The separate ganglion cell classes cross the midline at different locations along the length of the chiasm, reflecting their distinct periods of production as the chiasm develops in a caudo-rostral direction. In some mammals, uncrossed axons are mixed with crossed axons in each hemi-chiasm, whereas in others they remain segregated. These configurations are the product of different developmental mechanisms. The morphology of the chiasm changes significantly during development. Neurons, glia, and the signals they produce play a role in pathway selection. In some animals fiber-fiber interactions are also critical, but only where crossed and uncrossed pathways are mixed in each hemi-chiasm. The importance of the temporal dimension in chiasm development is emphasized by the fact that in some animals uncrossed ganglion cells are generated abnormally early in relation to their retinal location. Furthermore, in albinos, where many cells do not exit the cell cycle at normal times, there are systematic chiasmatic abnormalities in ganglion cell projections.
Topics: Albinism; Animals; DNA-Binding Proteins; Hedgehog Proteins; Humans; Neuroglia; Neurons; Optic Chiasm; PAX2 Transcription Factor; Retina; Trans-Activators; Transcription Factors; Visual Pathways
PubMed: 11581492
DOI: 10.1152/physrev.2001.81.4.1393