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Trufanov SV, Malozhen SA, Antonov AA, Makarova MA. [Modern capabilities of ophthalmic tonometry in pathologically altered corneas]. Vestn Oftalmol 2022; 138:71-77. [PMID: 35234424 DOI: 10.17116/oftalma202213801171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Changes in intraocular pressure have great influence on the course of various processes in ocular tissues. Presently, the scientific discussion has returned to the theoretical issues of tonometry and the creation of models that would allow assessing the influence of various ocular parameters on IOP values. Some of the modern tonometers (Icare, Tono-Pen) are convenient and effective when measuring IOP in eyes with damaged, uneven or edematous cornea. It is necessary to analyze the results of ophthalmic tonometry by modern methods in accordance with the data of direct intracameral manometry in pathological conditions of the cornea and after keratoplasty.
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Affiliation(s)
- S V Trufanov
- Research Institute of Eye Diseases, Moscow, Russia
| | - S A Malozhen
- Research Institute of Eye Diseases, Moscow, Russia
| | - A A Antonov
- Research Institute of Eye Diseases, Moscow, Russia
| | - M A Makarova
- Research Institute of Eye Diseases, Moscow, Russia
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Wang P, Song Y, Lin F, Wang Z, Gao X, Cheng W, Chen M, Peng Y, Liu Y, Zhang X, Chen S. Comparison of Non-contact Tonometry and Goldmann Applanation Tonometry Measurements in Non-pathologic High Myopia. Front Med (Lausanne) 2022; 9:819715. [PMID: 35308502 PMCID: PMC8927768 DOI: 10.3389/fmed.2022.819715] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/22/2021] [Accepted: 02/10/2022] [Indexed: 11/13/2022] Open
Abstract
PurposeTo compare intraocular pressure (IOP) values obtained using Goldmann applanation tonometry (IOPGAT) and non-contact tonometry (IOPNCT) in a non-pathologic high myopia population.MethodsA total of 720 eyes from 720 Chinese adults with non-pathologic high myopia were enrolled in this cross-sectional study. Demographic and ocular characteristics, including axial length, refractive error, central corneal thickness (CCT), and corneal curvature (CC) were recorded. Each patient was successively treated with IOPNCT and IOPGAT. Univariate and multivariable linear regression analyses were conducted to detect factors associated with IOPNCT and IOPGAT, as well as the measurement difference between the two devices (IOPNCT−GAT).ResultsIn this non-pathologic high myopia population, the mean IOPNCT and IOPGAT values were 17.60 ± 2.76 mmHg and 13.85 ± 2.43 mmHg, respectively. The IOP measurements of the two devices were significantly correlated (r = 0.681, P < 0.001), however, IOPNCT overestimated IOPGAT with a mean difference of 3.75 mmHg (95% confidence interval: 3.60–3.91 mmHg). In multivariate regression, IOPNCT was significantly associated with body mass index (standardized β = 0.075, p = 0.033), systolic blood pressure (SBP) (standardized β = 0.170, p < 0.001), and CCT (standardized β = 0.526, p < 0.001). As for IOPGAT, only SBP (standardized β = 0.162, p < 0.001), CCT (standardized β = 0.259, p < 0.001), and CC (standardized β = 0.156, p < 0.001) were significantly correlated. The mean IOPNCT−GAT difference increased with younger age (standardized β = −0.134, p < 0.001), higher body mass index (standardized β = 0.091, p = 0.009), higher SBP (standardized β = 0.074, p = 0.027), thicker CCT (standardized β = 0.506, p < 0.001), and lower IOPGAT (standardized β = −0.409, p < 0.001).ConclusionIn the non-pathologic high myopia population, IOPNCT overestimated IOPGAT at 3.75 ± 2.10 mmHg. This study suggests that the difference between the values obtained by the two devices, and their respective influencing factors, should be considered in the clinical evaluation and management of highly myopic populations.
