1
|
Pei Y, Han S, Lu M, Yang Y, Ma K. Preparing porcine lens to mimic human lens capsule. J Cataract Refract Surg 2024; 50:963-969. [PMID: 38758190 PMCID: PMC11338039 DOI: 10.1097/j.jcrs.0000000000001485] [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: 01/27/2024] [Revised: 05/02/2024] [Accepted: 05/09/2024] [Indexed: 05/18/2024]
Abstract
PURPOSE To develop a chemical method that makes porcine lens anterior capsule resemble human lens anterior capsule in tear force and perforating force. SETTING Beijing Tongren Hospital, Beijing, China. DESIGN Experimental study. METHODS Porcine eyes were divided into groups, and reagents (0.9% physiological saline, 0.1% sodium hypochlorite, 0.3% sodium hypochlorite, and 0.5% sodium hypochlorite) were injected into the anterior chamber, respectively, recorded as Groups A, B, C, and D, respectively. A senior physician collected each group of anterior capsules after performing continuous circular capsulorhexis and assessing the anterior capsule's tearing and perforation forces. An additional group, which consisted of human lens anterior capsules taken in the operating room from patients with cataract, recorded as Group E. A tensile system was used to measure each sample's tensile force. RESULTS A significant difference was found between Group A and any other group in maximum tensile force and average tensile force in both transverse and longitudinal directions. No significant difference was found between any 2 groups from Group B to Group E. According to the surgeon's assessment, the tear force characteristic of the porcine lens anterior capsule treated with 0.1%, 0.3%, and 0.5% sodium hypochlorite solution was similar to that of the human lens anterior capsule. CONCLUSIONS Porcine lens capsule treated using this method can be used for training of new surgeons. The porcine lens anterior capsule treated with 0.5% sodium hypochlorite, which results showed most resembled human lens anterior capsule, can be used for robotic training.
Collapse
Affiliation(s)
- Yajing Pei
- From the Department of Ophthalmology, Shanxi Eye Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China (Pei); School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing, China (Han); State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China (Lu); School of Mechanical Engineering & Automation, Beihang University, Beijing, China (Yang); Beijing Institute of Ophthalmology, Beijing TongRen Eye Center, Beijing TongRen Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Lab, Beijing, China (Ma)
| | - Shaofeng Han
- From the Department of Ophthalmology, Shanxi Eye Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China (Pei); School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing, China (Han); State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China (Lu); School of Mechanical Engineering & Automation, Beihang University, Beijing, China (Yang); Beijing Institute of Ophthalmology, Beijing TongRen Eye Center, Beijing TongRen Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Lab, Beijing, China (Ma)
| | - Mingfeng Lu
- From the Department of Ophthalmology, Shanxi Eye Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China (Pei); School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing, China (Han); State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China (Lu); School of Mechanical Engineering & Automation, Beihang University, Beijing, China (Yang); Beijing Institute of Ophthalmology, Beijing TongRen Eye Center, Beijing TongRen Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Lab, Beijing, China (Ma)
| | - Yang Yang
- From the Department of Ophthalmology, Shanxi Eye Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China (Pei); School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing, China (Han); State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China (Lu); School of Mechanical Engineering & Automation, Beihang University, Beijing, China (Yang); Beijing Institute of Ophthalmology, Beijing TongRen Eye Center, Beijing TongRen Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Lab, Beijing, China (Ma)
| | - Ke Ma
- From the Department of Ophthalmology, Shanxi Eye Hospital Affiliated to Shanxi Medical University, Taiyuan, Shanxi, China (Pei); School of Energy, Power and Mechanical Engineering, North China Electric Power University, Beijing, China (Han); State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China (Lu); School of Mechanical Engineering & Automation, Beihang University, Beijing, China (Yang); Beijing Institute of Ophthalmology, Beijing TongRen Eye Center, Beijing TongRen Hospital, Capital Medical University, Beijing Ophthalmology and Visual Sciences Key Lab, Beijing, China (Ma)
| |
Collapse
|
2
|
Safarian Baloujeh E, González-Méijome JM. Wavefront Changes during a Sustained Reading Task in Presbyopic Eyes. SENSORS (BASEL, SWITZERLAND) 2024; 24:3866. [PMID: 38931650 PMCID: PMC11207348 DOI: 10.3390/s24123866] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/22/2024] [Revised: 06/08/2024] [Accepted: 06/12/2024] [Indexed: 06/28/2024]
Abstract
The objective of this study was to assess the effect of sustained reading on the temporal changes in the wavefront error in the presbyopic eye. The wavefront aberration of the eyes was measured using an IRX3 Shack-Hartmann aberrometer before and after (immediately, 5 min, and 10 min after) a reading task. Temporal changes in C20, C40, and C3-1 coefficient values of the eyes were plotted, showing a predominant number of V-shaped patterns (for C40 and C3-1) and inverse V-shaped patterns (for C20) among the study group, and the percentages (between 27 and 73%) were reported. The median of the total RMS of aberrations and the RMS of HOA (higher-order aberrations), which included comatic (3rd order) and spherical-like aberrations (4th and 6th order), increased immediately after finishing the near-vision reading task and then decreased. The median of RMS of comatic aberrations had a similar pattern of variations, while the median of RMS of spherical-like aberrations displayed an opposite pattern. Simulating the aberration changes due to lens decentration caused by relaxed zonules during 4 D accommodation in an eye model demonstrated that the expected range of changes for the vertical coma and spherical aberrations are in the order of 0.001 and 0.01 μm, respectively, which could justify why the observed changes were not statistically significant. The observed dynamic changes in HOA might be linked to the biomechanical characteristics and alterations in the displacement of the crystalline lens following prolonged near-vision tasks in presbyopic people. Although some predominant patterns under some conditions were shown, they exhibit considerable inter-subject and inter-ocular variability. This might be due to slight misalignments while fixating on the internal extended object in the aberrometer.
