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Guo Y, Guo LL, Yang W, Tian L, Jie Y. Age-related analysis of corneal biomechanical parameters in healthy Chinese individuals. Sci Rep 2024; 14:21713. [PMID: 39289420 PMCID: PMC11408652 DOI: 10.1038/s41598-024-72054-2] [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: 03/21/2024] [Accepted: 09/03/2024] [Indexed: 09/19/2024] Open
Abstract
To report the correlation between corneal biomechanical parameters and age in healthy Chinese individuals. This cross-sectional study was conducted on 864 eyes of 543 healthy participants. A comprehensive ophthalmic examination and corneal biomechanics examination using Corneal Visualization Scheimpflug Technology (Corvis ST) were conducted. Based on age, all participants were further divided into five age groups (n) as follows: group A, 11-20 years (105); group B, 21-30 years (112); group C, 31-40 years (113); group D, 41-50 years (100); and group E, > 50 years (113). Using Corvis ST, we examined 35 corneal biomechanical parameters and compared them across the different age groups. Spearman's correlation coefficients and stepwise multivariate linear regression models were used to investigate whether the corneal biomechanical parameters were related to demographic and ocular characteristics. A correlation analysis between the left and right eyes revealed that 13 parameters were significantly associated with eye differences. Among the 35 corneal biomechanical parameters, 28 exhibited significant differences across the age groups, with stiffness parameter at applanation 1(SPA1) showing an upward trend after the age of 30 and stress-strain index (SSI) demonstrates a statistically significant upward trend when comparing the five age groups in the study. Additionally, Spearman's correlation analysis and stepwise multivariate linear regression analysis revealed that 11 corneal biomechanical parameters were positively correlated with age and 10 were negatively correlated with age. Corvis biomechanical index (CBI) was significantly negatively correlated with intraocular pressure (IOP) and central corneal thickness (CCT), SSI was significantly positively correlated with age and IOP, and SPA1 were positively correlated with IOP and CCT. In conclusion, most corneal biomechanical parameters showed a significant correlation with age, with corneal stiffness progressively increasing alongside advancing age, IOP, or CCT.
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Affiliation(s)
- Yihan Guo
- Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Li-Li Guo
- The First People's Hospital of Xuzhou, Xuzhou, China
| | - Weiqiang Yang
- Beijing Chaoyang Hospital, Capital Medical University, Beijing, China
| | - Lei Tian
- Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
| | - Ying Jie
- Beijing Ophthalmology and Visual Sciences Key Laboratory, Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
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Zhang T, Ye H, Xiao W, Chen R, Huasheng Y. Corneal Morphological and Biomechanical Changes in Thyroid-Associated Ophthalmopathy. Cornea 2024; 43:564-570. [PMID: 37607298 PMCID: PMC10980175 DOI: 10.1097/ico.0000000000003357] [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: 04/18/2023] [Revised: 06/08/2023] [Accepted: 06/12/2023] [Indexed: 08/24/2023]
Abstract
PURPOSE This study aimed to evaluate corneal morphological and biomechanical changes in patients with thyroid-associated ophthalmopathy (TAO) and their correlations with activity and severity. METHODS Patients diagnosed with TAO were recruited and divided into groups by activity and severity. All subjects underwent a complete ophthalmic examination, including magnetic resonance imaging. Corneal topography was measured using a Pentacam device, and biomechanical parameters were obtained using a CorVis ST tonometer. Correlations among the corneal parameters, clinical activity score, and NOSPECS score were analyzed. Areas under the receiver operating characteristic curves were calculated to evaluate the diagnostic accuracy of corneal changes for active and severe TAO. RESULTS Fifty-three eyes with TAO and 16 healthy eyes were enrolled in our study. The back elevation, CorVis biomechanical index, tomographic and biomechanical index, stiffness parameter at the first applanation, deviation from normality in back elevation, relational thickness, and overall deviation from normality were significantly increased in patients with TAO (all P <0.05), whereas the smallest corneal thickness, maximum Ambrósio relational thickness, and deformation amplitude (DA) ratio were significantly decreased (all P <0.05). The clinical activity score was strongly positively correlated with back elevation (γ = 0.515, P <0.001). The NOSPECS score was strongly positively correlated with relational thickness and tomographic and biomechanical index (γ = 0.429 and 0.515, P <0.001) and negatively correlated with maximum Ambrósio relational thickness (γ = -0.53, P <0.001). Moreover, maximum Ambrósio relational thickness and the Ambrósio relational thickness through the horizontal meridian showed desirable diagnostic capacity in distinguishing mild TAO from moderate-severe TAO (areas under the receiver operating characteristic curve, 0.799 and 0.769). CONCLUSIONS Corneal morphological and biomechanical changes were found in patients with TAO, which might be related to the presence of inflammation. Measurements of corneal morphological and biomechanical parameters could serve as references in evaluating TAO.
