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Abstract
The prognosis of going blind is very stressful for patients diagnosed with "glaucoma". Worries and fear of losing independence is a constant mental burden, with secondary risks of depression and social isolation. But stress is not only a result of glaucoma but also a possible cause (risk factor). This should not be surprising, given that chronic stress can trigger "psychosomatic" organ dysfunctions anywhere in the body. Why should the organ "eye" be an exception? Indeed, glaucoma patients often suspect that severe emotional stress caused their visual field loss or "foggy vision". The hypothesis that stress is a possible cause of glaucoma is supported by different observations: (i) acute and chronic stress increases intraocular pressure and (ii) long-term stress can lead to vascular dysregulation of the microcirculation in the eye and brain ("Flammer's syndrome"), leading to partial hypoxia and hypoglycaemia (hypo-metabolism). Even if nerve cells do not die, they may then become inactive ("silent" neurons). (iii) Degenerative changes have been reported in the brain of glaucoma patients, affecting not only anterograde or transsynaptic areas of the central visual pathway, but degeneration is also found (iv) in brain areas involved in emotional appraisal and the physiological regulation of stress hormones. There are also psychological hints indicating that stress is a cause of glaucoma: (v) Glaucoma patients with Flammer's syndrome show typical personality traits that are associated with low stress resilience: they often have cold hands or feet, are ambitious (professionally successful), perfectionistic, obsessive, brooding and worrying a lot. (vi) If stress hormone levels and inflammation parameters are reduced in glaucoma patients by relaxation with meditation, this correlates with normalisation of intraocular pressure, and yet another clue is that (vii) visual field improvements after non-invasive current stimulation therapy, that are known to improve circulation and neuronal synchronisation, are much most effective in patients with stress resilient personalities. An appreciation of stress as a "cause" of glaucoma suggests that in addition to standard therapy (i) stress reduction through relaxation techniques should be recommended (e.g. meditation), and (ii) self-medication compliance should not be induced by kindling anxiety and worries with negative communication ("You will go blind!"), but communication should be positive ("The prognosis is optimistic").
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Affiliation(s)
- Bernhard A Sabel
- Otto-von-Guericke Universität Magdeburg, Institut für Medizinische Psychologie, Deutschland
| | - Luisa Lehnigk
- Otto-von-Guericke Universität Magdeburg, Institut für Medizinische Psychologie, Deutschland
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Sabel BA, Flammer J, Merabet LB. Residual vision activation and the brain-eye-vascular triad: Dysregulation, plasticity and restoration in low vision and blindness - a review. Restor Neurol Neurosci 2019; 36:767-791. [PMID: 30412515 PMCID: PMC6294586 DOI: 10.3233/rnn-180880] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Vision loss due to ocular diseases such as glaucoma, optic neuropathy, macular degeneration, or diabetic retinopathy, are generally considered an exclusive affair of the retina and/or optic nerve. However, the brain, through multiple indirect influences, has also a major impact on functional visual impairment. Such indirect influences include intracerebral pressure, eye movements, top-down modulation (attention, cognition), and emotionally triggered stress hormone release affecting blood vessel dysregulation. Therefore, vision loss should be viewed as the result of multiple interactions within a “brain-eye-vascular triad”, and several eye diseases may also be considered as brain diseases in disguise. While the brain is part of the problem, it can also be part of the solution. Neuronal networks of the brain can “amplify” residual vision through neuroplasticity changes of local and global functional connectivity by activating, modulating and strengthening residual visual signals. The activation of residual vision can be achieved by different means such as vision restoration training, non-invasive brain stimulation, or blood flow enhancing medications. Modulating brain functional networks and improving vascular regulation may offer new opportunities to recover or restore low vision by increasing visual field size, visual acuity and overall functional vision. Hence, neuroscience offers new insights to better understand vision loss, and modulating brain and vascular function is a promising source for new opportunities to activate residual vision to achieve restoration and recovery to improve quality of live in patients suffering from low vision.
