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Ghosh A, Bera AK, Singh V, Basu S, Pati F. Bioprinting of anisotropic functional corneal stroma using mechanically robust multi-material bioink based on decellularized cornea matrix. BIOMATERIALS ADVANCES 2024; 165:214007. [PMID: 39216318 DOI: 10.1016/j.bioadv.2024.214007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/27/2024] [Revised: 07/08/2024] [Accepted: 08/23/2024] [Indexed: 09/04/2024]
Abstract
Corneal scarring is a common cause of blindness, affecting millions globally each year. A huge gap between the demand and supply of donor tissue currently limits corneal transplantation, the only definitive therapy for patients with corneal scarring. To overcome this challenge, researchers have harnessed the efficacy of 3D bioprinting to fabricate artificial corneal stromal constructs. With all the different bioinks available, the decellularized corneal matrix-based bioprinted construct can fulfill the required biological functionality but is limited by the lack of mechanical stiffness. Additionally, from a biophysical standpoint, it is necessary for an ideal corneal substitute to mimic the anisotropy of the cornea from the central optic zone to the surrounding periphery. In this study, we enhanced the mechanical robustness of decellularized cornea matrix (DCM) hydrogel by blending it with another natural polymer, sonicated silk fibroin solution in a defined ratio. Although hybrid hydrogel has an increased complex modulus than DCM hydrogel, it has a lower in vitro degradation rate and increased opaqueness due to the presence of crystalline beta-sheet conformation within the hydrogel. Therefore, we used this multi-material bioink-based approach to fabricate a corneal stromal equivalent where the outer peripheral corneal rim was printed with a mechanically robust polymeric blend of DCM and sonicated silk fibroin and the central optic zone was printed with only DCM. The bioprinted corneal stroma thus maintained its structural integrity and did not break when lifted with forceps. The two different bioinks were encapsulated with human limbus-derived mesenchymal stem cells (hLMSC) individually and 3D bioprinted in different patterns (concentric and parallel) to attain a native-like structure in terms of architecture and transparency. Thus, the bilayer cornea constructs maintained high cell viability and expressed keratocyte core proteins indicating optimal functionality. This approach helped to gain insight into bioprinting corneas with heterogeneous mechanical property without disturbing the structural clarity of the central optic zone.
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Affiliation(s)
- Anwesha Ghosh
- Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Kandi, Sangareddy 502284, Telangana, India
| | - Ashis Kumar Bera
- Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Kandi, Sangareddy 502284, Telangana, India
| | - Vivek Singh
- Centre Ocular Regeneration, Prof. Brien Holden Eye Research Centre L.V. Prasad Eye Institute, Hyderabad 500034, Telangana, India
| | - Sayan Basu
- Centre Ocular Regeneration, Prof. Brien Holden Eye Research Centre L.V. Prasad Eye Institute, Hyderabad 500034, Telangana, India
| | - Falguni Pati
- Department of Biomedical Engineering, Indian Institute of Technology Hyderabad, Kandi, Sangareddy 502284, Telangana, India.
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Jiang L, Dai C, Wei Y, Zhao B, Li Q, Wu Z, Zou L, Ye Z, Yang Z, Huang L, Shi Y. Identification of LRRC46 as a novel candidate gene for high myopia. SCIENCE CHINA. LIFE SCIENCES 2024; 67:1941-1956. [PMID: 38874710 DOI: 10.1007/s11427-024-2583-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/26/2024] [Accepted: 03/19/2024] [Indexed: 06/15/2024]
Abstract
High myopia (HM) is the primary cause of blindness, with the microstructural organization and composition of collagenous fibers in the cornea and sclera playing a crucial role in the biomechanical behavior of these tissues. In a previously reported myopic linkage region, MYP5 (17q21-22), a potential candidate gene, LRRC46 (c.C235T, p.Q79X), was identified in a large Han Chinese pedigree. LRRC46 is expressed in various eye tissues in humans and mice, including the retina, cornea, and sclera. In subsequent cell experiments, the mutation (c.C235T) decreased the expression of LRRC46 protein in human corneal epithelial cells (HCE-T). Further investigation revealed that Lrrc46-/- mice (KO) exhibited a classical myopia phenotype. The thickness of the cornea and sclera in KO mice became thinner and more pronounced with age, the activity of limbal stem cells decreased, and microstructural changes were observed in the fibroblasts of the sclera and cornea. We performed RNA-seq on scleral and corneal tissues of KO and normal control wild-type (WT) mice, which indicated a significant downregulation of the collagen synthesis-related pathway (extracellular matrix, ECM) in KO mice. Subsequent in vitro studies further indicated that LRRC46, a member of the important LRR protein family, primarily affected the formation of collagens. This study suggested that LRRC46 is a novel candidate gene for HM, influencing collagen protein VIII (Col8a1) formation in the eye and gradually altering the biomechanical structure of the cornea and sclera, thereby promoting the occurrence and development of HM.
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Affiliation(s)
- Lingxi Jiang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Chao Dai
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Yao Wei
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Bo Zhao
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
- Department of Ophthalmology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Qi Li
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Zhengzheng Wu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
- Department of Ophthalmology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
| | - Liang Zou
- School of Food and Bioengineering, Chengdu University, Chengdu, 610106, China
| | - Zimeng Ye
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China
- School of Medicine, University of Sydney, Sydney, 2050, Australia
| | - Zhenglin Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China.
- Department of Ophthalmology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China.
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, China.
- Jinfeng Laboratory, Chongging, 40000, China.
| | - Lulin Huang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China.
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, China.
| | - Yi Shi
- Sichuan Provincial Key Laboratory for Human Disease Gene Study and the Center for Medical Genetics, Department of Laboratory Medicine, Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China.
- Department of Ophthalmology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, 610072, China.
- Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences & Sichuan Provincial People's Hospital, Chengdu, 610072, China.
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Liu MX, Zhu KY, Li DL, Dong XX, Liang G, Grzybowski A, Pan CW. Corneal Biomechanical Characteristics in Myopes and Emmetropes Measured by Corvis ST: A Meta-Analysis. Am J Ophthalmol 2024; 264:154-161. [PMID: 38556185 DOI: 10.1016/j.ajo.2024.03.024] [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: 09/28/2023] [Revised: 02/17/2024] [Accepted: 03/25/2024] [Indexed: 04/02/2024]
Abstract
PURPOSE To comprehensively identify the corneal biomechanical differences measured by Corvis ST between different degrees of myopia and emmetropia. DESIGN Systematic review and meta-analysis. METHODS Electronic databases, including PubMed, Embase, and Web of Science, were systematically searched for studies comparing the corneal biomechanics among various degrees of myopes and emmetropes using Corvis ST. The weighted mean differences and 95% confidence intervals were calculated. Meta-analysis was performed in high and nonhigh myopes and in myopes and emmetropes, respectively. RESULTS Eleven studies were included in this study. The meta-analysis among myopes and emmetropes included 1947 myopes and 621 emmetropes, and 443 high myopes and 449 nonhigh myopes were included in the meta-analysis among high and nonhigh myopia. Myopes showed the cornea with significantly longer time at the first applanation (A1t) and lower length at the second applanation (A2L) than emmetropes. High myopes showed significantly greater A1t, velocity at the second applanation (A2v), deformation amplitude at the highest concavity (HC-DA), and peak distance at the highest concavity (HC-PD) and decreased time at the second applanation (A2t) and radius of the highest concavity (HC-R). CONCLUSIONS Corneal biomechanics is different in myopia, especially in high myopia. Compared with nonhigh myopes, the corneas of high myopes deformed slower during the first applanation, faster during the second applanation, and showed greater deformation amplitude, indicating greater elasticity and viscidity.
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Affiliation(s)
- Min-Xin Liu
- School of Public Health (M.X.L., D.L.L., X.X.D., C.W.P.), Suzhou Medical College of Soochow University, Suzhou, China
| | - Ke-Yao Zhu
- Pasteurien College of Soochow University (K.Y.Z.), Suzhou, China
| | - Dan-Lin Li
- School of Public Health (M.X.L., D.L.L., X.X.D., C.W.P.), Suzhou Medical College of Soochow University, Suzhou, China
| | - Xing-Xuan Dong
- School of Public Health (M.X.L., D.L.L., X.X.D., C.W.P.), Suzhou Medical College of Soochow University, Suzhou, China
| | - Gang Liang
- Department of Ophthalmology (G.L.), The Affiliated Hospital of Yunnan University, Kunming, China
| | - Andrzej Grzybowski
- Institute for Research in Ophthalmology (A.G.), Foundation for Ophthalmology Development, Poznan, Poland
| | - Chen-Wei Pan
- School of Public Health (M.X.L., D.L.L., X.X.D., C.W.P.), Suzhou Medical College of Soochow University, Suzhou, China.
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Zhou C, Zhou Z, Feng X, Zou D, Zhou Y, Zhang B, Chen J, Wang F, Liao D, Li J, Jin Z, Ren Q. The retinal oxygen metabolism and hemodynamics as a substitute for biochemical tests to predict nonproliferative diabetic retinopathy. JOURNAL OF BIOPHOTONICS 2024; 17:e202300567. [PMID: 38527858 DOI: 10.1002/jbio.202300567] [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: 12/30/2023] [Revised: 02/19/2024] [Accepted: 03/17/2024] [Indexed: 03/27/2024]
Abstract
Predicting the occurrence of nonproliferative diabetic retinopathy (NPDR) using biochemical parameters is invasive, which limits large-scale clinical application. Noninvasive retinal oxygen metabolism and hemodynamics of 215 eyes from 73 age-matched healthy subjects, 90 diabetic patients without DR, 40 NPDR, and 12 DR with postpanretinal photocoagulation were measured with a custom-built multimodal retinal imaging device. Diabetic patients underwent biochemical examinations. Two logistic regression models were developed to predict NPDR using retinal and biochemical metrics, respectively. The predictive model 1 using retinal metrics incorporated male gender, insulin treatment condition, diastolic duration, resistance index, and oxygen extraction fraction presented a similar predictive power with model 2 using biochemical metrics incorporated diabetic duration, diastolic blood pressure, and glycated hemoglobin A1c (area under curve: 0.73 vs. 0.70; sensitivity: 76% vs. 68%; specificity: 64% vs. 62%). These results suggest that retinal oxygen metabolic and hemodynamic biomarkers may replace biochemical parameters to predict the occurrence of NPDR .
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Affiliation(s)
- Chuanqing Zhou
- College of Medical Instruments, Shanghai University of Medicine and Health Sciences, Shanghai, China
| | - Zixia Zhou
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Ximeng Feng
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
| | - Da Zou
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
| | - Yilin Zhou
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, USA
| | - Bin Zhang
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Jiabao Chen
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Fei Wang
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Dingying Liao
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Jinying Li
- Department of Ophthalmology, Peking University Shenzhen Hospital, Shenzhen, China
| | - Zi Jin
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Qiushi Ren
- Institute of Biomedical Engineering, Peking University Shenzhen Graduate School, Shenzhen, China
- Institute of Biomedical Engineering, Shenzhen Bay Laboratory, Shenzhen, China
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing, China
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Sanyal S, Ravula V. Mitigation of pesticide-mediated ocular toxicity via nanotechnology-based contact lenses: a review. ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH INTERNATIONAL 2024; 31:46602-46624. [PMID: 37542697 DOI: 10.1007/s11356-023-28904-z] [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: 03/05/2023] [Accepted: 07/17/2023] [Indexed: 08/07/2023]
Abstract
The xenobiotic stress exerted by pesticides leads to the deterioration of human and animal health including ocular health. Acute or prolonged exposure to these agricultural toxicants has been implicated in a number of pathological conditions of the eye such as irritation, epiphora or hyper-lacrimation, abrasions on the ocular surface, and decreased visual acuity. The issue is compounded by the fact that tissues of the eye absorb pesticides faster than other organs of the body and are more susceptible to damage as well. However, there is a lacuna in our knowledge regarding the ways by which pesticide exposure-mediated ocular insult might be counteracted. Topical instillation of drugs known to combat the pesticide induced toxicity has been explored to mitigate the detrimental impact of pesticide exposure. However, topical eye drop solutions exhibit very low bioavailability and limited drug residence duration in the tear film decreasing their efficacy. Contact lenses have been explored in this respect to increase bioavailability of ocular drugs, while nanoparticles have lately been utilized to increase drug bioavailability and increase drug residence duration in different tissues. The current review focuses on drug delivery and futuristic aspects of corneal protection from ocular toxicity using contact lenses.
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Affiliation(s)
- Shalini Sanyal
- Laboratory of Self Assembled Biomaterials and Translational Science, Institute for Stem Cell Science and Regenerative Medicine (DBT-inStem), GKVK Post, Bellary Road, Bengaluru, 560065, Karnataka, India.
| | - Venkatesh Ravula
- Laboratory of Self Assembled Biomaterials and Translational Science, Institute for Stem Cell Science and Regenerative Medicine (DBT-inStem), GKVK Post, Bellary Road, Bengaluru, 560065, Karnataka, India
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Hashemi A, Nabovati P, Hashemi H, Mortazavi AG, Khabazkhoob M. Corneal densitometry and associated factors in an elderly population. Clin Exp Optom 2024; 107:522-529. [PMID: 37674266 DOI: 10.1080/08164622.2023.2242864] [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] [Received: 04/15/2023] [Accepted: 07/26/2023] [Indexed: 09/08/2023] Open
Abstract
CLINICAL RELEVANCE Knowing normative corneal optical density (COD) values is important for identifying pathologic corneal changes. BACKGROUND The aim of this work is to determine the distribution and associated factors of COD in the elderly population. METHODS This report is a part of a cross-sectional population-based study conducted on the elderly population (≥60 years) of Tehran, Iran from Jan 2019 to Jan 2020. Using a multi-stage stratified random cluster sampling method, a total of 160 clusters were randomly selected from 22 districts of Tehran city. Study participants underwent a complete ocular examination including measurement of visual acuity, refraction, and slit-lamp biomicroscopy. Corneal densitometry was evaluated using the Pentacam HR. Generalized estimating equation (GEE) models were used to investigate associations of COD with study variables. RESULTS A total of 3633 eyes from 2068 individuals were analysed. Of these, 1256 (60.7%) were female, and the mean age of the individuals was 66.42 ± 5.28 (60 to 95) years. The mean entire COD was 21.96 ± 4.45 greyscale unit (GSU) (95% CI: 21.57-22.34). There was a statistically significant difference in the mean COD between the anterior, central, and posterior layers (p < 0.001); the highest and lowest average COD was related to the anterior and posterior corneal layers, respectively. The lowest and highest mean COD were observed in the 0-2 mm [17.21GSU (95% CI:16.87-17.55)], and 10-12 mm annular zones [31.4 GSU (95% CI: 30.89-31.91)], respectively (p < 0.001). According to the multiple GEE model, the COD had a statistically significant direct relationship with age, central corneal thickness, and mean keratometry, while it was significantly inversely associated with female sex, anterior chamber depth, white-to-white distance, and corneal volume. CONCLUSION These normal values of COD in the present study could be used as reference data in older adults. The associated factors of COD should be taken into account to avoid misinterpretation of physiologic changes as pathologic processes.