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Affiliation(s)
- Te Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Huijing Ye
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Wei Xiao
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Rongxin Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
| | - Yang Huasheng
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-Sen University, Guangdong Provincial Key Laboratory of Ophthalmology and Visual Science, Guangzhou, China
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Pérez-Corral J, Cardona G, Piñero DP, Barroso D, Armadans L. Short- and mid-term changes in CORVIS ST parameters in successful, adult orthokeratology patients. Clin Exp Optom 2023; 106:726-733. [PMID: 36375143 DOI: 10.1080/08164622.2022.2140031] [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: 03/27/2022] [Revised: 07/12/2022] [Accepted: 10/20/2022] [Indexed: 11/16/2022] Open
Abstract
CLINICAL RELEVANCE The changes in various biomechanical and tomographic characteristics of the cornea associated with orthokeratology may allow us to identify potential mid- and long-term structural alterations, resulting in a better understanding of the governing mechanisms of this procedure and in its optimisation. BACKGROUND The study aimed at describing short and mid-term changes in CORVIS ST® parameters and indices in orthokeratology (ortho-k), and their diurnal variations. METHODS A prospective observational study was designed in which several CORVIS ST® parameters of 75 new adult participants successfully fitted with overnight ortho-k Seefree® (Conóptica - Hecht Contactlinsen) contact lenses were explored. Measurements were conducted in baseline (BL) conditions and in the morning and evening at the one-night (1 NM/1NT), one-week (1WM/1 WT) and 3-month (3 MM/3MT) follow-up visits. RESULTS Statistically significant differences were found in DARatio_2 mm, IntRad, ARTh, CBI and TBI following overnight ortho-k, when compared with BL values, with most values reaching stability at 1WM or reverting to BL values at 3 MM. The ARTh and CBI parameters showed some of the most significant temporal variations (both p < 0.001), probably reflecting the encountered differences in central corneal thickness between BL and 1WM (p = 0.010) and between BL and 3 MM (p = 0.016). In general, corneal rigidity was higher in the morning at all follow-up visits, and decreased during the day. No statistically significant changes in adjusted intraocular pressure values were found. CONCLUSION Ortho-k in adults may be considered a safe procedure in terms of short and mid-term changes in CORVIS ST® parameters. The observed alterations in most of the parameters provided by the Corvis ST® probably responded to the well-described changes in corneal pachymetry and tomography, rather than to actual alterations in corneal rigidity.
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Affiliation(s)
- Joan Pérez-Corral
- School of Optics and Optometry, Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Spain
| | - Genis Cardona
- School of Optics and Optometry, Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Spain
| | - David P Piñero
- Department of Optics, Pharmacology and Anatomy, University of Alicante, Alicante, Spain
| | - David Barroso
- School of Optics and Optometry, Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Spain
| | - Laura Armadans
- School of Optics and Optometry, Department of Optics and Optometry, Universitat Politècnica de Catalunya, Terrassa, Spain
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Lanza M, Mozzillo E, Boccia R, Fedi L, Di Candia F, Tinto N, Melillo P, Simonelli F, Franzese A. Analysis of Corneal Deformation in Paediatric Patients Affected by Maturity Onset Diabetes of the Young Type 2. Diagnostics (Basel) 2023; 13:diagnostics13081500. [PMID: 37189601 DOI: 10.3390/diagnostics13081500] [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: 03/16/2023] [Revised: 04/15/2023] [Accepted: 04/19/2023] [Indexed: 05/17/2023] Open
Abstract
BACKGROUND To evaluate corneal deformation in Maturity Onset Diabetes of the Young type 2 (MODY2), paediatric subjects were analysed using a Scheimpflug-based device. The purpose of this analysis was to find new biomarkers for MODY2 disease and to gain a better understanding of the pathogenesis of the disease. METHODS A total of 15 patients with genetic and metabolic diagnoses of MODY2 (mean age 12.8 ± 5.66 years) and 15 age-matched healthy subjects were included. The biochemical and anthropometric data of MODY2 patients were collected from clinical records, and a complete ophthalmic check with a Pentacam HR EM-3000 Specular Microscope and Corvis ST devices was performed in both groups. RESULTS Highest concavity (HC) deflection length, Applanation 1 (A1) deflection amplitude, and A1 deflection area showed significantly lower values in MODY2 patients compared to healthy subjects. A significant positive correlation was observed between Body Mass Index (BMI) and HC deflection area and between waist circumference (WC) and the following parameters: maximum deformation amplitude, HC deformation amplitude, and HC deflection area. The glycosylated hemoglobin level (HbA1c) showed a significant positive correlation with Applanation 2 time and HC time. CONCLUSIONS The obtained results show, for the first time, differences regarding corneal distortion features in the MODY2 population compared with healthy eyes.