Collapse
Affiliation(s)
- Ebrahim Safarian Baloujeh
- Consejo Superior de Investigaciones Científicas (CSIC), Instituto de Nanociencia y Materiales de Aragón (INMA), 50009 Zaragoza, Spain
- Departamento de Física Aplicada, Universidad de Zaragoza, 50009 Zaragoza, Spain
| | - José M. González-Méijome
- Clinical and Experimental Optometry Research Laboratory (CEORLab), Department and Center of Physics—Optometry and Vision Science, School of Science, 4710-057 Braga, Portugal;
| |
Collapse
|
3
|
Rich W, Pan M, Liu J, Swindle-Reilly KE, Reilly MA. A method for generating zonular tension in the murine eye by embedding and compressing the globe in a hydrogel. Exp Eye Res 2024; 240:109809. [PMID: 38311284 DOI: 10.1016/j.exer.2024.109809] [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: 10/20/2023] [Revised: 12/08/2023] [Accepted: 01/25/2024] [Indexed: 02/10/2024]
Abstract
The ocular lens is the primary organ within the eye responsible for accommodation. During accommodation, the lens is subject to biomechanical forces. We previously demonstrated that stretching the porcine lens can increase lens epithelial cell proliferation. Although murine lenses are commonly employed in lens research, murine lens stretching has remained unexplored. Murine lens stretching thus represents a novel source of potential discovery in lens research. In the present study, we describe a method for stretching the murine lens by compressing the murine globe embedded in a hydrogel. We hypothesized that, as the eye is compressed along the optic axis, the lens would stretch through zonular tension due to the equatorial region of the eye bulging outward. Our results showed that this led to a compression-dependent increase in murine lens epithelial cell proliferation, suggesting that compression of the embedded murine globe is a viable technique for studying the mechanobiology of the lens epithelium.
Collapse
Affiliation(s)
- Wade Rich
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Manqi Pan
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA
| | - Jun Liu
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA; Department of Ophthalmology and Visual Sciences, The Ohio State University, Columbus, OH, USA
| | - Katelyn E Swindle-Reilly
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA; Department of Ophthalmology and Visual Sciences, The Ohio State University, Columbus, OH, USA; William G. Lowrie Department of Chemical and Biomolecular Engineering, The Ohio State University, Columbus, OH, USA
| | - Matthew A Reilly
- Department of Biomedical Engineering, The Ohio State University, Columbus, OH, USA; Department of Ophthalmology and Visual Sciences, The Ohio State University, Columbus, OH, USA.
| |
Collapse
|
4
|
Wei H, Wolffsohn JS, Gomes de Oliveira O, Davies LN. An Artificial Lens Capsule with a Lens Radial Stretching System Mimicking Dynamic Eye Focusing. Polymers (Basel) 2021; 13:polym13203552. [PMID: 34685312 PMCID: PMC8540979 DOI: 10.3390/polym13203552] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2021] [Revised: 10/08/2021] [Accepted: 10/09/2021] [Indexed: 11/17/2022] Open
Abstract
Presbyopia is a common eye disorder among aged people which is attributed to the loss of accommodation of the crystalline lens due to the increasing stiffness. One of the potential techniques to correct presbyopia involves removing the lens substance inside the capsule and replacing it with an artificial lens. The development of such devices, e.g., accommodating intraocular lenses (AIOLs), relies on the understanding of the biomechanical behaviour of the lens capsule and the essential design verification ex vivo. To mimic the eye’s dynamic focusing ability (accommodation), an artificial lens capsule (ALC), from silicone rubber accompanied by a lens radial stretching system (LRSS) was developed. The ALC was manufactured to offer a dimension and deforming behaviour replicating the human lens capsule. The LRSS was calibrated to provide a radial stretch simulating the change of diameter of capsules during accommodating process. The biomechanical function of the ALC was addressed by studying its evolution behaviour and reaction force under multiaxial stretch from the LRSS. The study highlighted the convenience of this application by performing preliminary tests on prototypes of ophthalmic devices (e.g., AIOLs) to restore accommodation.
