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fMRI of Retina-Originated Phosphenes Experienced by Patients with Leber Congenital Amaurosis

A phenomenon characterized by the experience of seeing light without any light actually entering the eye is called phosphenes or photopsias. Phosphenes can occur spontaneously or via induction by external stimuli. Previous reports regarding phosphenes have primarily focused on externally induced pho...

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Autores principales: Ashtari, Manzar, Cyckowski, Laura, Yazdi, Alborz, Viands, Amanda, Marshall, Kathleen, Bókkon, István, Maguire, Albert, Bennett, Jean
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Public Library of Science 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897613/
https://www.ncbi.nlm.nih.gov/pubmed/24465873
http://dx.doi.org/10.1371/journal.pone.0086068
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author Ashtari, Manzar
Cyckowski, Laura
Yazdi, Alborz
Viands, Amanda
Marshall, Kathleen
Bókkon, István
Maguire, Albert
Bennett, Jean
author_facet Ashtari, Manzar
Cyckowski, Laura
Yazdi, Alborz
Viands, Amanda
Marshall, Kathleen
Bókkon, István
Maguire, Albert
Bennett, Jean
author_sort Ashtari, Manzar
collection PubMed
description A phenomenon characterized by the experience of seeing light without any light actually entering the eye is called phosphenes or photopsias. Phosphenes can occur spontaneously or via induction by external stimuli. Previous reports regarding phosphenes have primarily focused on externally induced phosphenes such as by applying alternating or direct current to the cortex. A few of these reports used functional magnetic resonance (fMRI) to study activations induced by cortical phosphenes. However, there are no fMRI reports on spontaneous phosphenes originating from the retina and the resulting pattern of cortical activations. We performed fMRI during a reversing checkerboard paradigm in three LCA patients who underwent unilateral gene therapy and reported experiencing frequent phosphene on a daily basis. We observed bilateral cortical activation covering the entire visual cortices when patients reported experiencing phosphenes. In contrast, in the absence of phosphenes, activation was regulated by patient's visual ability and demonstrated improved cortical activation due to gene therapy. These fMRI results illustrate the potential impact of phosphene perception on visual function and they may explain some of the variability that clinicians find in visual function testing in retinal degeneration. Although we did not perform correlations between visual function and phosphenes, we hope data presented here raises awareness of this phenomenon and its potential effect on visual function and the implications for clinical testing. We recommend a thorough history for phosphene experiences be taken in patients with retinal disease who are candidates for gene or molecular therapy. Lastly, these data illustrate the potential power of fMRI as an outcome measure of gene therapy and the negative impact phosphenes may have on vision testing. fMRI has proven to be a sensitive, non-invasive, and reproducible test paradigm for these purposes and can complement standard visual function testing.
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spelling pubmed-38976132014-01-24 fMRI of Retina-Originated Phosphenes Experienced by Patients with Leber Congenital Amaurosis Ashtari, Manzar Cyckowski, Laura Yazdi, Alborz Viands, Amanda Marshall, Kathleen Bókkon, István Maguire, Albert Bennett, Jean PLoS One Research Article A phenomenon characterized by the experience of seeing light without any light actually entering the eye is called phosphenes or photopsias. Phosphenes can occur spontaneously or via induction by external stimuli. Previous reports regarding phosphenes have primarily focused on externally induced phosphenes such as by applying alternating or direct current to the cortex. A few of these reports used functional magnetic resonance (fMRI) to study activations induced by cortical phosphenes. However, there are no fMRI reports on spontaneous phosphenes originating from the retina and the resulting pattern of cortical activations. We performed fMRI during a reversing checkerboard paradigm in three LCA patients who underwent unilateral gene therapy and reported experiencing frequent phosphene on a daily basis. We observed bilateral cortical activation covering the entire visual cortices when patients reported experiencing phosphenes. In contrast, in the absence of phosphenes, activation was regulated by patient's visual ability and demonstrated improved cortical activation due to gene therapy. These fMRI results illustrate the potential impact of phosphene perception on visual function and they may explain some of the variability that clinicians find in visual function testing in retinal degeneration. Although we did not perform correlations between visual function and phosphenes, we hope data presented here raises awareness of this phenomenon and its potential effect on visual function and the implications for clinical testing. We recommend a thorough history for phosphene experiences be taken in patients with retinal disease who are candidates for gene or molecular therapy. Lastly, these data illustrate the potential power of fMRI as an outcome measure of gene therapy and the negative impact phosphenes may have on vision testing. fMRI has proven to be a sensitive, non-invasive, and reproducible test paradigm for these purposes and can complement standard visual function testing. Public Library of Science 2014-01-21 /pmc/articles/PMC3897613/ /pubmed/24465873 http://dx.doi.org/10.1371/journal.pone.0086068 Text en © 2014 Ashtari et al http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are properly credited.
spellingShingle Research Article
Ashtari, Manzar
Cyckowski, Laura
Yazdi, Alborz
Viands, Amanda
Marshall, Kathleen
Bókkon, István
Maguire, Albert
Bennett, Jean
fMRI of Retina-Originated Phosphenes Experienced by Patients with Leber Congenital Amaurosis
title fMRI of Retina-Originated Phosphenes Experienced by Patients with Leber Congenital Amaurosis
title_full fMRI of Retina-Originated Phosphenes Experienced by Patients with Leber Congenital Amaurosis
title_fullStr fMRI of Retina-Originated Phosphenes Experienced by Patients with Leber Congenital Amaurosis
title_full_unstemmed fMRI of Retina-Originated Phosphenes Experienced by Patients with Leber Congenital Amaurosis
title_short fMRI of Retina-Originated Phosphenes Experienced by Patients with Leber Congenital Amaurosis
title_sort fmri of retina-originated phosphenes experienced by patients with leber congenital amaurosis
topic Research Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3897613/
https://www.ncbi.nlm.nih.gov/pubmed/24465873
http://dx.doi.org/10.1371/journal.pone.0086068
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