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Affiliation(s)
- Michele Lanza
- Multidisciplinary Department of Medical Surgical and Dental Specialties, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Enza Mozzillo
- Department of Translational Medical Sciences, Regional Center of Pediatric Diabetes, Federico II University of Naples, 80131 Naples, Italy
| | - Rosa Boccia
- Multidisciplinary Department of Medical Surgical and Dental Specialties, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Ludovica Fedi
- Department of Translational Medical Sciences, Regional Center of Pediatric Diabetes, Federico II University of Naples, 80131 Naples, Italy
| | - Francesca Di Candia
- Department of Translational Medical Sciences, Regional Center of Pediatric Diabetes, Federico II University of Naples, 80131 Naples, Italy
| | - Nadia Tinto
- Department of Molecular Medicine and Medical Biotechnology, CEINGE Advanced Biotechnologies, Federico II University of Naples, 80131 Naples, Italy
| | - Paolo Melillo
- Multidisciplinary Department of Medical Surgical and Dental Specialties, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Francesca Simonelli
- Multidisciplinary Department of Medical Surgical and Dental Specialties, University of Campania Luigi Vanvitelli, 80138 Naples, Italy
| | - Adriana Franzese
- Department of Translational Medical Sciences, Regional Center of Pediatric Diabetes, Federico II University of Naples, 80131 Naples, Italy
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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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Özdoğan S, Gürelik G, Bilgihan K. Analysis of corneal biomechanical properties 25 years after myopic photorefractive keratectomy. Int Ophthalmol 2023; 43:325-331. [PMID: 35918497 DOI: 10.1007/s10792-022-02436-w] [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: 01/15/2022] [Accepted: 07/05/2022] [Indexed: 02/07/2023]
Abstract
PURPOSE To evaluate corneal biomechanical changes using Corvis ST in patients treated with photorefractive keratectomy (PRK) 25 years ago. METHODS In this study, 32 post-PRK and 38 normal eyes underwent Corvis ST (CST) assessments. The measured CST factors were: time of highest concavity (HC), time of applanation 1 (AT1), time of applanation 2 (AT2), length of applanation 1 (AL1), length of applanation 2 (AL2), velocity of applanation 1 (AV1), velocity of applanation 2 (AV2), deformation amplitude (DA), peak distance (PD), integrated radius (IR), Ambrosio relational thickness horizontal (ARTh), stiffness parameter at first applanation (SP-A1), DA ratio (2 mm), Belin/Ambrosio enhanced ectasia display (BAD) and corneal biomechanical index (CBI). RESULTS The mean [± standard deviation (SD)] age was 51.4 ± 7.36 years in PRK, 51.4 ± 3.62 in control group. PRK was performed 24.69 ± 1.78 years ago. ARTh, SP-A1, AT1, AL1, and AL2 were lower in PRK. PD, AT2, DA ratio (2 mm), and IR were statistically higher in PRK (P < 0.01). In PRK and control group the mean value of CBI was 0.91 ± 0.11 and 0.50 ± 0.27 (P < 0.001), and mean value of BAD was 3.34 ± 1.53 and 1.1 ± 0.70 (P < 0.001). In PRK 71.9% of eyes were classed "high risk CBI plus diseased BAD" and 25% remained in the "high risk CBI and normal BAD" group. CONCLUSIONS In this study, most of the post-PRK eyes which were clinically and topographically normal were classified as "high risk CBI plus diseased BAD" and had significantly worse CBI and BAD values than the control group. This leads to the conclusion that CBI and BAD alone are not appropriate to evaluate post-PRK ectasia.
