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Ritter M, Hummer A, Pawloff M, Ledolter AA, Linhardt D, Woletz M, Deak GG, Sacu S, Ristl R, Ramazanova D, Holder GE, Windischberger C, Schmidt-Erfurth UM. Retinotopic cortical mapping in objective functional monitoring of macular therapy. Br J Ophthalmol 2024:bjophthalmol-2021-320723. [PMID: 38811051 DOI: 10.1136/bjo-2021-320723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2021] [Accepted: 05/15/2024] [Indexed: 05/31/2024]
Abstract
BACKGROUND/AIMS To determine the suitability of functional MRI (fMRI) as an objective measure of macular function following therapeutic intervention; conventional psychophysical measures rely heavily on patient compliance. METHODS Twenty patients with neovascular age-related macular degeneration (nAMD) were studied with high-resolution fMRI, visual acuity, reading accuracy and speed, contrast sensitivity (CS) and microperimetry (MP) before and after 3 monthly intravitreal injections of ranibizumab. Population-receptive field retinotopic maps calculated from fMRI data were compared with psychophysical measures and optical coherence tomography. RESULTS Best-corrected visual acuity (BCVA) responders (≥5 letters) showed an increase of 29.5% in activated brain area, while non-responders showed a decrease of 0.8%. Radial histograms over eccentricity allowed quantification of the absolute number of significant voxels and thus differences before and after treatment. Responders showed increases in foveal (α<0.5°) activation, while non-responders did not. Absence of intraretinal fluid and preservation of outer retinal layers was associated with higher numbers of active V1 voxels and better BCVA. Higher voxel numbers were associated with improved reading performance and, less marked, with BCVA, CS and MP. CONCLUSION The data show that retinotopic mapping using fMRI can successfully be applied objectively to evaluate the therapeutic response in nAMD patients treated with anti-vascular endothelial growth factor therapy. This demonstrates the ability of retinotopic mapping to provide an objective assessment of functional recovery at a cortical level; the technique can therefore be applied, in other degenerative macular diseases, to the assessment of potential therapeutic interventions such as gene therapy or cell replacement therapy.
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Affiliation(s)
- Markus Ritter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Allan Hummer
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Maximilian Pawloff
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Anna A Ledolter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - David Linhardt
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Michael Woletz
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Gabor Gyoergy Deak
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Stefan Sacu
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Robin Ristl
- Section for Medical Statistics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Dariga Ramazanova
- Section for Medical Statistics, Center for Medical Statistics, Informatics and Intelligent Systems, Medical University of Vienna, Vienna, Austria
| | - Graham E Holder
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- UCL Institute of Ophthalmology, London, UK
| | - Christian Windischberger
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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Pawloff M, Linhardt D, Woletz M, Hummer A, Sacu S, Vasileiadi M, Garikoitz LU, Holder G, Schmidt-Erfurth UM, Windischberger C, Ritter M. Comparison of Stimulus Types for Retinotopic Cortical Mapping of Macular Disease. Transl Vis Sci Technol 2023; 12:6. [PMID: 36912591 PMCID: PMC10020948 DOI: 10.1167/tvst.12.3.6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2022] [Accepted: 01/19/2023] [Indexed: 03/14/2023] Open
Abstract
Purpose Retinotopic maps acquired using functional magnetic resonance imaging (fMRI) provide a valuable adjunct in the assessment of macular function at the level of the visual cortex. The present study quantitatively assessed the performance of different visual stimulation approaches for mapping visual field coverage. Methods Twelve patients with geographic atrophy (GA) secondary to age-related macular degeneration (AMD) were examined using high-resolution ultra-high field fMRI (Siemens Magnetom 7T) and microperimetry (MP; Nidek MP-3). The population receptive field (pRF)-based coverage maps obtained with two different stimulus techniques (moving bars, and rotating wedges and expanding rings) were compared with the results of MP. Correspondence between MP and pRF mapping was quantified by calculating the simple matching coefficient (SMC). Results Stimulus choice is shown to bias the spatial distribution of pRF centers and eccentricity values with pRF sizes obtained from wedge/ring or bar stimulation showing systematic differences. Wedge/ring stimulation results show a higher number of pRF centers in foveal areas and strongly reduced pRF sizes compared to bar stimulation runs. A statistical comparison shows significantly higher pRF center numbers in the foveal 2.5 degrees region of the visual field for wedge/ring compared to bar stimuli. However, these differences do not significantly influence SMC values when compared to MP (bar <2.5 degrees: 0.88 ± 0.13; bar >2.5 degrees: 0.88 ± 0.11; wedge/ring <2.5 degrees: 0.89 ± 0.12 wedge/ring; >2.5 degrees: 0.86 ± 0.10) for the peripheral visual field. Conclusions Both visual stimulation designs examined can be applied successfully in patients with GA. Although the two designs show systematic differences in the distribution of pRF center locations, this variability has minimal impact on the SMC when compared to the MP outcome.
