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Eye (London, England) Jan 2021Optical coherence tomography (OCT) is a non-invasive medical imaging technology that is playing an increasing role in the routine assessment and management of patients... (Review)
Review
Optical coherence tomography (OCT) is a non-invasive medical imaging technology that is playing an increasing role in the routine assessment and management of patients with neuro-ophthalmic conditions. Its ability to characterise the optic nerve head, peripapillary retinal nerve fibre layer and cellular layers of the macula including the ganglion cell layer enables qualitative and quantitative assessment of optic nerve disease. In this review, we discuss technical features of OCT and OCT-based imaging techniques in the neuro-ophthalmic context, potential pitfalls to be aware of, and specific applications in more common neuro-ophthalmic conditions including demyelinating, inflammatory, ischaemic and compressive optic neuropathies, optic disc drusen and raised intracranial pressure. We also review emerging applications of OCT angiography within neuro-ophthalmology.
Topics: Humans; Ophthalmology; Optic Disk; Optic Disk Drusen; Optic Nerve Diseases; Tomography, Optical Coherence
PubMed: 33239763
DOI: 10.1038/s41433-020-01288-x -
Survey of Ophthalmology 2016Optic disk drusen occur in 0.4% of children and consist of acellular intracellular and extracellular deposits that often become calcified over time. They are typically... (Review)
Review
Optic disk drusen occur in 0.4% of children and consist of acellular intracellular and extracellular deposits that often become calcified over time. They are typically buried early in life and generally become superficial, and therefore visible, later in childhood, at the average age of 12 years. Their main clinical significance lies in the ability of optic disk drusen, particularly when buried, to simulate true optic disk edema. Misdiagnosing drusen as true disk edema may lead to an invasive and unnecessary workup for elevated intracranial pressure. Ancillary testing, including ultrasonography, fluorescein angiography, fundus autofluorescence, and optical coherence tomography, may aid in the correct diagnosis of optic disk drusen. Complications of optic disk drusen in children include visual field defects, hemorrhages, choroidal neovascular membrane, nonarteritic anterior ischemic optic neuropathy, and retinal vascular occlusions. Treatment options for these complications include ocular hypotensive agents for visual field defects and intravitreal anti-vascular endothelial growth factor agents for choroidal neovascular membranes. In most cases, however, children with optic disk drusen can be managed by observation with serial examinations and visual field testing once true optic disk edema has been excluded.
Topics: Child; Fluorescein Angiography; Fundus Oculi; Global Health; Humans; Incidence; Optic Disk; Optic Disk Drusen; Tomography, Optical Coherence; Visual Acuity; Visual Fields
PubMed: 27033945
DOI: 10.1016/j.survophthal.2016.03.007 -
Indian Journal of Ophthalmology Dec 2019Melanocytoma is a deeply pigmented variant of melanocytic nevus that classically occurs in the optic disk, sometimes with contiguous involvement of the adjacent retina... (Review)
Review
Melanocytoma is a deeply pigmented variant of melanocytic nevus that classically occurs in the optic disk, sometimes with contiguous involvement of the adjacent retina or choroid. Historically, this tumor was often confused with malignant melanoma both clinically and histopathologically. Today, however, it is generally recognized by its typical clinical features that differ from most melanomas and erroneous enucleation is rarely done. Histopathologically, melanocytoma is composed of intensely pigmented round to oval nevus cells with benign features. Although traditionally believed to be a relatively stationary lesion, it is now known to exhibit minor enlargement in 10--15% of cases and can cause minor visual loss by a variety of mechanisms. In rare instance, it can induce severe visual loss due to spontaneous necrosis of the lesion or compressive optic neuropathy. More importantly, it can exhibit malignant transformation into melanoma in 1--2% of cases. Ophthalmologists should be familiar with melanocytoma of the optic disk and affected patients should be followed periodically.
Topics: Cell Transformation, Neoplastic; Humans; Melanoma; Nevus, Pigmented; Optic Disk; Optic Nerve Neoplasms
PubMed: 31755427
DOI: 10.4103/ijo.IJO_2039_19 -
Ophthalmology Feb 2021The spaceflight-associated neuro-ocular syndrome (SANS) affects astronauts on missions to the International Space Station (ISS). The SANS has blurred vision and ocular...
PURPOSE
The spaceflight-associated neuro-ocular syndrome (SANS) affects astronauts on missions to the International Space Station (ISS). The SANS has blurred vision and ocular changes as typical features. The objective of this study was to investigate if microgravity can create deformations or movements of the eye or optic nerve, and if such changes could be linked to SANS.