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Affiliation(s)
- Alireza Hashemi
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
| | - Payam Nabovati
- Rehabilitation Research Center, Department of Optometry, Iran University of Medical Sciences, Tehran, Iran
| | - Hassan Hashemi
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Abol Ghasem Mortazavi
- Department of Neurosurgery, Sina Hospital, Tehran University of Medical Sciences, Tehran, Iran
| | - Mehdi Khabazkhoob
- Department of Basic Sciences, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran
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Wu W, Wang Y, Chen J, Zhang F. The biomechanical proteins different between low myopic corneas and moderate to high myopic corneas in human. Cont Lens Anterior Eye 2024; 47:102134. [PMID: 38472014 DOI: 10.1016/j.clae.2024.102134] [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] [Received: 03/11/2023] [Revised: 02/20/2024] [Accepted: 03/01/2024] [Indexed: 03/14/2024]
Abstract
PURPOSE To explore the biomechanical proteins different between low myopic corneas and moderate to high myopic corneas. METHODS A total of 27 myopic corneas were used for the Tandem Mass Tag (TMT) proteomics analysis. Differentially expressed proteins (DEPs) were clustered with fold changes > 1.20 or < 0.83 and p < 0.05. Proteins and Proteins Interactions (PPIs) were conducted to find hub proteins; Uniprot database was to screen proteins with biomechanical functions, and Parallel Reaction Monitoring (PRM) was performed to verify the TMT results. Pearson analysis was used to reveal the correlations between myopic degrees and biomechanical proteins. The Immunofluorescence (IF) staining was used to observe the protein distributions. RESULTS In total, 34 DEPs were observed between moderate myopic corneas and low myopic corneas; 103 DEPs were observed between high myopic corneas and low myopic corneas, 20 proteins overlapped. The PPIs analysis showed keratin 2, keratins 10 and PRSS1 were hub proteins. The Uniprot function analysis suggested keratin 2 and keratin 10 exhibited biomechanical functions. The PRM demonstrated keratin 2 and keratin 10 levels were significantly lower in moderate and high myopic corneas, which was consistent with the TMT proteomics results. IF staining also demonstrated keratin 2 and keratin 10 were less distributed in moderate and high myopic corneas than in low myopic corneas. CONCLUSIONS The levels of biomechanical proteins keratin 2 and keratin 10 are significantly lower in moderate and high myopic corneas than in low myopic corneas.
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Affiliation(s)
- Wenjing Wu
- Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University, Beijing, China, No. 1, Dongjiaomin Lane, Dongcheng District, Beijing 100730, China
| | - Yan Wang
- Tianjin Eye Hospital, Tianjin Ophthalmology and Visual Science Key Laboratory, Nankai University Eye Hospital, Nankai University Eye Institute, Tianjin, China, No 4. Gansu Rd, Heping District, Tianjin 300020, China
| | - Jingyi Chen
- Tianjin Eye Hospital, Tianjin Ophthalmology and Visual Science Key Laboratory, Nankai University Eye Hospital, Nankai University Eye Institute, Tianjin, China, No 4. Gansu Rd, Heping District, Tianjin 300020, China
| | - Fengju Zhang
- Beijing Tongren Eye Center, Beijing Tongren Hospital of Capital Medical University, Beijing, China, No. 1, Dongjiaomin Lane, Dongcheng District, Beijing 100730, China.
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Liu MX, Li DL, Yin ZJ, Li YZ, Zheng YJ, Qin Y, Ma R, Liang G, Pan CW. Corneal stress‒strain index in relation to retinal nerve fibre layer thickness among healthy young adults. Eye (Lond) 2024; 38:1654-1659. [PMID: 38402288 PMCID: PMC11156841 DOI: 10.1038/s41433-024-02985-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2023] [Revised: 01/19/2024] [Accepted: 02/05/2024] [Indexed: 02/26/2024] Open
Abstract
BACKGROUND/OBJECTIVES To determine the relationship between corneal stress-strain index (SSI) and retinal nerve fibre layer (RNFL) thickness. SUBJECTS/METHODS 1645 healthy university students from a university-based study contributed to the analysis. The RNFL thickness was measured by high-definition optical coherence tomography (HD-OCT), axial length (AL) was measured by IOL Master, and corneal biomechanics including SSI, biomechanical corrected intraocular pressure (bIOP), and central corneal thickness (CCT) were measured by Corvis ST. Multivariate linear regression was performed to evaluate the relationship between the SSI and RNFL thickness after adjusting for potential covariates. RESULTS The mean age of the participants was 19.0 ± 0.9 years, and 1132 (68.8%) were women. Lower SSI was significantly associated with thinner RNFL thickness ( β =8.601, 95% confidence interval [CI] 2.999-14.203, P = 0.003) after adjusting for age, CCT, bIOP, and AL. No significant association between SSI and RNFL was found in men, while the association was significant in women in the fully adjusted model. The association was significant in the nonhigh myopic group ( P for trend = 0.021) but not in the highly myopic group. Eyes with greater bIOP and lower SSI had significantly thinner RNFL thickness. CONCLUSIONS Eyes with lower SSI had thinner RNFL thickness after adjusting for potential covariates, especially those with higher bIOP. Our findings add novel evidence of the relationship between corneal biomechanics and retinal ganglion cell damage.
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Affiliation(s)
- Min-Xin Liu
- School of Public Health, Suzhou Medical College of Soochow University, Suzhou, China
| | - Dan-Lin Li
- School of Public Health, Suzhou Medical College of Soochow University, Suzhou, China
| | - Zhi-Jian Yin
- Department of Ophthalmology, the First Affiliated Hospital of Dali University, Dali, China
| | - Yue-Zu Li
- Department of Ophthalmology, the Affiliated Hospital of Yunnan University, Kunming, China
- Department of Ophthalmology, the Second People's Hospital of Yunnan Province, Kunming, China
| | - Ya-Jie Zheng
- Department of Ophthalmology, the Affiliated Hospital of Yunnan University, Kunming, China
- Department of Ophthalmology, the Second People's Hospital of Yunnan Province, Kunming, China
| | - Yu Qin
- Department of Ophthalmology, the Affiliated Hospital of Yunnan University, Kunming, China
- Department of Ophthalmology, the Second People's Hospital of Yunnan Province, Kunming, China
| | - Rong Ma
- Department of Ophthalmology, the Affiliated Hospital of Yunnan University, Kunming, China
- Department of Ophthalmology, the Second People's Hospital of Yunnan Province, Kunming, China
| | - Gang Liang
- Department of Ophthalmology, the Affiliated Hospital of Yunnan University, Kunming, China.
- Department of Ophthalmology, the Second People's Hospital of Yunnan Province, Kunming, China.
| | - Chen-Wei Pan
- School of Public Health, Suzhou Medical College of Soochow University, Suzhou, China.
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Wang Q, Chen Y, Shen K, Zhou X, Shen M, Lu F, Zhu D. Spatial mapping of corneal biomechanical properties using wave-based optical coherence elastography. JOURNAL OF BIOPHOTONICS 2024; 17:e202300534. [PMID: 38453148 DOI: 10.1002/jbio.202300534] [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: 12/12/2023] [Revised: 01/20/2024] [Accepted: 02/11/2024] [Indexed: 03/09/2024]
Abstract
Quantifying the mechanical properties of the cornea can provide valuable insights into the occurrence and progression of keratoconus, as well as the effectiveness of corneal crosslinking surgery. This study presents a non-contact and non-invasive wave-based optical coherence elastography system that utilizes air-pulse stimulation to create a two-dimensional map of corneal elasticity. Homogeneous and dual concentration phantoms were measured with the sampling of 25 × 25 points over a 6.6 × 6.6 mm2 area, to verify the measurement capability for elastic mapping and the spatial resolution (0.91 mm). The velocity of elastic waves distribution of porcine corneas before and after corneal crosslinking surgery were further mapped, showing a significant change in biomechanics in crosslinked region. This system features non-invasiveness and high resolution, holding great potential for application in ophthalmic clinics.
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Affiliation(s)
- Qingying Wang
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Yulei Chen
- Department of Ophthalmology, Dongguan Tungwah Hospital, Dongguan, China
| | - Kexin Shen
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Xingyu Zhou
- Eye Hospital and School of Ophthalmology and Optometry, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Meixiao Shen
- National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Fan Lu
- State Key Laboratory of Ophthalmology, Optometry and Visual Science, Eye Hospital, Wenzhou Medical University, Wenzhou, China
- National Clinical Research Center for Ocular Diseases, Eye Hospital, Wenzhou Medical University, Wenzhou, China
| | - Dexi Zhu
- National Engineering Research Center of Ophthalmology and Optometry, Eye Hospital, Wenzhou Medical University, Wenzhou, China
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10
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Li GY, Feng X, Yun SH. In Vivo Optical Coherence Elastography Unveils Spatial Variation of Human Corneal Stiffness. IEEE Trans Biomed Eng 2024; 71:1418-1429. [PMID: 38032780 PMCID: PMC11086014 DOI: 10.1109/tbme.2023.3338086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/02/2023]
Abstract
OBJECTIVE The mechanical properties of corneal tissues play a crucial role in determining corneal shape and have significant implications in vision care. This study aimed to address the challenge of obtaining accurate in vivo data for the human cornea. METHODS We have developed a high-frequency optical coherence elastography (OCE) technique using shear-like antisymmetric (A0)-mode Lamb waves at frequencies above 10 kHz. RESULTS By incorporating an anisotropic, nonlinear constitutive model and utilizing the acoustoelastic theory, we gained quantitative insights into the influence of corneal tension on wave speeds and elastic moduli. Our study revealed significant spatial variations in the shear modulus of the corneal stroma on healthy subjects for the first time. Over an age span from 21 to 34 (N = 6), the central corneas exhibited a mean shear modulus of 87 kPa, while the corneal periphery showed a significant decrease to 44 kPa. The central cornea's shear modulus decreases with age with a slope of -19 +/- 8 kPa per decade, whereas the periphery showed non-significant age dependence. The limbus demonstrated an increased shear modulus exceeding 100 kPa. We obtained wave displacement profiles that are consistent with highly anisotropic corneal tissues. CONCLUSION Our approach enabled precise measurement of corneal tissue elastic moduli in situ with high precision (<7%) and high spatial resolution (<1 mm). Our results revealed significant stiffness variation from the central to peripheral corneas. SIGNIFICANCE The high-frequency OCE technique holds promise for biomechanical evaluation in clinical settings, providing valuable information for refractive surgeries, degenerative disorder diagnoses, and intraocular pressure assessments.
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11
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Kim GS, Moon HH, Lee HS, Jeong JS. Compound Acoustic Radiation Force Impulse Imaging of Bovine Eye by Using Phase-Inverted Ultrasound Transducer. SENSORS (BASEL, SWITZERLAND) 2024; 24:2700. [PMID: 38732804 PMCID: PMC11085659 DOI: 10.3390/s24092700] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Revised: 04/19/2024] [Accepted: 04/22/2024] [Indexed: 05/13/2024]
Abstract
In general, it is difficult to visualize internal ocular structure and detect a lesion such as a cataract or glaucoma using the current ultrasound brightness-mode (B-mode) imaging. This is because the internal structure of the eye is rich in moisture, resulting in a lack of contrast between tissues in the B-mode image, and the penetration depth is low due to the attenuation of the ultrasound wave. In this study, the entire internal ocular structure of a bovine eye was visualized in an ex vivo environment using the compound acoustic radiation force impulse (CARFI) imaging scheme based on the phase-inverted ultrasound transducer (PIUT). In the proposed method, the aperture of the PIUT is divided into four sections, and the PIUT is driven by the out-of-phase input signal capable of generating split-focusing at the same time. Subsequently, the compound imaging technique was employed to increase signal-to-noise ratio (SNR) and to reduce displacement error. The experimental results demonstrated that the proposed technique could provide an acoustic radiation force impulse (ARFI) image of the bovine eye with a broader depth-of-field (DOF) and about 80% increased SNR compared to the conventional ARFI image obtained using the in-phase input signal. Therefore, the proposed technique can be one of the useful techniques capable of providing the image of the entire ocular structure to diagnose various eye diseases.
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Affiliation(s)
| | | | | | - Jong Seob Jeong
- Department of Biomedical Engineering, Dongguk University, Seoul 04620, Republic of Korea; (G.S.K.); (H.H.M.); (H.S.L.)
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12
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Huo Y, Chen X, Khan GA, Wang Y. Corneal biomechanics in early diagnosis of keratoconus using artificial intelligence. Graefes Arch Clin Exp Ophthalmol 2024; 262:1337-1349. [PMID: 37943332 DOI: 10.1007/s00417-023-06307-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 10/18/2023] [Accepted: 10/23/2023] [Indexed: 11/10/2023] Open
Abstract
Keratoconus is a blinding eye disease that affects activities of daily living; therefore, early diagnosis is crucial. Great efforts have been made toward an early diagnosis of keratoconus. Recent studies have shown that corneal biomechanics is associated with the occurrence and progression of keratoconus. Hence, detecting changes in corneal biomechanics may provide a novel strategy for early diagnosis. However, an early keratoconus diagnosis remains challenging due to the subtle and localized nature of its lesions. Artificial intelligence has been used to help address this problem. Herein, we reviewed the literature regarding three aspects of keratoconus (keratoconus, early keratoconus, and keratoconus grading) based on corneal biomechanical properties using artificial intelligence. Furthermore, we summarized the current research progress, limitations, and possible prospects.