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Affiliation(s)
- Maximilian Pawloff
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - David Linhardt
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Michael Woletz
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Allan Hummer
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Stefan Sacu
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Maria Vasileiadi
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Lerma Usabiaga Garikoitz
- BCBL Basque Center on Cognition, Brain and Language Donostia, San Sebastian, Gipuzkoa, Spain
- IKERBASQUE Basque Foundation for Science, Bilbao, Spain
| | - Graham Holder
- Department of Ophthalmology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- UCL Institute of Ophthalmology, London, UK
| | | | - Christian Windischberger
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Markus Ritter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
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Castaldi E, Lunghi C, Morrone MC. Neuroplasticity in adult human visual cortex. Neurosci Biobehav Rev 2020; 112:542-552. [DOI: 10.1016/j.neubiorev.2020.02.028] [Citation(s) in RCA: 52] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2019] [Revised: 12/30/2019] [Accepted: 02/20/2020] [Indexed: 12/27/2022]
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Enhanced Visual Attentional Modulation in Patients with Inherited Peripheral Retinal Degeneration in the Absence of Cortical Degeneration. Neural Plast 2019; 2019:8136354. [PMID: 31341470 PMCID: PMC6614956 DOI: 10.1155/2019/8136354] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 06/11/2019] [Indexed: 12/20/2022] Open
Abstract
The role of attentional mechanisms in peripheral vision loss remains an outstanding question. Our study was aimed at determining the effect of genetically determined peripheral retinal dystrophy caused by Retinitis Pigmentosa (RP) on visual cortical function and tested the recruitment of attentional mechanisms using functional magnetic resonance imaging (fMRI). We included thirteen patients and twenty-two age- and gender-matched controls. We analyzed cortical responses under attentional demands and passive viewing conditions while presenting a visual stimulus covering the central and paracentral visual field. Brain activity was studied in visual areas V1, V2, and V3 as well as in cortical regions of interest corresponding to the preserved and the damaged visual field. The influence of visual field extent and age of disease onset were also investigated. Cortical thickness of visual areas was also measured. We found that cortical visual responses under attentional demands were increased in patients with larger degeneration of visual field, as demonstrated by significant interaction effects between group and task conditions. Moreover, activation during the task condition was increased for patients in two cortical regions of interest corresponding to the preserved and damaged visual field, specifically in patients with severe visual field loss. These findings were observed in the presence of preserved visual cortical structure. We conclude that RP patients have enhanced visual attention recruitment despite their retinal degeneration, while cortical structure and overall response levels remain intact. The unmasking of feedback signals from higher level visual regions involved in attentional processes may explain the increased cortical responses. These findings are relevant for the design of strategies for treating retinal diseases, based on attentional cuing.
