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Wang K, Pu Y, Chen L, Hoshino M, Uesugi K, Yagi N, Chen X, Usui Y, Hanashima A, Hashimoto K, Mohri S, Pierscionek BK. Optical development in the murine eye lens of accelerated senescence-prone SAMP8 and senescence-resistant SAMR1 strains. Exp Eye Res 2024; 241:109858. [PMID: 38467176 DOI: 10.1016/j.exer.2024.109858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2024] [Revised: 02/28/2024] [Accepted: 03/08/2024] [Indexed: 03/13/2024]
Abstract
The eye lens is responsible for focusing objects at various distances onto the retina and its refractive power is determined by its surface curvature as well as its internal gradient refractive index (GRIN). The lens continues to grow with age resulting in changes to the shape and to the GRIN profile. The present study aims to investigate how the ageing process may influence lens optical development. Murine lenses of accelerated senescence-prone strain (SAMP8) aged from 4 to 50 weeks; senescence-resistant strain (SAMR1) aged from 5 to 52 weeks as well as AKR strain (served as control) aged from 6 to 70 weeks were measured using the X-ray interferometer at the SPring-8 synchrotron Japan within three consecutive years from 2020 to 2022. Three dimensional distributions of the lens GRIN were reconstructed using the measured data and the lens shapes were determined using image segmentation in MatLab. Variations in the parameters describing the lens shape and the GRIN profile with age were compared amongst three mouse strains. With advancing age, both the lens anterior and posterior surface flattens and the lens sagittal thickness increase in all three mouse strains (Anterior radius of curvature increase at 0.008 mm/week, 0.007 mm/week and 0.002 mm/week while posterior radius of curvature increase at 0.002 mm/week, 0.007 mm/week and 0.003 mm/week respectively in AKR, SAMP8 and SAMR1 lenses). Compared with the AKR strain, the SAMP8 samples demonstrate a higher rate of increase in the posterior curvature radius (0.007 mm/week) and the thickness (0.015 mm/week), whilst the SAMR1 samples show slower increases in the anterior curvature radius (0.002 mm/week) and its thickness (0.013 mm/week). There are similar age-related trends in GRIN shape in the radial direction (in all three types of murine lenses nr2 and nr6 increase with age while nr4 decrease with age consistently) but not in the axial direction amongst three mouse strains (nz1 of AKR lens decrease while of SAMP8 and SAMR1 increase with age; nz2 of all three models increase with age; nz3 of AKR lens increase while of SAMP8 and SAMR1 decrease with age). The ageing process can influence the speed of lens shape change and affect the GRIN profile mainly in the axial direction, contributing to an accelerated decline rate of the optical power in the senescence-prone strain (3.5 D/week compared to 2.3 D/week in the AKR control model) but a retardatory decrease in the senescence-resistant strain (2.1 D/week compared to the 2.3D/week in the AKR control model).
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Affiliation(s)
- Kehao Wang
- School of Engineering Medicine and School of Biological Science and Medical Engineering, Beihang University, Beijing, China.
| | - Yutian Pu
- School of Engineering Medicine and School of Biological Science and Medical Engineering, Beihang University, Beijing, China.
| | - Leran Chen
- Peking University First Hospital, Beijing, China.
| | - Masato Hoshino
- Japan Synchrotron Radiation Research Institute (Spring-8), 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan.
| | - Kentaro Uesugi
- Japan Synchrotron Radiation Research Institute (Spring-8), 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan.
| | - Naoto Yagi
- Japan Synchrotron Radiation Research Institute (Spring-8), 1-1-1, Kouto, Sayo-cho, Sayo-gun, Hyogo, 679-5198, Japan.
| | - Xiaoyong Chen
- Department of Ophthalmology, Peking University Third Hospital, Beijing Key Laboratory of Restoration of Damaged Ocular Nerve, Peking University Third Hospital, China.
| | - Yuu Usui
- First Department of Physiology, Kawasaki Medical School, Kurashiki, Okayama, Japan.
| | - Akira Hanashima
- First Department of Physiology, Kawasaki Medical School, Kurashiki, Okayama, Japan.
| | - Ken Hashimoto
- First Department of Physiology, Kawasaki Medical School, Kurashiki, Okayama, Japan.
| | - Satoshi Mohri
- First Department of Physiology, Kawasaki Medical School, Kurashiki, Okayama, Japan.
| | - Barbara K Pierscionek
- Faculty of Health, Education, Medicine and Social Care, Medical Technology Research Centre, Anglia Ruskin University, Bishops Hall Lane, Chelmsford, United Kingdom.
