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Sun Y, Guo Y, Pang R, Peng J, Cao K, Wang N. Corneal biomechanical properties and potential influencing factors in varying degrees of myopia. Sci Rep 2024; 14:20626. [PMID: 39232107 PMCID: PMC11374800 DOI: 10.1038/s41598-024-71676-w] [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: 05/30/2024] [Accepted: 08/29/2024] [Indexed: 09/06/2024] Open
Abstract
To compare the corneal biomechanical parameters measured by Corvis ST in subjects with varying degrees of myopia. And the factors that may affect corneal biomechanical properties were also investigated. Participants in this prospective cross-sectional study were classified into three groups according to spherical equivalent (SE) and axial length (AL): Non-myopia (NM, SE > - 0.50 D and AL < 26 mm), Mild-to-moderate myopia (MM, - 6.00 D < SE ≤ - 0.50 D and AL < 26 mm), high myopia (HM, SE ≤ - 6.00 D or AL ≥ 26 mm). Ten corneal biomechanical parameters were finally included. Linear mixed-effects model accounting for using both eyes in the same participant was carried out to evaluate how the corneal biomechanical parameter was influenced by varying degrees of myopia after adjusting for biomechanically corrected intraocular pressure (bIOP) and central corneal thickness (CCT). Further, multiple linear regression was performed to explore the correlation between corneal biomechanical parameter and SE, AL, bIOP or CCT. A total of 304 eyes from 224 healthy myopic subjects were recorded. There were 95 eyes with NM, 122 eyes with MM, and 87 eyes with HM. After adjusting for bIOP and CCT, eyes with high myopia showed shorter highest concavity time (HC-time, p = 0.025), greater peak distance (PD, p = 0.001), greater deflection amplitude (DA-Max, p = 0.002), smaller whole eye movement (WEM-Max, p < 0.001) and reduced stiffness parameter (SP-A1, p < 0.001). Multiple regression analysis showed that five parameters (HC-time, p < 0.001; PD, p < 0.001; DA-Max, p = 0.001; WEM-Max, p < 0.001; and SP-A1, p < 0.001) of Corvis ST were significantly correlated with AL, and one parameter (Corvis biomechanical index, p = 0.016) has significant relationship with SE. With the increase of myopia, significant changes in several corneal biomechanical parameters indicated a progressive decrease in corneal stiffness, independent of bIOP and CCT. Corneal biomechanical parameters may be predictors of scleral mechanical strength in high myopia, which has certain application value in clinical management of myopia.
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Affiliation(s)
- Yunxiao Sun
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaominxiang Street, Dongcheng District, Beijing, 100730, China
| | - Yiqin Guo
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaominxiang Street, Dongcheng District, Beijing, 100730, China
| | - Ruiqi Pang
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaominxiang Street, Dongcheng District, Beijing, 100730, China
| | - Jieting Peng
- Eye College of Chengdu University of TCM, Chengdu, Sichuan, China
| | - Kai Cao
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China
| | - Ningli Wang
- Beijing Ophthalmology and Visual Sciences Key Lab, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, No. 1 Dongjiaominxiang Street, Dongcheng District, Beijing, 100730, China.
- Beijing Institute of Ophthalmology, Beijing Tongren Hospital, Capital Medical University, Beijing, China.
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Redaelli E, Calvo B, Rodriguez Matas JF, Luraghi G, Grasa J. Non-contact tonometry: predicting intraocular pressure using a material-corneal thickness-independent methodology. Front Bioeng Biotechnol 2024; 12:1406870. [PMID: 39119274 PMCID: PMC11306172 DOI: 10.3389/fbioe.2024.1406870] [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: 03/25/2024] [Accepted: 06/17/2024] [Indexed: 08/10/2024] Open
Abstract
Introduction: Glaucoma, a leading cause of blindness worldwide, is primarily caused by elevated intraocular pressure (IOP). Accurate and reliable IOP measurements are the key to diagnose the pathology in time and to provide for effective treatment strategies. The currently available methods for measuring IOP include contact and non contact tonometers (NCT), which estimate IOP based on the corneal deformation caused by an external load, that in the case of NCT is an air pulse. The deformation of the cornea during the tonometry is the result of the coupling between the IOP, the mechanical properties of the corneal tissue, the corneal thickness, and the external force applied. Therefore, there is the need to decouple the four contributions to estimate the IOP more reliably. Methods: This paper aims to propose a new methodology to estimate the IOP based on the analysis of the mechanical work performed by the air jet and by the IOP during the NCT test. A numerical eye model is presented, initially deformed by the action of a falling mass to study the energy balance. Subsequently, Fluid-Structure Interaction (FSI) simulations are conducted to simulate the action of Corvis ST. Results and discussion: The new IOP estimation procedure is proposed based on the results of the simulations. The methodology is centred on the analysis of the time of maximum apex velocity rather than the point of first applanation leading to a new IOP estimation not influenced by the geometrical and mechanical corneal factors.
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Affiliation(s)
- Elena Redaelli
- Aragón Institute of Engineering Research (I3A), Universidad de Zaragoza, Zaragoza, Spain
| | - Begoña Calvo
- Aragón Institute of Engineering Research (I3A), Universidad de Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomecánica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
| | - Jose Felix Rodriguez Matas
- LaBS, Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Milan, Italy
| | - Giulia Luraghi
- LaBS, Department of Chemistry, Materials and Chemical Engineering “Giulio Natta”, Politecnico di Milano, Milan, Italy
| | - Jorge Grasa
- Aragón Institute of Engineering Research (I3A), Universidad de Zaragoza, Zaragoza, Spain
- Centro de Investigación Biomecánica en Red en Bioingeniería, Biomateriales y Nanomedicina (CIBER-BBN), Zaragoza, Spain
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Pradhan ZS, Sreenivasaiah S, Deshmukh S, Mangala L, Shroff S, Devi S, Webers CA, Rao HL. Factors affecting corneal deformation amplitude measured by Corvis ST in eyes with open-angle glaucoma. Indian J Ophthalmol 2024; 72:533-537. [PMID: 38099366 PMCID: PMC11149506 DOI: 10.4103/ijo.ijo_822_23] [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: 03/28/2023] [Accepted: 09/15/2023] [Indexed: 12/19/2023] Open
Abstract
PURPOSE To evaluate the factors affecting corneal deformation amplitude (DA) measured using Corvis ST in eyes with open-angle glaucoma. METHODS This prospective, longitudinal study included 48 eyes with open-angle glaucoma who required additional intraocular pressure (IOP)-lowering drops. All eyes underwent a complete eye examination at baseline, including a Corvis ST, which was repeated 4-8 weeks after the change in therapy. Factors affecting the corneal biomechanics, namely the DA, were determined using mixed effect models. RESULTS The mean age of the cohort was 65.0 ± 7.9 years. The mean IOP reduced from 23.4 ± 5.4 mmHg to 17.9 ± 5 mmHg after the change in glaucoma treatment ( P < 0.001). The DA increased from 0.89 ± 0.16 mm to 1.00 ± 0.13 mm after IOP reduction ( P < 0.001). On mixed effect model analysis, IOP (-0.02 ± 0.001, P < 0.001) and corneal pachymetry (-0.0003 ± 0.0001, P = 0.02) affected the change in the DA. CONCLUSION IOP and corneal pachymetry affect the DA and must be accounted for when using Corvis ST to evaluate corneal biomechanics in glaucoma.
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Affiliation(s)
- Zia S Pradhan
- Department of Glaucoma, Narayana Nethralaya, Bangalore, Karnataka, India
| | | | - Sujit Deshmukh
- Department of Glaucoma, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Lavi Mangala
- Department of Glaucoma, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Sujani Shroff
- Department of Glaucoma, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Sathi Devi
- Department of Glaucoma, Narayana Nethralaya, Bangalore, Karnataka, India
| | - Carroll Ab Webers
- Department of Glaucoma, University Eye Clinic Maastricht, University Medical Center, Maastricht, The Netherlands
| | - Harsha L Rao
- Department of Glaucoma, University Eye Clinic Maastricht, University Medical Center, Maastricht, The Netherlands
- Department of Glaucoma, Narayana Nethralaya, 63, Bannerghatta Road, Hulimavu, Bangalore, Karnataka, India
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Baptista PML, Ferreira AS, Silva NP, Figueiredo ARM, Sampaio IC, Reis RVF, Ambrósio R, Menéres PMAM, Beirão JNM, Menéres MJFS. Scheimpflug-Based Corneal Biomechanical Analysis As A Predictor of Glaucoma in Eyes With High Myopia. Clin Ophthalmol 2024; 18:545-563. [PMID: 38410632 PMCID: PMC10895980 DOI: 10.2147/opth.s426635] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Accepted: 01/04/2024] [Indexed: 02/28/2024] Open
Abstract
Purpose To address if corneal biomechanical behavior has a predictive value for the presence of glaucomatous optical neuropathy in eyes with high myopia. Patients and Methods This observational cross-sectional study included 209 eyes from 108 consecutive patients, divided into four groups: high myopia and primary open-angle glaucoma (POAG) - HMG, n = 53; high myopia without POAG - HMNG, n = 53; non-myopic with POAG - POAG, n = 50; non-myopic and non-POAG- NMNG, n = 53. Biomechanical assessment was made through a Scheimpflug-camera-based technology. Receiver operating characteristic curves were made for the discrimination between groups. Multivariable logistic regression models were performed to address the predictive value of corneal biomechanics for the presence of glaucoma. Results Areas Under the Receiver Operating Characteristic (AUROCs) above 0.6 were found in 6 parameters applied to discriminate between HMG and HMNG and six parameters to discriminate between POAG and NMNG. The biomechanical models with the highest power of prediction for the presence of glaucoma included 5 parameters with an AUROC of 0.947 for eyes with high myopia and 6 parameters with an AUROC of 0.857 for non-myopic eyes. In the final model, including all eyes, and adjusted for the presence of high myopia, the highest power of prediction for the presence of glaucoma was achieved including eight biomechanical parameters, with an AUROC of 0.917. Conclusion Corneal biomechanics demonstrated differences in eyes with glaucoma and mainly in myopic eyes. A biomechanical model based on multivariable logistic regression analysis and adjusted for high myopia was built, with an overall probability of 91.7% for the correct prediction of glaucomatous damage.
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Affiliation(s)
- Pedro M L Baptista
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - André S Ferreira
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Faculdade de Medicina da Universidade do Porto, Universidade do Porto, Porto, Portugal
| | - Nisa P Silva
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Ana R M Figueiredo
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Isabel C Sampaio
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Rita V F Reis
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Renato Ambrósio
- 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 Ophthalmology, 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
| | - Pedro M A M Menéres
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - João N M Beirão
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Maria J F S Menéres
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
- Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
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Miao YY, Ma XM, Qu ZX, Eliasy A, Wu BW, Xu H, Wang P, Zheng XB, Wang JJ, Ye YF, Chen SH, Elsheikh A, Bao FJ. Performance of Corvis ST Parameters Including Updated Stress-Strain Index in Differentiating Between Normal, Forme-Fruste, Subclinical, and Clinical Keratoconic Eyes. Am J Ophthalmol 2024; 258:196-207. [PMID: 37879454 DOI: 10.1016/j.ajo.2023.10.015] [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: 05/31/2023] [Revised: 10/18/2023] [Accepted: 10/20/2023] [Indexed: 10/27/2023]
Abstract
PURPOSE This study seeks to evaluate the ability of the updated stress strain index (SSIv2) and other Corvis ST biomechanical parameters in distinguishing between keratoconus at different disease stages and normal eyes. DESIGN Diagnostic accuracy analysis to distinguish disease stages. METHODS 1084 eyes were included and divided into groups of normal (199 eyes), forme fruste keratoconus (FFKC, 194 eyes), subclinical keratoconus (SKC, 113 eyes), mild clinical keratoconus (CKC-Ⅰ, 175 eyes), moderate clinical keratoconus (CKC-Ⅱ, 204 eyes), and severe clinical keratoconus (CKC-Ⅲ, 199 eyes). Each eye was subjected to a Corvis ST examination to determine the central corneal thickness (CCT), biomechanically corrected intraocular pressure (bIOP), SSIv2 (updated stress-strain index), and other 8 Corvis parameters including the stress-strain index (SSIv1), stiffness parameter at first applanation (SP-A1), first applanation time (A1T), Ambrósio relational thickness to the horizontal profile (ARTh), integrated inverse radius (IIR), maximum deformation amplitude (DAM), ratio between deformation amplitude at the apex and at 2 mm nasal and temporal (DARatio2), and Corvis biomechanical index (CBI). The sensitivity and specificity of these parameters in diagnosing keratoconus were analyzed through receiver operating characteristic curves. RESULTS Before and after correction for CCT and bIOP, SSIv2 and ARTh were significantly higher and IIR and CBI were significantly lower in the normal group than in the FFKC group, SKC group and the 3 CKC groups (all P < .05). There were also significant correlations between the values of SSIv2, ARTh, IIR, CBI, and the CKC severity (all P < .05). AUC of SSIv2 was significantly higher than all other Corvis parameters in distinguishing normal eyes from FFKC, followed by IIR, ARTh and CBI. CONCLUSION Corvis ST's updated stress-strain index, SSIv2, demonstrated superior performance in differentiating between normal and keratoconic corneas, and between corneas with different keratoconus stages. Similar, but less pronounced, performance was demonstrated by the IIR, ARTh and CBI.