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Affiliation(s)
- Yan Huo
- School of Medicine, Nankai University, Tianjin, China
| | - Xuan Chen
- School of Medicine, Nankai University, Tianjin, China
| | - Gauhar Ali Khan
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Yan Wang
- School of Medicine, Nankai University, Tianjin, China.
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Nankai University Affiliated Eye Hospital, 4 Gansu Road, He-ping District, Tianjin, 300020, China.
- Nankai Eye Institute, Nankai University, Tianjin, China.
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13
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Li GY, Feng X, Yun SH. Simultaneous tensile and shear measurement of the human cornea in vivo using S0- and A0-wave optical coherence elastography. Acta Biomater 2024; 175:114-122. [PMID: 38101555 PMCID: PMC10872441 DOI: 10.1016/j.actbio.2023.12.019] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2023] [Revised: 11/09/2023] [Accepted: 12/08/2023] [Indexed: 12/17/2023]
Abstract
Understanding corneal stiffness is valuable for improving refractive surgery, detecting corneal abnormalities, and assessing intraocular pressure. However, accurately measuring the elastic properties, specifically the tensile and shear moduli that govern mechanical deformation, has been challenging. To tackle this issue, we have developed guided-wave optical coherence elastography that can simultaneously excite and analyze symmetric (S0) and anti-symmetric (A0) elastic waves in the cornea at around 10 kHz frequencies, enabling us to extract tensile and shear properties from measured wave dispersion curves. We verified the technique using elastomer phantoms and ex vivo porcine corneas and investigated the dependence on intraocular pressure using acoustoelastic theory that incorporates corneal tension and a nonlinear constitutive tissue model. In a pilot study involving six healthy human subjects aged 31 to 62, we measured shear moduli (Gzx) of 94±20 kPa (mean±standard deviation) and tensile moduli (Exx) of 4.0±1.1 MPa at central corneas. Our preliminary analysis of age-dependence revealed contrasting trends: -8.3±4.5 kPa/decade for shear and 0.30±0.21 MPa/decade for tensile modulus. This OCE technique has the potential to become a highly useful clinical tool for the quantitative biomechanical assessment of the cornea. STATEMENT OF SIGNIFICANCE: This article reports an innovative elastography technique using two guided elastic waves, demonstrating the measurement of both tensile and shear moduli in human cornea in vivo with unprecedented precision. This technique paves the way for comprehensive investigations into corneal mechanics and holds clinical significance in various aspects of corneal health and disease management.
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Affiliation(s)
- Guo-Yang Li
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, MA 02114, USA
| | - Xu Feng
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, MA 02114, USA
| | - Seok-Hyun Yun
- Harvard Medical School and Wellman Center for Photomedicine, Massachusetts General Hospital, 50 Blossom St., Boston, MA 02114, USA; Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA 02139, USA.
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14
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Aydamirov AS, Emekli DT, Ismayilov AS. Evaluation of the effects of strabismus surgery on corneal backward light scattering. Photodiagnosis Photodyn Ther 2023; 44:103771. [PMID: 37640202 DOI: 10.1016/j.pdpdt.2023.103771] [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] [Received: 06/23/2023] [Revised: 08/10/2023] [Accepted: 08/25/2023] [Indexed: 08/31/2023]
Abstract
BACKGROUND Investigation of the effects of conventional strabismus surgeries on corneal densitometry (CD). METHODS Patients who had strabismus surgery between May 2022 and July 2022 were included in the study. CD software with a Pentacam device was used to determine corneal backward light scattering. CD data were analysed preoperatively and 1 month postoperatively. Patients were classified as those who had single muscle and two-muscle surgery. RESULTS The study included 33 eyes of 28 patients. The mean age of the patients was 20.51 ± 8.22 (5-35) years. Of the eyes, 19 underwent single muscle recession surgery. Two-muscle surgeries (recession and resection combination) were performed in 14 eyes. In the 1st month postoperative, the mean CD value decreased statistically significantly only in the total cornea apical 0-2 mm zone among the layers examined (p = 0.039). There was no significant change in the other layers (p > 0.05 for all). Single-muscle and two-muscle surgery groups were similar in the amount of CD reduction, except for one layer. CONCLUSIONS CD did not change in most of the corneal layers examined in the first month postoperatively. Single muscle and two-muscle horizontal rectus surgeries did not impair corneal clarity in the postoperative 1st month.
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Affiliation(s)
| | - Duygu Topaktaş Emekli
- Department of Ophthalmology, Adana City Training and Research Hospital, Adana, Turkey
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15
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Zhou H, Zhang S, Lei M, Cai Y, Wang H, Sun J, Cui J, Liu C, Qu X. A suture-free, shape self-adaptive and bioactive PEG-Lysozyme implant for Corneal stroma defect repair and rapid vision restoration. Bioact Mater 2023; 29:1-15. [PMID: 37456580 PMCID: PMC10338238 DOI: 10.1016/j.bioactmat.2023.05.008] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2023] [Revised: 04/20/2023] [Accepted: 05/09/2023] [Indexed: 07/18/2023] Open
Abstract
Corneal transplantation is a prevailing treatment to repair injured cornea and restore vision but faces the limitation of donor tissue shortage clinically. In addition, suturing-needed transplantation potentially causes postoperative complications. Herein, we design a PEG-Lysozyme injective hydrogel as a suture-free, shape self-adaptive, bioactive implant for corneal stroma defect repair. This implant experiences a sol-gel phase transition via an in situ amidation reaction between 4-arm-PEG-NHS and lysozyme. The physicochemical properties of PEG-Lysozyme can be tuned by the components ratio, which confers the implant mimetic corneal modulus and provides tissue adhesion to endure increased intraocular pressure. In vitro tests prove that the implant is beneficial to Human corneal epithelial cells growth and migration due to the bioactivity of lysozyme. Rabbit lamellar keratoplasty experiment demonstrates that the hydrogel can be filled into defect to form a shape-adaptive implant adhered to native stroma. The implant promotes epithelialization and stroma integrity, recovering the topology of injured cornea to normal. A newly established animal forging behavior test prove a rapid visual restoration of rabbits when use implant in a suture free manner. In general, this work provides a promising preclinical practice by applicating a self-curing, shape self-adaptive and bioactive PEG-Lysozyme implant for suture-free stroma repair.
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Affiliation(s)
- Hang Zhou
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Material Science and Engineering, Frontiers Science Center for Materiobiology and Dynamic Chemistry, East China University of Science and Technology, Shanghai, 200237, China
| | - Shaohua Zhang
- Eye Institute and Department of Ophthalmology, NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai Key Laboratory of Visual Impairment and Restoration, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China
| | - Miao Lei
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Material Science and Engineering, Frontiers Science Center for Materiobiology and Dynamic Chemistry, East China University of Science and Technology, Shanghai, 200237, China
| | - Yixin Cai
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Material Science and Engineering, Frontiers Science Center for Materiobiology and Dynamic Chemistry, East China University of Science and Technology, Shanghai, 200237, China
| | - Honglei Wang
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Material Science and Engineering, Frontiers Science Center for Materiobiology and Dynamic Chemistry, East China University of Science and Technology, Shanghai, 200237, China
| | - Jianguo Sun
- Eye Institute and Department of Ophthalmology, NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai Key Laboratory of Visual Impairment and Restoration, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China
| | - Jingyuan Cui
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Material Science and Engineering, Frontiers Science Center for Materiobiology and Dynamic Chemistry, East China University of Science and Technology, Shanghai, 200237, China
- Wenzhou Institute of Shanghai University, Wenzhou, 325000, China
| | - Changsheng Liu
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Material Science and Engineering, Frontiers Science Center for Materiobiology and Dynamic Chemistry, East China University of Science and Technology, Shanghai, 200237, China
| | - Xue Qu
- Key Laboratory for Ultrafine Materials of Ministry of Education, School of Material Science and Engineering, Frontiers Science Center for Materiobiology and Dynamic Chemistry, East China University of Science and Technology, Shanghai, 200237, China
- Wenzhou Institute of Shanghai University, Wenzhou, 325000, China
- Shanghai Frontier Science Center of Optogenetic Techniques for Cell Metabolism, Shanghai, 200237, China
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16
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Zhang Y, Zhang XJ, Yuan N, Wang YM, Ip P, Chen LJ, Tham CC, Pang CP, Yam JC. Secondhand smoke exposure and ocular health: A systematic review. Surv Ophthalmol 2023; 68:1166-1207. [PMID: 37479063 DOI: 10.1016/j.survophthal.2023.07.001] [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] [Received: 01/18/2023] [Revised: 07/04/2023] [Accepted: 07/10/2023] [Indexed: 07/23/2023]
Abstract
The toxicology of secondhand smoke (SHS), along with the harm of its exposure to human health, has been generally acknowledged; however, specific evidence is lacking on the association between SHS exposure and ocular health. In this systematic review (PROSPERO registration number: CRD42022247992), we included 55 original articles published by 12 May 2023, which dealt with SHS exposure and ocular disorders, such as eye irritation, conjunctivitis, dry eye diseases, uveitis, myopia, astigmatism, contact lens discomfort, age-related macular degeneration, glaucoma, and thyroid eye disease that addressed the ocular neurovascular structures of the macular, retinal nerve fiber layer, choroid, and corneal biomechanical parameters. We found compelling correlational evidence for eye irritation, conjunctivitis, and dry eye symptoms-supporting that SHS exposure was positively associated with inflammatory and allergic changes in the eyes. Yet, evidence about the associations between SHS exposure and other ocular disorders, structures, and parameters is still limited or controversial. Given the limitations of existing literature, more investigations with high quality and rigorous design are warranted to elucidate the potentially harmful effects of SHS exposure on ocular health.
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Affiliation(s)
- Youjuan Zhang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China; The Nethersole School of Nursing, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Xiu Juan Zhang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China; Joint Shantou International Eye Center, Shantou University, Shantou, China
| | - Nan Yuan
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China; Kunming Bright Eye Hospital, Kunming, China
| | - Yu Meng Wang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China; Department of Neurobiology, Interdisciplinary Center for Neurosciences (IZN), Heidelberg University, Heidelberg, Germany
| | - Patrick Ip
- Department of Paediatrics and Adolescent Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Li Jia Chen
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China; Joint Shantou International Eye Center, Shantou University, Shantou, China; Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong SAR, China; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Clement C Tham
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China; Joint Shantou International Eye Center, Shantou University, Shantou, China; Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong SAR, China; Hong Kong Eye Hospital, Hong Kong SAR, China; Department of Ophthalmology, Hong Kong Children's Hospital, Hong Kong SAR, China; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Chi Pui Pang
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China; Joint Shantou International Eye Center, Shantou University, Shantou, China; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Jason C Yam
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong SAR, China; Joint Shantou International Eye Center, Shantou University, Shantou, China; Department of Ophthalmology and Visual Sciences, Prince of Wales Hospital, Hong Kong SAR, China; Hong Kong Eye Hospital, Hong Kong SAR, China; Department of Ophthalmology, Hong Kong Children's Hospital, Hong Kong SAR, China; Hong Kong Hub of Paediatric Excellence, The Chinese University of Hong Kong, Hong Kong SAR, China.
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17
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Liu MX, Li DL, Yin ZJ, Li YZ, Zheng YJ, Qin Y, Liang G, Pan CW. Smoking, alcohol consumption and corneal biomechanical parameters among Chinese university students. Eye (Lond) 2023; 37:2723-2729. [PMID: 36697900 PMCID: PMC10482929 DOI: 10.1038/s41433-023-02405-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 11/28/2022] [Accepted: 01/16/2023] [Indexed: 01/26/2023] Open
Abstract
BACKGROUND/OBJECTIVES Smoking and alcohol consumption are important risk factors for several ocular disorders, but their effects on corneal biomechanics remain unclear. Our study aims to explore the association between smoking and alcohol consumption with corneal biomechanical parameters measured by Corvis-ST (CST) among university students. SUBJECTS/METHODS A total of 1645 healthy university students from a university-based study were included, and all participants underwent corneal biomechanical parameters measurement by CST. We selected 10 reliable parameters that can reflect the corneal deformation response. All participants had a standardised interview to determine their smoking and alcohol consumption status. RESULTS The mean age of the participants was 19.0 ± 0.9 years, and 1132 (68.8%) were women. Smoking was significantly associated with stiffer corneas. Smokers showed significantly slower second applanation velocity (A2v) (β = 0.007 m/s, 95% confidence interval 0.001 to 0.014, P = 0.032) and lower integrated radius (IR) (β = -0.214 mm-1, 95% confidence interval -0.420 to -0.007, P = 0.043) than non-smokers after adjusting for age, gender, eye-rubbing, myopia, and body mass index (BMI). Smokers with BMI no less than 24.0 showed slower A2v and lower IR. Alcohol consumption and passive smoking were found no significant association with corneal biomechanics. CONCLUSION Smokers had less deformable corneas, especially those with BMI no less than 24.0. Our findings provide new evidence for the association between smoking and ocular disorders associated with corneal biomechanics like glaucoma.
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Affiliation(s)
- Min-Xin Liu
- School of Public Health, Medical College of Soochow University, Suzhou, China
| | - Dan-Lin Li
- School of Public Health, Medical College of Soochow University, Suzhou, China
| | - Zhi-Jian Yin
- Department of Ophthalmology, The First Affiliated Hospital of Dali University, Dali, China
| | - Yue-Zu Li
- Department of Ophthalmology, The Affiliated Hospital of Yunnan University, Kunming, China
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, China
| | - Ya-Jie Zheng
- Department of Ophthalmology, The Affiliated Hospital of Yunnan University, Kunming, China
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, China
| | - Yu Qin
- Department of Ophthalmology, The Affiliated Hospital of Yunnan University, Kunming, China
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, China
| | - Gang Liang
- Department of Ophthalmology, The Affiliated Hospital of Yunnan University, Kunming, China.
