title: Optical coherence tomography and neurodegeneration: are eyes the windows to the brain?
abstract: Central nervous system (CNS) pathologies have ocular manifestations due to direct and/or retrograde degeneration of the visual pathways, most often related to a direct injury to the optic nerve, retinal ganglion cells and/or its surrounding cells. These ocular manifestations can be recognized and monitored by a non-invasive technique called Optical Coherence Tomography (OCT).
  
  
  
  This review article describes the OCT technique and its application in various neurological pathologies. OCT helps in the measurement of retinal nerve fiber layer thickness (RNFLT) and macular thickness which consists of retinal ganglion cells. OCT provides a near-histological level of image resolution up to 5µm by using principles of interferometry that can detect CNS inflammatory, as well as degenerative, pathologies (i.e Multiple Sclerosis, Parkinson's disease and Alzheimer's Disease etc.) at initial clinical and possibly subclinical stages. Expert Commentary: RNFLT and macular volumes measured by OCT can serve as biomarkers for early recognition and progression of a variety of neurological disease, although the specificity of these findings in clinical diagnosis requires further refinement. An early biomarker can help in an earlier therapeutic intervention and thus preventing further progression and provide the opportunity for possible regenerative interventions of the underlying disease process. With the advent of "next-generation" OCT technology an increase in use is foreseen in research as well as in clinical practice.
authors.affiliation: a Department of Neurology , University of Alabama , Birmingham , Alabama 35294-2172 , United States.
authors.forename: Sahil
authors.initials: S
authors.lastname: Gupta
authors.affiliation: b Buffalo Neuroimaging analyisis Center, Jacobs School of Medicine and Biomedical Sciences , University at Buffalo , Buffalo , New York , USA.
authors.forename: Robert
authors.initials: R
authors.lastname: Zivadinov
authors.affiliation: c Department of Pharmaceutical Sciences and Neurology , State University of New York , Buffalo , NY , USA.
authors.forename: Murali
authors.initials: M
authors.lastname: Ramanathan
authors.affiliation: d Jacobs MS Center for Treatment and Research, Jacobs School of Medicine and Biomedical Sciences , University at Buffalo , Buffalo , NY , USA.
authors.forename: Bianca
authors.initials: B
authors.lastname: Weinstock-Guttman
mesh_terms: D001921:Brain; D006801:Humans; D009103:Multiple Sclerosis / Q000175:diagnosis; D019636:Neurodegenerative Diseases / Q000175:diagnosis; D009900:Optic Nerve; D012165:Retinal Ganglion Cells; D041623:Tomography, Optical Coherence
keywords: Macular Volume; Multiple sclerosis; OCT; RNFL; neurodegeneration; optical coherence tomography