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Ritter M, Hummer A, Ledolter AA, Holder GE, Windischberger C, Schmidt-Erfurth UM. Correspondence between retinotopic cortical mapping and conventional functional and morphological assessment of retinal disease. Br J Ophthalmol 2018; 103:208-215. [PMID: 29699983 DOI: 10.1136/bjophthalmol-2017-311443] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Accepted: 04/12/2018] [Indexed: 11/04/2022]
Abstract
PURPOSE The present study describes retinotopic mapping of the primary visual cortex using functional MRI (fMRI) in patients with retinal disease. It addresses the relationship between fMRI data and data obtained by conventional assessment including microperimetry (MP) and structural imaging. METHODS Initial testing involved eight patients with central retinal disease (Stargardt disease, STGD) and eight with peripheral retinal disease (retinitis pigmentosa, RP), who were examined using fMRI and MP (Nidek MP-1). All had a secure clinical diagnosis supported by electrophysiological data. fMRI used population-receptive field (pRF) mapping to provide retinotopic data that were then compared with the results of MP, optical coherence tomography and fundus autofluorescence imaging. RESULTS Full analysis, following assessment of fMRI data reliability criteria, was performed in five patients with STGD and seven patients with RP; unstable fixation was responsible for unreliable pRF measurements in three patients excluded from final analysis. The macular regions in patients with STGD with central visual field defects and outer retinal atrophy (ORA) at the macula correlated well with pRF coverage maps showing reduced density of activated voxels at the occipital pole. Patients with RP exhibited peripheral ORA and concentric visual field defects both on MP and pRF mapping. Anterior V1 voxels, corresponding to peripheral regions, showed no significant activation. Correspondence between MP and pRF mapping was quantified by calculating the simple matching coefficient. CONCLUSION Retinotopic maps acquired by fMRI provide a valuable adjunct in the assessment of retinal dysfunction. The addition of microperimetric data to pRF maps allowed better assessment of macular function than MP alone. Unlike MP, pRF mapping provides objective data independent of psychophysical perception from the patient.
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Affiliation(s)
- Markus Ritter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Allan Hummer
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
| | - Anna A Ledolter
- Department of Ophthalmology, Medical University of Vienna, Vienna, Austria
| | - Graham E Holder
- Department of Ophthalmology, National University of Singapore, National University Hospital, Singapore.,UCL Institute of Ophthalmology, University College London, London, UK.,Moorfields Eye Hospital, London, UK
| | - Christian Windischberger
- MR Center of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Vienna, Austria
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Vottonen P. Anti-vascular endothelial growth factors treatment of wet age-related macular degeneration: from neurophysiology to cost-effectiveness. Acta Ophthalmol 2018; 96 Suppl A109:1-46. [PMID: 29468838 DOI: 10.1111/aos.13706] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- Pasi Vottonen
- Department of Ophthalmology; Kuopio University Hospital; University of Eastern Finland; Kuopio Finland
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7
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Ferreira S, Pereira AC, Quendera B, Reis A, Silva ED, Castelo-Branco M. Primary visual cortical remapping in patients with inherited peripheral retinal degeneration. NEUROIMAGE-CLINICAL 2016; 13:428-438. [PMID: 28116235 PMCID: PMC5233796 DOI: 10.1016/j.nicl.2016.12.013] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/31/2016] [Revised: 11/10/2016] [Accepted: 12/14/2016] [Indexed: 12/17/2022]
Abstract
Human studies addressing the long-term effects of peripheral retinal degeneration on visual cortical function and structure are scarce. Here we investigated this question in patients with Retinitis Pigmentosa (RP), a genetic condition leading to peripheral visual degeneration. We acquired functional and anatomical magnetic resonance data from thirteen patients with different levels of visual loss and twenty-two healthy participants to study primary (V1) visual cortical retinotopic remapping and cortical thickness. We identified systematic visual field remapping in the absence of structural changes in the primary visual cortex of RP patients. Remapping consisted in a retinotopic eccentricity shift of central retinal inputs to more peripheral locations in V1. Importantly, this was associated with changes in visual experience, as assessed by the extent of the visual loss, with more constricted visual fields resulting in larger remapping. This pattern of remapping is consistent with expansion or shifting of neuronal receptive fields into the cortical regions with reduced retinal input. These data provide evidence for functional changes in V1 that are dependent on the magnitude of peripheral visual loss in RP, which may be explained by rapid cortical adaptation mechanisms or long-term cortical reorganization. This study highlights the importance of analyzing the retinal determinants of brain functional and structural alterations for future visual restoration approaches.