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Affiliation(s)
- Sibel Özdoğan
- Dr. Abdurrahman Yurtarslan Oncology Training and Research Hospital, 06400, Ankara, Turkey.
| | - Gökhan Gürelik
- Departments of Ophthalmology, Gazi University Medical School, Ankara, Turkey
| | - Kamil Bilgihan
- Departments of Ophthalmology, Gazi University Medical School, Ankara, Turkey
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Tai HY, Lin JJ, Huang YH, Shih PJ, Wang IJ, Yen JY. Correlation between corneal dynamic responses and keratoconus topographic parameters. J Int Med Res 2022; 50:3000605221108100. [PMID: 35766023 PMCID: PMC9247384 DOI: 10.1177/03000605221108100] [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] [Indexed: 11/16/2022] Open
Abstract
Objective To investigate the correlation between corneal biomechanical properties and
topographic parameters using machine learning networks for automatic
severity diagnosis and reference benchmark construction. Methods This was a retrospective study involving 31 eyes from 31 patients with
keratonus. Two clustering approaches were used (i.e., shape-based and
feature-based). The shape-based method used a keratoconus benchmark
validated for indicating the severity of keratoconus. The feature-based
method extracted imperative features for clustering analysis. Results There were strong correlations between the symmetric modes and the
keratoconus severity and between the asymmetric modes and the location of
the weak centroid. The Pearson product-moment correlation coefficient (PPMC)
between the symmetric mode and normality was 0.92 and between the asymmetric
mode and the weak centroid value was 0.75. Conclusion This study confirmed that there is a relationship between the keratoconus
signs obtained from topography and the corneal dynamic behaviour captured by
the Corvis ST device. Further studies are required to gather more patient
data to establish a more extensive database for validation.
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Affiliation(s)
- Hsi-Yun Tai
- Department of Mechanical Engineering, National Taiwan University, Taipei
| | - Jun-Ji Lin
- Department of Mechanical Engineering, National Taiwan University, Taipei
| | - Yi-Hung Huang
- Department of Mechanical Engineering, National Taiwan University, Taipei
| | - Po-Jen Shih
- Department of Biomedical Engineering, National Taiwan University, Taipei
| | - I-Jong Wang
- Department of Ophthalmology, National Taiwan University Hospital, Taipei
| | - Jia-Yush Yen
- Department of Mechanical Engineering, National Taiwan University, Taipei
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Kumar M, Shetty R, Lalgudi VG, Roy AS, Khamar P, Vincent SJ. Corneal Biomechanics and Intraocular Pressure Following Scleral Lens Wear in Penetrating Keratoplasty and Keratoconus. Eye Contact Lens 2022; 48:206-209. [PMID: 35333810 DOI: 10.1097/icl.0000000000000886] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/11/2021] [Indexed: 11/25/2022]
Abstract
OBJECTIVE To compare corneal biomechanics and intraocular pressure (IOP) in keratoconus and penetrating keratoplasty eyes before and after nonfenestrated scleral lens wear. METHODS Twenty-three participants were enrolled, and 37 eyes were included in the analysis (11 penetrating keratoplasty and 26 keratoconus). A range of corneal biomechanical parameters and IOP were measured using the CORVIS ST before and after 8 hr of nonfenestrated scleral lens wear (Keracare, Acculens, Denver, CO). RESULTS Before lens wear, penetrating keratoplasty eyes displayed significantly greater median values for central corneal thickness (97 μm thicker, P=0.02), IOP (3.89 mm Hg higher, P=0.01), and biomechanical parameter A2 length (0.48 mm longer, P=0.003) compared with keratoconic eyes. No significant changes in corneal biomechanical parameters or IOP were observed after scleral lens wear in either group (all P>0.05). CONCLUSION Although nonfenestrated scleral contact lenses can induce a subatmospheric pressure after lens settling and compress tissue surrounding the limbus, no significant changes were detected in the corneal biomechanical parameters studied using CORVIS ST after scleral lens wear in eyes with penetrating keratoplasty and keratoconus.
