Using magnetic resonance imaging to assess visual deficits: a review

Abstract

PurposeOver the last two decades, magnetic resonance imaging (MRI) has been widely used in neuroscience research to assess both structure and function in the brain in health and disease. With regard to vision research, prior to the advent of MRI, researchers relied on animal physiology and human post‐mortem work to assess the impact of eye disease on visual cortex and connecting structures. Using MRI, researchers can non‐invasively examine the effects of eye disease on the whole visual pathway, including the lateral geniculate nucleus, striate and extrastriate cortex. This review aims to summarise research using MRI to investigate structural, chemical and functional effects of eye diseases, including: macular degeneration, retinitis pigmentosa, glaucoma, albinism, and amblyopia.Recent FindingsStructural MRI has demonstrated significant abnormalities within both grey and white matter densities across both visual and non‐visual areas. Functional MRI studies have also provided extensive evidence of functional changes throughout the whole of the visual pathway following visual loss, particularly in amblyopia. MR spectroscopy techniques have also revealed several abnormalities in metabolite concentrations in both glaucoma and age‐related macular degeneration. GABA‐edited MR spectroscopy on the other hand has identified possible evidence of plasticity within visual cortex.SummaryCollectively, using MRI to investigate the effects on the visual pathway following disease and dysfunction has revealed a rich pattern of results allowing for better characterisation of disease. In the future MRI will likely play an important role in assessing the impact of eye disease on the visual pathway and how it progresses over time.

Age-related macular degeneration affects the optic radiation white matter projecting to locations of retinal damage

“…A number of studies have recently reported changes in white matter microstructure along the primary visual pathways as a result of ophthalmic eye disease [see (Prins et al 2016b;Brown et al 2016;Wandell 2016;Rokem et al 2017) for reviews]. Major examples of impaired white matter tissue microstructure within the primary visual pathways have shown that retinitis pigmentosa (Pan et al 2007), Leber hereditary optic neuropathy (Barcella et al 2010;Milesi et al 2012;Rizzo et al 2012;Ogawa et al 2014), amblyopia (Allen et al 2015;Duan et al 2015), glaucoma (Dai et al 2013;Engelhorn et al 2012;Garaci et al 2009;Lee et al 2014;Hernowo et al 2011) and optic neuritis (Ciccarelli et al 2005;Sergott 2011;Li et al 2009) can affect white matter microstructure estimated in vivo using either diffusion-weighted magnetic resonance imaging methods or volumetric analyses.…”

Disability caused by post-stroke visual impairment as an underestimated clinical problem — case report

“…Similar to the cases of logotherapy in patients with speech disorders or early kinesitherapy in patients with motor dysfunction, visual impairments require complex management [9][10][11][12]. It is essential that patients with visual disorders are thoroughly examined by a neurologist and ophthalmologist and undergo follow-up neuroimaging visualising and assessing the extent of cerebral stroke (preferably using MRI) as well as perimetry tests [13][14][15]. Complex medical attention, objectivisation of disorders, and evaluation of prognosis favourably affect the patient`s mental condition, which prevents reactive mood disorders enhancing disability [16].…”

Whole-globe biomechanics using high-field MRI

“…Currently, there are few methods for non-invasively measuring tissue deformation over the whole globe, which include ultrasound, optical coherence tomography (OCT), and computed tomography (CT), but they all have important limitations (Bajwa et al, 2015; Brown et al, 2016; Fortune, 2015). Ultrasound has excellent penetration depth allowing for quantitative biomechanical analysis of the sclera and cornea, but insufficient resolution to discern the fine structures of the optic nerve head (ONH) (He and Liu, 2009; Palko et al, 2016).…”