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Key Words
- FPZ, Function Projection Zone
- Functional magnetic resonance imaging (fMRI)
- Human
- LE, Left Eye
- LH, Left Hemisphere
- LPZ, Lesion Projection Zone
- MRI, Magnetic Resonance Imaging
- Plasticity
- Primary visual cortex
- RE, Right Eye
- RH, Right Hemisphere
- RNFL, Retinal Nerve Fiber Layer
- RP, Retinitis Pigmentosa
- Reorganization
- Retinitis pigmentosa
- Retinotopy
- fMRI, functional Magnetic Resonance Imaging
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Affiliation(s)
- Sónia Ferreira
- Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Andreia Carvalho Pereira
- Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Bruno Quendera
- Institute of Nuclear Sciences Applied to Health (ICNAS), Brain Imaging Network of Portugal, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Aldina Reis
- Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; Ophthalmology Unit, Centro Hospitalar e Universitário de Coimbra (CHUC), 3000-075 Coimbra, Portugal
| | - Eduardo Duarte Silva
- Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal
| | - Miguel Castelo-Branco
- Visual Neuroscience Laboratory, Institute for Biomedical Imaging and Life Sciences (CNC.IBILI), Faculty of Medicine, University of Coimbra, 3000-548 Coimbra, Portugal; Institute of Nuclear Sciences Applied to Health (ICNAS), Brain Imaging Network of Portugal, University of Coimbra, 3000-548 Coimbra, Portugal
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Hummer A, Ritter M, Tik M, Ledolter AA, Woletz M, Holder GE, Dumoulin SO, Schmidt-Erfurth U, Windischberger C. Eyetracker-based gaze correction for robust mapping of population receptive fields. Neuroimage 2016; 142:211-224. [PMID: 27389789 DOI: 10.1016/j.neuroimage.2016.07.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2016] [Revised: 06/14/2016] [Accepted: 07/02/2016] [Indexed: 11/26/2022] Open
Abstract
Functional MRI enables the acquisition of a retinotopic map that relates regions of the visual field to neural populations in the visual cortex. During such a "population receptive field" (PRF) experiment, stable gaze fixation is of utmost importance in order to correctly link the presented stimulus patterns to stimulated retinal regions and the resulting Blood Oxygen Level Dependent (BOLD) response of the appropriate region within the visual cortex. A method is described that compensates for unstable gaze fixation by recording gaze position via an eyetracker and subsequently modifies the input stimulus underlying the PRF analysis according to the eyetracking measures. Here we show that PRF maps greatly improve when the method is applied to data acquired with either saccadic or smooth eye movements. We conclude that the technique presented herein is useful for studies involving subjects with unstable gaze fixation, particularly elderly patient populations.
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Affiliation(s)
- A Hummer
- MR Centre of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - M Ritter
- Department of Ophthalmology and Optometry, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - M Tik
- MR Centre of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - A A Ledolter
- Department of Ophthalmology and Optometry, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - M Woletz
- MR Centre of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - G E Holder
- Institute of Ophthalmology, University College London, 11-43 Bath Street, London, EC1V 2PD, UK; Moorfields Eye Hospital, 162 City Road, London, EC1V 9EL, UK
| | - S O Dumoulin
- Experimental Psychology, Helmholtz Institute, Utrecht University, Heidelberglaan 1, 3584 CS Utrecht, The Netherlands; Spinoza Centre for Neuroimaging, Meibergdreef 75, 1105BK, Amsterdam, The Netherlands
| | - U Schmidt-Erfurth
- Department of Ophthalmology and Optometry, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria
| | - C Windischberger
- MR Centre of Excellence, Center for Medical Physics and Biomedical Engineering, Medical University of Vienna, Währinger Gürtel 18-20, 1090 Vienna, Austria.