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, China.
| | - Chen-Wei Pan
- School of Public Health, Medical College of Soochow University, Suzhou, China.
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Zhang R, Li B, Li H. Extracellular-Matrix Mechanics Regulate the Ocular Physiological and Pathological Activities. J Ophthalmol 2023; 2023:7626920. [PMID: 37521908 PMCID: PMC10386902 DOI: 10.1155/2023/7626920] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2023] [Revised: 07/06/2023] [Accepted: 07/13/2023] [Indexed: 08/01/2023] Open
Abstract
The extracellular matrix (ECM) is a noncellular structure that plays an indispensable role in a series of cell life activities. Accumulating studies have demonstrated that ECM stiffness, a type of mechanical forces, exerts a pivotal influence on regulating organogenesis, tissue homeostasis, and the occurrence and development of miscellaneous diseases. Nevertheless, the role of ECM stiffness in ophthalmology is rarely discussed. In this review, we focus on describing the important role of ECM stiffness and its composition in multiple ocular structures (including cornea, retina, optic nerve, trabecular reticulum, and vitreous) from a new perspective. The abnormal changes in ECM can trigger physiological and pathological activities of the eye, suggesting that compared with different biochemical factors, the transmission and transduction of force signals triggered by mechanical cues such as ECM stiffness are also universal in different ocular cells. We expect that targeting ECM as a therapeutic approach or designing advanced ECM-based technologies will have a broader application prospect in ophthalmology.
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Affiliation(s)
- Ran Zhang
- Department of Ophthalmology & Optometry, North Sichuan Medical College, Nanchong 637000, Sichuan, China
- Department of Ophthalmology, Central Hospital of Suining City, Suining 629000, Sichuan, China
| | - Bo Li
- Department of Ophthalmology, Central Hospital of Suining City, Suining 629000, Sichuan, China
| | - Heng Li
- Department of Ophthalmology & Optometry, North Sichuan Medical College, Nanchong 637000, Sichuan, China
- Department of Ophthalmology, Central Hospital of Suining City, Suining 629000, Sichuan, China
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19
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Kumar R, Sinha NR, Mohan RR. Corneal gene therapy: Structural and mechanistic understanding. Ocul Surf 2023; 29:279-297. [PMID: 37244594 DOI: 10.1016/j.jtos.2023.05.007] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Cornea, a dome-shaped and transparent front part of the eye, affords 2/3rd refraction and barrier functions. Globally, corneal diseases are the leading cause of vision impairment. Loss of corneal function including opacification involve the complex crosstalk and perturbation between a variety of cytokines, chemokines and growth factors generated by corneal keratocytes, epithelial cells, lacrimal tissues, nerves, and immune cells. Conventional small-molecule drugs can treat mild-to-moderate traumatic corneal pathology but requires frequent application and often fails to treat severe pathologies. The corneal transplant surgery is a standard of care to restore vision in patients. However, declining availability and rising demand of donor corneas are major concerns to maintain ophthalmic care. Thus, the development of efficient and safe nonsurgical methods to cure corneal disorders and restore vision in vivo is highly desired. Gene-based therapy has huge potential to cure corneal blindness. To achieve a nonimmunogenic, safe and sustained therapeutic response, the selection of a relevant genes, gene editing methods and suitable delivery vectors are vital. This article describes corneal structural and functional features, mechanistic understanding of gene therapy vectors, gene editing methods, gene delivery tools, and status of gene therapy for treating corneal disorders, diseases, and genetic dystrophies.
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Affiliation(s)
- Rajnish Kumar
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA; Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow campus, UP, 226028, India
| | - Nishant R Sinha
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA
| | - Rajiv R Mohan
- Harry S. Truman Memorial Veterans' Hospital, Columbia, MO, 65201, USA; One-health One-medicine Vision Research Program, Departments of Veterinary Medicine and Surgery & Biomedical Sciences, College of Veterinary Medicine, University of Missouri, Columbia, MO, 65211, USA; Mason Eye Institute, School of Medicine, University of Missouri, Columbia, MO, 65212, USA.
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20
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Ma G, Cai J, Zhong R, He W, Ye H, Duvvuri C, Song C, Feng J, An L, Qin J, Huang Y, Xu J, Twa MD, Lan G. Corneal Surface Wave Propagation Associated with Intraocular Pressures: OCT Elastography Assessment in a Simplified Eye Model. Bioengineering (Basel) 2023; 10:754. [PMID: 37508781 PMCID: PMC10376591 DOI: 10.3390/bioengineering10070754] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/18/2023] [Accepted: 06/21/2023] [Indexed: 07/30/2023] Open
Abstract
Assessing corneal biomechanics in vivo has long been a challenge in the field of ophthalmology. Despite recent advances in optical coherence tomography (OCT)-based elastography (OCE) methods, controversy remains regarding the effect of intraocular pressure (IOP) on mechanical wave propagation speed in the cornea. This could be attributed to the complexity of corneal biomechanics and the difficulties associated with conducting in vivo corneal shear-wave OCE measurements. We constructed a simplified artificial eye model with a silicone cornea and controllable IOPs and performed surface wave OCE measurements in radial directions (54-324°) of the silicone cornea at different IOP levels (10-40 mmHg). The results demonstrated increases in wave propagation speeds (mean ± STD) from 6.55 ± 0.09 m/s (10 mmHg) to 9.82 ± 0.19 m/s (40 mmHg), leading to an estimate of Young's modulus, which increased from 145.23 ± 4.43 kPa to 326.44 ± 13.30 kPa. Our implementation of an artificial eye model highlighted that the impact of IOP on Young's modulus (ΔE = 165.59 kPa, IOP: 10-40 mmHg) was more significant than the effect of stretching of the silicone cornea (ΔE = 15.79 kPa, relative elongation: 0.98-6.49%). Our study sheds light on the potential advantages of using an artificial eye model to represent the response of the human cornea during OCE measurement and provides valuable insights into the impact of IOP on wave-based OCE measurement for future in vivo corneal biomechanics studies.
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Affiliation(s)
- Guoqin Ma
- School of Mechatronic Engineering and Automation, Foshan University, Foshan 528000, China
| | - Jing Cai
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China
| | - Rijian Zhong
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China
| | - Weichao He
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China
| | - Haoxi Ye
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China
| | | | - Chengjin Song
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China
| | - Jinping Feng
- Institute of Engineering and Technology, Hubei University of Science and Technology, Xianning 437100, China
| | - Lin An
- Weiren Meditech Co., Ltd., Foshan 528000, China
| | - Jia Qin
- Weiren Meditech Co., Ltd., Foshan 528000, China
| | - Yanping Huang
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China
- Weiren Meditech Co., Ltd., Foshan 528000, China
| | - Jingjiang Xu
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China
- Weiren Meditech Co., Ltd., Foshan 528000, China
| | - Michael D. Twa
- College of Optometry, University of Houston, Houston, TX 77204, USA
| | - Gongpu Lan
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan 528000, China
- Weiren Meditech Co., Ltd., Foshan 528000, China
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21
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Lan G, Twa MD, Song C, Feng J, Huang Y, Xu J, Qin J, An L, Wei X. In vivo corneal elastography: A topical review of challenges and opportunities. Comput Struct Biotechnol J 2023; 21:2664-2687. [PMID: 37181662 PMCID: PMC10173410 DOI: 10.1016/j.csbj.2023.04.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2023] [Revised: 04/07/2023] [Accepted: 04/12/2023] [Indexed: 05/16/2023] Open
Abstract
Clinical measurement of corneal biomechanics can aid in the early diagnosis, progression tracking, and treatment evaluation of ocular diseases. Over the past two decades, interdisciplinary collaborations between investigators in optical engineering, analytical biomechanical modeling, and clinical research has expanded our knowledge of corneal biomechanics. These advances have led to innovations in testing methods (ex vivo, and recently, in vivo) across multiple spatial and strain scales. However, in vivo measurement of corneal biomechanics remains a long-standing challenge and is currently an active area of research. Here, we review the existing and emerging approaches for in vivo corneal biomechanics evaluation, which include corneal applanation methods, such as ocular response analyzer (ORA) and corneal visualization Scheimpflug technology (Corvis ST), Brillouin microscopy, and elastography methods, and the emerging field of optical coherence elastography (OCE). We describe the fundamental concepts, analytical methods, and current clinical status for each of these methods. Finally, we discuss open questions for the current state of in vivo biomechanics assessment techniques and requirements for wider use that will further broaden our understanding of corneal biomechanics for the detection and management of ocular diseases, and improve the safety and efficacy of future clinical practice.
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Affiliation(s)
- Gongpu Lan
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Michael D. Twa
- College of Optometry, University of Houston, Houston, TX 77204, United States
| | - Chengjin Song
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
| | - JinPing Feng
- Institute of Engineering and Technology, Hubei University of Science and Technology, Xianning, Hubei 437100, China
| | - Yanping Huang
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Jingjiang Xu
- Guangdong-Hong Kong-Macao Intelligent Micro-Nano Optoelectronic Technology Joint Laboratory, School of Physics and Optoelectronic Engineering, Foshan University, Foshan, Guangdong 528000, China
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Jia Qin
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Lin An
- Weiren Meditech Co., Ltd., Foshan, Guangdong 528000, China
| | - Xunbin Wei
- Biomedical Engineering Department, Peking University, Beijing 100081, China
- International Cancer Institute, Peking University, Beijing 100191, China
- Institute of Medical Technology, Peking University Health Science Center, Beijing 100191, China
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22
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Han H, Li S, Xu M, Zhong Y, Fan W, Xu J, Zhou T, Ji J, Ye J, Yao K. Polymer- and lipid-based nanocarriers for ocular drug delivery: Current status and future perspectives. Adv Drug Deliv Rev 2023; 196:114770. [PMID: 36894134 DOI: 10.1016/j.addr.2023.114770] [Citation(s) in RCA: 68] [Impact Index Per Article: 68.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2022] [Revised: 02/21/2023] [Accepted: 03/02/2023] [Indexed: 03/09/2023]
Abstract
Ocular diseases seriously affect patients' vision and life quality, with a global morbidity of over 43 million blindness. However, efficient drug delivery to treat ocular diseases, particularly intraocular disorders, remains a huge challenge due to multiple ocular barriers that significantly affect the ultimate therapeutic efficacy of drugs. Recent advances in nanocarrier technology offer a promising opportunity to overcome these barriers by providing enhanced penetration, increased retention, improved solubility, reduced toxicity, prolonged release, and targeted delivery of the loaded drug to the eyes. This review primarily provides an overview of the progress and contemporary applications of nanocarriers, mainly polymer- and lipid-based nanocarriers, in treating various eye diseases, highlighting their value in achieving efficient ocular drug delivery. Additionally, the review covers the ocular barriers and administration routes, as well as the prospective future developments and challenges in the field of nanocarriers for treating ocular diseases.
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Affiliation(s)
- Haijie Han
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China; Zhejiang Provincial Key Lab of Ophthalmology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China
| | - Su Li
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China
| | - Mingyu Xu
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China
| | - Yueyang Zhong
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China; Zhejiang Provincial Key Lab of Ophthalmology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China
| | - Wenjie Fan
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China
| | - Jingwei Xu
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China; Zhejiang Provincial Key Lab of Ophthalmology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China
| | - Tinglian Zhou
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China
| | - Jian Ji
- MOE Key Laboratory of Macromolecule Synthesis and Functionalization of Ministry of Education, Department of Polymer Science and Engineering, Zhejiang University, Hangzhou 310027, People's Republic of China
| | - Juan Ye
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China; Zhejiang Provincial Key Lab of Ophthalmology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China.
| | - Ke Yao
- Eye Center, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China; Zhejiang Provincial Key Lab of Ophthalmology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, 88 Jiefang Road, Hangzhou 310009, People's Republic of China.
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23
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Liu MX, Zhou M, Li DL, Dong XX, Liang G, Pan CW. Corneal Biomechanics in Primary Open Angle Glaucoma and Ocular Hypertension: A Systematic Review and Meta-analysis. J Glaucoma 2023; 32:e24-e32. [PMID: 36583701 DOI: 10.1097/ijg.0000000000002170] [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: 10/16/2022] [Accepted: 12/07/2022] [Indexed: 12/31/2022]
Abstract
PRCIS Normal tension glaucoma patients had softer corneas than normal controls, whereas high-tension glaucoma and ocular hypertension patients had stiffer corneas. PURPOSE To comprehensively identify the corneal biomechanical differences of patients with primary open angle glaucoma (POAG) and ocular hypertension (OHT) using the Ocular Response Analyzer or the Corvis ST. METHODS The electronic databases PubMed, Embase, and Web of Science were comprehensively searched for studies comparing corneal biomechanical differences between POAG and OHT patients with normal controls by Ocular Response Analyzer or Corvis ST. The weighted mean differences and 95% confidence intervals (CIs) were calculated. Subgroup analyses were performed according to the subtypes of POAG, including high-tension glaucoma (HTG) and normal tension glaucoma (NTG). RESULTS Thirty-one case-control studies were ultimately included, with 2462 POAG patients, 345 OHT patients, and 3281 normal controls. The corneal hysteresis (CH), corneal resistance factor (CRF), and highest concavity time (HC-t) were all lower in POAG patients than in normal controls. The CH, time at the second applanation (A2t), HC-t, highest concavity radius (HC-R), and deformation amplitude at the highest concavity (HC-DA) were lower in OHT patients, while the CRF, time at the first applanation (A1t), and stiffness parameter at the first applanation (SP-A1) were greater in OHT patients than in normal controls. The subgroup analyses showed that the CH, A2t, length at the second applanation (A2L), and HC-DA were lower in HTG, and the CH, CRF, A1t, and HC-t were lower in NTG patients than in normal controls. CONCLUSION The corneas of NTG patients are more deformable than normal controls, whereas the corneas of HTG and OHT patients are stiffer.