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Gupta A, Ruminski D, Villar AJ, Toledo RD, Gondek G, Pierscionek B, Artal P, Grulkowski I. Age-related changes in geometry and transparency of human crystalline lens revealed by optical signal discontinuity zones in swept-source OCT images. Eye Vis (Lond) 2023; 10:46. [PMID: 38037146 PMCID: PMC10691129 DOI: 10.1186/s40662-023-00365-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/29/2023] [Accepted: 10/26/2023] [Indexed: 12/02/2023]
Abstract
BACKGROUND The shape and microstructure of the human crystalline lens alter with ageing, and this has an effect on the optical properties of the eye. The aim of this study was to characterise the age-related differences in the morphology and transparency of the eye lenses of healthy subjects through the optical signal discontinuity (OSD) zones in optical coherence tomography (OCT) images. We also investigated the association of those changes with the optical quality of the eye and visual function. METHODS OCT images of the anterior segment of 49 eyes of subjects (9-78 years) were acquired, and the OSD zones (nucleus, C1-C4 cortical zones) were identified. Central thickness, curvature and optical density were measured. The eye's optical quality was evaluated by the objective scatter index (OSI). Contrast sensitivity and visual acuity tests were performed. The correlation between extracted parameters and age was assessed. RESULTS The increase in lens thickness with age was dominated by the thickening of the cortical zone C3 (0.0146 mm/year). The curvature radii of the anterior lens surface and both anterior and posterior nucleo-cortical interfaces decreased with age (- 0.053 mm/year, - 0.013 mm/year and - 0.006 mm/year, respectively), and no change was observed for the posterior lens radius. OCT-based densitometry revealed significant correlations with age for all zones except for C1β, and the highest increase in density was in the C2-C4 zones (R = 0.45, 0.74, 0.56, respectively, P < 0.001). Increase in OSI was associated with the degradation of visual function. CONCLUSIONS OCT enables the identification of OSD zones of the crystalline lens. The most significant age-related changes occur in the C3 zone as it thickens with age at a faster rate and becomes more opaque than other OSD zones. The changes are associated with optical quality deterioration and reduction of visual performance. These findings contribute to a better understanding of the structure-function relationship of the ageing lens and offer insights into both pathological and aging alterations.
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Affiliation(s)
- Ashish Gupta
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100, Toruń, Poland
| | - Daniel Ruminski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100, Toruń, Poland
| | - Alfonso Jimenez Villar
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100, Toruń, Poland
| | - Raúl Duarte Toledo
- Laboratorio de Óptica, Centro de Investigación en Óptica y Nanofísica, Universidad de Murcia, Edif. CIOyN, N º34, Campus de Espinardo, 30100, Murcia, Spain
| | - Grzegorz Gondek
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100, Toruń, Poland
| | - Barbara Pierscionek
- Faculty of Health, Education, Medicine, and Social Care, Medical Technology Research Center, Chelmsford Campus, Anglia Ruskin University, Bishop Hall Ln, Chelmsford, CM1 1SQ, UK
| | - Pablo Artal
- Laboratorio de Óptica, Centro de Investigación en Óptica y Nanofísica, Universidad de Murcia, Edif. CIOyN, N º34, Campus de Espinardo, 30100, Murcia, Spain
| | - Ireneusz Grulkowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University in Toruń, Grudziądzka 5, 87-100, Toruń, Poland.
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Jiang MS, Xu XL, Yang T, Zhang XD, Li F. Reply to comment by Ronald A. Schachar on the publication "Refractive index redistribution with accommodation based on finite volume-constant age-dependent mechanical modeling". Vision Res 2020; 168:31-32. [PMID: 32062175 DOI: 10.1016/j.visres.2020.01.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 01/01/2020] [Accepted: 01/02/2020] [Indexed: 11/25/2022]
Affiliation(s)
- Min-Shan Jiang
- Engineering Research Center of Optical Instruments and Systems, Ministry of Education, Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai, China
| | - Xiao-Li Xu
- Engineering Research Center of Optical Instruments and Systems, Ministry of Education, Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai, China
| | - Ting Yang
- Engineering Research Center of Optical Instruments and Systems, Ministry of Education, Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai, China
| | - Xue-Dian Zhang
- Engineering Research Center of Optical Instruments and Systems, Ministry of Education, Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai, China
| | - Feng Li
- Engineering Research Center of Optical Instruments and Systems, Ministry of Education, Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai, China.
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Del Águila-Carrasco AJ, Kruger PB, Lara F, López-Gil N. Aberrations and accommodation. Clin Exp Optom 2019; 103:95-103. [PMID: 31284325 DOI: 10.1111/cxo.12938] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 05/22/2019] [Accepted: 05/23/2019] [Indexed: 12/26/2022] Open
Abstract
Modern methods of measuring the refractive state of the eye include wavefront sensors which make it possible to monitor both static and dynamic changes of the ocular wavefront while the eye observes a target positioned at different distances away from the eye. In addition to monitoring the ocular aberrations, wavefront refraction methods allow measurement of the accommodative response while viewing with the eye's habitual chromatic and monochromatic aberrations present, with these aberrations removed, and with specific aberrations added or removed. A large number of experiments describing the effects of accommodation on aberrations and vice versa are reviewed, pointing out the implications for fundamental questions related to the mechanism of accommodation.
