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Kim C, Demer JL. Magnetic Resonance Imaging of Globe Translation in Abducens Palsy. Am J Ophthalmol 2024; 258:8-13. [PMID: 37774994 DOI: 10.1016/j.ajo.2023.09.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Revised: 09/13/2023] [Accepted: 09/16/2023] [Indexed: 10/01/2023]
Abstract
PURPOSE It has been supposed that rectus muscle paralysis would cause proptosis due to the reduction in active posterior tension. This study aimed to test this proposition by evaluating globe translation during horizontal duction in patients with abducens palsy. DESIGN Prospective, single-center, fellow-eye controlled, case series. METHODS Horizontal globe rotation and translation were quantified using orbital magnetic resonance imaging of patients with isolated unilateral abducens nerve palsy without other ocular motility disorders. Unaffected fellow eyes served as the control group. Digital image analysis was performed. RESULTS The study included 5 female and 2 male patients with a mean ± standard deviation age of 52 ± 15 years. The average esotropia was 39.0 ± 9.6 diopters. Mean adduction was similar at 54.9 ± 10.4° in palsied eyes and 52.0 ± 7.1° in fellow eyes. However, abduction in palsied eyes was significantly less at 11.4 ± 7.1° than 37.1 ± 11.4° in fellow eyes (P = .0023). Average anterior translation in adduction was 0.46 ± 0.42 mm in palsied orbits, similar to 0.35 ± 0.47 mm in fellow orbits (P = .90). Anterior translation in abduction averaged 0.17 ± 0.53 mm in palsied orbits, similar to 0.27 ± 0.73 mm in fellow orbits (P = .80). Average medial translation in adduction at 0.32 ± 0.23 mm in palsied orbits was statistically similar to 0.12 ± 0.44 mm in fellow orbits (P = .54). Average lateral translation in abduction at 0.19 ± 0.18 mm in palsied orbits was similar to 0.33 ± 0.15 mm in control orbits (P = .38). CONCLUSION Abducens palsy does not alter normal eye translation during horizontal duction.
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Affiliation(s)
- Changzoo Kim
- From the Stein Eye Institute and Department of Ophthalmology (C.K., J.L.D), University of California, Los Angeles, California, USA; Department of Ophthalmology (C.K.), College of Medicine, Kosin University, Busan, Korea
| | - Joseph L Demer
- From the Stein Eye Institute and Department of Ophthalmology (C.K., J.L.D), University of California, Los Angeles, California, USA; Department of Neurology (J.L.D.), University of California, Los Angeles, California, USA; Bioengineering Department (J.L.D.), University of California, Los Angeles, California, USA.
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Shahiri M, Jóźwik A, Asejczyk M. Opto-mechanical self-adjustment model of the human eye. BIOMEDICAL OPTICS EXPRESS 2023; 14:1923-1944. [PMID: 37206139 PMCID: PMC10191641 DOI: 10.1364/boe.484824] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/04/2023] [Revised: 03/10/2023] [Accepted: 03/11/2023] [Indexed: 05/21/2023]
Abstract
The eye has specific optical and biomechanical properties that jointly regulate the eye's quality of vision, shape, and elasticity. These two characteristics are interdependent and correlated. Contrary to most currently available computational models of the human eye that only focus on biomechanical or optical aspects, the current study explores the inter-relationships between biomechanics, structure, and optical properties. Possible combinations of mechanical properties, boundary conditions, and biometrics were specified to ensure the opto-mechanical (OM) integrity to compensate for physiological changes in intraocular pressure (IOP) without compromising image acuity. This study evaluated the quality of the vision by analyzing the minimum spot diameters formed on the retina and drew how the self-adjustment mechanism affects the eye globe shape by adopting a finite element (FE) model of the eyeball. The model was verified by a water drinking test with biometric measurement (OCT Revo NX, Optopol) and tonometry (Corvis ST, Oculus).
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Zhang L, Evans A, von Ruhland C, Draman MS, Edkins S, Vincent AE, Berlinguer-Palmini R, Rees DA, Haridas AS, Morris D, Tee AR, Ludgate M, Turnbull DM, Karpe F, Dayan CM. Distinctive Features of Orbital Adipose Tissue (OAT) in Graves' Orbitopathy. Int J Mol Sci 2020; 21:E9145. [PMID: 33266331 PMCID: PMC7730568 DOI: 10.3390/ijms21239145] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Revised: 11/20/2020] [Accepted: 11/28/2020] [Indexed: 12/12/2022] Open
Abstract
Depot specific expansion of orbital-adipose-tissue (OAT) in Graves' Orbitopathy (GO) is associated with lipid metabolism signaling defects. We hypothesize that the unique adipocyte biology of OAT facilitates its expansion in GO. A comprehensive comparison of OAT and white-adipose-tissue (WAT) was performed by light/electron-microscopy, lipidomic and transcriptional analysis using ex vivo WAT, healthy OAT (OAT-H) and OAT from GO (OAT-GO). OAT-H/OAT-GO have a single lipid-vacuole and low mitochondrial number. Lower lipolytic activity and smaller adipocytes of OAT-H/OAT-GO, accompanied by similar essential linoleic fatty acid (FA) and (low) FA synthesis to WAT, revealed a hyperplastic OAT expansion through external FA-uptake via abundant SLC27A6 (FA-transporter) expression. Mitochondrial dysfunction of OAT in GO was apparent, as evidenced by the increased mRNA expression of uncoupling protein 1 (UCP1) and mitofusin-2 (MFN2) in OAT-GO compared to OAT-H. Transcriptional profiles of OAT-H revealed high expression of Iroquois homeobox-family (IRX-3&5), and low expression in HOX-family/TBX5 (essential for WAT/BAT (brown-adipose-tissue)/BRITE (BRown-in-whITE) development). We demonstrated unique features of OAT not presented in either WAT or BAT/BRITE. This study reveals that the pathologically enhanced FA-uptake driven hyperplastic expansion of OAT in GO is associated with a depot specific mechanism (the SLC27A6 FA-transporter) and mitochondrial dysfunction. We uncovered that OAT functions as a distinctive fat depot, providing novel insights into adipocyte biology and the pathological development of OAT expansion in GO.