DESIGN
Cohort study.
PARTICIPANTS
Twenty-two astronauts (age 48 ± 4 years).
METHODS
The intervention consisted of time in microgravity at the ISS. We co-registered pre- and postspaceflight magnetic resonance imaging (MRI) scans and generated centerline representations of the optic nerve. The coordinates for the optic nerve head (ONH) and optic chiasm (OC) ends of the optic nerve were recorded along with the entire centerline path.
MAIN OUTCOME MEASURES
Optic nerve length, ONH movement, and OC movement after time in microgravity.
RESULTS
Optic nerve length increased (0.80 ± 0.74 mm, P < 0.001), primarily reflecting forward ONH displacement (0.63 ± 0.53 mm, P < 0.001). The forward displacement was positively related to mission duration, preflight body weight, and clinical manifestations of SANS. We also detected upward displacement of the OC (0.39 ± 0.50 mm, P = 0.002), indicative of brain movement, but this observation could not be linked to SANS.
CONCLUSIONS
The spaceflight-induced optic nerve lengthening and anterior movement of the ONH support that SANS is caused by an altered pressure difference between the brain and the eye, leading to a forward push on the posterior of the eye. Body weight is a potential contributing risk factor. Direct assessment of intracranial pressure in space is required to verify the implicated mechanism behind the ocular findings in SANS.
Topics: Astronauts; Cohort Studies; Extraterrestrial Environment; Female; Humans; Intracranial Pressure; Magnetic Resonance Imaging; Male; Middle Aged; Optic Disk; Optic Nerve; Papilledema; Space Flight; Syndrome; Time Factors; Vision Disorders; Weightlessness
PubMed: 32659310
DOI: 10.1016/j.ophtha.2020.07.007 -
Annals of the Academy of Medicine,... Feb 2020
Topics: Glaucoma; Humans; Optic Disk
PubMed: 32246705
DOI: No ID Found -
Arquivos Brasileiros de Oftalmologia 2022Evaluation of the optic disc is important for the correct diagnosis and follow-up of optic neuropathies, especially glaucoma. The characteristics of the optic disc... (Review)
Review
Evaluation of the optic disc is important for the correct diagnosis and follow-up of optic neuropathies, especially glaucoma. The characteristics of the optic disc depend on various factors, including demographic and population aspects, and analysis of these characteristics may vary according to the methods used. The size and format of the neural rim along with the nerve fiber layer are important to the clinician's judgment regarding the susceptibility of the subject to develop glaucoma. In this study, we reviewed the literature to summarize the main methods and its characteristics in the evaluation of the optic nerve head.
Topics: Humans; Optic Disk; Glaucoma; Optic Nerve Diseases
PubMed: 35170637
DOI: 10.5935/0004-2749.20220080 -
Archives of Pathology & Laboratory... Jan 2017Ischemic optic neuropathy (ION) describes a state of hypoxic injury of the optic nerve. Clinically, ION is divided into anterior and posterior forms defined by the... (Review)
Review
Ischemic optic neuropathy (ION) describes a state of hypoxic injury of the optic nerve. Clinically, ION is divided into anterior and posterior forms defined by the presence or absence of optic disc swelling, respectively. It is further classified as arteritic when secondary to vasculitis, and nonarteritic when not. The site of vascular occlusion for anterior ION from giant cell arteritis is the short posterior ciliary arteries, but mechanical vascular obstruction does not play a role in most nonarteritic cases. Histologically, ION is characterized by axon and glial necrosis, edema, and a sparse mononuclear response. Like other ischemic injuries, the morphologic alternations in the nerve are time dependent. A variant of ION called cavernous degeneration (of Schnabel) features large cystic spaces filled with mucin. Several conditions can histologically mimic cavernous degeneration of the optic nerve. The scarcity of cases of ION examined histologically has contributed to an incomplete understanding of its pathogenesis.
Topics: Arteritis; Diagnosis, Differential; Humans; Optic Disk; Optic Nerve; Optic Neuropathy, Ischemic
PubMed: 28029908
DOI: 10.5858/arpa.2016-0027-RS -
Journal of Neuro-ophthalmology : the... Sep 2017Few diseases blur the margins between their childhood and adult-onset varieties as much as optic neuritis. This report will review our state of knowledge of pediatric... (Meta-Analysis)
Meta-Analysis Review
Few diseases blur the margins between their childhood and adult-onset varieties as much as optic neuritis. This report will review our state of knowledge of pediatric optic neuritis, as well as its relationship to the latest consensus definitions of neuroinflammatory disease. Current diagnostic and treatment options will be explored, as well as our potential to uncover an understanding of pediatric optic neuritis through systematic prospective studies. The risk of evolving multiple sclerosis is probably less than in adults, but pediatric optic neuritis is more likely to be an initial manifestation of acute disseminated encephalomyelitis. Steroids may hasten visual recovery, but they do not change visual outcome except in cases because of neuromyelitis optica. The role of puberty in modifying the presentation and risk associations is unknown. Prospective studies are required to resolve these diagnostic and management issues.