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Intraocular pressure measurement: A Review. Surv Ophthalmol 2022; 67:1319-1331. [DOI: 10.1016/j.survophthal.2022.03.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2021] [Revised: 02/16/2022] [Accepted: 03/01/2022] [Indexed: 11/21/2022]
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Díaz-Barreda MD, Sánchez-Marín I, Boned-Murillo A, Pérez-Navarro I, Martínez J, Pardina-Claver E, Pérez D, Ascaso FJ, Ibáñez J. Modification of Corneal Biomechanics and Intraocular Pressure Following Non-Penetrating Deep Sclerectomy. J Clin Med 2022; 11:jcm11051216. [PMID: 35268307 PMCID: PMC8911357 DOI: 10.3390/jcm11051216] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 02/16/2022] [Accepted: 02/21/2022] [Indexed: 12/18/2022] Open
Abstract
Changes in the cornea can influence outcomes in patients with primary open-angle glaucoma (POAG). We aimed to evaluate the relevance of changes in corneal biomechanics and intraocular pressure (IOP) in patients undergoing non-penetrating deep sclerectomy (NPDS) with the Esnoper V2000 implant® (AJL Ophthalmic S.A., Gasteiz, Spain). We included 42 eyes of 42 patients with POAG scheduled for NPDS with the Esnoper V2000 implant. Biomechanical properties were measured by Ocular Response Analyzer® G3 (ORA; Reichert Inc., Depew, NY, USA). Corneal hysteresis (CH), corneal resistance factor (CRF), corneal compensated IOP (IOPcc), and Goldmann-correlated IOP (IOPg) were measured the day before surgery and on day 1, 7, and 30 and 2 and 3 months after surgery. CH initially increased, fell below the presurgical value at 30 days after the surgery, and increased again at 2 and 3 months. CRF, IOPcc, and IOPg decreased on the first day after surgery, then followed a trend of increasing but stayed below pre-surgery levels. All values reached statistical significance. While observed changes in corneal biomechanics after NPDS and Esnoper V2000 implant were significant, more studies are needed if we are to understand their influence on corneal biomechanics and their clinical relevance in POAG.
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Affiliation(s)
- María Dolores Díaz-Barreda
- Department of Ophthalmology, Hospital Clínico Universitario Lozano Blesa, 50009 Zaragoza, Spain; (I.S.-M.); (A.B.-M.); (I.P.-N.); (J.M.); (E.P.-C.); (D.P.); (J.I.)
- Department of Surgery, School of Medicine, University of Zaragoza, 50009 Zaragoza, Spain
- Aragon Health Research Institute (IIS Aragón), 50009 Zaragoza, Spain
- Correspondence: (M.D.D.-B.); (F.J.A.); Tel.: +34-629-863-827 (M.D.D.-B.); +34-686-574-389 (F.J.A.)
| | - Ignacio Sánchez-Marín
- Department of Ophthalmology, Hospital Clínico Universitario Lozano Blesa, 50009 Zaragoza, Spain; (I.S.-M.); (A.B.-M.); (I.P.-N.); (J.M.); (E.P.-C.); (D.P.); (J.I.)
| | - Ana Boned-Murillo
- Department of Ophthalmology, Hospital Clínico Universitario Lozano Blesa, 50009 Zaragoza, Spain; (I.S.-M.); (A.B.-M.); (I.P.-N.); (J.M.); (E.P.-C.); (D.P.); (J.I.)
- Department of Surgery, School of Medicine, University of Zaragoza, 50009 Zaragoza, Spain
- Aragon Health Research Institute (IIS Aragón), 50009 Zaragoza, Spain
| | - Itziar Pérez-Navarro
- Department of Ophthalmology, Hospital Clínico Universitario Lozano Blesa, 50009 Zaragoza, Spain; (I.S.-M.); (A.B.-M.); (I.P.-N.); (J.M.); (E.P.-C.); (D.P.); (J.I.)
| | - Juana Martínez
- Department of Ophthalmology, Hospital Clínico Universitario Lozano Blesa, 50009 Zaragoza, Spain; (I.S.-M.); (A.B.-M.); (I.P.-N.); (J.M.); (E.P.-C.); (D.P.); (J.I.)
| | - Elena Pardina-Claver
- Department of Ophthalmology, Hospital Clínico Universitario Lozano Blesa, 50009 Zaragoza, Spain; (I.S.-M.); (A.B.-M.); (I.P.-N.); (J.M.); (E.P.-C.); (D.P.); (J.I.)
| | - Diana Pérez
- Department of Ophthalmology, Hospital Clínico Universitario Lozano Blesa, 50009 Zaragoza, Spain; (I.S.-M.); (A.B.-M.); (I.P.-N.); (J.M.); (E.P.-C.); (D.P.); (J.I.)
