Diffusion tensor magnetic resonance imaging in the diagnosis of visual pathway neurodegeneration in glaucoma

Vp, Erichev; La, Panyushkina; Ia, Novikov; Vv, Bryukhov

doi:10.17116/oftalma2015131259-63

Cited by 3 publications

(4 citation statements)

References 14 publications

(17 reference statements)

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“…In addition, reduced FA predicts a smaller lateral geniculate nucleus (LGN) ( 77 ). Some studies also reported reduced FA within the LGN ( 91 ) that correlated to the MDVF ( 78 ). Nevertheless, assessing DTI changes within the LGN, a small subcortical bundle of grey matter, may be less reliable than measuring diffusion changes within white matter.…”

Section: Resultsmentioning

confidence: 98%

Diffusion tensor imaging of optic neuropathies: a narrative review

Cooper,

Tchernykh,

Shmuel

et al. 2024

Quant Imaging Med Surg

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Background and Objective Diffusion tensor imaging (DTI) has been implemented in a breadth of scientific investigations of optic neuropathies, though it has yet to be fully adopted for diagnosis or prognosis. This is potentially due to a lack of standardization and weak replication of results. The aim of this investigation was to review DTI results from studies specific to three distinct optic neuropathies in order to probe its current clinical utility. Methods We reviewed the DTI literature specific to primary open-angle glaucoma (POAG), optic neuritis (ON), and traumatic optic neuropathy (TON) by systematically searching the PubMed database on March 1 st , 2023. Four distinct DTI metrics are considered: fractional anisotropy (FA), along with mean diffusivity (MD, axial diffusivity (AD), and radial diffusivity (RD). Results from within-group, between-group, and correlational studies were thoroughly assessed. Key Content and Findings POAG studies most consistently report a decrease in FA, especially in the optic radiations, followed in prevalence by an increase in RD and then MD, whilst AD yields conflicting results between studies. It is notable that there is not an equal distribution of investigated DTI metrics, with FA utilized the most, followed by MD, RD, and AD. Studies of ON are similar in that the most consistent findings are specific to FA, RD, and MD. These results are specific to the optic nerve and radiation since only one study measured the intermediary regions. More studies are needed to assess the effect that ON has on the tracts of the visual system. Finally, only three studies assessing DTI of TON have been performed to date, displaying low to moderate replicability of results. To improve the level of agreement between studies assessing each optic neuropathy, an increased level of standardization is recommended. Conclusions Both POAG and ON studies have yielded some prevalent DTI findings, both for contrast and correlation-based assessments. Although the clinical need is high for TON, considering the limitations of the current diagnostic tools, too few studies exist to make confident conclusions. Future use of standardized and longitudinal DTI, along with the foreseen methodological and technical improvements, is warranted to effectively study optic neuropathies.

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Section: Resultsmentioning

confidence: 98%

Diffusion tensor imaging of optic neuropathies: a narrative review

Cooper,

Tchernykh,

Shmuel

et al. 2024

Quant Imaging Med Surg

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“…This possibility is not excluded since the major aqueous humour outflow occurs through the anterior pathways (in particular, through the trabecular (85%) and uveoscleral (5-15%) pathways, and, partially, through the iris) as well as through the posterior pathways (through the vitreous body in the perineural spaces of the optic nerve and perivascular spaces of the retinal vascular system) [23,13]. Since the aqueous humor is produced by the ciliary processes in the posterior chamber and, afterwards, flows to the anterior chamber [3,1], the excess of peroxidation products can get into the aqueous humor from ciliary body, iris, and other tissues due to various pathogenic factors (ocular hypertension, inflammation, etc. ).…”

Section: Resultsmentioning

confidence: 99%

“…Primary open angle glaucoma (POAG) is a polyetiologic disease with a threshold effect and which is associated with many risk factors, including intraocular pressure rates, age, hereditary background, diabetes mellitus, etc.. Primary open angle glaucoma development is caused by metabolic and microstructural changes at the cellular level as a consequence of disorders in involutive and biomechanical processes, insufficient vascular autoregulation and insufficient blood flow, increased nerve cell apoptosis, and decreased natural neuroprotection. The disease is also associated with elastotic characteristics of the sclera, vascular dysregulation, age, changes in immune factors, ethnicity, atherosclerosis, and others [1,2,3,4,5].…”

Section: Introductionmentioning

confidence: 99%

Oxidation and peroxidation in the uvea of the rabbit eyes with experimental uveitis and ocular hypertension