Topics: Child; Diagnostic Imaging; Humans; Magnetic Resonance Imaging; Optic Disk; Optic Neuritis; Tomography, Optical Coherence; Visual Acuity
PubMed: 28806345
DOI: 10.1097/WNO.0000000000000551 -
Asia-Pacific Journal of Ophthalmology...To describe the optic nerve head (ONH) abnormalities in nonpathologic highly myopic eyes based on swept-source optical coherence tomography (OCT) and the relationship...
PURPOSE
To describe the optic nerve head (ONH) abnormalities in nonpathologic highly myopic eyes based on swept-source optical coherence tomography (OCT) and the relationship with visual field (VF).
DESIGN
Secondary analysis from a longitudinal cohort study.
METHODS
Highly myopic patients without myopic maculopathy of category 2 or higher were enrolled. All participants underwent a swept-source OCT examination focused on ONH. We differentiated between 3 major types (optic disc morphologic abnormality, papillary/peripapillary tissue defect, and papillary/peripapillary schisis) and 12 subtypes of ONH abnormalities. The prevalence and characteristics of ONH abnormalities and the relationship with VF were analyzed.
RESULTS
A total of 857 participants (1389 eyes) were included. Among the 1389 eyes, 91.86%, 68.61%, and 34.92% of them had at least 1, 2, or 3 ONH abnormalities, respectively, which corresponded to 29.55%, 31.79%, and 35.67% of VF defects, respectively. Among the 12 subtypes of the 3 major types, peripapillary hyperreflective ovoid mass-like structure, visible retrobulbar subarachnoid space, and prelaminar schisis were the most common, respectively. Perimetric defects corresponding to OCT abnormalities were more commonly found in eyes with peripapillary retinal detachment, peripapillary retinoschisis, and peripapillary hyperreflective ovoid mass-like structure. Glaucoma-like VF defects were more common in eyes with deep optic cups (28.17%) and with optic disc pit/pit-like change (18.92%).
CONCLUSIONS
We observed and clarified the ONH structural abnormalities in eyes with nonpathologic high myopia. These descriptions may be helpful to differentiate changes in pathologic high myopia or glaucoma.
Topics: Humans; Optic Disk; Visual Fields; Longitudinal Studies; Myopia; Glaucoma; Eye Abnormalities; Tomography, Optical Coherence; Vision Disorders
PubMed: 37851563
DOI: 10.1097/APO.0000000000000636 -
International Journal of Molecular... Jan 2023Glaucoma is one of the most common causes of treatable visual impairment in the developed world, affecting approximately 64 million people worldwide, some of whom will... (Review)
Review
Glaucoma is one of the most common causes of treatable visual impairment in the developed world, affecting approximately 64 million people worldwide, some of whom will be bilaterally blind from irreversible optic nerve damage. The optic nerve head is a key site of damage in glaucoma where there is fibrosis of the connective tissue in the lamina cribrosa (LC) extracellular matrix. As a ubiquitous second messenger, calcium (Ca) can interact with various cellular proteins to regulate multiple physiological processes and contribute to a wide range of diseases, including cancer, fibrosis, and glaucoma. Our research has shown evidence of oxidative stress, mitochondrial dysfunction, an elevated expression of Ca entry channels, Ca-dependent pumps and exchangers, and an abnormal rise in cytosolic Ca in human glaucomatous LC fibroblast cells. We have evidence that this increase is dependent on Ca entry channels located in the plasma membrane, and its release is from internal stores in the endoplasmic reticulum (ER), as well as from the mitochondria. Here, we summarize some of the molecular Ca-dependent mechanisms related to this abnormal Ca-signalling in human glaucoma LC cells, with a view toward identifying potential therapeutic targets for ongoing optic neuropathy.
Topics: Humans; Calcium; Myofibroblasts; Glaucoma; Optic Disk; Fibrosis; Intraocular Pressure
PubMed: 36674805
DOI: 10.3390/ijms24021287