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Affiliation(s)
- Yuan-Yuan Miao
- National Clinical Research Center for Ocular Diseases, Eye Hospital, WenZhou Medical University (Y.-Y.M., Z.-X.Q., B.-W.W., H.X., P.W., X.-B.Z., J.-J.W., Y.-F.Y., S.-H.C., F.-J.B), Wenzhou, Zhejiang, China
| | - Xiao-Min Ma
- Shanghai Eighth People's Hospital (X.-M.M.), Shanghai, China
| | - Zhan-Xin Qu
- National Clinical Research Center for Ocular Diseases, Eye Hospital, WenZhou Medical University (Y.-Y.M., Z.-X.Q., B.-W.W., H.X., P.W., X.-B.Z., J.-J.W., Y.-F.Y., S.-H.C., F.-J.B), Wenzhou, Zhejiang, China
| | - Ashkan Eliasy
- School of Engineering, University of Liverpool (A.Eli., A.Els.), Liverpool, United Kingdom
| | - Bo-Wen Wu
- National Clinical Research Center for Ocular Diseases, Eye Hospital, WenZhou Medical University (Y.-Y.M., Z.-X.Q., B.-W.W., H.X., P.W., X.-B.Z., J.-J.W., Y.-F.Y., S.-H.C., F.-J.B), Wenzhou, Zhejiang, China
| | - Hui Xu
- National Clinical Research Center for Ocular Diseases, Eye Hospital, WenZhou Medical University (Y.-Y.M., Z.-X.Q., B.-W.W., H.X., P.W., X.-B.Z., J.-J.W., Y.-F.Y., S.-H.C., F.-J.B), Wenzhou, Zhejiang, China
| | - Pu Wang
- National Clinical Research Center for Ocular Diseases, Eye Hospital, WenZhou Medical University (Y.-Y.M., Z.-X.Q., B.-W.W., H.X., P.W., X.-B.Z., J.-J.W., Y.-F.Y., S.-H.C., F.-J.B), Wenzhou, Zhejiang, China
| | - Xiao-Bo Zheng
- National Clinical Research Center for Ocular Diseases, Eye Hospital, WenZhou Medical University (Y.-Y.M., Z.-X.Q., B.-W.W., H.X., P.W., X.-B.Z., J.-J.W., Y.-F.Y., S.-H.C., F.-J.B), Wenzhou, Zhejiang, China; The Institute of Ocular Biomechanics, Wenzhou Medical University (X.-B.Z., J.-J.W., S.-H.C., F.-J.B.), Wenzhou, Zhejiang, China
| | - Jun-Jie Wang
- National Clinical Research Center for Ocular Diseases, Eye Hospital, WenZhou Medical University (Y.-Y.M., Z.-X.Q., B.-W.W., H.X., P.W., X.-B.Z., J.-J.W., Y.-F.Y., S.-H.C., F.-J.B), Wenzhou, Zhejiang, China; The Institute of Ocular Biomechanics, Wenzhou Medical University (X.-B.Z., J.-J.W., S.-H.C., F.-J.B.), Wenzhou, Zhejiang, China
| | - Yu-Feng Ye
- National Clinical Research Center for Ocular Diseases, Eye Hospital, WenZhou Medical University (Y.-Y.M., Z.-X.Q., B.-W.W., H.X., P.W., X.-B.Z., J.-J.W., Y.-F.Y., S.-H.C., F.-J.B), Wenzhou, Zhejiang, China
| | - Shi-Hao Chen
- National Clinical Research Center for Ocular Diseases, Eye Hospital, WenZhou Medical University (Y.-Y.M., Z.-X.Q., B.-W.W., H.X., P.W., X.-B.Z., J.-J.W., Y.-F.Y., S.-H.C., F.-J.B), Wenzhou, Zhejiang, China; The Institute of Ocular Biomechanics, Wenzhou Medical University (X.-B.Z., J.-J.W., S.-H.C., F.-J.B.), Wenzhou, Zhejiang, China.
| | - Ahmed Elsheikh
- School of Engineering, University of Liverpool (A.Eli., A.Els.), Liverpool, United Kingdom; National Institute for Health Research (NIHR) Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology (A.Els.), London, United Kingdom; Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University (A.Els.), Beijing, China
| | - Fang-Jun Bao
- National Clinical Research Center for Ocular Diseases, Eye Hospital, WenZhou Medical University (Y.-Y.M., Z.-X.Q., B.-W.W., H.X., P.W., X.-B.Z., J.-J.W., Y.-F.Y., S.-H.C., F.-J.B), Wenzhou, Zhejiang, China; The Institute of Ocular Biomechanics, Wenzhou Medical University (X.-B.Z., J.-J.W., S.-H.C., F.-J.B.), Wenzhou, Zhejiang, China.
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Antonov AA, Volzhanin AV, Klinicheva EA, Karpilova MA. [Influence of corneal curvature and peripheral thickness on tonometry readings]. Vestn Oftalmol 2024; 140:43-50. [PMID: 38739130 DOI: 10.17116/oftalma202414002243] [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] [Indexed: 05/14/2024]
Abstract
PURPOSE This study investigates the influence of peripheral corneal thickness (PCT) and its curvature on tonometry readings. MATERIAL AND METHODS The study included 49 patients (49 eyes) who were indicated for glaucoma surgery. Using bidirectional applanation tonometry, the following parameters were obtained: IOPcc, IOPg - intraocular pressure (IOP) corrected for corneal compensation, taken as the most reliable indicator; IOP converted to Goldmann measurement, taken as the result of applanation tonometry, ΔIOP (IOPcc-IOPg), CH and CRF (corneal hysteresis and corneal resistance factor). During corneal topography, the corneal thickness was studied in the center, PCT at 1.5; 2, 3, 4 and 5 mm from the center in four meridians, as well as ΔPCT (PCT 3 mm - PCT 1.5 mm), the curvature of the anterior and posterior surfaces of the cornea and the depth of the anterior chamber. Aberrometry was used to obtain refractometry data and the curvature of the anterior surface of the cornea. The influence of the studied parameters on ΔIOP was evaluated. RESULTS ΔIOP correlated with CRF (r= -0.652), CH (r= -0.873), central corneal thickness (r= -0.293), PCT at all distances except 5 mm (r= -0.297; -0.287; -0.302; -0.303), with the strong and weak meridians of the anterior surface of the cornea (r=0.328; r=0.315), with the strong and weak meridians of the posterior surface, as well as the average curvature of the posterior surface (r=0.307; r=0.332; r=0.328). After step-by-step selection of the above parameters for creating a linear regression model for ΔIOP calculation, CH, CRF and PCT1.5mm remained in the model. The model describes ΔIOP with high accuracy (R2=0.974). CONCLUSION Biomechanical parameters of the cornea are the leading factor of applanation tonometry error. Individual linear dimensions of the cornea (thickness, curvature) have a lesser effect.
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Affiliation(s)
- A A Antonov
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
| | - A V Volzhanin
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
| | - E A Klinicheva
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
| | - M A Karpilova
- Krasnov Research Institute of Eye Diseases, Moscow, Russia
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Nakaniida Y, Tokumo K, Onoe H, Okada N, Nakakura S, Asaoka R, Kiuchi Y. Comparison of Corvis ST Parameters between Primary Open-Angle Glaucoma and Primary Angle-Closure Glaucoma. J Clin Med 2023; 12:5108. [PMID: 37568510 PMCID: PMC10419864 DOI: 10.3390/jcm12155108] [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: 07/09/2023] [Revised: 07/22/2023] [Accepted: 07/31/2023] [Indexed: 08/13/2023] Open
Abstract
BACKGROUND We compared corneal visualization Scheimpflug technology (CST) parameters between eyes with primary open-angle glaucoma (POAG) and primary angle-closure glaucoma (PACG). METHODS A retrospective analysis was performed on data from 89 eyes with POAG and 83 eyes with PACG that had CST examinations. CST parameters were compared between eyes with POAG and those with PACG using a linear mixed model (LMM). RESULTS No differences were observed in age, central corneal thickness, intraocular pressure, or use of antiglaucoma eye drops between the two groups. Patients with PACG had a significantly shorter axial length (AL), a higher proportion of females, CST parameters, longer applanation 2 (A2) time, deeper A2 deformation amplitude, shorter peak distance, longer whole eye movement, and longer whole eye movement time than patients with POAG. The highest concavity (HC) length and PD showed a significant positive correlation with AL. However, A1 length, A1 deformation amplitude, A2 time, A2 velocity, A2 length, A2 deformation amplitude, HC time, whole eye movement, and whole eye movement time were negatively correlated with AL. CONCLUSIONS The biomechanical properties of the cornea differed between POAG and PACG. In some parts, AL differences between the POAG and PACG groups might contribute to the variation in CST parameters.
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Affiliation(s)
- Yuta Nakaniida
- Department of Ophthalmology and Visual Science, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Kana Tokumo
- Department of Ophthalmology and Visual Science, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Hiromitsu Onoe
- Department of Ophthalmology and Visual Science, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Naoki Okada
- Department of Ophthalmology and Visual Science, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
| | - Shunsuke Nakakura
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, 68-1 Aboshi Waku, Himeji 671-1227, Japan
| | - Ryo Asaoka
- Department of Ophthalmology, Seirei Hamamatsu General Hospital, 2-12-12 Sumiyoshi, Naka-ku, Hamamatsu 430-8558, Japan
- Seirei Christopher University, 3453 Mikatabara, Kita-ku, Hamamatsu 433-8558, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology and Visual Science, Hiroshima University, 1-2-3 Kasumi, Minami-ku, Hiroshima 734-8551, Japan
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Correlations among Corneal Biomechanical Parameters, Stiffness, and Thickness Measured Using Corvis ST and Pentacam in Patients with Ocular Hypertension. J Ophthalmol 2022; 2022:7387581. [PMID: 36510627 PMCID: PMC9741532 DOI: 10.1155/2022/7387581] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2022] [Revised: 11/15/2022] [Accepted: 11/23/2022] [Indexed: 12/05/2022] Open
Abstract
Background To preliminary explore the correlations among corneal biomechanical parameters, stiffness, and thickness in patients with ocular hypertension (OHT) before and after treatment with topical antiglaucoma medications. Methods This was a retrospective study that included 35 eyes with newly diagnosed OHT. Axial length (AL), apical corneal thickness, and minimum corneal thickness were measured using Pentacam. The lengths, velocities, and times of the first and second corneal applanations (A1L, A1V, A1T, A2L, A2V, and A2T, respectively); the highest concavity radius; highest concavity peak distance (PDHC); highest concavity deformation amplitude (DAHC); highest concavity time (HCT); pachymetry (PACH); stress-strain index (SSI); stiffness parameter-A1 (SP-A1); deformation amplitude ratio (DA ratio); integrated radius (IR); Ambrosio's relational thickness horizontal (ARTh); corneal biomechanical index; noncorrected intraocular pressure (IOPnct); and biomechanically corrected IOP (bIOP) values were measured using the corneal visualization Scheimpflug technology (Corvis ST/CST). Results After 5 weeks of treatment, Goldman applanation tonometer-IOP, IOPnct, bIOP, PACH, A1T, A2V, SSI, SP-A1, and ARTh decreased, but A1V, A2T, PDHC, DAHC, DA ratio, and IR increased significantly (all p < 0.05). SP-A1 and A1T were positively associated with premedication IOP and IOP changes, whereas A1V, A2T, PDHC, and IR were negatively associated (all p < 0.05). DAHC and DA ratio had significantly negative correlations with IOP variations. PDHC was found to be positively correlated with AL (p < 0.05). A positive relationship was noted between SP-A1 and HCT before medication (p < 0.05). Conclusions SP-A1 was significantly and consistently associated with IOP. HCT might be correlated with SP-A1. SP-A1 and CST parameters could serve as potential biomarkers for evaluating OHT treatment efficacy.