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Prins D, Hanekamp S, Cornelissen FW. Structural brain MRI studies in eye diseases: are they clinically relevant? A review of current findings. Acta Ophthalmol 2016; 94:113-21. [PMID: 26361248 DOI: 10.1111/aos.12825] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2014] [Accepted: 07/09/2015] [Indexed: 01/10/2023]
Abstract
Many eye diseases reduce visual acuity or are associated with visual field defects. Because of the well-defined retinotopic organization of the connections of the visual pathways, this may affect specific parts of the visual pathways and cortex, as a result of either deprivation or transsynaptic degeneration. For this reason, over the past several years, numerous structural magnetic resonance imaging (MRI) studies have examined the association of eye diseases with pathway and brain changes. Here, we review structural MRI studies performed in human patients with the eye diseases albinism, amblyopia, hereditary retinal dystrophies, age-related macular degeneration (AMD) and glaucoma. We focus on two main questions. First, what have these studies revealed? Second, what is the potential clinical relevance of their findings? We find that all the aforementioned eye diseases are indeed associated with structural changes in the visual pathways and brain. As such changes have been described in very different eye diseases, in our view the most parsimonious explanation is that these are caused by the loss of visual input and the subsequent deprivation of the visual pathways and brain regions, rather than by transsynaptic degeneration. Moreover, and of clinical relevance, for some of the diseases - in particular glaucoma and AMD - present results are compatible with the view that the eye disease is part of a more general neurological or neurodegenerative disorder that also affects the brain. Finally, establishing structural changes of the visual pathways has been relevant in the context of new therapeutic strategies to restore retinal function: it implies that restoring retinal function may not suffice to also effectively restore vision. Future structural MRI studies can contribute to (i) further establish relationships between ocular and neurological neurodegenerative disorders, (ii) investigate whether brain degeneration in eye diseases is reversible, (iii) evaluate the use of neuroprotective medication in ocular disease, (iv) determine optimal timing for retinal implant insertion and (v) establish structural MRI examination as a diagnostic tool in ophthalmology.
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Affiliation(s)
- Doety Prins
- Laboratory of Experimental Ophthalmology; University of Groningen; University Medical Center Groningen; Groningen the Netherlands
| | - Sandra Hanekamp
- Laboratory of Experimental Ophthalmology; University of Groningen; University Medical Center Groningen; Groningen the Netherlands
| | - Frans W. Cornelissen
- Laboratory of Experimental Ophthalmology; University of Groningen; University Medical Center Groningen; Groningen the Netherlands
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Haak KV, Morland AB, Rubin GS, Cornelissen FW. Preserved retinotopic brain connectivity in macular degeneration. Ophthalmic Physiol Opt 2016; 36:335-43. [PMID: 26923706 DOI: 10.1111/opo.12279] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 01/06/2016] [Indexed: 01/11/2023]
Abstract
PURPOSE The eye disease macular degeneration (MD) is a leading cause of blindness worldwide. There is no cure for MD, but several promising treatments aimed at restoring vision at the level of the retina are currently under investigation. These treatments assume that the patient's brain can still process appropriately the retinal input once it is restored, but whether this assumption is correct has yet to be determined. METHODS We used functional magnetic resonance imaging (fMRI) and connective field modelling to determine whether the functional connectivity between the input-deprived portions of primary visual cortex (V1) and early extrastriate areas (V2/3) is still retinotopically organised. Specifically, in both patients with juvenile macular degeneration and age-matched controls with simulated retinal lesions, we assessed the extent to which the V1-referred connective fields of extrastriate voxels, as estimated on the basis of spontaneous fMRI signal fluctuations, adhered to retinotopic organisation. RESULTS We found that functional connectivity between the input-deprived portions of visual areas V1 and extrastriate cortex is still largely retinotopically organised in MD, although on average less so than in controls. Patients with stable fixation exhibited normal retinotopic connectivity, however, suggesting that for the patients with unstable fixation, eye-movements resulted in spurious, homogeneous signal modulations across the entire input-deprived cortex, which would have hampered our ability to assess their spatial structure of connectivity. CONCLUSIONS Despite the prolonged loss of visual input due to MD, the cortico-cortical connections of input-deprived visual cortex remain largely intact. This suggests that the restoration of sight in macular degeneration can rely on a largely unchanged retinotopic representation in early visual cortex following loss of central retinal function.
