Optical coherence tomography and OCT-angiography in neurologic and neuro-ophthalmologic diseases: Current applications and future perspectives

Optical coherence tomography (OCT) and OCT-angiography (OCTA) have emerged as useful tools for noninvasive imaging in the neurologic field. This chapter elucidates their utility in detecting biomarkers for the diagnosis and monitoring of progression and response to treatment in different prevalent neurologic conditions. The retina, an extension of the central nervous system, presents a unique opportunity for monitoring brain pathology due to its accessibility. Through highly resolved scans of the retina and optic nerve, OCT and OCTA facilitate the identification of subtle clinical changes occurring during neuroinflammatory, neurodegenerative, and ischemic processes in disorders like multiple sclerosis, Alzheimer and Parkinson disease, anterior ischemic optic neuropathies, and papilledema. Peripapillary nerve fiber layer and macular internal retinal layer thickness on OCT, and vessel density in the superficial retina on OCTA seem to be the most sensitive parameters in detecting axonal injury and neurodegeneration. These metrics hold promise as surrogate markers for cerebral alterations. While OCT and OCTA show considerable potential, continued research is necessary to validate their reliability and clinical significance, considering potential confounding factors such as concurrent ophthalmic pathologies. Nonetheless, these advancements represent significant progress toward enhancing the diagnosis, management, and prediction of outcomes in various neuro-ophthalmic disorders.