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Affiliation(s)
| | - Philip B Kruger
- College of Optometry, The State University of New York, New York, NY, USA
| | - Francisco Lara
- Vision Science Research Group (CiViUM), Instituto Universitario de Investigación en Envejecimiento (IUIE), University of Murcia, Murcia, Spain
| | - Norberto López-Gil
- Vision Science Research Group (CiViUM), Instituto Universitario de Investigación en Envejecimiento (IUIE), University of Murcia, Murcia, Spain
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Wang K, Pierscionek BK. Biomechanics of the human lens and accommodative system: Functional relevance to physiological states. Prog Retin Eye Res 2019; 71:114-131. [DOI: 10.1016/j.preteyeres.2018.11.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2018] [Revised: 09/24/2018] [Accepted: 11/07/2018] [Indexed: 12/28/2022]
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Jiang MS, Xu XL, Yang T, Zhang XD, Li F. Refractive index redistribution with accommodation based on finite volume-constant age-dependent mechanical modeling. Vision Res 2019; 160:52-59. [PMID: 31095964 DOI: 10.1016/j.visres.2019.04.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/29/2019] [Accepted: 04/05/2019] [Indexed: 11/28/2022]
Abstract
The human lens is considered to have a gradient refractive index (GRIN) distribution. The recently developed accommodating volume-constant age-dependent optical (AVOCADO) model can accurately describe the separate GRIN distributions in the axial and radial directions. Our study uses a finite element method to simulate the accommodation process and calculate the GRIN redistribution based on the AVOCADO model for 25-, 35- and 45-year-old lenses. The parameter p describes the steepness of the GRIN profile towards the lens periphery. The results show that axial p values increase with age. Under accommodation, the axial p value increases, while the radial p value decreases. We also use a ray tracing method to evaluate the optical performance of the lens. The aim of this paper is thus to provide an anatomically finite mechanical lens model with separate axial and radial refractive index profiles for a better understanding of accommodation at different ages.
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Affiliation(s)
- Min-Shan Jiang
- Engineering Research Center of Optical Instruments and Systems, Ministry of Education, Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai 200093, China; Department of Biomedical Engineering, Florida International University, Miami, FL 33174, USA
| | - Xiao-Li Xu
- Engineering Research Center of Optical Instruments and Systems, Ministry of Education, Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Ting Yang
- Engineering Research Center of Optical Instruments and Systems, Ministry of Education, Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Xue-Dian Zhang
- Engineering Research Center of Optical Instruments and Systems, Ministry of Education, Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai 200093, China
| | - Feng Li
- Engineering Research Center of Optical Instruments and Systems, Ministry of Education, Shanghai Key Lab of Modern Optical Systems, University of Shanghai for Science and Technology, Shanghai 200093, China.
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Riehle N, Thude S, Götz T, Kandelbauer A, Thanos S, Tovar GE, Lorenz G. Influence of PDMS molecular weight on transparency and mechanical properties of soft polysiloxane-urea-elastomers for intraocular lens application. Eur Polym J 2018. [DOI: 10.1016/j.eurpolymj.2018.02.029] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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Wang K, Venetsanos D, Wang J, Pierscionek BK. Gradient moduli lens models: how material properties and application of forces can affect deformation and distributions of stress. Sci Rep 2016; 6:31171. [PMID: 27507665 PMCID: PMC4979009 DOI: 10.1038/srep31171] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Accepted: 07/13/2016] [Indexed: 11/11/2022] Open
Abstract
The human lens provides one-third of the ocular focussing power and is responsible for altering focus over a range of distances. This ability, termed accommodation, defines the process by which the lens alters shape to increase or decrease ocular refractive power; this is mediated by the ciliary muscle through the zonule. This ability decreases with age such that around the sixth decade of life it is lost rendering the eye unable to focus on near objects. There are two opponent theories that provide an explanation for the mechanism of accommodation; definitive support for either of these requires investigation. This work aims to elucidate how material properties can affect accommodation using Finite Element models based on interferometric measurements of refractive index. Gradients of moduli are created in three models from representative lenses, aged 16, 35 and 48 years. Different forms of zonular attachments are studied to determine which may most closely mimic the physiological form by comparing stress and displacement fields with simulated shape changes to accommodation in living lenses. The results indicate that for models to mimic accommodation in living eyes, the anterior and posterior parts of the zonule need independent force directions. Choice of material properties affects which theory of accommodation is supported.
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Affiliation(s)
- Kehao Wang
- Faculty of Science Engineering and Computing, Penrhyn Road, KT1 2EE, Kingston-upon-Thames, UK
| | - Demetrios Venetsanos
- Faculty of Science Engineering and Computing, Penrhyn Road, KT1 2EE, Kingston-upon-Thames, UK
| | - Jian Wang
- Faculty of Science Engineering and Computing, Penrhyn Road, KT1 2EE, Kingston-upon-Thames, UK
| | - Barbara K Pierscionek
- Faculty of Science Engineering and Computing, Penrhyn Road, KT1 2EE, Kingston-upon-Thames, UK
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