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Affiliation(s)
- Koen V Haak
- Donders Institute for Brain, Cognition and Behaviour, Centre for Cognitive Neuroimaging, Radboud University, Nijmegen, The Netherlands.,York Neuroimaging Centre, Department of Psychology, University of York, York, UK
| | - Antony B Morland
- York Neuroimaging Centre, Department of Psychology, University of York, York, UK.,Hull-York Medical School, York, UK
| | - Gary S Rubin
- Institute of Ophthalmology, University College London, London, UK
| | - Frans W Cornelissen
- Laboratory for Experimental Ophthalmology, University of Groningen, University Medical Center, Groningen, The Netherlands
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Lenoble Q, Tran THC, Szaffarczyk S, Boucart M. Categorization Task over a Touch Screen in Age-Related Macular Degeneration. Optom Vis Sci 2015; 92:986-94. [PMID: 26398350 DOI: 10.1097/opx.0000000000000694] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
PURPOSE In our modern society, many touch screen applications require hand-eye coordination to associate an icon with its specific contextual unit on phones, on computers, or in public transport. We assessed the ability of patients with age-related macular degeneration (AMD) to explore scenes and to associate a target (animal or object) with a unique congruent scene (e.g., to match a fish with the sea) presented between three other distractors on a touch screen computer. METHODS Twenty-four patients with AMD (64 to 90 years) with best-corrected visual acuity between 20/40 and 20/400 as well as 17 age-matched (60 to 94 years) and 15 young (22 to 34 years) participants with normal visual acuity had to match a target with a congruent scene by moving their index finger on a 22-in touch screen. RESULTS Patients were as accurate (98.7% correct responses) as the age-matched control (98.9% correct responses) and young participants (99.3% correct responses) at performing the task. The duration of exploration was significantly longer for the AMD patients (mean, 4.13 seconds) compared with the age-matched group (mean, 2.96 seconds). The young participants were also significantly faster than the old group (mean, 0.93 seconds). The movement parameters of the older participants (patients and old control subjects) were affected compared with the young; the peak speed decreased (-8 cm/s) and the movement duration increased (+0.9 seconds) with age compared with the young group. CONCLUSIONS People with AMD are able to perform a contextual association task on a touch screen with high accuracy. The AMD patients were specifically affected in the "exploration" phase; their accuracy and movement parameters did not differ from the old control group. Our study suggests that the decline associated with AMD is more focused on the duration of exploration than on movement parameters in touch screen use.
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Affiliation(s)
- Quentin Lenoble
- *PhD †MD, PhD ‡BS SCALab, UMR CNRS 9193, Université de Lille, France (QL, SS, MB); and Service d'Ophtalmologie, Hôpital Saint Vincent de Paul, Lille, France (THCT)
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12
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Abd Hamid AI, Speck O, Hoffmann MB. Quantitative assessment of visual cortex function with fMRI at 7 Tesla-test-retest variability. Front Hum Neurosci 2015; 9:477. [PMID: 26388756 PMCID: PMC4555013 DOI: 10.3389/fnhum.2015.00477] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Accepted: 08/17/2015] [Indexed: 11/13/2022] Open
Abstract
fMRI-based retinotopic mapping was used to assess systematic variations in activated cortical surface area, amplitude, and coherence across sessions. Seven healthy subjects were scanned at 7 T in three separate sessions with intervals of 51.4 ± 5.4 days (Sessions 1 and 2) and 167.9 ± 24.4 days (Sessions 2 and 3). We found a reduction between Sessions 1 and 2 for activated cortical surface area, between Sessions 1 and 3 for amplitude, and between Sessions 1 and 2/3 for coherence. The results do not support head motion as a major cause of the observed effect seen in Session 1, suggesting that cognitive effects were the underlying cause of change. The phase correlations for both eccentricity and polar angle mapping were highly correlated between sessions, demonstrating the stability of the maps. Furthermore, the sensitivity in determining inter-session changes of cortical surface area, response amplitude, and coherence were, at a 5% significance level, estimated to be 1.5, 6, and 5%, respectively. Any future longitudinal fMRI study should carefully evaluate activation across sessions to determine the eligibility of inclusion of all time points. This experimental design provides guidance in methodological issues of clinical longitudinal fMRI-studies, specifically regarding effects of subject experience.