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Abdi P, Farsiani AR, Fallah Tafti MR, Latifi G, Abdi P. Effect of ocular biometric factors on corneal biomechanical properties. Int Ophthalmol 2022; 43:1877-1888. [DOI: 10.1007/s10792-022-02587-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 11/12/2022] [Indexed: 11/25/2022]
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10
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Heidari H, Momeni-Moghaddam H, Jadidi K, Pirhadi S, Moshirfar M. Changes in Stress-Strain Index and Corneal Biomechanics in Granular Corneal Dystrophy. J Clin Med 2022; 11:jcm11216571. [PMID: 36362797 PMCID: PMC9657534 DOI: 10.3390/jcm11216571] [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: 10/10/2022] [Revised: 10/31/2022] [Accepted: 11/03/2022] [Indexed: 11/09/2022] Open
Abstract
Background: The aim of this study was to assess stress-strain index (SSI) and corneal biomechanical parameters in eyes with granular corneal dystrophy (GCD). Methods: This case-control study included 12 eyes of 12 patients with GCD (mean age 45.2 ± 18.7 years) and 20 eyes of 20 healthy individuals (mean age 54.4 ± 3.8 years). In addition to SSI, dynamic corneal response (DCR) parameters were assessed at the first and second applanation, including length (AL1, AL2), velocity (AV1, AV2), time (AT1, AT2), and deformation amplitude (DA A1, DA A2), and at the highest concavity (HC) phase, including DA, peak distance (PD), radius (HCR), and DA ratio (DAR 1 and 2 mm), by Corvis ST. Central corneal thickness (CCT) and biomechanically corrected intraocular pressure (bIOP) were considered covariates in comparing DCR parameters between the two groups. Results: SSI was statistically significantly lower in eyes with GCD than in normal eyes (p = 0.04). The corneal velocity towards the first applanation was 0.02 m/s faster in the GCD eyes AV1 (0.15 ± 0.02 vs. 0.13 ± 0.02 m/s, p < 0.001) and IR (7.48 ± 1.01 vs. 6.80 ± 1.22 mm, p = 0.003) parameters were significantly higher in the GDC group, while AT1 (7.33 ± 0.66 vs. 7.47 ± 0.36 ms, p = 0.002) and HCR (7.42 ± 0.76 vs. 8.20 ± 1.08 mm, p = 0.014) were significantly lower in the normal group. Conclusions: GCD led to a change in biomechanical properties of the cornea. SSI refers to fewer stiff corneas in GDC than normal.
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Affiliation(s)
- Hamidreza Heidari
- Rehabilitation Research Center, Iran University of Medical Sciences, Tehran 14496-14535, Iran
| | - Hamed Momeni-Moghaddam
- Rehabilitation Sciences Research Center, Zahedan University of Medical Sciences, Zahedan 43463-98167, Iran
- Correspondence: (H.M.-M.); (M.M.)
| | - Khosrow Jadidi
- Vision Health Research Center, Semnan University of Medical Sciences, Semnan 35147-99442, Iran
| | - Shiva Pirhadi
- Vision Health Research Center, Semnan University of Medical Sciences, Semnan 35147-99442, Iran
- Department of Biomedical Engineering, Science and Research Branch, Islamic Azad University, Tehran 14496-14535, Iran
| | - Majid Moshirfar
- Hoopes Vision Research Center, Hoopes Vision, 11820 S. State St. #200, Draper, UT 84020, USA
- John A. Moran Eye Center, University of Utah School of Medicine, Salt Lake City, UT 84132, USA
- Utah Lions Eye Bank, Murray, UT 84107, USA
- Correspondence: (H.M.-M.); (M.M.)
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11
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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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12
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Zhao Y, Li Y, Hong J, Le Q, Xu J. Fourier-Domain Optical Coherence Tomographic Assessment of Changes in the Schlemm's Canal of Nonglaucomatous Subjects After Keratoplasty. Front Physiol 2021; 12:716117. [PMID: 34925051 PMCID: PMC8675085 DOI: 10.3389/fphys.2021.716117] [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: 05/28/2021] [Accepted: 10/28/2021] [Indexed: 11/13/2022] Open
Abstract
Purpose: This study aimed to evaluate the impact of keratoplasty on the in vivo anatomical structures in the Schlemm's canal (SC) of nonglaucomatous subjects using Fourier-domain optical coherence tomography (FD-OCT). Methods: Sixty-six nonglaucomatous eyes that underwent penetrating keratoplasty (PK), deep anterior lamellar keratoplasty (DALK), or triple surgery were enrolled in this prospective, comparative, observational study. The SC imaging was performed using FD-OCT before and after surgery in both the nasal and temporal quadrants. Patient demographics, SC parameters [e.g., cross-sectional area (CSA), meridional diameter of SC (MSC), sagittal diameter of SC (SSC), and circumference (CCF)], and the correlations between the variation of SC parameters and intraocular pressure (IOP) were analyzed. Results: The mean age of all subjects was 40.27 ± 18.97 years. Among all cases, the nasal, temporal, and mean MSC significantly decreased on the first day after surgery and then increased at 1 week (p = 0.04, 0.017, and 0.01, respectively). Temporal CSA (tCSA), temporal MSC (tMSC), and temporal circumference (tCCF) after PK (p = 0.017, 0.020, and 0.018, respectively) and nasal MSC (nMSC) after DALK (p = 0.025) decreased significantly on the first day after surgery. The shift in mean IOP was significantly correlated with the changes in tMSC (r = 0.341, p = 0.003) and CCF (r = 0.207, p = 0.048). Conclusion: SC had significant in vivo morphological changes in the early period after keratoplasty in nonglaucomatous eyes, accompanied with elevation of IOP. Early intervention might be necessary to prevent secondary glaucoma early after keratoplasty.
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Affiliation(s)
- Yujin Zhao
- Department of Ophthalmology and Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| | - Yue Li
- Department of Ophthalmology and Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| | - Jiaxu Hong
- Department of Ophthalmology and Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China.,Key Laboratory of Myopia, National Health and Family Planning Commission, Shanghai, China
| | - Qihua Le
- Department of Ophthalmology and Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
| | - Jianjiang Xu
- Department of Ophthalmology and Visual Science, Eye and ENT Hospital, Shanghai Medical College, Fudan University, Shanghai, China.,NHC Key Laboratory of Myopia (Fudan University), Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, China
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13
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Tian L, Zhang D, Guo L, Qin X, Zhang H, Zhang H, Jie Y, Li L. Comparisons of corneal biomechanical and tomographic parameters among thin normal cornea, forme fruste keratoconus, and mild keratoconus. EYE AND VISION 2021; 8:44. [PMID: 34784958 PMCID: PMC8596950 DOI: 10.1186/s40662-021-00266-y] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/29/2021] [Accepted: 10/23/2021] [Indexed: 12/27/2022]
Abstract
Background To compare the dynamic corneal response (DCR) and tomographic parameters of thin normal cornea (TNC) with thinnest corneal thickness (TCT) (≤ 500 µm), forme fruste keratoconus (FFKC) and mild keratoconus (MKC) had their central corneal thickness (CCT) matched by Scheimpflug imaging (Pentacam) and corneal visualization Scheimpflug technology (Corvis ST). Methods CCT were matched in 50 eyes with FFKC, 50 eyes with MKC, and 53 TNC eyes with TCT ≤ 500 µm. The differences in DCR and tomographic parameters among the three groups were compared. The receiver operating characteristic (ROC) curve was used to analyze the diagnostic significance of these parameters. Back propagation (BP) neural network was used to establish the keratoconus diagnosis model. Results Fifty CCT-matched FFKC eyes, 50 MKC eyes and 50 TNC eyes were included. The age and biomechanically corrected intraocular pressure (bIOP) did not differ significantly among the three groups (all P > 0.05). The index of height asymmetry (IHA) and height decentration (IHD) differed significantly among the three groups (all P < 0.05). IHD also had sufficient strength (area under the ROC curves (AUC) > 0.80) to differentiate FFKC and MKC from TNC eyes. Partial DCR parameters showed significant differences between the MKC and TNC groups, and the deflection amplitude of the first applanation (A1DA) showed a good potential to differentiate (AUC > 0.70) FFKC and MKC from TNC eyes. Diagnosis model by BP neural network showed an accurate diagnostic efficiency of about 91%. Conclusions The majority of the tomographic and DCR parameters differed among the three groups. The IHD and partial DCR parameters assessed by Corvis ST distinguished FFKC and MKC from TNC when controlled for CCT.
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Affiliation(s)
- Lei Tian
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.,Beijing Advanced Innovation Center for Big Data-Based Precision Medicine, Beihang University & Capital Medical University, Beijing Tongren Hospital, Beijing, 100730, China
| | - Di Zhang
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China.,School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China
| | - Lili Guo
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China
| | - Xiao Qin
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China.,School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China
| | - Hui Zhang
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China.,School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China
| | - Haixia Zhang
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China.,School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China
| | - Ying Jie
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Ophthalmology & Visual Sciences Key Laboratory, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730, China.
| | - Lin Li
- Beijing Key Laboratory of Fundamental Research on Biomechanics in Clinical Application, Capital Medical University, Beijing, 100069, China. .,School of Biomedical Engineering, Capital Medical University, Beijing, 100069, China.
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Razeghinejad MR, Farsiani AR, Salout R, Owji N, Masoumpour M, Kharmandar A, Zamani M. Corneal biomechanical properties in hyperthyroidism and thyroid eye disease. Saudi J Ophthalmol 2021; 34:251-255. [PMID: 34527867 PMCID: PMC8409357 DOI: 10.4103/1319-4534.322605] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2019] [Revised: 04/21/2020] [Accepted: 07/06/2020] [Indexed: 11/17/2022] Open
Abstract
PURPOSE: The purpose of this study is to compare the corneal biomechanical properties of hyperthyroids without ophthalmopathy (HWO), thyroid eye disease (TED), and euthyroid participants. METHODS: In this prospective comparative study, one eye per patient included in the analysis and according to exclusion criteria, 38 eyes of 40 HWO patients, 31 eyes of 40 TED patients, and 150 eyes of 160 age- and sex-matched euthyroid participants were enrolled. All participants were evaluated by an endocrinologist and oculoplastic surgeon for evaluation of thyroid function and orbitopathy, respectively. Measurements of corneal biomechanical properties were performed using ocular response analyzer and Corvis ST tonometers. RESULTS: In the HWO group, applanation-1 length (A1 L), applanation-2 velocity (A2V) (P < 0.001), and corneal resistant factor (P = 0.043) were higher than the control group and corneal hysteresis (CH) was lower (P = 0.018). In the TED group, A1 L, A2V (P < 0.001), and highest concavity radius (HCR) (P = 0.027) were higher than the control group, and the CH (P = 0.007) and highest concavity deformation amplitude (HCDA) (P = 0.001) were lower. Furthermore, the level HCDA in the TED group was lower than HWO group (P = 0.011). The level of upper scleral show and palpebral fissure had a negative correlation with CH and HCDA. The amount of exophthalmos level had a positive correlation with HCR. CONCLUSION: Corneal biomechanical properties in the HWO and TED groups were different from the normal euthyroid individuals and may be taken into account in managing situation like glaucoma and refractive surgeries.
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Affiliation(s)
- M Reza Razeghinejad
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Glaucoma Research Center, Wills Eye Hospital, Philadelphia, PA, USA
| | - Amir R Farsiani
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Department of Ophthalmology, School of Medicine, Zanjan University of Medical sciences, Zanjan, Iran
| | - Ramin Salout
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Salouti Eye Research Center, Salouti Eye Clinic, Shiraz, Iran
| | - Naser Owji
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Masoumeh Masoumpour
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Alireza Kharmandar
- Endocrine and Metabolism Research Center, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Mohammad Zamani
- Salouti Eye Research Center, Salouti Eye Clinic, Shiraz, Iran
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15
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Influence of corneal shape parameters on corneal deformation responses measured with a Scheimpflug camera. Int Ophthalmol 2021; 41:2853-2859. [PMID: 33880682 DOI: 10.1007/s10792-021-01844-8] [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: 10/01/2020] [Accepted: 04/08/2021] [Indexed: 10/21/2022]
Abstract
PURPOSE To investigate the effect of corneal shape parameters on corneal deformation responses measured with a Scheimpflug camera. METHODS A total of 241 eyes of 241 participants were enrolled in this study. The anterior and posterior corneal curvature radii (CCR), anterior and posterior corneal Q-values, and corneal diameters of the participants were measured using the Pentacam HR. A total of 17 corneal deformation parameters including time, velocity, deflection amplitude, length, and area during ingoing applanation, highest concavity, and outgoing applanation were recorded by corneal visualization using Scheimpflug technology (Corvis ST). The effect of corneal shape parameters on corneal deformation responses was evaluated using multivariate regression models. RESULTS Multivariate regression analyses showed that six, five, four, and three corneal deformation parameters were significantly correlated with anterior CCR, posterior CCR, anterior Q-value, and posterior Q-value, respectively. Steeper anterior corneal curvature was associated with faster velocity during ingoing applanation and greater deformation during outgoing applanation. Steeper posterior corneal curvature was correlated with faster velocity during outgoing applanation and greater deformation during ingoing applanation. Eyes that had steeper corneal curvatures were associated with less stiff corneas. More negative anterior Q-value corresponded with faster velocity and greater deformation during ingoing applanation. Eyes that had more prolate posterior corneal surfaces showed more resistance to corneal deformation at the highest concavity. However, corneal diameter was not selected in any corneal deformation parameters models. CONCLUSION Corneal deformation response is significantly influenced by anterior and posterior corneal curvature and corneal asphericity, but not corneal diameter.