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Affiliation(s)
- Min-Xin Liu
- School of Public Health, Medical College of Soochow University, Suzhou
| | - Miao Zhou
- Department of Ophthalmology, Peking University People's Hospital, Beijing
| | - Dan-Lin Li
- School of Public Health, Medical College of Soochow University, Suzhou
| | - Xing-Xuan Dong
- School of Public Health, Medical College of Soochow University, Suzhou
| | - Gang Liang
- Department of Ophthalmology, The Affiliated Hospital of Yunnan University, Kunming
- Department of Ophthalmology, The Second People's Hospital of Yunnan Province, Kunming, China
| | - Chen-Wei Pan
- School of Public Health, Medical College of Soochow University, Suzhou
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24
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Silver FH, Deshmukh T, Benedetto D, Gonzalez-Mercedes M. Dynamic Ocular Response to Mechanical Loading: The Role of Viscoelasticity in Energy Dissipation by the Cornea. Biomimetics (Basel) 2023; 8:63. [PMID: 36810394 PMCID: PMC9944807 DOI: 10.3390/biomimetics8010063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Revised: 01/26/2023] [Accepted: 01/31/2023] [Indexed: 02/05/2023] Open
Abstract
We have used vibrational optical coherence tomography (VOCT) to measure the resonant frequency, elastic modulus, and loss modulus of components of the anterior segment of pig eyes in vitro. Such basic biomechanical properties of the cornea have been shown to be abnormal not only in diseases of the anterior segment but also in posterior segment diseases as well. This information is needed to better understand corneal biomechanics in health and disease and to be able to diagnose the early stages of corneal pathologies. Results of dynamic viscoelastic studies on whole pig eyes and isolated corneas indicate that at low strain rates (30 Hz or less), the viscous loss modulus is as high as 0.6 times the elastic modulus for both whole eyes and corneas. This large viscous loss is similar to that of skin, which has been hypothesized to be dependent upon the physical association of proteoglycans with collagenous fibers. The energy dissipation properties of the cornea provide a mechanism to dissipate energy associated with blunt trauma, thereby preventing delamination and failure. The cornea possesses the ability to store impact energy and transmit excess energy to the posterior segment of the eye through its serial connection to the limbus and sclera. In this manner, the viscoelastic properties of the cornea, in concert with that of the posterior segment of the pig eye, function to prevent mechanical failure of the primary focusing element of the eye. Results of resonant frequency studies suggest that the 100-120 Hz and 150-160 Hz resonant frequency peaks reside in the anterior segment of the cornea since the removal of the anterior segment of the cornea decreases the peak heights at these resonant frequencies. These results suggest that there is more than one collagen fibril network found in the anterior portion of the cornea that provides structural integrity to prevent corneal delamination and that VOCT may be useful clinically to diagnose corneal diseases.
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Affiliation(s)
- Frederick H. Silver
- Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Rutgers, The State University of New Jersey, Piscataway, NJ 08854, USA
- OptoVibronex, LLC, Ben Franklin Tech Partners, Bethlehem, PA 18015, USA
| | - Tanmay Deshmukh
- OptoVibronex, LLC, Ben Franklin Tech Partners, Bethlehem, PA 18015, USA
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25
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Borrelli M, Witt J, Roth M, Reichl S, Bradenbrink P, Schoppe M, Schrader S, Geerling G. Keratin films for ocular surface reconstruction: Wound healing in an in-vivo model. Exp Eye Res 2023; 227:109356. [PMID: 36563893 DOI: 10.1016/j.exer.2022.109356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Revised: 11/16/2022] [Accepted: 12/19/2022] [Indexed: 12/24/2022]
Abstract
The most commonly used tissue substitute for ocular surface reconstruction is human amniotic membrane (AM). Because of its low biomechanical strength and intransparency there is a need to search for alternatives of consistent quality. This study, further explored the biocompatibility of Keratin Film (KF) and its ability to sustain corneal epithelial wound healing. In three equal groups of 5 New Zeeland white rabbits a 4 mm superficial keratectomy was created in the right eye. Five eyes received a KF, five a human AM graft and the remaining five no implant. All eyes were treated with ofloxacin and dexamethasone eye drops and followed up for 10 days. Corneal fluorescein staining, vascularization, and transparency were assessed using slit lamp biomicroscopy according to a standardized grading score during and at the end of follow-up. The corneal-scleral-button was excised and processed for histology. After 10 days all eyes which had received a KF showed complete epithelial healing and no signs of neovascularization. In the AM group 1 eye showed a persistent epithelial defect at day 10 and 2 eyes showed neovascularization at day 7 resolving at day 10. Transparency improved progressively both in the KF group as well as in the AM group towards the end of the follow. Histology showed a multilayer epithelium firmly adherent to the KF with no evidence of keratocyte migration or inflammatory reaction in the corneal stroma. In this study on rabbit eyes KF better supported corneal epithelial wound healing than amniotic membrane.
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Affiliation(s)
- M Borrelli
- Department of Ophthalmology, University of Duesseldorf, Germany.
| | - J Witt
- Department of Ophthalmology, University of Duesseldorf, Germany
| | - M Roth
- Department of Ophthalmology, University of Duesseldorf, Germany
| | - S Reichl
- Institute of Pharmaceutical Technology, Technical University of Braunschweig, Germany
| | - P Bradenbrink
- Department of Ophthalmology, University of Duesseldorf, Germany
| | - M Schoppe
- Department of Pathology, University of Duesseldorf, Germany
| | - S Schrader
- Department of Ophthalmology, Carl von Ossietzky University Oldenburg, Germany
| | - G Geerling
- Department of Ophthalmology, University of Duesseldorf, Germany
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26
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Yuhas PT, Roberts CJ. Clinical Ocular Biomechanics: Where Are We after 20 Years of Progress? Curr Eye Res 2023; 48:89-104. [PMID: 36239188 DOI: 10.1080/02713683.2022.2125530] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Purpose: Ocular biomechanics is an assessment of the response of the structures of the eye to forces that may lead to disease development and progression, or influence the response to surgical intervention. The goals of this review are (1) to introduce basic biomechanical principles and terminology, (2) to provide perspective on the progress made in the clinical study and assessment of ocular biomechanics, and (3) to highlight critical studies conducted in keratoconus, laser refractive surgery, and glaucoma in order to aid interpretation of biomechanical parameters in the laboratory and in the clinic.Methods: A literature review was first conducted of basic biomechanical studies related to ocular tissue. The subsequent review of ocular biomechanical studies was limited to those focusing on keratoconus, laser refractive surgery, or glaucoma using the only two commercially available devices that allow rapid assessment of biomechanical response in the clinic.Results: Foundational studies on ocular biomechanics used a combination of computer modeling and destructive forces on ex-vivo tissues. The knowledge gained from these studies could not be directly translated to clinical research and practice until the introduction of non-contact tonometers that quantified the deformation response of the cornea to an air puff, which represents a non-destructive, clinically appropriate load. The corneal response includes a contribution from the sclera which may limit corneal deformation. Two commercial devices are available, the Ocular Response Analyzer which produces viscoelastic parameters with a customized load for each eye, and the Corvis ST which produces elastic parameters with a consistent load for every eye. Neither device produces the classic biomechanical properties reported in basic studies, but rather biomechanical deformation response parameters which require careful interpretation.Conclusions: Research using clinical tools has enriched our understanding of how ocular disease alters ocular biomechanics, as well as how ocular biomechanics may influence the pathophysiology of ocular disease and response to surgical intervention.
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Affiliation(s)
- Phillip T Yuhas
- College of Optometry, The Ohio State University, Columbus, OH, USA
| | - Cynthia J Roberts
- Department of Ophthalmology and Visual Sciences, College of Medicine, The Ohio State University, Columbus, OH, USA.,Department of Biomedical Engineering, College of Engineering, The Ohio State University, Columbus, OH, USA
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27
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Global trends and prospects in research of artificial cornea over past 20 years: a bibliometric and visualized analysis. Int Ophthalmol 2022; 43:2003-2015. [DOI: 10.1007/s10792-022-02600-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2022] [Accepted: 11/17/2022] [Indexed: 11/28/2022]
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McAuley R, Nolan A, Curatolo A, Alexandrov S, Zvietcovich F, Varea Bejar A, Marcos S, Leahy M, Birkenfeld JS. Co-axial acoustic-based optical coherence vibrometry probe for the quantification of resonance frequency modes in ocular tissue. Sci Rep 2022; 12:18834. [PMID: 36336702 PMCID: PMC9637745 DOI: 10.1038/s41598-022-21978-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 10/07/2022] [Indexed: 11/08/2022] Open
Abstract
We present a co-axial acoustic-based optical coherence vibrometry probe (CoA-OCV) for vibro-acoustic resonance quantification in biological tissues. Sample vibrations were stimulated via a loudspeaker, and pre-compensation was used to calibrate the acoustic spectrum. Sample vibrations were measured via phase-sensitive swept-source optical coherence tomography (OCT). Resonance frequencies of corneal phantoms were measured at varying intraocular pressures (IOP), and dependencies on Young´s Modulus (E), phantom thickness and IOP were observed. Cycling IOP revealed hysteresis. For E = 0.3 MPa, resonance frequencies increased with IOP at a rate of 3.9, 3.7 and 3.5 Hz/mmHg for varied thicknesses and 1.7, 2.5 and 2.8 Hz/mmHg for E = 0.16 MPa. Resonance frequencies increased with thickness at a rate of 0.25 Hz/µm for E = 0.3 MPa, and 0.40 Hz/µm for E = 0.16 MPa. E showed the most predominant impact in the shift of the resonance frequencies. Full width at half maximum (FWHM) of the resonance modes increased with increasing thickness and decreased with increasing E. Only thickness and E contributed to the variance of FWHM. In rabbit corneas, resonance frequencies of 360-460 Hz were observed. The results of the current study demonstrate the feasibility of CoA-OCV for use in future OCT-V studies.
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Affiliation(s)
- Ryan McAuley
- Tissue Optics and Microcirculation Imaging Facility, School of Physics, University of Galway, Galway, Ireland.
| | - A Nolan
- Tissue Optics and Microcirculation Imaging Facility, School of Physics, University of Galway, Galway, Ireland
| | - A Curatolo
- Instituto de Óptica, Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
- International Centre for Translational Eye Research, Warsaw, Poland
| | - S Alexandrov
- Tissue Optics and Microcirculation Imaging Facility, School of Physics, University of Galway, Galway, Ireland
| | - F Zvietcovich
- Instituto de Óptica, Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
| | - A Varea Bejar
- Instituto de Óptica, Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
| | - S Marcos
- Instituto de Óptica, Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
- Center for Visual Science, The Institute of Optics, Flaum Eye Institute, University of Rochester, Rochester, New York, USA
| | - M Leahy
- Tissue Optics and Microcirculation Imaging Facility, School of Physics, University of Galway, Galway, Ireland
| | - J S Birkenfeld
- Instituto de Óptica, Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain.
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29
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Yang S, Zhang J, Tan Y, Wang Y. Unraveling the mechanobiology of cornea: From bench side to the clinic. Front Bioeng Biotechnol 2022; 10:953590. [PMID: 36263359 PMCID: PMC9573972 DOI: 10.3389/fbioe.2022.953590] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2022] [Accepted: 09/06/2022] [Indexed: 11/18/2022] Open
Abstract
The cornea is a transparent, dome-shaped structure on the front part of the eye that serves as a major optic element and a protector from the external environment. Recent evidence shows aberrant alterations of the corneal mechano-environment in development and progression of various corneal diseases. It is, thus, critical to understand how corneal cells sense and respond to mechanical signals in physiological and pathological conditions. In this review, we summarize the corneal mechano-environment and discuss the impact of these mechanical cues on cellular functions from the bench side (in a laboratory research setting). From a clinical perspective, we comprehensively review the mechanical changes of corneal tissue in several cornea-related diseases, including keratoconus, myopia, and keratectasia, following refractive surgery. The findings from the bench side and clinic underscore the involvement of mechanical cues in corneal disorders, which may open a new avenue for development of novel therapeutic strategies by targeting corneal mechanics.
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Affiliation(s)
- Shu Yang
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin, China
- Department of Ophthalmology, The First People’s Hospital of Huzhou, Huzhou, Zhejiang, China
| | - Jing Zhang
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin, China
- School of Optometry, Hong Kong Polytechnic University, Hong Kong SAR, China
| | - Youhua Tan
- Hong Kong Polytechnic University Shenzhen Research Institute, Shenzhen, China
- Department of Biomedical Engineering, Hong Kong Polytechnic University, Hong Kong SAR, China
- *Correspondence: Youhua Tan, ; Yan Wang,
| | - Yan Wang
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
- Tianjin Eye Institute, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Hospital, Tianjin, China
- *Correspondence: Youhua Tan, ; Yan Wang,
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30
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Padmanabhan P, Lopes BT, Eliasy A, Abass A, Vinciguerra R, Vinciguerra P, Ambrósio R, Elsheikh A. Evaluation of corneal biomechanical behavior in vivo for healthy and keratoconic eyes using the stress-strain index. J Cataract Refract Surg 2022; 48:1162-1167. [PMID: 35333824 DOI: 10.1097/j.jcrs.0000000000000945] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2021] [Accepted: 03/19/2022] [Indexed: 11/26/2022]
Abstract
PURPOSE To evaluate the characteristics of corneal material properties in healthy individuals and keratoconic patients using the stress-strain index (SSI). SETTING Vincieye Clinic in Milan, Italy, and Instituto de Olhos Renato Ambrósio in Rio de Janeiro, Brazil. DESIGN Retrospective observational cross-sectional study. METHODS Records of 1221 patients were divided into 3 groups: healthy corneas (n = 728), bilateral keratoconus (KC, n = 388), and very asymmetric ectasia (VAE, n = 105) when patients presented with clinical ectasia in 1 eye and normal topography (VAE-NT) in the fellow eye. All patients were examined with Pentacam HR and Corvis ST. Severity of KC cases was stratified according to the Pentacam topographic KC classification. The SSI distribution across the different groups and its correlation with age, biomechanically corrected intraocular pressure (bIOP), and central corneal thickness (CCT) were assessed. RESULTS A statistically significant difference between healthy individuals and each of the keratoconic groups ( P < .001) was observed, and a progressive reduction in the SSI was observed across the groups. A significant correlation was observed between the SSI and age in all groups ( P < .010) but KC severe subgroup ( P = .361). No correlation between the SSI and bIOP and CCT was observed in all KC subgroups and VAE-NT groups ( P > .050). Among healthy eyes, there was only a mild correlation between the SSI and bIOP ( R = 0.12, P = .002) and CCT ( R = 0.13, P = .001). CONCLUSIONS This study estimates the in vivo corneal material properties in healthy individuals and patients with KC using a new method. The SSI showed a progressive deterioration within the advance in disease stages while being relatively independent of bIOP and CCT but positively correlated with age.
