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Errera C, Romann J, Solecki L, Gaucher D, Ballonzoli L, Bourcier T, Sauer A. Retinal microvascular changes in unilateral functional amblyopia detected by oct-angiography and follow-up during treatment. Eur J Ophthalmol 2024; 34:399-407. [PMID: 37464746 DOI: 10.1177/11206721231188987] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/20/2023]
Abstract
OBJECTIVE To evaluate the macular microvascular changes using optical coherence tomographic angiography (OCT-A) in children with unilateral amblyopia and their reversibility during treatment. METHODS Patients with unilateral strabismic or anisometropic amblyopia or residual amblyopia from early congenital cataract surgery, examined between October 2019 and March 2021, were included. Vessel density and perfusion density in the superficial capillary plexus and area, perimeter and circularity of the foveal avascular zone (FAZ) were analysed using OCT-A in amblyopic eyes, contralateral eyes and control group healthy eyes. Correlation analyses between the microvascular parameters and the visual acuity were performed. In a pilot study on a few patients from the amblyopic cohort, longitudinal follow-up during treatment was also performed. RESULTS A total of 128 eyes of 64 patients were included: 32 amblyopic eyes compared with 32 contralateral eyes and 64 control eyes. Vessel density and perfusion density in the superficial capillary plexus were significantly lower in amblyopic eyes compared to control eyes in 6 × 6 mm (p < 0.02) and 3 × 3 mm (p < 0.01) scans. Correlation analyses showed a linear decrease in vessel density and perfusion density with decreasing visual acuity. The microvascular changes observed were reversible with the occlusion treatment of amblyopia (p < 0.001). CONCLUSIONS The study found a decrease in vessel density and perfusion density in the macula of children with unilateral functional amblyopia. These microvascular changes were correlated with visual acuity and appeared to be reversible with treatment of amblyopia. On the whole, OCT-A appears to be a relevant complementary examination when it comes to diagnosing and monitoring functional amblyopia.
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Affiliation(s)
- Charlotte Errera
- Department of Ophthalmology, Strasbourg University Hospital, FMTS, Strasbourg, France
| | - Julia Romann
- Department of Ophthalmology, Strasbourg University Hospital, FMTS, Strasbourg, France
| | - Lauriana Solecki
- Department of Ophthalmology, Strasbourg University Hospital, FMTS, Strasbourg, France
| | - David Gaucher
- Department of Ophthalmology, Strasbourg University Hospital, FMTS, Strasbourg, France
| | - Laurent Ballonzoli
- Department of Ophthalmology, Strasbourg University Hospital, FMTS, Strasbourg, France
| | - Tristan Bourcier
- Department of Ophthalmology, Strasbourg University Hospital, FMTS, Strasbourg, France
| | - Arnaud Sauer
- Department of Ophthalmology, Strasbourg University Hospital, FMTS, Strasbourg, France
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In vivo MRI evaluation of early postnatal development in normal and impaired rat eyes. Sci Rep 2021; 11:15513. [PMID: 34330952 PMCID: PMC8324881 DOI: 10.1038/s41598-021-93991-2] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2020] [Accepted: 07/01/2021] [Indexed: 11/08/2022] Open
Abstract
This study employed in vivo 7-T magnetic resonance imaging (MRI) to evaluate the postnatal ocular growth patterns under normal development or neonatal impairments in Sprague-Dawley rats. Using T2-weighted imaging on healthy rats from postnatal day (P) 1 (newborn) to P60 (adult), the volumes of the anterior chamber and posterior chamber (ACPC), lens, and vitreous humor increased logistically with ACPC expanding by 33-fold and the others by fivefold. Intravitreal potassium dichromate injection at P1, P7, and P14 led to T1-weighted signal enhancement in the developing retina by 188-289%. Upon unilateral hypoxic-ischemic encephalopathy at P7, monocular deprivation at P15, and monocular enucleation at P1, T2-weighted imaging of the adult rats showed decreased ocular volumes to different extents. In summary, in vivo high-field MRI allows for non-invasive evaluation of early postnatal development in the normal and impaired rat eyes. Chromium-enhanced MRI appeared effective in examining the developing retina before natural eyelid opening at P14 with relevance to lipid metabolism. The reduced ocular volumes upon neonatal visual impairments provided evidence to the emerging problems of why some impaired visual outcomes cannot be solely predicted by neurological assessments and suggested the need to look into both the eye and the brain under such conditions.