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Affiliation(s)
- Lei Zhang
- School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK; (A.E.); (C.v.R.); (M.S.D.); (S.E.); (D.A.R.); (A.R.T.); (M.L.); (C.M.D.)
| | - Anna Evans
- School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK; (A.E.); (C.v.R.); (M.S.D.); (S.E.); (D.A.R.); (A.R.T.); (M.L.); (C.M.D.)
| | - Chris von Ruhland
- School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK; (A.E.); (C.v.R.); (M.S.D.); (S.E.); (D.A.R.); (A.R.T.); (M.L.); (C.M.D.)
| | - Mohd Shazli Draman
- School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK; (A.E.); (C.v.R.); (M.S.D.); (S.E.); (D.A.R.); (A.R.T.); (M.L.); (C.M.D.)
| | - Sarah Edkins
- School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK; (A.E.); (C.v.R.); (M.S.D.); (S.E.); (D.A.R.); (A.R.T.); (M.L.); (C.M.D.)
| | - Amy E. Vincent
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle NE2 4HH, UK; (A.E.V.); (D.M.T.)
| | | | - D. Aled Rees
- School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK; (A.E.); (C.v.R.); (M.S.D.); (S.E.); (D.A.R.); (A.R.T.); (M.L.); (C.M.D.)
| | - Anjana S Haridas
- Department of Ophthalmology, Cardiff & Vale University Health Board, Cardiff CF14 4XW, UK; (A.S.H.); (D.M.)
| | - Dan Morris
- Department of Ophthalmology, Cardiff & Vale University Health Board, Cardiff CF14 4XW, UK; (A.S.H.); (D.M.)
| | - Andrew R. Tee
- School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK; (A.E.); (C.v.R.); (M.S.D.); (S.E.); (D.A.R.); (A.R.T.); (M.L.); (C.M.D.)
| | - Marian Ludgate
- School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK; (A.E.); (C.v.R.); (M.S.D.); (S.E.); (D.A.R.); (A.R.T.); (M.L.); (C.M.D.)
| | - Doug M. Turnbull
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Faculty of Medical Sciences, Newcastle University, Newcastle NE2 4HH, UK; (A.E.V.); (D.M.T.)
| | - Fredrik Karpe
- Oxford Centre for Diabetes, Endocrinology and Metabolism, Radcliffe Department of Medicine, University of Oxford, Oxford OX3 7LE, UK;
- NIHR Oxford Biomedical Research Center, OUH Foundation Trust, Oxford OX4 2PG, UK
| | - Colin M. Dayan
- School of Medicine, Cardiff University, Heath Park, Cardiff CF14 4XN, UK; (A.E.); (C.v.R.); (M.S.D.); (S.E.); (D.A.R.); (A.R.T.); (M.L.); (C.M.D.)
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Sengupta S, Smith DS, Smith AK, Welch EB, Smith SA. Dynamic Imaging of the Eye, Optic Nerve, and Extraocular Muscles With Golden Angle Radial MRI. Invest Ophthalmol Vis Sci 2017; 58:4390–4398. [PMID: 28813574 PMCID: PMC5559179 DOI: 10.1167/iovs.17-21861] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Purpose The eye and its accessory structures, the optic nerve and the extraocular muscles, form a complex dynamic system. In vivo magnetic resonance imaging (MRI) of this system in motion can have substantial benefits in understanding oculomotor functioning in health and disease, but has been restricted to date to imaging of static gazes only. The purpose of this work was to develop a technique to image the eye and its accessory visual structures in motion. Methods Dynamic imaging of the eye was developed on a 3-Tesla MRI scanner, based on a golden angle radial sequence that allows freely selectable frame-rate and temporal-span image reconstructions from the same acquired data set. Retrospective image reconstructions at a chosen frame rate of 57 ms per image yielded high-quality in vivo movies of various eye motion tasks performed in the scanner. Motion analysis was performed for a left-right version task where motion paths, lengths, and strains/globe angle of the medial and lateral extraocular muscles and the optic nerves were estimated. Results Offline image reconstructions resulted in dynamic images of bilateral visual structures of healthy adults in only ∼15-s imaging time. Qualitative and quantitative analyses of the motion enabled estimation of trajectories, lengths, and strains on the optic nerves and extraocular muscles at very high frame rates of ∼18 frames/s. Conclusions This work presents an MRI technique that enables high-frame-rate dynamic imaging of the eyes and orbital structures. The presented sequence has the potential to be used in furthering the understanding of oculomotor mechanics in vivo, both in health and disease.
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Affiliation(s)
- Saikat Sengupta
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - David S Smith
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States
| | - Alex K Smith
- The Centre for Functional MRI of the Brain, The University of Oxford, Oxford, United Kingdom
| | - E Brian Welch
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States
| | - Seth A Smith
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, Tennessee, United States.,Department of Biomedical Engineering, Vanderbilt University, Nashville, Tennessee, United States
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