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Affiliation(s)
- Prema Padmanabhan
- From the Department of Cornea and Refractive Surgery, Sankara Nethralaya, Chennai, India (Padmanabhan); School of Engineering, University of Liverpool, Liverpool, United Kingdom (Lopes, Eliasy, Abass, R. Vinciguerra, Elsheikh); Department of Ophthalmology and Visual Sciences, Federal University of Sao Paulo, Sao Paulo, Brazil (Lopes, Ambrósio); Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, Brazil (Lopes, Ambrósio); Department of Production Engineering and Mechanical Design, Faculty of Engineering, Port Said University, Port Fuad, Egypt (Abass); Humanitas San Pio X Hospital, Milan, Italy (R. Vinciguerra); IRCCS Humanitas Research Hospital, Milan, Italy (P. Vinciguerra); Department of Biomedical Sciences, Humanitas University, Milan, Italy (P. Vinciguerra); Department of Ophthalmology, Federal University of the State of Rio de Janeiro, Rio de Janeiro, Brazil (Ambrósio); Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China (Elsheikh); NIHR Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, United Kingdom (Elsheikh)
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Yang J, Wu S, Ren Q, Wang J, Gao Z, Li X, Chen W. Adhesion is safe to the refractive surgeries: A theoretical analysis. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2022. [DOI: 10.1016/j.medntd.2022.100136] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022] Open
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Lei M, Zhang S, Zhou H, Wan H, Lu Y, Lin S, Sun J, Qu X, Liu C. Electrical Signal Initiates Kinetic Assembly of Collagen to Construct Optically Transparent and Geometry Customized Artificial Cornea Substitutes. ACS NANO 2022; 16:10632-10646. [PMID: 35802553 DOI: 10.1021/acsnano.2c02291] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
Corneal transplantation is an effective treatment for reconstructing injured corneas but is very limited due to insufficient donors, which has led to a growing demand for development of artificial corneal substitutes (ACSs). Collagen is a potential building block for ACS fabrication, whereas technically there are limited capabilities to control the collagen assembly for creating highly transparent collagen ACSs. Here, we report an electro-assembly technique to kinetically control collagen assembly on the nanoscale that allows the yielding collagen ACSs with structure determined superior optics. Structurally, the kinetically electro-assembled collagen (KEA-Col) is composed of partially aligned microfibrils (∼10 nm in diameter) with compacted lamellar organization. Optical analysis reveals that such microstructure is directly responsible for its optimal light transmittance by reducing light scattering. Moreover, this method allows the creation of complex three-dimensional geometries and thus is convenient to customize collagen ACSs with specific curvatures to meet refractive power requirements. Available properties (e.g., optics and mechanics) of cross-linked KEA-Cols were studied to meet the clinical requirement as ACSs, and in vitro tests further proved their beneficial characteristics of cell growth and migration. An in vivo study established a rabbit lamellar keratectomy corneal wound model and demonstrated the customized collagen ACSs can adapt to the defective cornea and support epithelial healing as well as stroma integration and reconstruction with lower immunoreaction compared with commercial xenografts, which suggests its promising application prospects. More broadly, this work illustrates the potential for enlisting electrical signals to mediate collagen's assembly and microstructure organization for specific structural functionalization for regenerative medicine.
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Affiliation(s)
- Miao Lei
- Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Shaohua Zhang
- Eye Institute and Department of Ophthalmology, NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai Key Laboratory of Visual Impairment and Restoration, Eye & ENT Hospital, Fudan University, Shanghai 200031, China
| | - Hang Zhou
- Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Haoran Wan
- Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Yi Lu
- Eye Institute and Department of Ophthalmology, NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai Key Laboratory of Visual Impairment and Restoration, Eye & ENT Hospital, Fudan University, Shanghai 200031, China
| | - Shaoliang Lin
- Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
| | - Jianguo Sun
- Eye Institute and Department of Ophthalmology, NHC Key Laboratory of Myopia (Fudan University); Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai Key Laboratory of Visual Impairment and Restoration, Eye & ENT Hospital, Fudan University, Shanghai 200031, China
| | - Xue Qu
- Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
- Shanghai Frontier Science Research Base of Optogenetic Techniques for Cell Metabolism, East China University of Science and Technology, Shanghai 200237, China
| | - Changsheng Liu
- Key Laboratory for Ultrafine Materials of Ministry of Education, Frontiers Science Center for Materiobiology and Dynamic Chemistry, School of Materials Science and Engineering, East China University of Science and Technology, Shanghai 200237, China
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Crespo MA, Jimenez HJ, Deshmukh T, Pulido JS, Saad AS, Silver FH, Benedetto DA, Rapuano CJ, Syed ZA. In Vivo Determination of the Human Corneal Elastic Modulus Using Vibrational Optical Coherence Tomography. Transl Vis Sci Technol 2022; 11:11. [PMID: 35822948 PMCID: PMC9288150 DOI: 10.1167/tvst.11.7.11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To determine the in vivo elastic modulus of the human cornea using vibrational optical coherence tomography (VOCT). Methods Vibrational analysis coupled with optical coherence tomography (OCT) was used to obtain the resonant frequency (RF) and elastic modulus of corneal structural components. VOCT corneal thickness values were measured using OCT images and correlated with corneal thickness determined with Pentacam (Oculus, Wetzlar, Germany). Moduli were obtained at two locations: central cornea (CC) and inferior cornea (IC). Measurements were obtained with and without anesthetic eye drops to assess their effect on the modulus measurements. Results VOCT thickness values correlated positively (R2 = 0.97) and linearly (y = 1.039x–16.89) with those of Pentacam. Five RF peaks (1–5) were present, although their presence was variable across eyes. The RF for peaks 1 to 5 in the CC and IC ranged from 73.5 ± 4.9 to 239 ± 3 Hz and 72.1 ± 6.3 to 238 ± 4 Hz, respectively. CC and IC moduli for peaks 1 to 5 ranged from 1.023 ± 0.104 to 6.87 ± 0.33 MPa and 0.98 ± 0.15 to 6.52 ± 0.79 MPa, respectively. Topical anesthesia did not significantly alter the modulus (P > 0.05 for all), except for peak 2 in the CC (P < 0.05). Conclusions This pilot study demonstrates the utility of VOCT as an in vivo, noninvasive technology to measure the elastic modulus in human corneas. The structural origin of these moduli is hypothesized based on previous reports, and further analyses are necessary for confirmation. Translational Relevance This work presents VOCT as a novel approach to assess the in vivo elastic modulus of the cornea, an indicator of corneal structural integrity and health.
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Affiliation(s)
- Marcos A Crespo
- Cornea Service, Wills Eye Hospital, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | - Hiram J Jimenez
- Vickie and Jack Farber Vision Research Center, Wills Eye Hospital, Philadelphia, PA, USA
| | | | - Jose S Pulido
- Vickie and Jack Farber Vision Research Center, Wills Eye Hospital, Philadelphia, PA, USA
| | - Ahmed Saeed Saad
- Cornea Service, Wills Eye Hospital, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | - Frederick H Silver
- OptoVibronex, LLC, Bethlehem, PA, USA.,Department of Pathology and Laboratory Medicine, Robert Wood Johnson Medical School, Piscataway, NJ, USA
| | | | - Christopher J Rapuano
- Cornea Service, Wills Eye Hospital, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
| | - Zeba A Syed
- Cornea Service, Wills Eye Hospital, Sidney Kimmel Medical College at Thomas Jefferson University, Philadelphia, PA, USA
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Lazaridis A, Spiru B, Giallouros E, Droutsas K, Messerschmidt-Roth A, Sekundo W. Corneal Remodeling After Myopic SMILE Versus FS-LASIK: A Spatial Analysis of Short- and Mid-Term Corneal Thickness, Volume, and Shape Changes. Cornea 2022; 41:826-832. [PMID: 34469342 DOI: 10.1097/ico.0000000000002833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2021] [Accepted: 06/09/2021] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the short- and mid-term changes of corneal thickness spatial profile (CTSP), corneal volume distribution (CVD), and corneal asphericity after small-incision lenticule extraction (SMILE) for correction of myopia and astigmatism and compare the results with femtosecond laser-assisted laser in situ keratomileusis (FS-LASIK). METHOD Thirty eyes of 18 patients who underwent SMILE were compared with a group of 30 eyes of 16 patients who underwent FS-LASIK. The groups were matched for preoperative central corneal thickness and lenticule thickness/ablation depth. Scheimpflug corneal tomography was performed preoperatively and postoperatively at 2 months and 3 years. The CTSP was evaluated on 4 concentric rings (2, 4, 6, and 8 mm). The CVD was evaluated at 3 concentric zones (3, 5, and 7 mm). Changes in the anterior and posterior asphericity at a 6-mm zone were also evaluated. RESULTS Between the 2-month and 3-year examination, the CTSP showed a similar increase for both groups at all measured points and rings ( P ≥ 0.168). The CVD also showed a similar increase for both groups at all measured zones ( P ≥ 0.278). The anterior corneal asphericity remained stable after SMILE (2-mo Q = 0.46 ± 0.27; 3-yr Q = 0.45 ± 0.27; P = 0.711) but decreased significantly after FS-LASIK (2-mo Q = 0.52 ± 0.47; 3-yr Q = 0.47 ± 0.44; P = 0.028). Similarly, the posterior corneal asphericity remained stable after SMILE (2-mo Q = -0.11 ± 0.15; 3-yr Q = -0.11 ± 0.13; P = 0.902) but decreased significantly after FS-LASIK (2-mo Q = -0.13 ± 0.14; 3-yr Q = -0.16 ± 0.15; P = 0.034). CONCLUSIONS CTSP and CVD between the 2-month and 3-year examination showed a similar increase after SMILE and FS-LASIK. During the postoperative course, the anterior and posterior corneal asphericity remained more stable after SMILE compared with FS-LASIK.
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Affiliation(s)
- Apostolos Lazaridis
- Department of Ophthalmology, Philipps University of Marburg, Marburg, Germany
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35
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Song Y, Wu D, Shen M, Wang L, Wang C, Cai Y, Xue C, Cheng GPM, Zheng Y, Wang Y. Measuring Human Corneal Stromal Biomechanical Properties Using Tensile Testing Combined With Optical Coherence Tomography. Front Bioeng Biotechnol 2022; 10:882392. [PMID: 35669060 PMCID: PMC9163803 DOI: 10.3389/fbioe.2022.882392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2022] [Accepted: 05/02/2022] [Indexed: 11/30/2022] Open
Abstract
Purpose: To investigate the ex vivo elastic modulus of human corneal stroma using tensile testing with optical coherence tomography (OCT) imaging and its correlation with in vivo measurements using corneal visualization Scheimpflug technology. Methods: Twenty-four corneal specimens extracted from stromal lenticules through small incision lenticule extraction were cut into strips for uniaxial tensile tests. In vivo corneal biomechanical responses were evaluated preoperatively using the corneal visualization Scheimpflug technology (CorVis ST). The correlation of the elastic modulus with clinical characteristics and dynamic corneal response parameters were analyzed using Spearman’s correlation analysis. Results: The mean low strain tangent modulus (LSTM) of the human corneal stroma was 0.204 ± 0.189 (range 0.010–0.641) MPa, and high strain tangent modulus (HSTM) 5.114 ± 1.958 (range 2.755–9.976) MPa. Both LSTM (r = 0.447, p = 0.029) and HSTM (r = 0.557, p = 0.005) were positively correlated with the stress-strain index (SSI). LSTM was also positively correlated with the A1 deflection length (r = 0.427, p = 0.037) and A1 deflection area (r = 0.441, p = 0.031). HSTM was positively correlated with spherical equivalent (r = 0.425, p = 0.038). Conclusions: The correlation of corneal elastic modulus with A1 deflection parameters and SSI may indicate a relationship between these parameters and tissue elasticity. The HSTM decreased with the degree of myopia. Combining tensile test with OCT may be a promising approach to assess corneal biomechanical properties.