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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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Zhou Y, Liu Z, Tian L, Guo M, Li J. Finer cornea characterization with improved spatial resolution in Corvis ST. Biomed Signal Process Control 2021. [DOI: 10.1016/j.bspc.2020.102297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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18
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Baptista PM, Marta AA, Marques JH, Abreu AC, Monteiro S, Menéres P, Pinto MDC. The Role of Corneal Biomechanics in the Assessment of Ectasia Susceptibility Before Laser Vision Correction. Clin Ophthalmol 2021; 15:745-758. [PMID: 33642854 PMCID: PMC7903962 DOI: 10.2147/opth.s296744] [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: 12/10/2020] [Accepted: 01/20/2021] [Indexed: 01/02/2023] Open
Abstract
Purpose To describe the tomographic and corneal biomechanical status of a sample of eyes excluded from LVC and to present the differences in biomechanical behavior in relation to cutoffs of clinical- and tomography-based screening methods used in clinical practice. Patients and Methods Observational cross-sectional study including 61 eyes from 32 consecutive patients who were excluded from LVC in our department. Clinical and demographic data were collected from the patients’ clinical records. Tomographic data was assessed with a Scheimpflug camera (Pentacam, OCULUS®). Ablation depth (µm) and residual stromal bed (µm) were calculated by the WaveLight® EX500 laser system software (Alcon, EUA). The corneal biomechanical assessment was made through ultra-high speed Scheimpflug imaging during noncontact tonometry (Corvis ST, OCULUS®). Several ectasia risk scores were analyzed. Results Mean age was 31.0±6 years old and mean manifest spherical equivalent was −2.01 ± 2.3D. Belin–Ambrósio deviation index was the tomographic parameter with higher proportion of eyes within the ectasia high risk interval. In the biomechanical assessment, more than 95% of eyes met the criteria for ectasia susceptibility in four of the first generation and in two of the second generation parameters. In a cutoff based comparative analysis, eyes with Kmax ≥45.5 D, eyes with VCOMA <0 and eyes with ARTmax ≤350 presented significantly softer corneal biomechanical behavior. Conclusion The majority of eyes excluded from LVC in the present study met the criteria for ectasia susceptibility in several biomechanical parameters, validating the clinical and tomographic based screening prior to LVC in our center. Differences found in the biomechanical assessment regarding cutoffs used in clinical practice highlight its differential role in characterizing risk profile of these patients. Tomography should not be overlooked and the integration of all data, including treatment-related parameters, can be the future of risk ectasia screening prior LVC.
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Affiliation(s)
- Pedro Manuel Baptista
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal.,Instituto de Ciências Biomédicas Abel Salazar, Porto, Portugal
| | - Ana Ambrósio Marta
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - João Heitor Marques
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Ana Carolina Abreu
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Sílvia Monteiro
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
| | - Pedro Menéres
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal.,Instituto de Ciências Biomédicas Abel Salazar, Porto, Portugal
| | - Maria do Céu Pinto
- Ophthalmology Department, Centro Hospitalar Universitário do Porto, Porto, Portugal
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Wang X, McAlinden C, Zhang H, Yan J, Wang D, Wei W, Mi S. Assessment of corneal biomechanics, tonometry and pachymetry with the Corvis ST in myopia. Sci Rep 2021; 11:3041. [PMID: 33542296 PMCID: PMC7862660 DOI: 10.1038/s41598-020-80915-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2020] [Accepted: 12/16/2020] [Indexed: 11/09/2022] Open
Abstract
To evaluate the repeatability of Corvis ST corneal biomechanical, tonometry and pachymetry measurements, and agreement of pachymetry measures with the Pentacam HR and RTVue OCT. Three consecutive measurements of the right eye of 238 myopic subjects were acquired with the Corvis ST, Pentacam HR, and RTVue OCT. Repeatability of Corvis ST was evaluated by within-subject standard deviation [Sw] and repeatability limit [r]. The agreement of central corneal thickness (CCT) measurements were compared among the three instruments using the Bland-Altman limits of agreement. Comparisons were further stratified by CCT (Corneathin ≤ 500 µm; Corneanormal = 500-550 µm; Corneathick > 550 µm). Sw was below 1 mmHg in Corneathin, Corneanormal, and Corneathick groups for IOP and bIOP. Sw for SP-A1 were 4.880, 6.128, 7.719 mmHg/mm respectively. Sw for CBI were 0.228, 0.157, 0.076, and correspondingly Sw for TBI and SSI were 0.094 and 0.056, 0.079 and 0.053, 0.070 and 0.053. The Bland-Altman plots for CCT implied poor agreement with mean differences of 29.49 µm between Corvis and OCT, 9.33 µm between Pentacam and OCT, and 20.16 µm between Corvis and Pentacam. The Corvis ST showed good repeatability with the exception of CBI in the various CCT groups. The CCT measured by Corvis ST was not interchangeable with Pentacam HR and RTVue OCT.
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Affiliation(s)
- Xiaorui Wang
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, West Yanta Road, Xi'an, Shaanxi, China.,Laser Vision Center, The First Affiliated Hospital of Northwestern University, No. 30, Fenxiang Alley, Xi'an, Shaanxi, China.,Shaanxi Institute of Ophthalmology, Xi'an, China
| | - Colm McAlinden
- Department of Ophthalmology, Singleton Hospital, Swansea Bay University Health Board, Swansea, UK
| | - Hongbing Zhang
- Laser Vision Center, The First Affiliated Hospital of Northwestern University, No. 30, Fenxiang Alley, Xi'an, Shaanxi, China.,Shaanxi Institute of Ophthalmology, Xi'an, China
| | - Jie Yan
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, West Yanta Road, Xi'an, Shaanxi, China
| | - Dan Wang
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, West Yanta Road, Xi'an, Shaanxi, China
| | - Wei Wei
- Laser Vision Center, The First Affiliated Hospital of Northwestern University, No. 30, Fenxiang Alley, Xi'an, Shaanxi, China. .,Shaanxi Institute of Ophthalmology, Xi'an, China.
| | - Shengjian Mi
- Department of Ophthalmology, The First Affiliated Hospital of Xi'an Jiaotong University, No. 277, West Yanta Road, Xi'an, Shaanxi, China.
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The Relationship Between Corvis ST Tonometry Parameters and Ocular Response Analyzer Corneal Hysteresis. J Glaucoma 2020; 29:479-484. [PMID: 32134829 DOI: 10.1097/ijg.0000000000001486] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PRECIS Corvis ST Tonometry and Ocular Response Analyzer (ORA) measurements were conducted in primary open-angle glaucoma and normative subjects. Many parameters were significantly correlated, however, the strengths were weak to moderate. PURPOSE Reichert ORA parameters are derived from pressure information following the application of air-jet, whereas detailed structural observation can be made using the Corneal Visualization Scheimpflug Technology instrument (CST). The purpose of the study was to investigate the association between CST measurements and ORA measured corneal hysteresis (CH). METHODS Measurements of CST, ORA, axial length, average corneal curvature, central corneal thickness (CCT) and intraocular pressure with Goldmann applanation tonometry were carried out in 104 eyes of 104 patients with primary open-angle glaucoma and 35 eyes from normative subjects. The association between CST and ORA parameters was assessed using linear regression analysis, with model selection based on the second order bias corrected Akaike Information Criterion index. RESULTS Deformation amplitude ratio (corneal softness, R=-0.51), SP A1 (corneal stiffness, R=0.41), and Inverse Radius (integrated area under the curve of the inverse concave radius, R=-0.44) were significantly correlated with CH (P <0.05). The optimal model to explain CH using CST measurements was given by: CH=-76.3+4.6×A1 time (applanation time in the corneal inward movement)+1.9×A2 time (second applanation time in the corneal outward movement) + 3.1 × highest concavity deformation amplitude (magnitude of movement of the corneal apex from before deformation to its highest concavity) + 0.016×CCT (R=0.67; P<0.001). CONCLUSIONS CST parameters are significant, but weakly or moderately, related to ORA measured CH.
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A comparison of the corneal biomechanics in pseudoexfoliation glaucoma, primary open-angle glaucoma and healthy controls using Corvis ST. PLoS One 2020; 15:e0241296. [PMID: 33104764 PMCID: PMC7588080 DOI: 10.1371/journal.pone.0241296] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/12/2020] [Indexed: 11/24/2022] Open
Abstract
Purpose To compare the corneal biomechanical parameters between pseudoexfoliation glaucoma (PXG), primary open-angle glaucoma (POAG) and healthy controls using Corvis ST. Methods A prospective, cross-sectional study was conducted which included 132 treatment-naïve eyes which underwent Corvis ST. The study cohort comprised of 44 eyes with PXG, 42 eyes with POAG and 46 healthy controls. Corneal biomechanical parameters, which included corneal velocities, length of corneal applanated surface, deformation amplitude (DA), peak distance and radius of curvature, were compared between the groups using analysis of variance models. Results The 3 groups were demographically similar. The mean IOP was 15.7 ±3 mmHg in the control group, 21.3 ±5 mmHg in the POAG group and 25.8 ±7 mmHg in the PXG group (p<0.0001). Corneal pachymetry was similar across the 3 groups. Mean DA was significantly lower (p<0.0001) in the PXG group (0.86 ±0.18 mm) compared to the POAG group (0.97 ±0.14mm) and the control group (1.10 ±0.15mm). Corneal velocities were also found to be statistically significantly different between the groups. However, after adjusting for IOP, there was no difference in any of the biomechanical parameters between the 3 groups. Conclusion Corneal biomechanical parameters measured on Corvis ST are not different between eyes with PXG, POAG and healthy controls after adjusting for IOP.
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Chun H, Moon JI, Jung Y. Analysis of Factors Affecting Corneal Deflection Amplitude in Normal Korean Eyes. JOURNAL OF THE KOREAN OPHTHALMOLOGICAL SOCIETY 2020. [DOI: 10.3341/jkos.2020.61.5.538] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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Pradhan ZS, Deshmukh S, Dixit S, Gudetti P, Devi S, Webers CAB, Rao HL. A comparison of the corneal biomechanics in pseudoexfoliation syndrome, pseudoexfoliation glaucoma, and healthy controls using Corvis® Scheimpflug Technology. Indian J Ophthalmol 2020; 68:787-792. [PMID: 32317447 PMCID: PMC7350500 DOI: 10.4103/ijo.ijo_1550_19] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
Abstract
Purpose To compare the corneal biomechanical parameters among pseudoexfoliation syndrome (PXF), pseudoexfoliation glaucoma (PXG), and healthy controls using Corvis Scheimpflug Technology (ST). Methods A prospective, cross-sectional study of 141 treatment-naïve eyes that underwent Corvis ST was conducted. These included 42 eyes with PXF, 17 eyes of PXF with ocular hypertension (PXF + OHT) defined as intraocular pressure (IOP)> 21 mmHg without disc/field changes, 37 eyes with PXG, and 45 healthy controls. Corneal biomechanical parameters, which included corneal velocities, length of corneal applanated surface, deformation amplitude (DA), peak distance, and radius of curvature, were compared among the groups using analysis of variance models. Results The four groups were demographically similar. The mean IOP was lower in the controls (15.6 ± 3 mmHg) and PXF group (16.0 ± 3 mmHg) compared to the other two groups (>24 mmHg). Corneal pachymetry was similar across the four groups. Mean DA was significantly lower (P < 0.0001) in the PXG group (0.91 ± 0.18 mm) and the PXF + OHT group (0.94 ± 0.13 mm) when compared to the PXF (1.10 ± 0.11 mm) and control groups (1.12 ± 0.14 mm). Corneal velocities were also found to be statistically significantly lower in PXG and PXF + OHT compared to the PXF and control groups. However, after adjusting for age and IOP, there was no difference in any of the biomechanical parameters among the four groups. Conclusion Corneal biomechanical parameters measured on Corvis ST are not different between healthy controls and eyes with PXF and PXG. Since PXG is a high-pressure glaucoma, corneal biomechanics may not play an important role in its diagnosis and pathogenesis.
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Affiliation(s)
- Zia S Pradhan
- Department of Glaucoma, Narayana Nethralaya Foundation, Bengaluru, Karnataka, India
| | - Sujit Deshmukh
- Department of Glaucoma, Narayana Nethralaya Foundation, Bengaluru, Karnataka, India
| | - Shivani Dixit
- Department of Glaucoma, Narayana Nethralaya Foundation, Bengaluru, Karnataka, India
| | - Praveena Gudetti
- Department of Glaucoma, Narayana Nethralaya Foundation, Bengaluru, Karnataka, India
| | - Sathi Devi
- Department of Glaucoma, Narayana Nethralaya Foundation, Bengaluru, Karnataka, India
| | - Carroll A B Webers
- University Eye Clinic Maastricht, University Medical Center, Maastricht, The Netherlands
| | - Harsha L Rao
- Department of Glaucoma, Narayana Nethralaya Foundation, Bengaluru, Karnataka, India
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Matsuura M, Murata H, Fujino Y, Yanagisawa M, Nakao Y, Tokumo K, Nakakura S, Kiuchi Y, Asaoka R. Relationship between novel intraocular pressure measurement from Corvis ST and central corneal thickness and corneal hysteresis. Br J Ophthalmol 2019; 104:563-568. [DOI: 10.1136/bjophthalmol-2019-314370] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2019] [Revised: 05/30/2019] [Accepted: 06/17/2019] [Indexed: 11/03/2022]
Abstract
AimsCorvis ST (CST) yields biomechanical corrected IOP (bIOP) which is purported to be less dependent on biomechanical properties. In our accompanied paper, it was suggested that the repeatability of bIOP is high. The purpose of the current study was to assess the relationship between intraocular pressure (IOP) measured with CST and central corneal thickness (CCT) and corneal hysteresis (CH), in comparison with IOP measured with Goldmann applanation tonometry (GAT) and the ocular response analyzer (ORA).MethodsA total of 141 eyes from 141 subjects (35 healthy eyes and 106 glaucomatous eyes) underwent IOP measurements with GAT, CST and ORA. The relationships between IOP measurements (ORA-IOPg, ORA-IOPcc, CST-bIOP and GAT IOP) and biomechanical properties (CCT, CH and corneal resistance factor (CRF)) were analysed using the linear regression analysis.ResultsIOPg, IOPcc and GAT IOP were significantly associated with CCT (p<0.001), whereas bIOP was not significantly associated with CCT (p=0.19). IOPg, bIOP and GAT IOP were significantly associated with CH (IOPg: p<0.001; bIOP: p<0.001; GAT IOP: p=0.0054), whereas IOPcc was not significantly associated with CH (p=0.18). All of IOP records were associated with CRF (p<0.001).ConclusionThe bIOP measurement from CST is independent from CCT, but dependent on CH and CRF.