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Affiliation(s)
- Bernhard A Sabel
- Institute of Medical Psychology, Medical Faculty, Otto-von-Guericke University of Magdeburg, Magdeburg, Germany
| | - Josef Flammer
- Department of Ophthalmology, University of Basel, Basel, Switzerland
| | - Lotfi B Merabet
- Department of Ophthalmology, The Laboratory for Visual Neuroplasticity, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, USA
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Singh AK, Phillips F, Merabet LB, Sinha P. Why Does the Cortex Reorganize after Sensory Loss? Trends Cogn Sci 2018; 22:569-582. [PMID: 29907530 DOI: 10.1016/j.tics.2018.04.004] [Citation(s) in RCA: 39] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 04/01/2018] [Accepted: 04/17/2018] [Indexed: 01/05/2023]
Abstract
A growing body of evidence demonstrates that the brain can reorganize dramatically following sensory loss. Although the existence of such neuroplastic crossmodal changes is not in doubt, the functional significance of these changes remains unclear. The dominant belief is that reorganization is compensatory. However, results thus far do not unequivocally indicate that sensory deprivation results in markedly enhanced abilities in other senses. Here, we consider alternative reasons besides sensory compensation that might drive the brain to reorganize after sensory loss. One such possibility is that the cortex reorganizes not to confer functional benefits, but to avoid undesirable physiological consequences of sensory deafferentation. Empirical assessment of the validity of this and other possibilities defines a rich program for future research.
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Affiliation(s)
- Amy Kalia Singh
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Flip Phillips
- Department of Psychology and Neuroscience, Skidmore College, Saratoga Springs, NY, USA
| | - Lotfi B Merabet
- Laboratory for Visual Neuroplasticity, Department of Ophthalmology, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, MA, USA
| | - Pawan Sinha
- Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA.
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Sabel BA, Cárdenas-Morales L, Gao Y. Vision Restoration in Glaucoma by Activating Residual Vision with a Holistic, Clinical Approach: A Review. J Curr Glaucoma Pract 2018; 12:1-9. [PMID: 29861576 PMCID: PMC5981087 DOI: 10.5005/jp-journals-10028-1237] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2017] [Accepted: 11/22/2017] [Indexed: 01/07/2023] Open
Abstract
How to cite this article: Sabel BA, Cárdenas-Morales L, Gao Y. Vision Restoration in Glaucoma by activating Residual Vision with a Holistic, Clinical Approach: A Review. J Curr Glaucoma Pract 2018;12(1):1-9.
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Affiliation(s)
- Bernhard A Sabel
- Professor, SAVIR Center, Magdeburg, Germany; Institute for Medical Psychology, Otto von Guericke University of Magdeburg Magdeburg, Germany
| | - Lizbeth Cárdenas-Morales
- Lecturer, Institute for Medical Psychology, Otto von Guericke University of Magdeburg, Magdeburg, Germany
| | - Ying Gao
- Researcher, SAVIR Center, Magdeburg, Germany; Institute for Medical Psychology, Otto von Guericke University of Magdeburg Magdeburg, Germany
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Gall C, Schmidt S, Schittkowski MP, Antal A, Ambrus GG, Paulus W, Dannhauer M, Michalik R, Mante A, Bola M, Lux A, Kropf S, Brandt SA, Sabel BA. Alternating Current Stimulation for Vision Restoration after Optic Nerve Damage: A Randomized Clinical Trial. PLoS One 2016; 11:e0156134. [PMID: 27355577 PMCID: PMC4927182 DOI: 10.1371/journal.pone.0156134] [Citation(s) in RCA: 81] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 05/10/2016] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND Vision loss after optic neuropathy is considered irreversible. Here, repetitive transorbital alternating current stimulation (rtACS) was applied in partially blind patients with the goal of activating their residual vision. METHODS We conducted a multicenter, prospective, randomized, double-blind, sham-controlled trial in an ambulatory setting with daily application of rtACS (n = 45) or sham-stimulation (n = 37) for 50 min for a duration of 10 week days. A volunteer sample of patients with optic nerve damage (mean age 59.1 yrs) was recruited. The primary outcome measure for efficacy was super-threshold visual fields with 48 hrs after the last treatment day and at 2-months follow-up. Secondary outcome measures were near-threshold visual fields, reaction time, visual acuity, and resting-state EEGs to assess changes in brain physiology. RESULTS The rtACS-treated group had a mean improvement in visual field of 24.0% which was significantly greater than after sham-stimulation (2.5%). This improvement persisted for at least 2 months in terms of both within- and between-group comparisons. Secondary analyses revealed improvements of near-threshold visual fields in the central 5° and increased thresholds in static perimetry after rtACS and improved reaction times, but visual acuity did not change compared to shams. Visual field improvement induced by rtACS was associated with EEG power-spectra and coherence alterations in visual cortical networks which are interpreted as signs of neuromodulation. Current flow simulation indicates current in the frontal cortex, eye, and optic nerve and in the subcortical but not in the cortical regions. CONCLUSION rtACS treatment is a safe and effective means to partially restore vision after optic nerve damage probably by modulating brain plasticity. This class 1 evidence suggests that visual fields can be improved in a clinically meaningful way. TRIAL REGISTRATION ClinicalTrials.gov NCT01280877.