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Zhang Y, Fu T, Han S, Ding Y, Wang J, Zheng J, Li J. Monocular Deprivation Affects Visual Cortex Plasticity Through cPKCγ-Modulated GluR1 Phosphorylation in Mice. Invest Ophthalmol Vis Sci 2020; 61:44. [PMID: 32343785 PMCID: PMC7401946 DOI: 10.1167/iovs.61.4.44] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Purpose To determine how visual cortex plasticity changes after monocular deprivation (MD) in mice and whether conventional protein kinase C gamma (cPKCγ) plays a role in visual cortex plasticity. Methods cPKCγ membrane translocation levels were quantified by using immunoblotting to explore the effects of MD on cPKCγ activation. Electrophysiology was used to record field excitatory postsynaptic potential (fEPSP) amplitude with the goal of observing changes in visual cortex plasticity after MD. Immunoblotting was also used to determine the phosphorylation levels of GluR1 at Ser831. Light transmission was analyzed using electroretinography to examine the effects of MD and cPKCγ on mouse retinal function. Results Membrane translocation levels of cPKCγ significantly increased in the contralateral visual cortex of MD mice compared to wild-type (WT) mice (P < 0.001). In the contralateral visual cortex, long-term potentiation (LTP) and the phosphorylation levels of GluR1 at Ser 831 were increased in cPKCγ+/+ mice after MD. Interestingly, these levels could be downregulated by cPKCγ knockout compared to cPKCγ+/++MD mice (P < 0.001). Compared to the right eyes of WT mice, the amplitudes of a-waves and b-waves declined in deprived right eyes of mice after MD (P < 0.001). There were no significant differences when comparing cPKCγ+/+ and cPKCγ−/− mice with MD. Conclusions cPKCγ participates in the plasticity of the visual cortex after MD, which is characterized by increased LTP in the contralateral visual cortex, which may be a result of cPKCγ-mediated phosphorylation of GluR1 at Ser 831.
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Abstract
Amblyopia refers to visual impairment resulting from perturbations in visual experience during visual development, typically secondary to strabismus, uncorrected refractive error, and/or deprivation. Amblyopia has traditionally been considered a cortical disease, but the depth of our understanding of this complex neurodevelopmental condition is limited by our ability to appreciate structural pathophysiology in the visual pathway. Recent advances in Optical Coherence Tomography (OCT) have facilitated numerous studies of the structural changes in the retina and optic nerve, thereby expanding our appreciation for the pathogenesis of this condition. In this review, we summarize findings from studies evaluating retinal, retinal nerve fiber layer, and choroidal thickness changes in patients with amblyopia. Focusing on the largest and most recent studies, we discuss common limitations and confounding variables in these studies. We summarize recent advances in ocular imaging technology and reconcile the findings of early histological reports with those of structural OCT in amblyopia.
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Affiliation(s)
- Eric D Gaier
- a Department of Ophthalmology , Boston Children's Hospital , Boston , MA , USA.,b Harvard Medical School , Boston , MA , USA
| | - Ryan Gise
- b Harvard Medical School , Boston , MA , USA.,c Neuro-Ophthalmology Service, Department of Ophthalmology , Massachusetts Eye and Ear , Boston , MA , USA
| | - Gena Heidary
- a Department of Ophthalmology , Boston Children's Hospital , Boston , MA , USA.,b Harvard Medical School , Boston , MA , USA
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Lagali PS, Medina CF, Zhao BYH, Yan K, Baker AN, Coupland SG, Tsilfidis C, Wallace VA, Picketts DJ. Retinal interneuron survival requires non-cell-autonomous Atrx activity. Hum Mol Genet 2016; 25:4787-4803. [PMID: 28173139 DOI: 10.1093/hmg/ddw306] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2016] [Revised: 08/25/2016] [Accepted: 08/30/2016] [Indexed: 01/13/2023] Open
Abstract
ATRX is a chromatin remodeling protein that is mutated in several intellectual disability disorders including alpha-thalassemia/mental retardation, X-linked (ATR-X) syndrome. We previously reported the prevalence of ophthalmological defects in ATR-X syndrome patients, and accordingly we find morphological and functional visual abnormalities in a mouse model harboring a mutation occurring in ATR-X patients. The visual system abnormalities observed in these mice parallels the Atrx-null retinal phenotype characterized by interneuron defects and selective loss of amacrine and horizontal cells. The mechanisms that underlie selective neuronal vulnerability and neurodegeneration in the central nervous system upon Atrx mutation or deletion are unknown. To interrogate the cellular specificity of Atrx for its retinal neuroprotective functions, we employed a combination of temporal and lineage-restricted conditional ablation strategies to generate five different conditional knockout mouse models, and subsequently identified a non-cell-autonomous requirement for Atrx in bipolar cells for inhibitory interneuron survival in the retina. Atrx-deficient retinal bipolar cells exhibit functional, structural and molecular alterations consistent with impairments in neuronal activity and connectivity. Gene expression changes in the Atrx-null retina indicate defective synaptic structure and neuronal circuitry, suggest excitotoxic mechanisms of neurodegeneration, and demonstrate that common targets of ATRX in the forebrain and retina may contribute to similar neuropathological processes underlying cognitive impairment and visual dysfunction in ATR-X syndrome.
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Affiliation(s)
- Pamela S Lagali
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Chantal F Medina
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Brandon Y H Zhao
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Keqin Yan
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Adam N Baker
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada
| | - Stuart G Coupland
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Ophthalmology, University of Ottawa, Ottawa, ON K1H 8M5, Canada,,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Catherine Tsilfidis
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Ophthalmology, University of Ottawa, Ottawa, ON K1H 8M5, Canada,,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada
| | - Valerie A Wallace
- Vision Research Division, Krembil Research Institute, Toronto, Ontario, Canada M5T 2S8,,Department of Ophthalmology and Vision Sciences, University of Toronto, Toronto, ON M5T 3A9, Canada
| | - David J Picketts
- Regenerative Medicine Program, Ottawa Hospital Research Institute, Ottawa, ON K1H 8L6, Canada.,Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, ON K1H 8M5, Canada,,Department of Biochemistry, Microbiology, and Immunology, University of Ottawa, Ottawa, ON K1H 8M5, Canada
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