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Jiménez-villar A, Mączyńska E, Cichański A, Wojtkowski M, Kałużny BJ, Grulkowski I. High-speed OCT-based ocular biometer combined with an air-puff system for determination of induced retraction-free eye dynamics. BIOMEDICAL OPTICS EXPRESS 2019; 10:3663-3680. [PMID: 31467798 PMCID: PMC6706022 DOI: 10.1364/boe.10.003663] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Revised: 06/16/2019] [Accepted: 06/16/2019] [Indexed: 05/20/2023]
Abstract
We demonstrate a swept source OCT-based ocular biometer integrated with an air-puff stimulus to study the reaction of the eye to mechanical stimulation in vivo. The system enables simultaneous measurement of the stimulus strength and high-speed imaging of the eye dynamics along the visual axis. We characterize the stimulus and perform optimization of the data acquisition for a proper interpretation of the results. Access to the dynamics of axial eye length allows for a determination of the eye retraction, which is used to correct the air-puff induced displacement of ocular structures. We define the parameters to quantify the reaction of the eye to the air puff and determine their reproducibility in a group of healthy subjects. We observe the corneal deformation process and axial wobbling of the crystalline lens. OCT biometer combined with the air puff is the first instrument with the potential to provide comprehensive information on the biomechanics of ocular components.
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Affiliation(s)
- Alfonso Jiménez-villar
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, ul. Grudziądzka 5, 87-100 Toruń, Poland
| | - Ewa Mączyńska
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, ul. Grudziądzka 5, 87-100 Toruń, Poland
| | - Artur Cichański
- Institute of Mechanics and Machine Design, Faculty of Mechanical Engineering, UTP University of Science and Technology, Al. Prof. S. Kaliskiego 7, 85-796 Bydgoszcz, Poland
| | - Maciej Wojtkowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, ul. Grudziądzka 5, 87-100 Toruń, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, ul. Kasprzaka 44/52, 01-224 Warsaw, Poland
| | - Bartłomiej J. Kałużny
- Division of Ophthalmology and Optometry, Department of Ophthalmology, Collegium Medicum, Nicolaus Copernicus University, ul. Ujejskiego 75, 85-168 Bydgoszcz, Poland
| | - Ireneusz Grulkowski
- Institute of Physics, Faculty of Physics, Astronomy and Informatics, Nicolaus Copernicus University, ul. Grudziądzka 5, 87-100 Toruń, Poland
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Dynamic Scheimpflug Ocular Biomechanical Parameters in Healthy and Medically Controlled Glaucoma Eyes. J Glaucoma 2019; 28:588-592. [DOI: 10.1097/ijg.0000000000001268] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Matsuura M, Murata H, Fujino Y, Yanagisawa M, Nakao Y, Nakakura S, Kiuchi Y, Asaoka R. Repeatability of the Novel Intraocular Pressure Measurement From Corvis ST. Transl Vis Sci Technol 2019; 8:48. [PMID: 31275733 PMCID: PMC6594315 DOI: 10.1167/tvst.8.3.48] [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: 05/28/2018] [Accepted: 04/07/2019] [Indexed: 12/03/2022] Open
Abstract
Purpose To assess the repeatability of intraocular pressure (IOP) measured with the Corvis ST (CST) and the Ocular Response Analyzer (ORA). Methods A total of 141 eyes from 141 subjects were studied, including 35 healthy eyes and 106 glaucomatous eyes. All subjects underwent IOP evaluations with Goldmann applanation tonometer, CST, and ORA. With CST, biomechanical corrected IOP (bIOP) was calculated; bIOP is purported to be less dependent on biomechanical properties. For ORA, corneal-compensated intraocular pressure (IOPcc) and Goldmann-correlated IOP (IOPg) were derived. The repeatability of the various IOP values was assessed using the coefficient of variance (CV) and the intraclass correlation coefficient (ICC). Results The CV with bIOP (5.5 ± 3.1: mean ± standard deviation) was significantly smaller than the CVs measured with IOPg (7.3 ± 4.3) and IOPcc (7.2 ± 4.4). ICC values were 0.90, 0.80, and 0.86 with IOPg, IOPcc, and bIOP, respectively. Conclusions The bIOP showed a better prevision and repeatability for IOP measurement. Translational Relevance The bIOP measurement from CST had a better reproducible than IOPcc measurement from ORA.
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Affiliation(s)
- Masato Matsuura
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan.,Department of Ophthalmology, Graduate School of Medical Science, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Hiroshi Murata
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan
| | - Yuri Fujino
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan
| | - Mieko Yanagisawa
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan
| | - Yoshitaka Nakao
- Department of Ophthalmology and Visual Sciences, Hiroshima University, Hiroshima, Japan
| | - Shunsuke Nakakura
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan
| | - Ryo Asaoka
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan
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Hwang HS, Kim EC, Kim MS, Yang SW. A novel method for quantifying the biomechanical parameters of orbital soft tissue using a corneal dynamic scheimpflug analyser: a retrospective study. BMC Ophthalmol 2019; 19:53. [PMID: 30777066 PMCID: PMC6380054 DOI: 10.1186/s12886-019-1064-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2018] [Accepted: 02/01/2019] [Indexed: 12/26/2022] Open
Abstract
BACKGROUND To demonstrate that the Corvis ST could be used to quantify the biomechanical parameters of the orbital soft tissues by measuring and comparing whole eye movement (WEM) using the Corvis in normal eyes and in eyes of patients with Graves ophthalmopathy. METHODS Forty four eyes of 44 ophthalmologically normal subjects and 28 eyes of 28 patients with Graves ophthalmopathy were included in the study. After Corvis test, the examiners recorded WEM by air puff. In the patients with Graves ophthalmopathy, the partial correlation coefficient adjusted for age and gender was calculated to analyze the correlation between exopthalmometry and WEM. Same analysis was repeated for the correlation between and the cross sectional area (%) of the extraocular muscles in the orbit CT and WEM. RESULTS WEM was 0.314 ± 0.083 mm in the normal subjects and 0.227 ± 0.079 mm in the Graves ophthalmopathy group (p = 0.000). The exophthalmometry was not significantly correlated with WEM after adjusting for age and gender (R = 0.083, p = 0.688). In the 21 Graves ophthalmopathy patients examined by orbit CT, after adjusting for age and gender, WEM significantly decreased as the cross sectional area (%) of the extraocular muscles in the orbit increased (R = - 0.461, p = 0.047). CONCLUSIONS WEM by Corvis could be used to quantify the biomechanical parameters of the orbital soft tissue. However, it is unclear whether WEM effectively represents the orbital biomechanical parameters, because WEM is only 0.6% of the orbital depth.
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Affiliation(s)
- Ho Sik Hwang
- Department of Ophthalmology, Chuncheon Sacred Heart Hospital, Hallym University, Chuncheon, South Korea
| | - Eun Chul Kim
- Department of Ophthalmology, Bucheon St. Mary's Hospital, Catholic University of Korea, Bucheon, South Korea
| | - Man Soo Kim
- Department of Ophthalmology, Seoul St. Mary's Hospital, Catholic University of Korea, Banpodaero 222, Seocho-gu, Seoul, South Korea
| | - Suk-Woo Yang
- Department of Ophthalmology, Seoul St. Mary's Hospital, Catholic University of Korea, Banpodaero 222, Seocho-gu, Seoul, South Korea.
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Wallace HB, Misra SL, Li SS, McKelvie J. Biomechanical changes in the cornea following cataract surgery: A prospective assessment with the Corneal Visualisation Scheimpflug Technology. Clin Exp Ophthalmol 2019; 47:461-468. [PMID: 30474314 DOI: 10.1111/ceo.13451] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2018] [Revised: 11/02/2018] [Accepted: 11/09/2018] [Indexed: 01/26/2023]
Abstract
IMPORTANCE Intraocular pressure (IOP) is often reduced following cataract surgery. Postoperative changes in corneal stiffness are likely to be at least partly responsible for any reduction in IOP measured with applanation tonometry. BACKGROUND To determine the effect of cataract surgery and corneal incision size on corneal biomechanics. DESIGN Prospective randomized trial. PARTICIPANTS One hundred prospectively enrolled patients qualifying for cataract surgery. METHODS Participants were randomized to clear corneal incisions with a 2.20 or 2.85 mm keratome. Corneal Visualisation Scheimpflug Technology (Corvis-ST) tonometry and dynamic corneal response measurements were obtained preoperatively, and 3 mo postoperatively. Multiple regression analysis was completed using R software. MAIN OUTCOME MEASURES Corvis-ST biomechanical parameters. RESULTS Ninety-three eyes of 93 patients were included in the final analysis. Mean Corvis-ST biomechanically corrected IOP decreased by 3.63 mmHg postoperatively (95% confidence interval = 2.97-4.35, P ≤ 0.01), and central pachymetry increased by 6.96 μm (4.33-9.59, P ≤ 0.01). Independent of IOP and pachymetry changes, mean (±SE) corneal first applanation stiffness parameter reduced by 9.761 ± 3.729 (P = 0.01) postoperatively. First applanation velocity increased by 0.007 ± 0.002 ms, second applanation velocity increased by 0.012 ± 0.004 ms (P ≤ 0.01), the first applanation deformation amplitude increased by 0.008 ± 0.002 mm (P ≤ 0.01) and the deflection amplitude at highest concavity increased by 0.030 ± 0.069 (P ≤ 0.01). There were no significant differences between different incision size groups. CONCLUSIONS AND RELEVANCE Corneal stiffness is reduced 3 mo following cataract surgery and is associated with falsely low IOP measurements. This finding may be important for glaucoma patients and in particular when assessing the effectivity of minimally invasive glaucoma surgery devices.
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Affiliation(s)
- Henry B Wallace
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Stuti L Misra
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - Sunny S Li
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
| | - James McKelvie
- Department of Ophthalmology, Faculty of Medical and Health Sciences, New Zealand National Eye Centre, University of Auckland, Auckland, New Zealand
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Naderi M, Farsiani AR, Salouti R, Panahi Y, Zamani M, Azimi A, Sahebkar A. Evaluation of corneal biomechanical properties in mustard gas keratopathy. Saudi J Ophthalmol 2018; 33:24-27. [PMID: 30930659 PMCID: PMC6424689 DOI: 10.1016/j.sjopt.2018.11.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2017] [Revised: 10/16/2018] [Accepted: 11/05/2018] [Indexed: 11/25/2022] Open
Abstract
Background Degenerative biomechanical factors and immunologic processes with effect on collagen and corneal reparative process are known as the main cause of ocular surface dysfunction in mustard gas keratopathy (MGK) and may cause changes in the corneal biomechanical values. Therefore, we evaluate corneal biomechanical properties of these patients. Methods and materials This case-control study includes 61 chemical warfare victims with MGK. After omission according to our exclusion criteria, 88 eyes of patients with MGK were enrolled as the case group and also a group of 88 normal eyes, which were matched regarding their age and sex in the control group, were enrolled. Measurements of corneal biomechanical properties which reported by ORA and Corvis ST (CST) devices were compared. The SPSS software version 23.0 was used in the statistical analysis. For comparisons between groups, if the data had a normal distribution, were analyzed by Student’s t-test and ANOVA, and if the data didn’t have a normal distribution, Mann–Whitney U test, and Kruskal-Wallis were used. Furthermore, to identify a relationship between two groups of data Spearman's rank Correlation test was used. P value < 0.05 were considered statistically significant. Results In the MGK group, A1 length (A1L), A1 velocity (A1V), A2 velocity (A2V), deformation amplitude (DA) and peak distance (PD) were higher than the control group (P < 0.001). However, the corneal hysteresis (CH) (P = 0.003), corneal resistant factor (CRF), non-corrected IOP (IOPnct), corrected IOP based on corneal thickness (IOPpachy), and central corneal thickness (CCT) were lower than the control group (P < 0.001). The visual acuity according to the LogMAR scale and severity of MGK was positively associated with IOPpachy and negatively associated with CH, CRF, CCT and highest concavity radius (Radius). Conclusion Measurement of corneal biomechanical properties may be, have a useful role in the classification, monitoring or diagnosis of MGK.