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Affiliation(s)
- Carolin Gall
- Institute of Medical Psychology, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
- * E-mail:
| | - Sein Schmidt
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Michael P. Schittkowski
- Department of Ophthalmology, University Medical Center, Georg-August University of Goettingen, Goettingen, Germany
| | - Andrea Antal
- Department of Clinical Neurophysiology, University Medical Center, Georg-August University, Goettingen, Germany
| | - Géza Gergely Ambrus
- Department of Clinical Neurophysiology, University Medical Center, Georg-August University, Goettingen, Germany
| | - Walter Paulus
- Department of Clinical Neurophysiology, University Medical Center, Georg-August University, Goettingen, Germany
| | - Moritz Dannhauer
- Center for Integrative Biomedical Computing and the Scientific Computing and Imaging Institute, University of Utah, Salt Lake City, Utah, United States of America
| | - Romualda Michalik
- Institute of Medical Psychology, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Alf Mante
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Michal Bola
- Institute of Medical Psychology, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Anke Lux
- Institute for Biometry and Medical Informatics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Siegfried Kropf
- Institute for Biometry and Medical Informatics, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
| | - Stephan A. Brandt
- Department of Neurology, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Bernhard A. Sabel
- Institute of Medical Psychology, Medical Faculty, Otto-von-Guericke University Magdeburg, Magdeburg, Germany
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Alfaro A, Bernabeu Á, Agulló C, Parra J, Fernández E. Hearing colors: an example of brain plasticity. Front Syst Neurosci 2015; 9:56. [PMID: 25926778 PMCID: PMC4396351 DOI: 10.3389/fnsys.2015.00056] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2015] [Accepted: 03/23/2015] [Indexed: 12/11/2022] Open
Abstract
Sensory substitution devices (SSDs) are providing new ways for improving or replacing sensory abilities that have been lost due to disease or injury, and at the same time offer unprecedented opportunities to address how the nervous system could lead to an augmentation of its capacities. In this work we have evaluated a color-blind subject using a new visual-to-auditory SSD device called “Eyeborg”, that allows colors to be perceived as sounds. We used a combination of neuroimaging techniques including Functional Magnetic Resonance Imaging (fMRI), Diffusion Tensor Imaging (DTI) and proton Magnetic Resonance Spectroscopy (1H-MRS) to study potential brain plasticity in this subject. Our results suggest that after 8 years of continuous use of this device there could be significant adaptive and compensatory changes within the brain. In particular, we found changes in functional neural patterns, structural connectivity and cortical topography at the visual and auditive cortex of the Eyeborg user in comparison with a control population. Although at the moment we cannot claim that the continuous use of the Eyeborg is the only reason for these findings, our results may shed further light on potential brain changes associated with the use of other SSDs. This could help to better understand how the brain adapts to several pathologies and uncover adaptive resources such as cross-modal representations. We expect that the precise understanding of these changes will have clear implications for rehabilitative training, device development and for more efficient programs for people with disabilities.
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Affiliation(s)
- Arantxa Alfaro
- CIBER-BBN Madrid, Spain ; Hospital Vega Baja Orihuela, Spain
| | - Ángela Bernabeu
- Department of Magnetic Resonance, INSCANER S.L. Alicante, Spain
| | - Carlos Agulló
- Department of Magnetic Resonance, INSCANER S.L. Alicante, Spain
| | | | - Eduardo Fernández
- CIBER-BBN Madrid, Spain ; Institute of Bioengineering, Universidad Miguel Hernández Elche, Spain
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