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Affiliation(s)
- Mukesh Kumar
- Narayana Nethralaya (M.K., R.S., V.G.L., A.S.R., P.K.), Bangalore, India; and Centre for Vision and Eye Research (S.J.V.), School of Optometry & Vision Science, Queensland University of Technology, Brisbane, Australia
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Xu Y, Ye Y, Chong IT, Chen Z, Xu J, Yang Y, Yu K, Lam DCC, Yu M. A Novel Indentation Assessment to Measure Corneal Biomechanical Properties in Glaucoma and Ocular Hypertension. Transl Vis Sci Technol 2021; 10:36. [PMID: 34459861 PMCID: PMC8411863 DOI: 10.1167/tvst.10.9.36] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Purpose To evaluate the ability of the new in vivo corneal indentation device (CID) to measure corneal biomechanical properties. Methods and Results In total, 186 eyes from 46 healthy subjects, 107 patients with primary open-angle glaucoma, and 33 patients with ocular hypertension were enrolled in a cross-sectional study. Measurements were performed using corneal visualization Scheimpflug technology (Corvis ST) and the CID. The deformation amplitude (DA), inward applanation time, inward applanation velocity (A1V), outward applanation time (A2T), outward applanation velocity (A2V), highest concavity time, DA ratio, max inverse radius (MIR), integrated radius, and stiffness parameter A1 were included as Corvis ST parameters, and stiffness and modulus were included as CID parameters. Associations between the Corvis ST and CID parameters and correlations between central corneal thickness and corneal biomechanical parameters were analyzed. The stiffness was significantly correlated with all the Corvis ST parameters (P < 0.05). The modulus was significantly correlated with the DA, A1V, A2T, A2V, highest concavity time, and MIR (P < 0.05). The DA, inward applanation time, A1V, A2T, A2V, DA ratio, MIR, integrated radius, and stiffness parameter A1 values and both CID-derived values were significantly correlated with central corneal thickness (P < 0.05). Conclusions Parameters derived from the CID and Corvis ST demonstrated agreement in the measurement of corneal biomechanical properties. The stiffness and modulus can characterize in vivo corneal biomechanical properties. Translational Relevance Agreeing with the Corvis ST regarding the assessment of corneal biomechanical properties, the CID can be a novel clinical tool for biomechanical evaluation of the cornea.
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Affiliation(s)
- Yunzhi Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yiming Ye
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Iok Tong Chong
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Zidong Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jiangang Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yangfan Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Keming Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - David C C Lam
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Minbin Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Baptista PM, Ambrosio R, Oliveira L, Meneres P, Beirao JM. Corneal Biomechanical Assessment with Ultra-High-Speed Scheimpflug Imaging During Non-Contact Tonometry: A Prospective Review. Clin Ophthalmol 2021; 15:1409-1423. [PMID: 33854295 PMCID: PMC8039844 DOI: 10.2147/opth.s301179] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Accepted: 03/05/2021] [Indexed: 12/31/2022] Open
Abstract
BACKGROUND In recent years, increasing interest has arisen in the application of data from corneal biomechanics in many areas of ophthalmology, particularly to assist in the detection of early corneal ectasia or ectasia susceptibility, to predict corneal response to surgical or therapeutic interventions and in glaucoma management. Technology has evolved and, recently, the Scheimpflug principle was associated with a non-contact air-puff tonometer, allowing a thorough analysis of corneal biomechanics and a biomechanically corrected intraocular pressure assessment, opening up new perspectives both in ophthalmology and in other medical areas. Data from corneal biomechanics assessment are being integrated in artificial intelligence models in order to increase its value in clinical practice. OBJECTIVE To review the state of the art in the field of corneal biomechanics assessment with special emphasis to the technology based on ultra-high-speed Scheimpflug imaging during non-contact tonometry. SUMMARY A meticulous literature review was performed until the present day. We used 136 published manuscripts as our references. Both information from healthy individuals and descriptions of possible associations with systemic diseases are described. Additionally, it exposed information regarding several fields of ocular pathology, from cornea and ocular surface through areas of refractive surgery and glaucoma until vascular and structural diseases of the chorioretinal unit.