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Affiliation(s)
- Mostafa Naderi
- Chemical Injuries Research Center, System Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Amir Reza Farsiani
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Ramin Salouti
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran.,Salouti Eye Research Center, Salouti Eye Clinic, Shiraz, Iran
| | - Yunes Panahi
- Chemical Injuries Research Center, System Biology and Poisonings Institute, Baqiyatallah University of Medical Sciences, Tehran, Iran
| | - Mohammad Zamani
- Salouti Eye Research Center, Salouti Eye Clinic, Shiraz, Iran
| | - Ali Azimi
- Poostchi Ophthalmology Research Center, Department of Ophthalmology, School of Medicine, Shiraz University of Medical Sciences, Shiraz, Iran
| | - Amirhossein Sahebkar
- Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran.,Neurogenic Inflammation Research Center, Mashhad University of Medical Sciences, Mashhad, Iran.,School of Pharmacy, Mashhad University of Medical Sciences, Mashhad, Iran
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Lee H, Kang DSY, Ha BJ, Choi JY, Kim EK, Seo KY, Kim TI. Biomechanical Properties of the Cornea Using a Dynamic Scheimpflug Analyzer in Healthy Eyes. Yonsei Med J 2018; 59:1115-1122. [PMID: 30328327 PMCID: PMC6192879 DOI: 10.3349/ymj.2018.59.9.1115] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/18/2018] [Revised: 08/18/2018] [Accepted: 08/20/2018] [Indexed: 11/27/2022] Open
Abstract
PURPOSE To investigate biomechanical properties of the cornea using a dynamic Scheimpflug analyzer according to age. MATERIALS AND METHODS In this prospective, cross-sectional, observational study, participants underwent ophthalmic investigations including corneal biomechanical properties, keratometric values, intraocular pressure (IOP), and manifest refraction spherical equivalent (MRSE). We determined the relationship of biomechanical parameters and ocular/systemic variables (participant's age, MRSE, IOP, and mean keratometric values) by piecewise regression analysis, association of biomechanical parameters with variables by Spearman's correlation and stepwise multiple regression analyses, and reference intervals (RI) by the bootstrap method. RESULTS This study included 217 eyes of 118 participants (20-81 years of age). Piecewise regression analysis between Corvis-central corneal thickness (CCT) and participant's age revealed that the optimal cut-off value of age was 45 years. No clear breakpoints were detected between the corneal biomechanical parameters and MRSE, IOP, and mean keratometric values. Corneal velocity, deformation amplitude, radius, maximal concave power, Corvis-CCT, and Corvis-IOP exhibited correlations with IOP, regardless of age (all ages, 20-44 years, and over 44 years). With smaller deformation amplitude and corneal velocity as well as increased Corvis-IOP and Corvis-CCT, IOP became significantly increased. We provided the results of determination of confidence interval from RI data using bootstrap method in three separate age groups (all ages, 20-44 years, and over 44 years). CONCLUSION We demonstrated multiple corneal biomechanical parameters according to age, and reported that the corneal biomechanical parameters are influenced by IOP.
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Affiliation(s)
- Hun Lee
- Department of Ophthalmology, International St. Mary's Hospital, Catholic Kwandong University College of Medicine, Incheon, Korea
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
| | | | | | | | - Eung Kweon Kim
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
- Corneal Dystrophy Research Institute, Severance Biomedical Science Institute, Yonsei University College of Medicine, Seoul, Korea
| | - Kyoung Yul Seo
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea
| | - Tae Im Kim
- The Institute of Vision Research, Department of Ophthalmology, Yonsei University College of Medicine, Seoul, Korea.
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Hirasawa K, Nakakura S, Nakao Y, Fujino Y, Matsuura M, Murata H, Kiuchi Y, Asaoka R. Changes in Corneal Biomechanics and Intraocular Pressure Following Cataract Surgery. Am J Ophthalmol 2018; 195:26-35. [PMID: 30071213 DOI: 10.1016/j.ajo.2018.07.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/24/2017] [Revised: 07/18/2018] [Accepted: 07/20/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE To investigate the effects of cataract surgery on corneal biomechanics and intraocular pressure (IOP) measured with the updated Corvis ST tonometer (CST). DESIGN Prospective, interventional case series study. METHODS This study included 39 eyes of 39 cataract patients. CST measurements were performed at presurgery (Pre) as well as 1 week (1W), 1 month (1M), and 3 months (3M) postsurgery. The following CST parameters were recorded: deformation amplitude max (DA max), DA ratio max 1 mm and 2 mm, integrated radius, stiffness parameter at applanation 1 (SP A1), Ambrosio relational thickness to the horizontal profile (ARTh), Corvis biomechanical index (CBI), central corneal thickness (CCT), noncorrected intraocular pressure (IOPnct), and biomechanically corrected IOP (bIOP). IOP was also measured with Goldmann applanation tonometry and the noncontact tonometer CT-90A. All measurements were compared at each period using the linear mixed model, with and without adjustment for bIOP and CCT. RESULTS All IOP measurements decreased over time (P < .01). CCT was increased at 1W and 3M (P < .01), whereas ARTh was decreased at 1W and 1M (P < .01), but returned to its Pre level at 3M. DA max and Integrated radius were increased at 3M (P < .01), whereas SP A1 was decreased at 3M (P < .01). CBI was increased at 1W (P < .01), but returned to its Pre level at 1M. CONCLUSIONS IOP and Corneal biomechanical properties are changed after cataract surgery. In particular, SP A1 decreases while DA max and integrated radius increase, even at 3M, suggesting a less stiff cornea.
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Salouti R, Alishiri AA, Gharebaghi R, Naderi M, Jadidi K, Shojaei-Baghini A, Talebnejad M, Nasiri Z, Hosseini S, Heidary F. Comparison among Ocular Response Analyzer, Corvis ST and Goldmann applanation tonometry in healthy children. Int J Ophthalmol 2018; 11:1330-1336. [PMID: 30140637 DOI: 10.18240/ijo.2018.08.13] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2018] [Accepted: 04/23/2018] [Indexed: 11/23/2022] Open
Abstract
AIM To explore the relationship between different parameters of Ocular Response Analyzer (ORA) and Corvis ST (CST) in a sample of healthy Iranian school-aged children and the relationship between parameters of these 2 instruments against intraocular pressure (IOP), measured by the Goldmann applanation tonometer (GAT-IOP), age and gender, and find possible correlation between ORA and CST with GAT. METHODS This cross-sectional study included 90 healthy children. A general interview and complete eye examination were performed. Following successful GAT-IOP measurement, ORA and CST were conducted. The CST parameters were A 1/2 length (A1L, A2L), A 1/2 velocity (A1V, A2V), highest concavity deformation amplitude (HCDA), radius of curvature (RoC), peak distance (PD), central corneal thickness (CCT) and IOP. The ORA parameters were corneal hysteresis (CH), corneal resistance factor (CRF), Goldmann-correlated IOP (IOP-G) and corneal compensated IOP (IOP-CC). Extracted data was analyzed using the Statistical Package for Social Science software. RESULTS Totally 39 males with age of 9.08±1.60 (6-12)y and 51 females with age of 8.96±1.55 (6-13)y were included. Many CST parameters were significantly correlated with CH, CRF, IOP-G and IOP-CC. Some CST parameters had a significant correlation with GAT-IOP, including IOP-CST in both eyes and HCDA, A2L, PD, and RoC in the left eye, but none with age, except A2L in the right eye. The CRF measurement showed a significant correlation with GAT-IOP in both eyes and CH in the right eye, yet, none with age. Among all CST and ORA parameters, CCT-CST in both eyes and A1L in right eye had a significant correlation with gender, although this was a negligible negative correlation. Comparison of mean IOP values by different devices showed a significantly highest IOP overestimation by CST and lowest by IOP-CC compared with GAT. Also, IOP-G versus IOP-CST significantly had the lowest IOP overestimation among others. Overall, either low positive correlation or negligible correlation was found between IOP measurements by 3 instruments. CONCLUSION The study finds the highest IOP overestimation by CST and lowest by IOP-CC compared with GAT. Overall, either low positive correlation or negligible correlation is found between IOP measurements by the 3 instruments.
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Affiliation(s)
- Ramin Salouti
- Department of Ophthalmology, Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz 7134814336, Iran
| | - Ali Agha Alishiri
- Department of Ophthalmology, Baqiyatallah University of Medical Sciences, Tehran 141551856, Iran
| | - Reza Gharebaghi
- Department of Ophthalmology, Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz 7134814336, Iran
| | - Mostafa Naderi
- Department of Ophthalmology, Baqiyatallah University of Medical Sciences, Tehran 141551856, Iran
| | - Khosrow Jadidi
- Department of Ophthalmology, Baqiyatallah University of Medical Sciences, Tehran 141551856, Iran
| | - Ahmad Shojaei-Baghini
- Department of Ophthalmology, Baqiyatallah University of Medical Sciences, Tehran 141551856, Iran
| | - Mohammadreza Talebnejad
- Department of Ophthalmology, Poostchi Ophthalmology Research Center, Shiraz University of Medical Sciences, Shiraz 7134814336, Iran
| | - Zahra Nasiri
- Faculty of Mathematical Sciences, Tarbiat Modares University, Tehran 141551856, Iran
| | - Seyedmorteza Hosseini
- Department of Ophthalmology, Baqiyatallah University of Medical Sciences, Tehran 141551856, Iran
| | - Fatemeh Heidary
- Ophthalmic Research Center, Shahid Beheshti University of Medical Sciences; Immunoregulation Research Center, Shahed University, Tehran 141551856, Iran
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Asano S, Nakajima K, Kure K, Azuma K, Shimizu K, Murata H, Inoue T, Obata R, Asaoka R. Corneal biomechanical properties are associated with the activity and prognosis of Angioid Streaks. Sci Rep 2018; 8:8130. [PMID: 29802262 PMCID: PMC5970224 DOI: 10.1038/s41598-018-26430-4] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Accepted: 05/08/2018] [Indexed: 11/26/2022] Open
Abstract
The aim of the current study is to investigate corneal biomechanical properties in detail using Ocular Response Analyzer (ORA) and Corvis ST (CST) tonometry and to analyze the association between corneal biomechanical properties and the frequency of intravitreal anti-vascular endothelial growth factor (VEGF) injections (FIV) in AS eyes with choroidal neovascularization (CNV). Twenty-eight eyes of 15 patients with AS were enrolled. Mean age of AS patients was 67.9 ± 9.8 years. ORA and CST measurements were carried out, in addition to comprehensive ophthalmic examinations. LogMAR visual acuity (VA) and ΔVA (the change of VA from baseline to the final visit) were calculated in each eye. Also, the relationships between FIV, and the variables of initial age at the observation period, axial length, and corneal biomechanical properties were investigated in eyes with AS using linear mixed model with model selection using AICc. In 28 AS eyes, 16 eyes underwent intravitreal anti-VEGF injections during follow-up period. Lower corneal hysteresis (CH), higher corneal resistant factor (CRF) and higher CST measured the DA ratio were associated with the increase of FIV in AS eyes (p = 0.01, p = 0.002, p = 0.027, respectively), suggesting the usefulness for monitoring of corneal biomechanical properties.
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Affiliation(s)
- Shotaro Asano
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Kosuke Nakajima
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Kana Kure
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Keiko Azuma
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Kimiko Shimizu
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Hiroshi Murata
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Tatsuya Inoue
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Ryo Obata
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan
| | - Ryo Asaoka
- Department of Ophthalmology, Graduate School of Medicine and Faculty of Medicine, The University of Tokyo, Tokyo, 113-8655, Japan.
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Dynamischer Scheimpflug-Analyzer (Corvis ST) zur Bestimmung kornealer biomechanischer Parameter. Ophthalmologe 2018; 115:635-643. [DOI: 10.1007/s00347-018-0716-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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Evaluation of corneal biomechanics in patients with keratectasia following LASIK using dynamic Scheimpflug analyzer. Jpn J Ophthalmol 2018; 62:443-450. [PMID: 29700642 DOI: 10.1007/s10384-018-0594-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2017] [Accepted: 03/02/2018] [Indexed: 10/17/2022]
Abstract
PURPOSE To investigate the corneal biomechanics in eyes with keratectasia following LASIK using a dynamic Scheimpflug analyzer. DESIGN Case-Control study. METHOD The subjects in the study included 12 eyes with keratectasia after LASIK (KE), 24 eyes with keratoconus (KC), 17 eyes without keratectasia after LASIK (LASIK), and 34 eyes with normal corneas (Normal). Corneal biomechanics of the four groups were evaluated using a dynamic Scheimpflug analyzer. RESULTS Compared with Normal (7.06 ± 0.54), the radius at the highest concavity (radius, mm) of LASIK (5.96 ± 0.76), KE (4.93 ± 0.61) and KC (5.39 ± 1.02) were significantly small. The Deflection Amplitude (HCDLA, mm) of Normal (0.94 ± 0.07) was significantly lower than those of KE (1.11 ± 0.10) and KC (1.06 ± 0.16), and was not significantly different from that of LASIK (0.98 ± 0.07). There were significant differences between LASIK and KE in radius and HCDLA (P < 0.05), whereas KE and KC had no differences in these parameters. CONCLUSIONS Corneal biomechanical features evaluated using the dynamic Scheimpflug analyzer suggest that biomechanical properties in eyes with keratectasia, keratoconus, and LASIK are different from those of normal eyes. Although the biomechanics in eyes with keratectasia differs from that in eyes with LASIK, it is similar to that in eyes with keratoconus.