- Department of Surgery, School of Medicine, University of Zaragoza, 50009 Zaragoza, Spain
- Aragon Health Research Institute (IIS Aragón), 50009 Zaragoza, Spain
| | - Francisco Javier Ascaso
- Department of Ophthalmology, Hospital Clínico Universitario Lozano Blesa, 50009 Zaragoza, Spain; (I.S.-M.); (A.B.-M.); (I.P.-N.); (J.M.); (E.P.-C.); (D.P.); (J.I.)
- Department of Surgery, School of Medicine, University of Zaragoza, 50009 Zaragoza, Spain
- Aragon Health Research Institute (IIS Aragón), 50009 Zaragoza, Spain
- Correspondence: (M.D.D.-B.); (F.J.A.); Tel.: +34-629-863-827 (M.D.D.-B.); +34-686-574-389 (F.J.A.)
| | - Juan Ibáñez
- Department of Ophthalmology, Hospital Clínico Universitario Lozano Blesa, 50009 Zaragoza, Spain; (I.S.-M.); (A.B.-M.); (I.P.-N.); (J.M.); (E.P.-C.); (D.P.); (J.I.)
- Department of Surgery, School of Medicine, University of Zaragoza, 50009 Zaragoza, Spain
- Aragon Health Research Institute (IIS Aragón), 50009 Zaragoza, Spain
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Lubbad A, Oluwatoba-Popoola I, Haar M, Framme C, Bajor A. The influence of corneal density and thickness on tonometry measurement with goldmann applanation, non-contact and iCare tonometry methods. Int Ophthalmol 2022; 42:2167-2174. [PMID: 35023013 PMCID: PMC9287215 DOI: 10.1007/s10792-022-02216-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 01/03/2022] [Indexed: 11/25/2022]
Abstract
PURPOSE To evaluate the effect of corneal density and thickness on the accuracy of tonometry readings obtained via three most used techniques. METHOD Intraocular pressures of 45 patients' right eyes were measured using Goldmann Applanation, iCare, and non-contact tonometry methods. Corneal parameters were obtained using the Pentacam Camera System. Data obtained were analyzed using Paired t Test, Pearson's correlation coefficient, multiple linear regression analysis, and Bland-Altman plots. RESULTS The mean corneal thickness was 545.4 ± 3.93 μm. The mean corneal density of total, stromal, 0-2 mm, and 2-6 mm zones were 27.85 ± 6.23 GSU, 24.61 ± 6.05 GSU, 20.76 ± 2.96 GSU, and 20.81 ± 3.51 GSU respectively. IOP readings had a statistically significant correlation with corneal stromal thickness, as well as with total and stromal density. The stromal density, however, showed higher correlation with the three tonometry methods than did the total density (iCare: - .482 (0.001) stromal density versus- .464 (0.001) total density, NCT: - .376 (0.011) versus - .353 (0.017), GAT: - .306 (0.041) versus - .296 (0.048)). Statistical differences were found in comparing the iCare readings with GAT (P < 0,00) and with NCT (P < 0,00), with mean differences of 1.8 mmHg ± 2.6 and 2.0 mmHg ± 2.6 respectively. GAT and NCT measurements showed no statistical difference (P > 0.05). CONCLUSION This study shows that both central corneal thickness and stromal density are significant influential factors of reliable IOP readings. It is necessary to consider more corneal biomechanical properties, as well as exercise a high degree of caution in any new attempts towards adjusting an IOP-correction equation.
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Affiliation(s)
- Ahmed Lubbad
- Clinic for Ophthalmology, Hannover Medical School, Hannover, Germany.