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Affiliation(s)
- Pedro Manuel Baptista
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Porto, Portugal
| | - Renato Ambrosio
- Rio de Janeiro Corneal Tomography and Biomechanics Study Group, Rio de Janeiro, RJ, Brazil
- Department of Cornea and Refractive Surgery, Instituto de Olhos Renato Ambrósio, Rio de Janeiro, Brazil
- Department of Opthalmology, Federal University of the State of Rio de Janeiro (UNIRIO), Rio de Janeiro, Brazil
- Federal University of São Paulo (UNIFESP), São Paulo, Brazil
- Brazilian Study Group of Artificial Intelligence and Corneal Analysis - BrAIN, Rio de Janeiro & Maceió, Brazil
| | - Luis Oliveira
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Pedro Meneres
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Porto, Portugal
| | - Joao Melo Beirao
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Porto, Portugal
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Lanza M, De Rosa L, Sbordone S, Boccia R, Gironi Carnevale UA, Simonelli F. Analysis of Corneal Distortion after Myopic PRK. J Clin Med 2020; 10:jcm10010082. [PMID: 33379378 PMCID: PMC7794860 DOI: 10.3390/jcm10010082] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2020] [Revised: 12/14/2020] [Accepted: 12/24/2020] [Indexed: 01/22/2023] Open
Abstract
The purpose of the study is to evaluate the corneal biomechanical properties (CBP) and their behaviors after myopic refractive surgery both with Ocular Response Analyzer (ORA) and Corvis ST (CST). This retrospective study included 145 eyes of 145 patients with a mean age of 33.13 ± 9.24 years, who underwent myopic photorefractive keratectomy (PRK) for a refractive defect, measured as spherical equivalent, of mean −4.69 ± 2.04 D and have been evaluated before surgery and at 1, 3 and 6 months follow-up. Corneal hysteresis (CH) and corneal resistance factor (CRF) values significantly decreased after 1 month and remained statistically stable during further follow-ups. CST parameters had a different evolution: only second applanation time (AT2) differences showed a significant variation after 1 month that did not statistically change over time. Highest concavity deformation amplitude (HCDA), highest concavity peak distance (HCPD), first applanation time (AT1) and velocity (AV1) showed continuous significant differences both after 3 and after 6 months. This study suggests that after central surface ablation surgery, such as myopic PRK, corneal shape is remodeling, and its deformation parameters are going to change even at 6 months follow-up. This indicates that it should be important to evaluate refractive surgery patients during a longer follow-up because this could allow earlier diagnosis and better management of late-onset complications.
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Wang X, Xu G, Wang W, Wang J, Chen L, He M, Chen Z. Changes in corneal biomechanics in patients with diabetes mellitus: a systematic review and meta-analysis. Acta Diabetol 2020; 57:973-981. [PMID: 32201905 DOI: 10.1007/s00592-020-01481-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2019] [Accepted: 01/10/2020] [Indexed: 02/07/2023]
Abstract
AIMS To determine the changes in corneal biomechanical parameters in patients with diabetes mellitus (DM) in comparison with controls. METHODS Pertinent studies were identified by comprehensively search of PubMed, Embase, the Web of Science, the Cochrane Library, Scopus, the China National Knowledge Infrastructure and the Chinese biomedical disc (CBM) databases. Pooling analyses by random models using the D-L method were performed for corneal hysteresis (CH), the corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc) and Goldmann-correlated intraocular pressure (IOPg). RESULTS A total of 15 studies were included in the final analysis, involving 1506 eyes in the diabetic group and 2190 eyes in the control group. The diabetic group had significantly higher CH, CRF, IOPg and IOPcc values than the control group. The pooled mean differences were 1.34 mmHg (95% confidence interval [CI] 0.60-2.08 mmHg, P < 0.001) for IOPg and 0.85 mmHg (95% CI 0.18-1.51 mmHg, P = 0.013) for IOPcc, 0.38 mmHg (95% CI 0.01-0.75, P = 0.047) for CH and 0.63 mmHg (95% CI 0.27-0.98, P = 0.001) for the CRF. Sensitivity analyses using the leave-one-out method showed a consistent significant difference between the groups (all P < 0.001). CONCLUSIONS Corneal biomechanics changed in the patients with DM. High CH, CRF, IOPcc and IOPg values may be associated factors for diabetes mellitus. Future studies are warranted to clarify the underlying mechanisms and explore the relationship between corneal biomechanics, glaucoma and diabetes mellitus. REGISTRATION PROSPERO registration No CRD4201705465.
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Affiliation(s)
- Xiaoyi Wang
- Department of Ophthalmology Center, Huizhou Municipal Central Hospital, Huizhou, Guangdong Province, People's Republic of China
| | - Guihua Xu
- Department of Ophthalmology Center, Huizhou Municipal Central Hospital, Huizhou, Guangdong Province, People's Republic of China
| | - Wei Wang
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Juanjuan Wang
- Department of Ophthalmology Center, Huizhou Municipal Central Hospital, Huizhou, Guangdong Province, People's Republic of China
| | - Lili Chen
- Department of Ophthalmology Center, Huizhou Municipal Central Hospital, Huizhou, Guangdong Province, People's Republic of China
| | - Mingguang He
- Zhongshan Ophthalmic Center, State Key Laboratory of Ophthalmology, Sun Yat-Sen University, Guangzhou, People's Republic of China
| | - Zilin Chen
- Department of Ophthalmology Center, Huizhou Municipal Central Hospital, Huizhou, Guangdong Province, People's Republic of China.