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Evaluation of Corneal Biomechanics After Excimer Laser Corneal Refractive Surgery in High Myopic Patients Using Dynamic Scheimpflug Technology. Eye Contact Lens 2018; 43:371-377. [PMID: 27243355 DOI: 10.1097/icl.0000000000000280] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVE To compare the effect of femtosecond-assisted thin flap laser-assisted in situ keratomileusis (FS-LASIK) and photorefractive keratectomy with mitomycin-C (PRK-MMC) in highly myopic patients (>7.0 D [D]) on corneal biomechanical parameters. METHODS In this prospective comparative interventional case series, 60 patients (30 patients in each group) with a manifest refractive spherical equivalent (MRSE) greater than 7.0 D were enrolled. Corvis ST parameters were measured before and at 3 and 6 months postoperatively. RESULTS Preoperatively, mean MRSE was -8.65±1.51 D in FS-LASIK and -8.04±1.70 D in PRK-MMC groups (P=0.149), and corneal thickness was 570.67±36.79 μm and 507.12±32.55 μm, respectively (P<0.001). At 6 months, both groups showed significantly higher applanation (A) 2 time and A2-velocity (P<0.05 in both), whereas intraocular pressure (IOP), corrected IOP, A1 time, A1-velocity, and radius at highest concavity were significantly reduced (P<0.05 in all). In the FS-LASIK group, there was a significant increase in deformation amplitude (DA) (P=0.001), and significant decreases in A2-length (P=0.004). Peak distance increased in the PRK-MMC group (P=0.029). At 6 months, after controlling for fellow eye correlations and preoperative corneal thickness between the two groups, decreases in IOP, A1-time, A2-length and radius, and the increase in DA was greater in FS-LASIK. CONCLUSION This study demonstrated significant changes in Corvis ST ocular biomechanical metrics after both PRK-MMC and FS-LASIK in high myopic patients, indicating the significant effect of excimer laser refractive surgery on corneal biomechanical properties. However, changes that occur with FS-LASIK are more significant than with PRK-MMC. Further randomized studies are needed to better characterize the pattern of biomechanical changes associated with each type of surgery.
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Hugo J, Granget E, Ho Wang Yin G, Sampo M, Hoffart L. Intraocular pressure measurements and corneal biomechanical properties using a dynamic Scheimpflug analyzer, after several keratoplasty techniques, versus normal eyes. J Fr Ophtalmol 2017; 41:30-38. [PMID: 29191679 DOI: 10.1016/j.jfo.2017.06.006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2017] [Revised: 06/08/2017] [Accepted: 06/16/2017] [Indexed: 11/15/2022]
Abstract
PURPOSE To evaluate the biomechanical properties of the cornea and their impact on intraocular pressure (IOP) measurement after lamellar keratoplasty, compared to healthy eyes, using a non-contact tonometer with a Scheimpflug camera. METHODS This study, from 2014 to 2015, included 22 primary DSAEK, 5 DALK, 6 DSAEK after PK, and 50 control eyes. Using a non-contact tonometer with a high-speed Scheimpflug camera (CORVIS ST, Oculus Optikgeräte GmbH, Wetzlar, Germany), several biomechanical parameters were recorded, including radius at highest concavity (Rhc) and defomation amplitude (DA). Central corneal thickness (CCT) and uncorrected IOP, were also recorded. For the control eyes only, a corrected IOP was calculated, based on age, central corneal thickness, and biomechanical parameters. RESULTS Rhc was significantly lower after DALK (Rhc=5.54±0.71, P=0.007) and DSAEK (Rhc=6.26±0.77, P=0.042) compared to control eyes (Rhc=6.82±0.76). DA was higher after DALK and DSAEK, but not significantly (respectively 1.24±0.09 P=0.41 and 1.22±0.15, P=0.923) compared to normal eyes (1.18±0.15). Uncorrected IOP was not significantly different between post-keratoplasty and control eyes. In control eyes, the corrected IOP (15.23±1.88) was lower than the uncorrected IOP (16.10±2.34); a statistically significant positive correlation between Rhc and CCT (R2=0.6020, P<0001), and a significant negative correlation between DA and CCT (R2=-0.641, P<0.0001) were found. CONCLUSION Our study showed that, after lamellar keratoplasty, corneal biomechanics are altered. Corneas with higher ocular rigidity will show a lower DA and a higher Rhc.
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Affiliation(s)
- J Hugo
- Service d'ophtalmologie, hôpital de la Timone, 264, rue Saint-Pierre, 13385 Marseille, France.
| | - E Granget
- Service d'ophtalmologie, hôpital de la Timone, 264, rue Saint-Pierre, 13385 Marseille, France
| | - G Ho Wang Yin
- Service d'ophtalmologie, hôpital de la Timone, 264, rue Saint-Pierre, 13385 Marseille, France
| | - M Sampo
- Service d'ophtalmologie, hôpital de la Timone, 264, rue Saint-Pierre, 13385 Marseille, France
| | - L Hoffart
- Service d'ophtalmologie, hôpital de la Timone, 264, rue Saint-Pierre, 13385 Marseille, France
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Evaluation of Corneal Deformation Parameters Provided by the Corvis ST Tonometer After Trabeculectomy. J Glaucoma 2017; 26:166-172. [PMID: 27875486 DOI: 10.1097/ijg.0000000000000590] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The aims of this study were to evaluate how the corneal deformation parameters provided by the Corvis ST tonometer (CST) were influenced by pressure-lowering ocular surgery, and to determine the correlations of intraocular pressure (IOP) and axial length (AL) with CST corneal deformation parameters. METHODS This prospective 1-month study enrolled 22 subjects (22 eyes) who underwent trabeculectomy combined with mitomycin C. The corneal deformation parameters were measured using the CST. IOP was measured before and after surgery by a Goldmann applanation tonometer and the CST. The central corneal thickness and AL were also recorded. The correlations of the corneal deformation parameters with central corneal thickness, AL, and IOP changes were determined by linear regression analysis. RESULTS IOP decreased significantly after surgery. AL was significantly shorter at 1 week after surgery. There were significant changes in the CST parameters time 1, velocity 1, velocity 2, peak distance highest concavity, and deformation amplitude highest concavity at 1 week and 1 month after surgery and in time highest concavity at 1 week after surgery. The change in time 1 was significantly correlated with preoperative IOP and the IOP reductions, and was positively correlated with the decrease in AL at 1 week. The increase in velocity 1 was negatively correlated with preoperative IOP, and IOP reductions. The change in time highest concavity was negatively correlated with IOP before surgery and the decrease in IOP at 1 week. CONCLUSION CST is a good choice for measuring IOP, especially when aiming for normalization of IOP after glaucoma surgery.
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Abstract
Currently available clinical devices are unable to measure corneal biomechanics other than at the central region. Corneal stiffness (S), thickness, and radius of curvature was measured at the central cornea (primary fixation) and 3 mm from the temporal limbus (primary and nasal fixations). The corneal tangent modulus (E) of 25 healthy subjects was calculated from these data. After confirming normality, repeated measures analysis of variance (RMANOVA) revealed significant difference in S (F(2, 48) = 21.36, p < 0.001) at different corneal regions and direction of fixations. E also varied significantly at different corneal regions and direction of fixations (RMANOVA: F(2, 48) = 23.06, p < 0.001). A higher S and a lower E were observed at the temporal region compared with the corneal centre. Nasal fixation further increased S and E values compared with primary fixation. Due to the specific arrangement of corneal collagen fibrils, heterogeneity of corneal biomechanical properties is expected. In future clinical practice, localized corneal biomechanical alternation and measurement might assist corneal disease detection and post-surgery management. In addition, practitioners should be aware of the fixation effect on corneal biomechanical measurement.
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Hirasawa K, Matsuura M, Murata H, Nakakura S, Nakao Y, Kiuchi Y, Asaoka R. Association between Corneal Biomechanical Properties with Ocular Response Analyzer and Also CorvisST Tonometry, and Glaucomatous Visual Field Severity. Transl Vis Sci Technol 2017. [PMID: 28626602 PMCID: PMC5472364 DOI: 10.1167/tvst.6.3.18] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose To investigate the association between corneal biomechanical properties measured with the Ocular Response Analyzer (ORA) and also CorvisST (CST) tonometry, and glaucomatous visual field (VF) severity. Methods One hundred forty-six eyes of 91 patients with primary open-angle glaucoma who performed Humphrey Field Analyzer 30-2 or 24-2 SITA-Standard, ORA, and CST within 180 days were included in this multicentral, observational cross-sectional study. The association between ORA parameters (corneal hysteresis [CH] and corneal resistant factor [CRF]), CST parameters (A1 and A2 time, A1 and A2 length, A1 and A2 velocity, A1 and A2 deformation amplitude, highest deformation amplitude, highest concavity time, peak distance, and radius), and other basic parameters (age, intraocular pressure with Goldmann applanation tonometry, central corneal thickness, and axial length) against mean total deviation (mTD) were analyzed using a linear mixed-model and model selection with corrected Akaike Information Criterion (AICc). Results The optimal model of VF severity included ORA's CH as well as a number of CST parameters, including A1 length, A2 time, radius, and highest concavity deformation amplitude (AICc: 971.7). The possibility this model describes visual field severity more accurately than the optimal model without CST parameters was 99.98%. Conclusion Glaucomatous VF severity was best described by both ORA and CST parameters. Eyes with corneas that experience sharp and deep indentation at the maximum deformation, wide indentation at the first applanation, and early second applanation in the CST measurement are more likely to show advanced VF severity. Translational Relevance CorvisST tonometry parameters are related to VF severity in glaucoma patients.
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Affiliation(s)
- Kazunori Hirasawa
- Department of Ophthalmology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan.,Department of Orthoptics and Visual Science, School of Allied Health Sciences, Kitasato University, Kanagawa, Japan
| | - Masato Matsuura
- Department of Ophthalmology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Hiroshi Murata
- Department of Ophthalmology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
| | - Shunsuke Nakakura
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, Hyogo, Japan
| | - Yoshitaka Nakao
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
| | - Ryo Asaoka
- Department of Ophthalmology, The University of Tokyo Graduate School of Medicine, Tokyo, Japan
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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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Using CorvisST tonometry to assess glaucoma progression. PLoS One 2017; 12:e0176380. [PMID: 28472062 PMCID: PMC5417509 DOI: 10.1371/journal.pone.0176380] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2016] [Accepted: 04/10/2017] [Indexed: 11/19/2022] Open
Abstract
Purpose To investigate the utility of the Corneal Visualization Scheimpflug Technology instrument (CST) to assess the progression of visual field (VF) damage in primary open angle glaucoma patients. Method A total of 75 eyes from 111 patients with primary open-angle glaucoma were investigated. All patients underwent at least nine VF measurements with the Humphrey Field Analyzer, CST measurements, axial length (AL), central corneal thickness (CCT) and intraocular pressure (IOP) with Goldmann applanation tonometry (GAT). Mean total deviation (mTD) progression rates of the eight VFs, excluding the first VF, were calculated and the association between progression rate and the other listed measurements was analyzed using linear regression, and the optimal to describe mTD progression rate was selected based on the second order bias corrected Akaike Information Criterion (AICc) index. Results VF progression was described best in a model that included CST parameters as well as other ocular measurements. The optimal linear model to describe mTD progression rate was given by the equation: -8.9–0.068 x mean GAT + 0.68 x A1 time + 0.31 x A2 time -0.39 x A2 length– 1.26 x highest deformation amplitude. Conclusion CST measurements are useful when assessing VF progression in glaucoma patients. In particular, careful consideration should be given to patients where: (i) an eye is observed to be applanated fast in the first and second applanations, (ii) the applanated area is wide in the second applanation and (iii) the indentation is deep at the maximum deformation, since these eyes appear to be at greater risk of VF progression.
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Kato Y, Nakakura S, Matsuo N, Yoshitomi K, Handa M, Tabuchi H, Kiuchi Y. Agreement among Goldmann applanation tonometer, iCare, and Icare PRO rebound tonometers; non-contact tonometer; and Tonopen XL in healthy elderly subjects. Int Ophthalmol 2017; 38:687-696. [PMID: 28393323 DOI: 10.1007/s10792-017-0518-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2016] [Accepted: 04/04/2017] [Indexed: 11/29/2022]
Abstract
PURPOSE To evaluate the inter-device agreement among the Goldmann applanation tonometer (GAT), iCare and Icare PRO rebound tonometers, non-contact tonometer (NCT), and Tonopen XL tonometer. METHODS Sixty healthy elderly subjects were enrolled. The intraocular pressure (IOP) in each subject's right eye was measured thrice using each of the five tonometers. Intra-device agreement was evaluated by calculating intraclass correlation coefficients (ICCs). Inter-device agreement was evaluated by ICC and Bland-Altman analyses. RESULTS ICCs for intra-device agreement for each tonometer were >0.8. IOP as measured by iCare (mean ± SD, 11.6 ± 2.5 mmHg) was significantly lower (p < 0.05) than that measured by GAT (14.0 ± 2.8 mmHg), NCT (13.6 ± 2.5 mmHg), Tonopen XL (13.7 ± 4.1 mmHg), and Icare PRO (12.6 ± 2.2 mmHg; Bonferroni test). There was no significant difference in mean IOP among GAT, NCT, and Tonopen XL. Regarding inter-device agreement, ICC was lower between Tonopen XL and other tonometers (all ICCs < 0.4). However, ICCs of GAT, iCare, Icare PRO, and NCT showed good agreement (0.576-0.700). The Bland-Altman analysis revealed that the width of the 95% limits of agreement was larger between the Tonopen XL and the other tonometers ranged from 14.94 to 16.47 mmHg. Among the other tonometers, however, the widths of 95% limits of agreement ranged from 7.91 to 9.24 mmHg. CONCLUSION There was good inter-device agreement among GAT, rebound tonometers, and NCT. Tonopen XL shows the worst agreement with the other tonometers; therefore, we should pay attention to its' respective IOP. CLINICAL TRIAL REGISTRATION Japan Clinical Trials Register; number: UMIN000011544.