Mikheitseva¹,

Бондаренко²,

Kolomiichuk³

et al. 2019

Oftalmol Zh

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Background. The role of metabolic changes in the anterior eye tissues in the pathogenesis of uveal inflammation in patients with elevated intraocular pressure has been studied poorly. Of particular interest, in this respect, are free radical mechanisms, which can be a trigger of oxidant stress and cause damage to cell membranes in ocular tissues. Purpose. To study the activity of pro-oxidant enzymes and levels of lipid peroxidation products in the uvea tissues in the rabbits with experimental anterior non-infectious uveitis against the background of ocular hypertension. Material and Methods. Forty-one rabbits were divided into 4 study groups. Group 1: 10 animals with experimental ocular hypertension; group 2: 10 animals with experimental allergic uveitis; group 3: 12 animals with ocular hypertension and allergic uveitis; and group 4: 9 intact animals serving as controls. To simulate ocular hypertension in the groups 1 and 3, the animals were made a single 0.1 ml injection of 0.3% carbomer into the anterior chamber. The tissues of the uvea and the aqueous humour were studied biochemically. We estimated the activity of pro-oxidant enzymes, NADPH oxidase and xanthine oxidase, and the content of lipid peroxides: malonic dialdehyde and diene conjugates. The data of the experimental studies were processed using parametric statistical tests with an SPSS package and Statistica 5.5 Results. The activity of pro-oxidants enzymes was increased in all uvea tissues in all study groups; the maximal NADPH oxidase and xanthine oxidase activity was in the animals with both ocular hypertension and uveitis. The NADPH oxidase and xanthine oxidase activity was increased by 51.1% and 63.9% (р<0.001), respectively, as compared with controls. Lipid peroxidation with accumulation of toxic products in the uvea and aqueous humour was noted both in the ocular hypertension-only and uveitis-only groups; however, the maximal values were in an uveitis model against the background of ocular hypertension, where malonic dialdehyde and diene conjugates were increased, respectively, by 67.0% and 54.3% (р<0.001) in the aqueous humour, and, respectively, by 93.1% and 69.1% (р<0.001) in the uvea tissues, compared with controls. Conclusions. Our findings reveal an important link in the pathogenic action of elevated IOP which burdens inflammation in the uveal tissues through the activation of oxidative and peroxidative processes. In addition, our findings support the assumption that primary high-pressure glaucoma can be a factor which worsens inflammation in the anterior eye.

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“…и соавт. (2015) отметили достоверное снижение значений фракционной анизотропии у 12 пациентов с ПОУГ по сравнению с контрольной группой (медианы 0,74 и 0,77 соответственно, р<0,01) [47].…”

Section: результаты исследований анализирующих структурные изменения ...unclassified

Capabilities of Neuroimaging in Determining the Role of Metabolic Pathway of Neurodegeneration in the Pathophysiology of Glaucoma

Рожко

2023

Офтальмология. Восточная Европа

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Глаукома является мультифакторным нейродегенеративным заболеванием глаз и головного мозга. В статье описана роль энергетического метаболизма сетчатки и метаболических путей транссинаптической нейродегенерации в патофизиологии глаукомы. Выполнен обзор научных результатов структурных и функциональных методов нейровизуализации у пациентов с глаукомой. Описаны морфометрические изменения высоты и объема латеральных коленчатых тел, уменьшение белого и серого ве- щества в зрительной коре и повреждения в других областях головного мозга. Также оценены результаты функциональных связей головного мозга при различных стадиях заболевания и их корреляции со структурными изменениями. Особое внимание уделено метаболическим исследованиям путем количественного определения биохимических соединений с помощью протонной магнитно-резонансной спектроскопии и позитронно-эмиссионной томографии (ПЭТ), анализ которых показал, что на настоящий момент их результаты являются противоречивыми и разнородными. Неизвестно, являются ли выявленные паттерны снижения скорости церебрального метаболизма глюкозы патогномоничными для глаукомы, поэтому актуальны будущие исследования метаболизма нейроцитов при глаукоме с применением ПЭТ. Glaucoma is a multifactorial neurodegenerative disease of the eyes and brain. The article describes the role of retinal energy metabolism and transsynaptic neurodegeneration metabolic pathways in the pathophysiology of glaucoma. Review of scientific results of structural and functional neuroimaging methods in patients with glaucoma was performed. Morphometric changes in height and volume of the lateral geniculate body, a decrease in white and gray matter in the visual cortex, and damage in other areas of the brain described. The results of functional connections of the brain at various stages of disease and their correlation with structural changes were also assessed. Particular attention is paid to metabolic studies through the quantification of biochemical compounds using proton magnetic resonance spectroscopy and positron emission tomography (PET), the analysis of which has shown that the results are currently contradictory and heterogeneous. It is not known whether the observed patterns of decreased cerebral glucose metabolic rate are pathognomonic for glaucoma, so future PET studies of metabolism in glaucoma are relevant.

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Diffusion tensor magnetic resonance imaging in the diagnosis of visual pathway neurodegeneration in glaucoma

Cited by 3 publications

References 14 publications

Diffusion tensor imaging of optic neuropathies: a narrative review

Diffusion tensor imaging of optic neuropathies: a narrative review

Oxidation and peroxidation in the uvea of the rabbit eyes with experimental uveitis and ocular hypertension

Capabilities of Neuroimaging in Determining the Role of Metabolic Pathway of Neurodegeneration in the Pathophysiology of Glaucoma

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