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Jędzierowska M, Koprowski R, Wilczyński S, Krysik K. A new method for detecting the outer corneal contour in images from an ultra-fast Scheimpflug camera. Biomed Eng Online 2019; 18:115. [PMID: 31796067 PMCID: PMC6888987 DOI: 10.1186/s12938-019-0735-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2019] [Accepted: 11/22/2019] [Indexed: 01/28/2023] Open
Abstract
Background The Corvis® ST tonometer is an innovative device which, by combining a classic non-contact tonometer with an ultra-fast Scheimpflug camera, provides a number of parameters allowing for the assessment of corneal biomechanics. The acquired biomechanical parameters improve medical diagnosis of selected eye diseases. One of the key elements in biomechanical measurements is the correct corneal contour detection, which is the basis for further calculations. The presented study deals with the problem of outer corneal edge detection based on a series of images from the afore-mentioned device. Corneal contour detection is the first and extremely important stage in the acquisition and analysis of corneal dynamic parameters. Result A total of 15,400 images from the Corvis® ST tonometer acquired from 110 patients undergoing routine ophthalmologic examinations were analysed. A method of outer corneal edge detection on the basis of a series of images from the Corvis® ST was proposed. The method was compared with known and commonly used edge detectors: Sobel, Roberts, and Canny operators, as well as others, known from the literature. The analysis was carried out in MATLAB® version 9.0.0.341360 (R2016a) with the Image Processing Toolbox (version 9.4) and the Neural Network Toolbox (version 9.0). The method presented in this paper provided the smallest values of the mean error (0.16%), stability (standard deviation 0.19%) and resistance to noise, characteristic for Corvis® ST tonometry tests, compared to the methods known from the literature. The errors were 5.78 ± 9.19%, 3.43 ± 6.21%, and 1.26 ± 3.11% for the Roberts, Sobel, and Canny methods, respectively. Conclusions The proposed new method for detecting the outer corneal contour increases the accuracy of intraocular pressure measurements. It can be used to analyse dynamic parameters of the cornea.
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Affiliation(s)
- Magdalena Jędzierowska
- Institute of Biomedical Engineering, Faculty of Science and Technology, University of Silesia in Katowice, ul. Będzińska 39, 41-200, Sosnowiec, Poland.
| | - Robert Koprowski
- Institute of Biomedical Engineering, Faculty of Science and Technology, University of Silesia in Katowice, ul. Będzińska 39, 41-200, Sosnowiec, Poland
| | - Sławomir Wilczyński
- Department of Basic Biomedical Science, School of Pharmacy with the Division of Laboratory Medicine in Sosnowiec, Medical University of Silesia in Katowice, Kasztanowa Street 3, 41-200, Sosnowiec, Poland
| | - Katarzyna Krysik
- Department of Ophthalmology with Paediatric Unit, St. Barbara Hospital, Trauma Centre, Plac Medykow 1, 41-200, Sosnowiec, Poland
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Lam AKC, Leung SYY, Hon Y, Shu-Ho L, Wong KY, Tiu PK, Lam DCC. Influence of Short-Term Orthokeratology to Corneal Tangent Modulus: A Randomized Study. Curr Eye Res 2017; 43:474-481. [DOI: 10.1080/02713683.2017.1418895] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Affiliation(s)
- Andrew KC Lam
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Stanley YY Leung
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Ying Hon
- Centre for Myopia Research, School of Optometry, The Hong Kong Polytechnic University, Hong Kong, China
| | - Lu Shu-Ho
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Kit-ying Wong
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - Pui-kwan Tiu
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
| | - David CC Lam
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Hong Kong, China
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Corneal Biomechanical Properties in High Myopia Measured by Dynamic Scheimpflug Imaging Technology. Optom Vis Sci 2017; 94:1074-1080. [DOI: 10.1097/opx.0000000000001152] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
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Estimation of the Corneal Young's Modulus In Vivo Based on a Fluid-Filled Spherical-Shell Model with Scheimpflug Imaging. J Ophthalmol 2017; 2017:5410143. [PMID: 29250440 PMCID: PMC5698833 DOI: 10.1155/2017/5410143] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2017] [Revised: 07/19/2017] [Accepted: 08/01/2017] [Indexed: 11/23/2022] Open
Abstract
Current intraocular pressure (IOP) measurement using air puff could be erroneous without applying proper corrections. Although noncontact tonometry is not considered to be accurate, it is still popularly used by eye clinics. It is thus necessary to extract the correct information from their results. This study proposes a practical approach to correctly measure IOP in vivo. By embedding a new model-based correction to the Corvis® ST, we can extract the corneal Young's modulus from the patient data. This Young's modulus can be used to correct the IOP readings. The tests were applied to 536 right eyes of 536 healthy subjects (228 male and 308 female) between March of 2012 and April of 2016. The tests were applied to patients at the Department of Ophthalmology, National Taiwan University Hospital and the Hung-Chuo Eye Clinics. The statistical analysis showed that the value for the Young's modulus was independent of all the other parameters collected from the Corvis ST, including the corneal thickness and the intraocular pressure. Therefore, it is important to independently measure the Young's modulus instead of depending on the correlation with the other parameters. This study adds the methodology of measuring corneal stiffness in vivo for ophthalmologists' reference in diagnosis.