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Affiliation(s)
- Yoshitake Kato
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, 68-1 Aboshi Waku, Himeji, 671-1227, Japan
| | - Shunsuke Nakakura
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, 68-1 Aboshi Waku, Himeji, 671-1227, Japan.
| | - Naoko Matsuo
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, 68-1 Aboshi Waku, Himeji, 671-1227, Japan
| | - Kayo Yoshitomi
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, 68-1 Aboshi Waku, Himeji, 671-1227, Japan
| | - Marina Handa
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, 68-1 Aboshi Waku, Himeji, 671-1227, Japan
| | - Hitoshi Tabuchi
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, 68-1 Aboshi Waku, Himeji, 671-1227, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology and Visual Sciences, Graduate School of Biomedical Sciences, Hiroshima University, 1-2-3 Kasumi, Minami-Ku, Hiroshima, 734-8551, Japan
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Corneal biomechanical metrics of healthy Chinese adults using Corvis ST. Cont Lens Anterior Eye 2017; 40:97-103. [DOI: 10.1016/j.clae.2016.12.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2016] [Revised: 11/30/2016] [Accepted: 12/06/2016] [Indexed: 11/19/2022]
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Abstract
PURPOSE OF REVIEW The purpose of this review is to summarize the role of central corneal thickness (CCT) in the clinical management of a glaucoma patient. RECENT FINDINGS The prognostic value of CCT is well recognized in patients with ocular hypertension. However, its predictive value in other glaucoma suspects and patients with established glaucoma is less certain. Tonometry artefacts can result from variations in CCT. However, an adequately validated correction algorithm for Goldmann applanation tonometry measurements does not exist. Newer methods of tonometry are potentially less influenced by CCT but are limited in their clinical use. There may also be biological and genetic associations between corneal thickness and glaucoma. Demographics, environmental factors, glaucoma treatment and the measurement device used have a significant influence on CCT, and should be considered when interpreting the effect of cornea thickness in patients with glaucoma. New measurements of the biomechanical properties of the cornea are likely to be better approximations of the globe biomechanics than CCT, but these require further evaluation. SUMMARY The clinical significance of CCT is well recognized in the context of glaucoma diagnosis and management, though the extent of its importance remains debatable. Corneal biomechanical properties may be more significantly associated with glaucoma than CCT.
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Kato Y, Nakakura S, Asaoka R, Matsuya K, Fujio Y, Kiuchi Y. Cataract surgery causes biomechanical alterations to the eye detectable by Corvis ST tonometry. PLoS One 2017; 12:e0171941. [PMID: 28222145 PMCID: PMC5319737 DOI: 10.1371/journal.pone.0171941] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 01/27/2017] [Indexed: 02/06/2023] Open
Abstract
PURPOSE Modern cataract surgery is generally considered to bring about modest and sustained intraocular pressure (IOP) reduction. However, the pathophysiological mechanism for this remains unclear. Moreover, a change in ocular biomechanical properties after surgery can affect the measurement of IOP. The aim of the study is to investigate ocular biomechanics, before and following cataract surgery, using Corvis ST tonometry (CST). PATIENTS AND METHODS Fifty-nine eyes of 59 patients with cataract were analyzed. IOP with Goldmann applanation tonometry (IOP-G), axial length, corneal curvature and CST parameters were measured before cataract surgery and, up to 3 months, following surgery. Since CST parameters are closely related to IOP-G, linear modeling was carried out to investigate whether there was a change in CST measurements following cataract surgery, adjusted for a change in IOP-G. RESULTS IOP-G significantly decreased after surgery (mean±standard deviation: 11.8±3.1 mmHg) compared to pre-surgery (15.2±4.3 mmHg, P<0.001). Peak distance (the distance between the two surrounding peaks of the cornea at the highest concavity), maximum deformation amplitude (the movement of the corneal apex from the start of deformation to the highest concavity) and A1/A2 velocity (the corneal velocity during inward or outward movement) significantly increased after cataract surgery (P<0.05) while radius (the central curvature radius at the highest concavity) was significantly smaller following cataract surgery (P<0.05). Linear modeling supported many of these findings, suggesting that peak distance, maximum deformation amplitude and A2 velocity were increased, whereas A2 deformation amplitude and highest concavity time were decreased (after adjustment for IOP change), following cataract surgery. CONCLUSION Corneal biomechanical properties, as measured with CST, were observed to change significantly following cataract surgery. TRIAL REGISTRATION Japan Clinical Trials Registry UMIN000014370.
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Affiliation(s)
- Yoshitake Kato
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, Japan
| | - Shunsuke Nakakura
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, Japan
| | - Ryo Asaoka
- Department of Ophthalmology, The University of Tokyo, Tokyo, Japan
| | - Kanae Matsuya
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, Japan
| | - Yuki Fujio
- Department of Ophthalmology, Saneikai Tsukazaki Hospital, Himeji, Japan
| | - Yoshiaki Kiuchi
- Department of Ophthalmology and Visual Science, Hiroshima University, Hiroshima, Japan
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Singh M, Han Z, Nair A, Schill A, Twa MD, Larin KV. Applanation optical coherence elastography: noncontact measurement of intraocular pressure, corneal biomechanical properties, and corneal geometry with a single instrument. JOURNAL OF BIOMEDICAL OPTICS 2017; 22:20502. [PMID: 28241272 PMCID: PMC5316890 DOI: 10.1117/1.jbo.22.2.020502] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2016] [Accepted: 01/30/2017] [Indexed: 05/18/2023]
Abstract
Current clinical tools provide critical information about ocular health such as intraocular pressure (IOP). However, they lack the ability to quantify tissue material properties, which are potent markers for ocular tissue health and integrity. We describe a single instrument to measure the eye-globe IOP, quantify corneal biomechanical properties, and measure corneal geometry with a technique termed applanation optical coherence elastography (Appl-OCE). An ultrafast OCT system enabled visualization of corneal dynamics during noncontact applanation tonometry and direct measurement of micro air-pulse induced elastic wave propagation. Our preliminary results show that the proposed Appl-OCE system can be used to quantify IOP, corneal biomechanical properties, and corneal geometry, which builds a solid foundation for a unique device that can provide a more complete picture of ocular health.
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Affiliation(s)
- Manmohan Singh
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Zhaolong Han
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Achuth Nair
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Alexander Schill
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
| | - Michael D. Twa
- University of Alabama at Birmingham, School of Optometry, Birmingham, Alabama, United States
| | - Kirill V. Larin
- University of Houston, Department of Biomedical Engineering, Houston, Texas, United States
- Tomsk State University, Interdisciplinary Laboratory of Biophotonics, Tomsk, Russia
- Baylor College of Medicine, Molecular Physiology and Biophysics, Houston, Texas, United States
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Nakao Y, Kiuchi Y, Okimoto S. A Comparison of the Corrected Intraocular Pressure Obtained by the Corvis ST and Reichert 7CR Tonometers in Glaucoma Patients. PLoS One 2017; 12:e0170206. [PMID: 28095506 PMCID: PMC5240967 DOI: 10.1371/journal.pone.0170206] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 12/31/2016] [Indexed: 11/19/2022] Open
Abstract
The purpose of the study was to investigate the accuracy of two corrected intraocular pressure (IOP) measurements by Corvis Scheimpflug Technology (CST)-IOPpachy and by corneal-compensated IOP (IOPcc) using the Reichert 7CR (7CR) tonometers. We also investigated the effects of corneal anatomical and structural parameters on the IOP measurements. The participants included 90 primary open-angle glaucoma patients. We assessed the IOP measurements, obtained by the CST, 7CR, and Goldmann applanation tonometer (GAT), using a paired t-test with Bonferroni correction, Bland-Altman plots, and multiple regression analyses. The 7CR-IOPcc gave the highest value (15.5 ± 2.7 mmHg), followed by the 7CR-IOPg (13.7 ± 3.1 mmHg), GAT-IOP (13.6 ± 2.2 mmHg), CST-IOP (10.3 ± 2.6 mmHg), and CST-IOPpachy (9.7 ± 2.5 mmHg). The values of CST-IOPpachy were significantly lower than those obtained by the other IOP measurement methods (all, p < 0.01). The values of 7CR-IOPcc were significantly higher than those obtained by the other IOP measurement methods (all, p < 0.01). Bland-Altman plots showed a mean difference between the GAT-IOP and the other IOP measurements (CST-IOP, CST-IOPpachy, 7CR-IOPg, and 7CR-IOPcc), which were -3.20, -3.82, 0.14, and 2.00 mmHg, respectively. The widths of the 95% limits of agreement between all pairs of IOP measurements were greater than 3 mmHg. With the exception of the 7CR-IOPcc, all of the IOP variations were explained by regression coefficients involving gender, average corneal curvature, and central corneal thickness. The IOP values obtained by the GAT, CST, and 7CR were not interchangeable. Each new IOP measurement device that was corrected for ocular structure had its own limitations.
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Affiliation(s)
- Yoshitaka Nakao
- Ophthalmology and Visual Science Department, Hiroshima University, Hiroshima, Japan
- * E-mail:
| | - Yoshiaki Kiuchi
- Ophthalmology and Visual Science Department, Hiroshima University, Hiroshima, Japan
| | - Satoshi Okimoto
- Ophthalmology and Visual Science Department, Hiroshima University, Hiroshima, Japan
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Pahlitzsch M, Brünner J, Gonnermann J, Maier AKB, Torun N, Bertelmann E, Klamann MK. Comparison of ICare and IOPen vs Goldmann applanation tonometry according to international standards 8612 in glaucoma patients. Int J Ophthalmol 2016; 9:1624-1628. [PMID: 27990366 DOI: 10.18240/ijo.2016.11.14] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2015] [Accepted: 05/16/2016] [Indexed: 11/23/2022] Open
Abstract
AIM To compare IOPen and ICare rebound tonometry to Goldmann applanation tonometry (GAT) according to International Standards Organization (ISO) 8612 criteria. METHODS Totally 191 eyes (n=107 individuals) were included. Criteria of ISO 8612 were fulfilled: 3 clusters of IOP, measured by GAT, were formed. The GAT results were given as mean±standard deviation. RESULTS GAT (19.7±0.5 mm Hg) showed a significant correlation to ICare (19.8±0.5 mm Hg) (r=0.547, P<0.001) and IOPen (19.5±0.5 mm Hg) (r=0.526, P<0.001). According to ISO 8612 criteria in all 3 IOP groups the number of outliers (of the 95% limits of agreement) exceeded 5% for ICare and IOPen vs GAT: No.1 (n=68) 29.4% and 22.1%, No.2 (n=62) 35.5% and 37.1%, No.3 (n=61) 26.2% and 42.6%, respectively. CONCLUSION The strict requirements of the ISO 8612 are not fulfilled in a glaucoma collective by ICare and IOPen at present. As long as the Goldmann tonometry is applicable it should be used first of all for reproducible IOP readings. ICare and IOPen tonometry should be considered as an alternative tool, if application of Goldmann tonometry is not possible.
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Affiliation(s)
- Milena Pahlitzsch
- Glaucoma and Retinal Degeneration Research Group, UCL, Institute of Ophthalmology, Bath Street, London, EC1V 9EL, United Kingdom
| | - Jeanette Brünner
- Department of Ophthalmology, Campus Virchow Clinic, Charite University Medicine, Augustenburger Platz 1, Berlin13353, Germany
| | - Johannes Gonnermann
- Department of Ophthalmology, Campus Virchow Clinic, Charite University Medicine, Augustenburger Platz 1, Berlin13353, Germany
| | - Anna-Karina B Maier
- Department of Ophthalmology, Campus Virchow Clinic, Charite University Medicine, Augustenburger Platz 1, Berlin13353, Germany
| | - Necip Torun
- Department of Ophthalmology, Campus Virchow Clinic, Charite University Medicine, Augustenburger Platz 1, Berlin13353, Germany
| | - Eckart Bertelmann
- Department of Ophthalmology, Campus Virchow Clinic, Charite University Medicine, Augustenburger Platz 1, Berlin13353, Germany
| | - Matthias Kj Klamann
- Department of Ophthalmology, Campus Virchow Clinic, Charite University Medicine, Augustenburger Platz 1, Berlin13353, Germany
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