OCT
Optical Coherence Tomography (Retinal pRNFL & GCIPL Neuroaxonal Thickness)
光干渉断層計（OCT：網膜神経線維層 pRNFL・神経節細胞層 GCIPL 定量イメージング）
1. Biological & Technical Mechanism
Spectral-domain Optical Coherence Tomography (SD-OCT) generates cross-sectional tomograms of the retina at 3–5 μm axial resolution. Because retinal ganglion cell axons in the peripapillary Retinal Nerve Fiber Layer (pRNFL) lack myelin sheaths inside the eye before becoming myelinated past the lamina cribrosa in the optic nerve, thinning of the pRNFL and macular Ganglion Cell–Inner Plexiform Layer (GCIPL) provides a pure, unconfounded structural readout of neuroaxonal and neuronal loss—free from myelin edema or gliosis.
光干渉断層計（OCT）は、近赤外光の干渉を利用して網膜の各層構造を数マイクロメートルの空間分解能で非侵襲的に断層撮像する技術です。視神経乳頭周囲の網膜神経線維層（pRNFL）は、眼球を出た後に視神経として髄鞘化される前の「無髄の純粋な中枢神経軸索」で構成されており、また黄斑部の神経節細胞・内網状層（GCIPL）は中枢ニューロン細胞体そのものを反映します。そのため、pRNFL（基準値約95〜100μm、年間変化量約-0.5〜-1.5μm/年）およびGCIPLの菲薄化を計測することで、ミエリンの浮腫やグリオーシスの影響を受けずに純粋な軸索・神経細胞脱落速度を定量できます。
2. Open Science & Clinical Trial Significance
Adopted into the 2024 McDonald Criteria (inter-eye pRNFL/GCIPL asymmetry for optic nerve dissemination in space) and widely used as a primary outcome in remyelination and neuroprotection trials.
2024年改訂マクドナルド診断基準において視神経病変（第5領域）を証明する客観的検査（左右眼のGCIPL/pRNFL厚非対称性）として正式採用されたほか、再髄鞘化・神経保護治験やIMSVISUAL国際オープンコンソーシアムで標準評価指標として活用されています。
Related Neuroscience Terms & Standards
International consensus diagnostic framework integrating clinical attacks, MRI topography (Dissemination in Space/Time, optic nerve, CVS, PRLs), and CSF oligoclonal bands to diagnose MS.
Irreversible accumulation of neurological disability occurring outside of clinical relapses, driven by diffuse smoldering neuroinflammation, chronic active lesions, and neuroaxonal loss in MS.
Standard 0.0–10.0 ordinal clinical rating scale quantifying neurological disability across 8 functional systems and ambulation capacity in Multiple Sclerosis.
Axonal cytoskeletal protein released into CSF and blood upon neuroaxonal injury; a cross-disease biomarker of neurodegeneration rate in ALS, MS, AD, and FTD.
Intermediate filament protein of astrocytes released into CSF and blood during reactive astrogliosis; tracks smoldering PIRA progression in MS and amyloid-induced astrocytic reactivity in Alzheimer's.
Open Datasets & Research Publications Related to OCT
Dandiset 001537: Capillaries susceptible to frequent stall dynamics revealed by comparing OCT and Bessel-2PM measurements
BRAIN Initiative neurophysiology dataset deposited to DANDI Archive.
MSDA: COVID19 GDSI LocalDashboard - Federated MS Data Toolkit
Official open-source repository and tool for Multiple Sclerosis federated research and data harmonization under MS-DATA-ALLIANCE.
Global Data Sharing Initiative (GDSI): Containerized Federated Analysis Pipeline for MS Registries
International federated research initiative and containerized query framework allowing participating national MS registries to analyze disease-modifying therapy (DMT) safety, anti-CD20 outcomes, and PIRA progression without transferring identifiable patient data.
Multiple Sclerosis and Viruses: « Liaisons Dangereuses ».
Multiple sclerosis (MS) is a complex, multifactorial neurodegenerative disease with an aetiology that is still partially elusive. Several risk factors are associated with MS development including genetic predisposition and various environmental stressors; however, recently, viral infections have gained significant attention as a crucial environmental trigger. Despite the well-established link between Epstein-Barr virus (EBV) and MS susceptibility, a single-pathogen model fails to clearly characterise the molecular cascades driving the disease, suggesting that the transition from infection to autoimmune response involves more than one viral agent. In this review we examine the speculation that the interactions among different neurotropic viruses could serve a collective causative role in MS, which is under-researched in the literature at present. We summarise contradictory evidence on the role of different viral agents, including the Herpesviridae family (Human Cytomegalovirus, EBV, Herpes Simplex Viruses HSV-1 and HSV-2, and Varicella Zoster Virus), Paramyxoviridae family (Measles Virus and Rubella Virus), Influenza virus, SARS-CoV-2, and Human Endogenous Retroviruses (HERVs). Through interplay within shared molecular pathways, immune modulation, and activation of latent infections, these viruses may collectively influence the inflammatory and demyelinating processes that characterise MS. This review evaluates the etiological role of viral interplay in MS through the cumulative and interactive effects of these pathogens. The available epidemiological, immunological, and experimental data converge on the concept that viral co-exposures act synergistically to shape MS susceptibility in genetically predisposed individuals. Characterising these viral interactions presents a new research direction for the identification of novel biomarkers and the development of preventative strategies through the targeted control of viral networks.
CNM-Au8 Treatment Is Associated With Reduced Chronic Lesion Tissue Expansion in Relapsing-Remitting Multiple Sclerosis
BackgroundCNM-Au8, a catalytic nanocrystalline gold suspension, is proposed to support neuronal bioenergetics, but its effect on chronic lesion evolution in multiple sclerosis (MS) has not been reported. ObjectivesTo evaluate the effect of CNM-Au8 on chronic lesion tissue expansion (CLTE). Results...
MSDA Core Dataset (CDS): Standardized Global Real-World Data Harmonization Framework for Multiple Sclerosis
The MSDA Core Dataset (CDS) establishes a 44-variable international harmonization schema mapped to the OMOP Common Data Model, enabling privacy-preserving federated analytics across global Multiple Sclerosis registries.
Disclaimer: This encyclopedia entry is intended for academic neuroscience research and data science reference only, and does not constitute medical advice.