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Affiliation(s)
- Aini Ismafairus Abd Hamid
- Department of Biomedical Magnetic Resonance, Institute for Experimental Physics, Otto-von-Guericke University Magdeburg Magdeburg, Germany ; Department of Neurosciences, School of Medical Sciences Health Campus, Universiti Sains Malaysia Kubang Kerian, Malaysia
| | - Oliver Speck
- Department of Biomedical Magnetic Resonance, Institute for Experimental Physics, Otto-von-Guericke University Magdeburg Magdeburg, Germany ; Center for Behavioral Brain Sciences Magdeburg, Germany ; Leibniz Institute for Neurobiology Magdeburg, Germany ; German Center for Neurodegenerative Disease Magdeburg, Germany
| | - Michael B Hoffmann
- Center for Behavioral Brain Sciences Magdeburg, Germany ; Visual Processing Laboratory, Department of Ophthalmology, Otto-von-Guericke University Magdeburg Magdeburg, Germany
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13
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Haak KV, Langers DR, Renken R, van Dijk P, Borgstein J, Cornelissen FW. Abnormal visual field maps in human cortex: A mini-review and a case report. Cortex 2014; 56:14-25. [DOI: 10.1016/j.cortex.2012.12.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2012] [Revised: 11/21/2012] [Accepted: 12/04/2012] [Indexed: 10/27/2022]
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Lešták J, Tintěra J, Karel I, Svatá Z, Rozsíval P. Functional Magnetic Resonance Imaging in Patients with the Wet Form of Age-Related Macular Degeneration. Neuroophthalmology 2013; 37:192-197. [PMID: 28167987 DOI: 10.3109/01658107.2013.819581] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2013] [Revised: 06/07/2013] [Accepted: 06/10/2013] [Indexed: 11/13/2022] Open
Abstract
The study is designed to determine the relationship between the progress of the wet form of age-related macular degeneration and the activity of the visual cortex examined using functional magnetic resonance imaging. Ten patients with the wet form of age-related macular degeneration (9 female and 1 male) with a mean age of 74.7 years (58-85 years) at various stages of bilateral involvement of the disease were included. Patients did not suffer from any other ocular nor neurological disease. All the patients underwent functional magnetic resonance imaging examinations with stimulation of both eyes using a black-and-white checkerboard of size 25.8 × 16.2 degrees. The group was compared with a group of healthy subjects with an average age of 54.1 years (45-65 years). For statistical evaluation, the Mann-Whitney U test was used. Comparing the extent of visual cortex activations we found a statistically significant difference between both the groups (p = 0.0247). However, the dependence of functional magnetic resonance imaging activity on visual acuity was not statistically significant (p = 0.223). We conclude that in patients with the wet form of age-related macular degeneration, lower functional magnetic resonance imaging activity of the visual cortex was found compared with the control group of healthy subjects. Dependence of functional magnetic resonance imaging activity on visual acuity was not statistically significant.
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Affiliation(s)
- Jan Lešták
- JL ClinicV Hůrkách 1296/10, PragueCzech Republic; Faculty of Biomedical Engineering, Czech Technical University in PraguePragueCzech Republic; Faculty of Medicine in Hradec Králové, Charles University, Hradec KrálovéCzech Republic
| | | | - Ivan Karel
- JL Clinic V Hůrkách 1296/10, Prague Czech Republic
| | - Zuzana Svatá
- JL Clinic V Hůrkách 1296/10, Prague Czech Republic
| | - Pavel Rozsíval
- Faculty of Medicine in Hradec Králové, Charles University, Hradec Králové Czech Republic
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