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Long Q, Wang JY, Xu D, Li Y. Comparison of corneal biomechanics in Sjögren's syndrome and non-Sjögren's syndrome dry eyes by Scheimpflug based device. Int J Ophthalmol 2017; 10:711-716. [PMID: 28546925 DOI: 10.18240/ijo.2017.05.08] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2016] [Accepted: 12/29/2016] [Indexed: 11/23/2022] Open
Abstract
AIM To compare the corneal biomechanics of Sjögren's syndrome (SS) and non-SS dry eyes with Corneal Visualization Scheimpflug Technology (CorVis ST). METHODS Corneal biomechanics and tear film parameters, namely the Schirmer I test value, tear film break-up time (TBUT) and corneal staining score (CSS) were detected in 34 eyes of 34 dry eye patients with SS (SSDE group) and 34 dry eye subjects without SS (NSSDE group) using CorVis ST. The differences of the above parameters between the two groups were examined, and the relationship between corneal biomechanics and tear film parameters were observed. RESULTS The differences in age, sex, intraocular pressure (IOP) and central corneal thickness (CCT) were not significant between the two groups (P>0.05). The tear film parameters had significant differences between the SSDE group and NSSDE group (all P<0.05). Patients in the SSDE group had significantly lower A1-time and HC-time, but higher DA (P=0.01, 0.02, and 0.02, respectively) compared with the NSSDE group. In the SSDE group, DA was negatively correlated with TBUT (rho=-0.38, P=0.03); HC-time was negatively correlated with CSS (rho=-0.43, P=0.02). In the NSSDE group, HC-time was again negatively correlated with CSS (rho=-0.39, P=0.02). CONCLUSION There are differences in corneal biomechanical properties between SSDE and NSSDE. The cornea of SSDE tends to show less "stiffness", as seen by a significantly shorter A1-time and HC-time, but larger DA, compared with the cornea of NSSDE. Biomechanical parameters can be influenced by different tear film parameters in both groups.
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Affiliation(s)
- Qin Long
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
| | - Jing-Yi Wang
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
| | - Dong Xu
- Department of Rheumatology and Clinical Immunology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
| | - Ying Li
- Department of Ophthalmology, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences & Peking Union Medical College, Beijing 100730, China
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Applications of Scheimpflug Imaging in Glaucoma Management: Current and Potential Applications. J Ophthalmol 2016; 2016:3062381. [PMID: 28044101 PMCID: PMC5164893 DOI: 10.1155/2016/3062381] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Revised: 09/06/2016] [Accepted: 10/04/2016] [Indexed: 11/24/2022] Open
Abstract
Scheimpflug photography is the basis for a variety of imaging devices that are highly versatile. The applications of Scheimpflug imaging are wide in scope, spanning from evaluation of corneal ectasia to quantifying density in nuclear sclerotic cataracts. The potential uses for Scheimpflug-based devices are expanding and a number of them are relevant in glaucoma. In particular, they can provide three-dimensional image reconstruction of the anterior segment which includes assessment of the iridocorneal angle. Photographic analyses allow also for a noncontact method of estimating central corneal thickness (CCT) and intraocular pressure (IOP), as well as the study of various corneal biomechanical properties, which may be useful for stratifying glaucoma risk.
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