Collapse
Affiliation(s)
- Huidong Wei
- College of Health and Life Sciences, Aston University, Birmingham B4 7ET, UK;
- Rayner Intraocular Lenses Limited, Worthing BN14 8AQ, UK;
- Correspondence: (H.W.); (J.S.W.); Tel.: +44-(0)121-204-4140 (J.S.W.)
| | - James S. Wolffsohn
- College of Health and Life Sciences, Aston University, Birmingham B4 7ET, UK;
- Correspondence: (H.W.); (J.S.W.); Tel.: +44-(0)121-204-4140 (J.S.W.)
| | | | - Leon N. Davies
- College of Health and Life Sciences, Aston University, Birmingham B4 7ET, UK;
| |
Collapse
|
5
|
Liu Z, Wang R, Lin H, Liu Y. Lens regeneration in humans: using regenerative potential for tissue repairing. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:1544. [PMID: 33313289 PMCID: PMC7729322 DOI: 10.21037/atm-2019-rcs-03] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The crystalline lens is an important optic element in human eyes. It is transparent and biconvex, refracting light and accommodating to form a clear retinal image. The lens originates from the embryonic ectoderm. The epithelial cells at the lens equator proliferate, elongate and differentiate into highly aligned lens fiber cells, which are the structural basis for maintaining the transparency of the lens. Cataract refers to the opacity of the lens. Currently, the treatment of cataract is to remove the opaque lens and implant an intraocular lens (IOL). This strategy is inappropriate for children younger than 2 years, because a developing eyeball is prone to have severe complications such as inflammatory proliferation and secondary glaucoma. On the other hand, the absence of the crystalline lens greatly affects visual function rehabilitation. The researchers found that mammalian lenses possess regenerative potential. We identified lens stem cells through linear tracking experiments and designed a minimally invasive lens-content removal surgery (MILS) to remove the opaque lens material while preserving the lens capsule, stem cells and microenvironment. In infants with congenital cataract, functional lens regeneration in situ can be observed after MILS, and the prognosis of visual function is better than that of traditional surgery. Because of insufficient regenerative ability in humans, the morphology and volume of the regenerated lens cannot reach the level of a normal lens. The activation, proliferation and differentiation of lens stem cells and the alignment of lens fibers are regulated by epigenetic factors, growth factors, transcription factors, immune system and other signals and their interactions. The construction of appropriate microenvironment can accelerate lens regeneration and improve its morphology. The therapeutic concept of MILS combined with microenvironment manipulation to activate endogenous stem cells for functional regeneration of organs in situ can be extended to other tissues and organs with strong self-renewal and repair ability.
Collapse
Affiliation(s)
- Zhenzhen Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Ruixin Wang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Haotian Lin
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yizhi Liu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| |
Collapse
|
6
|
Kumar B, Chandler HL, Plageman T, Reilly MA. Lens Stretching Modulates Lens Epithelial Cell Proliferation via YAP Regulation. Invest Ophthalmol Vis Sci 2019; 60:3920-3929. [PMID: 31546253 PMCID: PMC7043215 DOI: 10.1167/iovs.19-26893] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2019] [Accepted: 08/13/2019] [Indexed: 01/13/2023] Open
Abstract
Purpose The continuous growth of the lens throughout life may contribute to the onset of age-related conditions in the lens (i.e., presbyopia and cataract). Volumetric growth is the result of continuous proliferation of lens epithelial cells (LECs). The driving factors controlling LEC proliferation are not well understood. This study tested the hypothesis that mechanical stretching modulates LEC proliferation. Methods Biomechanical regulation of LEC proliferation was investigated by culturing whole porcine lenses and connective tissues ex vivo under varying physiologically relevant stretching conditions using a bespoke lens stretching device. Additionally, some lenses were treated with a YAP function inhibitor to determine the Hippo signaling pathway's role in regulating lens growth. Resulting changes in LEC labeling index were analyzed using EdU incorporation and flow cytometry for each lens. Results LEC proliferation was found to be modulated by mechanical strain. Increasing both the magnitude of static stretching and the stretching frequency in cyclic stretching resulted in a proportional increase in the labeling indices of the LECs. Additionally, treatment with the YAP function inhibitor effectively eliminated this relationship. Conclusions These data demonstrate that LEC proliferation is regulated in part, by the mechanotransduction of stresses induced in the lens capsule and that YAP plays an important role in mechanosensing. These results have important implications for understanding lens growth and morphogenesis. The model may also be used to identify and evaluate targets for modulating lens growth.
Collapse
Affiliation(s)
- Bharat Kumar
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, United States
| | - Heather L. Chandler
- College of Optometry, The Ohio State University, Columbus, Ohio, United States
- College of Veterinary Medicine, The Ohio State University, Columbus, Ohio, United States
| | - Timothy Plageman
- College of Optometry, The Ohio State University, Columbus, Ohio, United States
| | - Matthew A. Reilly
- Department of Biomedical Engineering, The Ohio State University, Columbus, Ohio, United States
- Department of Ophthalmology and Visual Science, The Ohio State University, Columbus, Ohio, United States
| |
Collapse
|