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Affiliation(s)
- Yi Song
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Di Wu
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin, China.,Pacific University College of Optometry, Forest Grove, OR, United States
| | - Min Shen
- School of Mechanical Engineering, Tianjin University, Tianjin, China
| | - Like Wang
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China
| | - Congzheng Wang
- School of Mechanical Engineering, Tianjin University, Tianjin, China
| | - Yong Cai
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China
| | - Chao Xue
- Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin, China
| | - George P M Cheng
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Yongping Zheng
- Department of Biomedical Engineering, The Hong Kong Polytechnic University, Hong Kong, China.,Research Institute for Smart Ageing, The Hong Kong Polytechnic University, Hong Kong, China
| | - Yan Wang
- Clinical College of Ophthalmology, Tianjin Medical University, Tianjin, China.,Tianjin Eye Hospital, Tianjin Key Lab of Ophthalmology and Visual Science, Tianjin Eye Institute, Tianjin, China.,Nankai University Eye Institute, Nankai University Affiliated Eye Hospital, Nankai University, Tianjin, China
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36
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Zhao Y, Yang H, Li Y, Wang Y, Han X, Zhu Y, Zhang Y, Huang G. Quantitative Assessment of Biomechanical Properties of the Human Keratoconus Cornea Using Acoustic Radiation Force Optical Coherence Elastography. Transl Vis Sci Technol 2022; 11:4. [PMID: 35666497 PMCID: PMC9185997 DOI: 10.1167/tvst.11.6.4] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose Quantification of biomechanical properties of keratoconus (KC) corneas has great significance for early diagnosis and treatment of KC, but the corresponding clinical measurement remains challenging. Here, we developed an acoustic radiation force (ARF) optical coherence elastography technique and explored its potential for evaluating biomechanical properties of KC corneas. Methods An ARF system was used to induce the tissue deformation, which was detected by an optical coherence tomography system, and thus the localized point-by-point Young's modulus measurements were achieved. Then, two healthy rabbit eyes were imaged to test the system, after which the human keratoconus cornea was evaluated by using the same method. Three regions were selected for biomechanics analysis: the conical region, the transitional region, and the peripheral region. Results Young's moduli of transitional region ranged from 53.3 to 58.5 kPa. The corresponding values for the peripheral region were determined to be 58.6 kPa and 63.2 kPa, respectively. Young's moduli of the conical region were gradually increased by 18.3% from the center to the periphery, resulting in the minimum and maximum values of 44.9 kPa and 53.1 kPa, respectively. Furthermore, Young's moduli of the anterior and posterior of the center were determined to be 44.9 kPa and 50.7 kPa, respectively. Conclusions Differences in biomechanical properties between the three regions and slight variations within the conical region were clearly distinguished. Biomechanical weakening of the keratoconus cornea was mainly localized in the conical region, especially in the vertex position. Translational Relevance The system may provide a promising clinical tool for the noninvasive evaluation of local corneal biomechanics and thus may have potential applications in early keratoconus detection with further optimization.
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Affiliation(s)
- Yanzhi Zhao
- Nanchang University, Nanchang, P. R. China.,Department of Ophthalmology, The Third Affiliated Hospital of Nanchang University, Nanchang, P. R. China
| | - Hongwei Yang
- Nanchang University, Nanchang, P. R. China.,Department of Ophthalmology, The Third Affiliated Hospital of Nanchang University, Nanchang, P. R. China
| | - Yingjie Li
- Nanchang University, Nanchang, P. R. China.,Department of Ophthalmology, The Third Affiliated Hospital of Nanchang University, Nanchang, P. R. China
| | - Yongbo Wang
- Nanchang University, Nanchang, P. R. China.,Department of Ophthalmology, The Third Affiliated Hospital of Nanchang University, Nanchang, P. R. China
| | - Xiao Han
- Key Laboratory of Opto-Electronic Information Science and Technology of Jiangxi Province and Jiangxi Engineering Laboratory for Optoelectronics Testing Technology, Nanchang Hangkong University, Nanchang, P. R. China
| | - Yirui Zhu
- Key Laboratory of Opto-Electronic Information Science and Technology of Jiangxi Province and Jiangxi Engineering Laboratory for Optoelectronics Testing Technology, Nanchang Hangkong University, Nanchang, P. R. China
| | - Yubao Zhang
- Key Laboratory of Opto-Electronic Information Science and Technology of Jiangxi Province and Jiangxi Engineering Laboratory for Optoelectronics Testing Technology, Nanchang Hangkong University, Nanchang, P. R. China
| | - Guofu Huang
- Nanchang University, Nanchang, P. R. China.,Department of Ophthalmology, The Third Affiliated Hospital of Nanchang University, Nanchang, P. R. China
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Tafti MF, Aghamollaei H, Moghaddam MM, Jadidi K, Alio JL, Faghihi S. Emerging tissue engineering strategies for the corneal regeneration. J Tissue Eng Regen Med 2022; 16:683-706. [PMID: 35585479 DOI: 10.1002/term.3309] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2021] [Revised: 04/16/2022] [Accepted: 04/19/2022] [Indexed: 11/10/2022]
Abstract
Cornea as the outermost layer of the eye is at risk of various genetic and environmental diseases that can damage the cornea and impair vision. Corneal transplantation is among the most applicable surgical procedures for repairing the defected tissue. However, the scarcity of healthy tissue donations as well as transplantation failure has remained as the biggest challenges in confront of corneal grafting. Therefore, alternative approaches based on stem-cell transplantation and classic regenerative medicine have been developed for corneal regeneration. In this review, the application and limitation of the recently-used advanced approaches for regeneration of cornea are discussed. Additionally, other emerging powerful techniques such as 5D printing as a new branch of scaffold-based technologies for construction of tissues other than the cornea are highlighted and suggested as alternatives for corneal reconstruction. The introduced novel techniques may have great potential for clinical applications in corneal repair including disease modeling, 3D pattern scheming, and personalized medicine.
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Affiliation(s)
- Mahsa Fallah Tafti
- Stem Cell and Regenerative Medicine Group, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
| | - Hossein Aghamollaei
- Chemical Injuries Research Center, Systems Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | | | - Khosrow Jadidi
- Vision Health Research Center, Semnan University of Medical Sciences, Semnan, Iran
| | - Jorge L Alio
- Department of Research and Development, VISSUM, Alicante, Spain.,Cornea, Cataract and Refractive Surgery Department, VISSUM, Alicante, Spain.,Department of Pathology and Surgery, Division of Ophthalmology, Faculty of Medicine, Miguel Hernández University, Alicante, Spain
| | - Shahab Faghihi
- Stem Cell and Regenerative Medicine Group, National Institute of Genetic Engineering and Biotechnology, Tehran, Iran
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Brazuna R, Salomão M, Esporcatte B, Macedo M, Esporcatte L, Colombini GNUI, Ambrósio R. Corneal biomechanics and glaucoma beyond the bidirectional impact of intraocular pressure and corneal deformation response. REVISTA BRASILEIRA DE OFTALMOLOGIA 2022. [DOI: 10.37039/1982.8551.20220036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
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39
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Giraudet C, Diaz J, Le Tallec P, Allain JM. Multiscale mechanical model based on patient-specific geometry: Application to early keratoconus development. J Mech Behav Biomed Mater 2022; 129:105121. [DOI: 10.1016/j.jmbbm.2022.105121] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 01/19/2022] [Accepted: 02/03/2022] [Indexed: 11/30/2022]
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40
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Zvietcovich F, Larin KV. Wave-based optical coherence elastography: The 10-year perspective. PROGRESS IN BIOMEDICAL ENGINEERING (BRISTOL, ENGLAND) 2022; 4:012007. [PMID: 35187403 PMCID: PMC8856668 DOI: 10.1088/2516-1091/ac4512] [Citation(s) in RCA: 34] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
After 10 years of progress and innovation, optical coherence elastography (OCE) based on the propagation of mechanical waves has become one of the major and the most studied OCE branches, producing a fundamental impact in the quantitative and nondestructive biomechanical characterization of tissues. Preceding previous progress made in ultrasound and magnetic resonance elastography; wave-based OCE has pushed to the limit the advance of three major pillars: (1) implementation of novel wave excitation methods in tissues, (2) understanding new types of mechanical waves in complex boundary conditions by proposing advance analytical and numerical models, and (3) the development of novel estimators capable of retrieving quantitative 2D/3D biomechanical information of tissues. This remarkable progress promoted a major advance in answering basic science questions and the improvement of medical disease diagnosis and treatment monitoring in several types of tissues leading, ultimately, to the first attempts of clinical trials and translational research aiming to have wave-based OCE working in clinical environments. This paper summarizes the fundamental up-to-date principles and categories of wave-based OCE, revises the timeline and the state-of-the-art techniques and applications lying in those categories, and concludes with a discussion on the current challenges and future directions, including clinical translation research.
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Affiliation(s)
- Fernando Zvietcovich
- University of Houston, Biomedical Engineering, Houston, TX, United States, 77204
| | - Kirill V. Larin
- University of Houston, Biomedical Engineering, Houston, TX, United States, 77204,
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Karmiris E, Soulantzou K, Machairoudia G, Ntravalias T, Tsiogka A, Chalkiadaki E. Corneal Densitometry Assessed With Scheimpflug Camera in Healthy Corneas and Correlation With Specular Microscopy Values and Age. Cornea 2022; 41:60-68. [PMID: 33797466 DOI: 10.1097/ico.0000000000002722] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2020] [Accepted: 02/05/2021] [Indexed: 11/26/2022]
Abstract
PURPOSE To investigate correlations between specular microscopy endothelial parameters and age with corneal densitometry values, as they are presented from a Scheimpflug device, in different levels of the cornea. METHODS Two hundred eighty-four eyes of 142 healthy subjects were included in this observational, prospective study. Corneal densitometry was evaluated with Scheimpflug imaging system in the central 0- to 2-mm annular zone of the cornea, whereas the endothelial cell properties were assessed with the use of a noncontact specular microscope. RESULTS Corneal densitometry values of all corneal layers were statistically significant and positively correlated with age. In univariate linear regression analysis among corneal densitometry values and the endothelial parameters, only endothelial cell density (CD) was statistically significant and inversely correlated with densitometry values in all corneal layers. In stepwise multivariate linear regression analysis, after adjustment for age, hexagonality was statistically significant and inversely correlated with posterior densitometry values, whereas coefficient of variation was positively and significantly correlated with the anterior densitometry values. When repeating stepwise multivariate linear regression analysis without adjusting for age, CD was negatively and significantly correlated with corneal densitometry values of all layers, whereas coefficient of variation was positively and significantly correlated with anterior and total corneal densitometry values. CONCLUSIONS Corneal densitometry increases with age. It is also inversely correlated with CD, and this might be used as an indirect way to assess the status of the corneal endothelium.
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Affiliation(s)
- Efthymios Karmiris
- Ophthalmology Department, Hellenic Air Force General Hospital, Athens, Greece
| | | | - Genovefa Machairoudia
- Ophthalmology Department, Hellenic Air Force General Hospital and Attikon University Hospital, Athens, Greece ; and
| | - Thomas Ntravalias
- Ophthalmology Department, Hellenic Air Force General Hospital, Athens, Greece
| | - Anastasia Tsiogka
- Ophthalmology Department, Hellenic Army General Hospital, Athens, Greece
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Ida Y, Umetsu A, Furuhashi M, Watanabe M, Hikage F, Ohguro H. The EP2 agonist, omidenepag, alters the physical stiffness of 3D spheroids prepared from human corneal stroma fibroblasts differently depending on the osmotic pressure. FASEB J 2021; 36:e22067. [PMID: 34914140 DOI: 10.1096/fj.202101263r] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 10/23/2021] [Accepted: 11/10/2021] [Indexed: 11/11/2022]
Abstract
The objective of the current study was to examine the drug-induced effects of the EP2 agonist, omidenapag (OMD), on human corneal stroma, two- and three-dimensional (2D and 3D) cultures of human corneal stroma fibroblasts (HCSFs). The drug-induced effects on 2D monolayers and 3D spheroids were characterized by examining the ultrastructures by scanning electron microscope (SEM), transendothelial electrical resistance (TEER) measurements, and fluorescein isothiocyanate (FITC)-dextran permeability. The physical properties of 3D spheroids with respect to size and stiffness were also examined. In addition, the gene expressions of extracellular matrix (ECM) molecules, including collagen (COL) 1, 4, and 6, and fibronectin (FN), a tissue inhibitor of metalloproteinase (TIMP) 1-4, matrix metalloproteinase (MMP) 2, 9, and 14, aquaporin1 (AQP1), and several endoplasmic reticulum (ER) stress-related factors were evaluated. In the 2D HCSFs, OMD induced (1) a significant increase in ECM deposits, as evidenced by SEM, the mRNA expression of COL4 and FN, and (2) a decrease in TEER values and a concentration-dependent increase in FITC-dextran permeability. In the case of 3D spheroids, OMD had no effect on size but a substantial increase in stiffness was observed. Furthermore, such OMD-induced effects on stiffness were dramatically modulated by the osmotic pressure of the system. In contrast to the above 2D cultures, among the ECM molecules and the modulators of 3D spheroids, namely, TIMPS and MMPs, the down-regulation of COL1, TIMP1 and 2 and the up-regulation of MMP9 were observed. Interestingly, such diversity in terms of OMD-induced gene expressions between 2D and 3D cultures was also recognized in AQP1 (2D; no significant change, 3D; significant up-regulation) and ER stress-related genes. The findings presented herein suggest that the EP2 agonist, OMD, alters the physical stiffness of 3D spheroids obtained from human corneal stroma fibroblasts and this alteration is dependent on the osmotic pressures. 2D and 3D cell cultures may be useful for evaluating the drug induced effects of OMD toward human corneal stroma.
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Affiliation(s)
- Yosuke Ida
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Araya Umetsu
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Masato Furuhashi
- Department of Cardiovascular, Renal and Metabolic Medicine, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Megumi Watanabe
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Fumihito Hikage
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
| | - Hiroshi Ohguro
- Department of Ophthalmology, Sapporo Medical University School of Medicine, Sapporo, Japan
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Qiao X, Chen D, Huo H, Tang M, Tang Z, Dong Y, Liu X, Fan Y. Full-field strain mapping for characterization of structure-related variation in corneal biomechanical properties using digital image correlation (DIC) technology. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2021. [DOI: 10.1016/j.medntd.2021.100086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Li H, Chen M, Zhou Q, Pan X, Cheng J, Cong L, Zhang T, Dong Y, Xie L. Biomechanical Effects of Deep Anterior Lamellar Keratoplasty and Penetrating Keratoplasty for Keratoconus: A Finite Element Analysis. Transl Vis Sci Technol 2021; 10:15. [PMID: 34388236 PMCID: PMC8363774 DOI: 10.1167/tvst.10.9.15] [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] [Indexed: 11/24/2022] Open
Abstract
Purpose To theoretically compare corneal displacement and the von Mises (VM) stress distribution of deep anterior lamellar keratoplasty (DALK) and penetrating keratoplasty (PK) for keratoconus (KC) and to evaluate the effects of residual stromal thickness (RST) and intraocular pressure (IOP) on postoperative corneal biomechanics. Methods We performed DALK and PK simulations using Ansys by employing anisotropic nonlinear hyperelastic corneal material properties. We analyzed corneal displacement and VM stress in DALK and PK models under IOPs of 10, 15, 20, and 25 mmHg. We established two DALK models: The ideal-type DALK ensured that postoperative central corneal thickness was constant at 560 µm and the corneal graft thickness varied with RST. The clinical-type DALK ensured that corneal grafts had the same thickness (500 µm) regardless of RST. Then we analyzed the effects of RST and IOP on postoperative corneal displacement and VM stress. Results Corneal displacement and VM stress were lower in the DALK than in the PK model. In the ideal-type DALK model, an increase in RST was associated with increased deformation and decreased VM stress in the healing zone, except for a RST of 0 µm. In the clinical-type DALK model, deformation and VM stress in the healing zone decreased with an increase in RST, except for a RST of 0 µm. Conclusions DALK showed more stability than PK. For the ideal-type DALK model, an increase in RST resulted in decreased postoperative corneal biomechanics in the healing zone. For the clinical-type DALK model, corneal deformation and VM stress decreased with an increase in RST, which provides numerical evidence for the design of corneal transplantation for patients with KC. Translational Relevance In this computational modeling study, we first theoretically compared corneal biomechanics between DALK and PK for KC. Then, the effects of RST and IOP on postoperative corneal biomechanics were investigated. Our findings provide novel insights into the optimal design for corneal transplantation for patients with KC.
