Optical Coherence Tomography Angiography (OCTA) in Multiple Sclerosis and Neuromyelitis Optica Spectrum Disorder

Abstract

Vascular changes are increasingly recognized as important factors in the pathophysiology of neuroinflammatory disease, especially in multiple sclerosis (MS). The relatively novel technology of optical coherence tomography angiography (OCTA) images the retinal and choroidal vasculature non-invasively and in a depth-resolved manner. OCTA provides an alternative quantitative measure of retinal damage, by measuring vascular density instead of structural atrophy. Preliminary results suggest OCTA is sensitive to retinal damage in early disease stages, while also having less of a “floor-effect” compared with commonly used OCT metrics, meaning it can pick up further damage in a severely atrophied retina in later stages of disease. Furthermore, it may serve as a surrogate marker for vascular pathology in the central nervous system. Data to date consistently reveal lower densities of the retinal microvasculature in both MS and neuromyelitis optica spectrum disorder (NMOSD) compared with healthy controls, even in the absence of prior optic neuritis. Exploring the timing of vascular changes relative to structural atrophy may help answer important questions about the role of hypoperfusion in the pathophysiology of neuroinflammatory disease. Finally, qualitative characteristics of retinal microvasculature may help discriminate between different neuroinflammatory disorders. There are however still issues regarding image quality and development of standardized analysis methods before OCTA can be fully incorporated into clinical practice.

Deciphering the Retinal Epigenome during Development, Disease and Reprogramming: Advancements, Challenges and Perspectives

“…Optical coherence tomography, traditionally adopted to scan retinal thickness in age-related macular degeneration and glaucoma can be used to monitor other neurological conditions, such as multiple sclerosis and Parkinson’s disease [ 23 , 24 , 25 , 26 ], for which visual acuity tests can also be leveraged, involving measuring low-contrast letter acuity, the speed of rapid number naming and rapid picture naming [ 27 , 28 , 29 ]. Combined usage of optical coherence tomography and angiography can be adopted to identify early signs of multiple sclerosis as well as early, pre-symptomatic lesions as Alzheimer’s disease before the onset of cognitive signs, by monitoring the enlargement of the foveal avascular zone [ 30 , 31 ].…”

Optical coherence tomography angiography helps distinguish multiple sclerosis from AQP4‐IgG‐seropositive neuromyelitis optica spectrum disorder

“…Additionally, it images retinal vascular density in a depth‐resolved manner and provides an alternative quantitative measure of retinal damage with less “floor‐effect”. (Kleerekooper et al., 2020; Oertel et al., 2017) To the best of our knowledge, this is the first study to use OCT and OCTA metrics to assess the patterns of retinal structural and microvasculature changes in patients with MS and NMOSD.…”

Optical Coherence Tomography Angiography in Healthy Adult Subjects: Normative Values, Frequency, and Impact of Artifacts

“…Although vascular densities have been well described in diseased eyes [18][19][20][21], there is a lack of normal values of vascular densities in healthy eyes. Such data can be useful in the early detection of retinal abnormalities.…”