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Affiliation(s)
- Hua Li
- Department of Ophthalmology, Shanghai Ninth People's Hospital, Shanghai Jiaotong University School of Medicine, Shanghai, China
| | - Min Chen
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
| | - Qingjun Zhou
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
| | - Xiaojing Pan
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
| | - Jun Cheng
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
| | - Lin Cong
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
| | - Ting Zhang
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
| | - Yanling Dong
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
| | - Lixin Xie
- State Key Laboratory Cultivation Base, Shandong Provincial Key Laboratory of Ophthalmology, Shandong Eye Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Qingdao, China.,Qingdao Eye Hospital of Shandong First Medical University, Qingdao, China
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Customized eye modeling for optical quality assessment in myopic femto-LASIK surgery. Sci Rep 2021; 11:16049. [PMID: 34362982 PMCID: PMC8346559 DOI: 10.1038/s41598-021-95730-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 07/27/2021] [Indexed: 02/07/2023] Open
Abstract
Refractive surgery is recognized as an effective method for myopia treatment, but it can induce night vision disturbances such as glare. We present an eye modeling method for the optical quality assessment in response to the structural changes in the eyes by femto-LASIK surgery. Customized eye models were built from the measurements of 134 right eyes pre- and post-operatively. Optical performance was evaluated using spot diagrams, point spread functions (PSFs), modulation transfer functions (MTFs), and chromatic aberrations at various fields (0°-30°), different pupil diameters (2-6 mm), and initial myopias (- 1.25 to - 10.5 D). Pupil size and initial myopia are the two major factors that affect visual performance of post-operative eyes. The results of spot diagrams, PSFs, and MTFs indicated that post-operative visual performance deteriorated as the visual field and pupil size increased, and it was significantly influenced by initial myopia. Post-operative chromatic aberrations were also affected by initial myopia. As pupil size increased, the post-operative longitudinal chromatic aberrations tended to decrease slightly, while the transverse chromatic aberrations remained similar. The use of eye modeling for refractive surgery assessment could possibly provide a more personalized surgical approach, could improve the prediction accuracy of refractive surgery outcomes, and promote the invention and development of better surgical methods.
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New algorithm for corneal densitometry assessment based on anterior segment optical coherence tomography. Eye (Lond) 2021; 36:1675-1680. [PMID: 34341484 PMCID: PMC9307768 DOI: 10.1038/s41433-021-01707-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2020] [Revised: 07/01/2021] [Accepted: 07/16/2021] [Indexed: 11/08/2022] Open
Abstract
PURPOSE To describe a new algorithm to measure corneal densitometry based on images obtained by swept source anterior segment ocular coherence tomography (SS-AS-OCT) and establish standard densitometry values in a group of normal eyes. METHODS A total of 111 healthy participants (195 eyes) were enrolled in this study. Using a MATLAB designed algorithm, the cornea was segmented into three layers: anterior, posterior and mid-stroma, and it was divided into two concentric areas, 0-2 and 2-4 mm, resulting in nine areas for the analysis. The mean corneal densitometry values were calculated and expressed as grayscale units (GSU). RESULTS The mean age was 57 years (range 22-87), with 100 (51.3%) right eyes and 95 (48.7%) left eyes. The total corneal densitometry was 86.9 ± 12.1 GSU. The mid-stroma layer had the highest densitometry values, 87.4 ± 12.1 GSU, and the anterior layer had the lowest values, 81.9 ± 14.2 GSU. Densitometry differences between the anterior layer and the mid-stroma layer (P < 0.001), as well as the anterior layer and the posterior layer (P < 0.05) were statistically significant. The 0-2 mm concentric area had higher mean densitometry values, 97.8 ± 12.7 GSU, and the differences were significant compared to the 2-4 mm concentric area (P < 0.001). No correlation was found between the corneal densitometry values and gender or age. CONCLUSIONS The new MATLAB segmentation algorithm for the analysis of corneal SS-AS-OCT images is capable to objectively assess corneal densitometry. We provide standard and normal data for better clinical and research approach.
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Khosravimelal S, Mobaraki M, Eftekhari S, Ahearne M, Seifalian AM, Gholipourmalekabadi M. Hydrogels as Emerging Materials for Cornea Wound Healing. SMALL (WEINHEIM AN DER BERGSTRASSE, GERMANY) 2021; 17:e2006335. [PMID: 33887108 DOI: 10.1002/smll.202006335] [Citation(s) in RCA: 45] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2020] [Revised: 12/15/2020] [Indexed: 06/12/2023]
Abstract
Hydrogel biomaterials have many favorable characteristics including tuneable mechanical behavior, cytocompatibility, optical properties suitable for regeneration and restoration of the damaged cornea tissue. The cornea is a tissue susceptible to various injuries and traumas with a complicated healing cascade, in which conserving its transparency and integrity is critical. Accordingly, the hydrogels' known properties along with the stimulation of nerve and cell regeneration make them ideal scaffold for corneal tissue engineering. Hydrogels have been used extensively in clinical applications for the repair and replacement of diseased organs. The development and optimizing of novel hydrogels to repair/replace corneal injuries have been the main focus of researches within the last decade. This research aims to critically review in vitro, preclinical, as well as clinical trial studies related to corneal wound healing using hydrogels in the past 10 years, as this is considered as an emerging technology for corneal treatment. Several unique modifications of hydrogels with smart behaviors have undergone early phase clinical trials and showed promising outcomes. Financially, this considers a multibillion dollars industry and with huge interest from medical devices as well as pharmaceutical industries with several products may emerge within the next five years.
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Affiliation(s)
- Sadjad Khosravimelal
- Department of Medical Biotechnology, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, 1449614535, Iran
- Cellular and Molecular Research Centre, Iran University of Medical Sciences, Tehran, 1449614535, Iran
- Department of Tissue Engineering & Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, 1449614535, Iran
| | - Mohammadmahdi Mobaraki
- Department of Biomedical Engineering, Amirkabir University of Technology, Tehran, 1591634311, Iran
| | - Samane Eftekhari
- Department of Medical Biotechnology, Faculty of Allied Medicine, Iran University of Medical Sciences, Tehran, 1449614535, Iran
- Cellular and Molecular Research Centre, Iran University of Medical Sciences, Tehran, 1449614535, Iran
| | - Mark Ahearne
- Trinity Centre for Biomedical Engineering, School of Engineering, Trinity College Dublin, University of Dublin, Dublin, D02 R590, Republic of Ireland
| | - Alexander Marcus Seifalian
- Nanotechnology & Regenerative Medicine Commercialization Centre (NanoRegMed Ltd), London BioScience Innovation Centre, London, NW1 0NH, UK
| | - Mazaher Gholipourmalekabadi
- Cellular and Molecular Research Centre, Iran University of Medical Sciences, Tehran, 1449614535, Iran
- Department of Tissue Engineering & Regenerative Medicine, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, 1449614535, Iran
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Lan G, Aglyamov S, Larin KV, Twa MD. In vivo human corneal natural frequency quantification using dynamic optical coherence elastography: Repeatability and reproducibility. J Biomech 2021; 121:110427. [PMID: 33873114 DOI: 10.1016/j.jbiomech.2021.110427] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2020] [Revised: 03/20/2021] [Accepted: 03/29/2021] [Indexed: 12/14/2022]
Abstract
Reliable and quantitative assessment of corneal biomechanics is important for the detection and treatment of corneal disease. The present study evaluates the repeatability and reproducibility of a novel optical coherence tomography (OCT)-based elastography (OCE) method for in vivo quantification of corneal natural frequency in 20 normal human eyes. Sub-micron corneal oscillations were induced by repeated low-force (13 Pa) microliter air pulses at the corneal apex and were observed by common-path phase-sensitive OCT imaging adjacent to a measurement region of 1-6.25 mm2. Corneal natural frequencies were quantified using a single degree of freedom model based on the corneal oscillations. Corneal natural frequencies ranged from 234 to 277 Hz (coefficient of variation: 3.2%; n = 286 for a 2.5 × 2.5 mm2 area; time: 28.6 s). The same natural frequencies can be acquired using a smaller sampling size (n = 9 for 1 mm2) and a shorter time (0.9 s). Spatial distribution and local changes in natural frequencies can be distinguished using denser sampling (e.g., 26 × 41 points for 2.5 × 5 mm2). This novel optical method demonstrates highly repeatable and reliable in vivo measurements of human corneal natural frequencies. While further studies are required to fully characterize anatomical and structural dependencies, this method may be complementary to the current OCE methods used to estimate Young's modulus from strain- or shear-wave-based measurements for the quantitative determination of corneal biomechanics.
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Affiliation(s)
- Gongpu Lan
- Foshan University, School of Physics and Optoelectronic Engineering, Foshan, Guangdong 528000, China
| | - Salavat Aglyamov
- University of Houston, Mechanical Engineering, Houston, TX 77204, United States
| | - Kirill V Larin
- University of Houston, Biomedical Engineering, Houston, TX 77204, United States
| | - Michael D Twa
- University of Houston, College of Optometry, Houston, TX 77204, United States.
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Singh M, Nair A, Aglyamov SR, Larin KV. Compressional Optical Coherence Elastography of the Cornea. PHOTONICS 2021; 8:111. [PMID: 37727230 PMCID: PMC10508915 DOI: 10.3390/photonics8040111] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Assessing the biomechanical properties of the cornea is crucial for detecting the onset and progression of eye diseases. In this work, we demonstrate the application of compression-based optical coherence elastography (OCE) to measure the biomechanical properties of the cornea under various conditions, including validation in an in situ rabbit model and a demonstration of feasibility for in vivo measurements. Our results show a stark increase in the stiffness of the corneas as IOP was increased. Moreover, UV-A/riboflavin corneal collagen crosslinking (CXL) also dramatically increased the stiffness of the corneas. The results were consistent across 4 different scenarios (whole CXL in situ, partial CXL in situ, whole CXL in vivo, and partial CXL in vivo), emphasizing the reliability of compression OCE to measure corneal biomechanical properties and its potential for clinical applications.
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Affiliation(s)
- Manmohan Singh
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Room 2027, Houston, TX 77204, USA
| | - Achuth Nair
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Room 2027, Houston, TX 77204, USA
| | - Salavat R. Aglyamov
- Department of Mechanical Engineering, University of Houston, 4726 Calhoun Rd., Room N207, Houston, TX 77204, USA
| | - Kirill V. Larin
- Department of Biomedical Engineering, University of Houston, 3517 Cullen Blvd., Room 2027, Houston, TX 77204, USA
- Molecular Physiology and Biophysics, Baylor College of Medicine, One Baylor Plaza, BCM335, Houston, TX 77030, USA
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Corneal and lens densitometry in patients with vernal keratoconjunctivitis. Int Ophthalmol 2021; 41:2667-2676. [PMID: 33754236 PMCID: PMC7983973 DOI: 10.1007/s10792-021-01822-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Accepted: 03/16/2021] [Indexed: 10/25/2022]
Abstract
AIM To evaluate corneal and crystalline lens densitometry in patients with vernal keratoconjunctivitis (VKC). METHODS This is a case-control study. Patients with VKC and age-gender-matched healthy controls underwent a complete ophthalmologic examination with corneal and crystalline lens densitometry measurements. Additionally, the anterior chamber parameters comprise anterior and posterior Kmean and astigmatism, anterior chamber depth (ACD), anterior chamber volume (ACV), anterior chamber angle (ACA), pachymeter, and corneal volume (CV). Patients who had clinically grade 0 or grade 1 VKC and with only tarsal conjunctiva involvement during the conductance of the study were included. The variables were compared statistically. RESULTS One hundred and nine eyes were included in the study, in which fifty-one were in the VKC group. There were 25 males in the VKC group (26 female) and 22 males in the control group (36 female). A statistically significant difference was found between the groups in terms of posterior corneal astigmatism (p = 0.02). The mean corneal pachymeter, CV, ACD, ACA, and ACV were similar in both groups (p = 0.63, p = 0.26, p = 0.60, p = 0.41, and p = 0.32, respectively). The total mean corneal densitometry in the zones extending from 6 to 10 mm and 10 to 12 mm was increased in the VKC group compared to the control group (p = 0.04 and p = 0.012, respectively). The mean crystalline lens was found to be denser in the VKC group compared to the control group (8.96 ± 1.6 vs. 8.5 ± 0.57, respectively, p = 0.04). CONCLUSION Posterior corneal astigmatism is increased in VKC cases in comparison with age- and gender-matched controls. The peripheral anterior 6-12 mm annular corneal zone showed increased corneal densitometry in VKC cases compared to the healthy subjects. Additionally, the lens clarity is found to be decreased subclinically in VKC cases compared to control cases.
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