- , Carl-Neuberg-Str. 1, 30625, Hannover, Germany.
| | | | - Melanie Haar
- Clinic for Ophthalmology, Hannover Medical School, Hannover, Germany
| | - Carsten Framme
- Clinic for Ophthalmology, Hannover Medical School, Hannover, Germany
| | - Anna Bajor
- Clinic for Ophthalmology, Hannover Medical School, Hannover, Germany
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Wang J, Zhao Y, Yu AY, Wu J, Zhu M, Jiang M, Li X, Zhu D, Zhang P, Zheng X, Bao F, Elsheikh A. Effect of travoprost, latanoprost and bimatoprost PGF2α treatments on the biomechanical properties of in-vivo rabbit cornea. Exp Eye Res 2022; 215:108920. [PMID: 35007519 DOI: 10.1016/j.exer.2022.108920] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Revised: 12/07/2021] [Accepted: 12/31/2021] [Indexed: 11/04/2022]
Abstract
Prostaglandin F2α analogues (PGF2α), one of the most commonly prescribed classes of hypotensive agents, could decrease collagen fibril density and remodel the extracellular matrix in cornea. We hypothesized that PGF2α's would induce corneal softening, reduce the accuracy of intraocular pressure (IOP) measurement and lead to uncertainty in the effectiveness of the therapy. We determined the stress-strain behavior of rabbit cornea after PGF2α usage and evaluated the effect of biomechanical changes associated with PGF2α treatment on IOP measurements by Goldmann Applanation Tonometry (GAT). The tangent modulus decreased after PGF2α treatment, while the stromal interfibrillar spacing increased. PGF2α was shown to also affect the lateral eye with lower effect, which did not undergo direct eyedrop treatment. Significant decreases in the numerical predictions of GAT-IOP were predicted in all treated groups relative to control groups. Different PGF2α's (travoprost, latanoprost and bimatoprost) were associated with different extents of reduction in tissue stiffness and changes in corneal microstructure. PGF2α-induced changes in corneal mechanical properties could reduce the accuracy of IOP measurement and may cause an overestimation of the effect of PGF2α in lowering IOP, possibly leading to uncertainties in glaucoma management.
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Affiliation(s)
- JunJie Wang
- Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China; The Institute of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, 325027, China
| | - YiPing Zhao
- Department of Ophthalmology, Ninth People's Hospital, Shanghai JiaoTong University School of Medicine, Shanghai, 200025, China
| | - AYong Yu
- Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Jie Wu
- Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - ManMan Zhu
- Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - MuChen Jiang
- Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - Xuefei Li
- Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - DaTian Zhu
- Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - PeiPei Zhang
- Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China
| | - XiaoBo Zheng
- Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China; The Institute of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, 325027, China.
| | - FangJun Bao
- Eye Hospital, Wenzhou Medical University, Wenzhou, 325027, China; The Institute of Ocular Biomechanics, Wenzhou Medical University, Wenzhou, 325027, China.
| | - Ahmed Elsheikh
- School of Engineering, University of Liverpool, Liverpool, L69 3GH, UK; National Institute for Health Research (NIHR) Biomedical Research Centre for Ophthalmology, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK; Beijing Advanced Innovation Center for Biomedical Engineering, Beihang University, Beijing, China
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Karmiris E, Tsiripidis K, Gartaganis PS, Totou S, Vasilopoulou MG, Patelis A, Giannakis I, Chalkiadaki E. Comparison of intraocular pressure obtained by Goldmann applanation tonometer, Corvis ST and an airpuff tonometer in healthy adults. Eur J Ophthalmol 2021; 32:11206721211069227. [PMID: 34955039 DOI: 10.1177/11206721211069227] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
PURPOSE To assess the agreement among four types of intraocular pressure (IOP) measurements: IOP obtained by Goldmann applanation tonometer (IOP-GAT),IOP obtained by an air-puff tonometer (Nidek NT-510)(IOP-NCT), the non-corrected IOP obtained by the Corneal Visualization Scheimpflug Technology (IOP-Corvis) and the biomechanically corrected IOP obtained by the Corvis ST (bIOP-Corvis) in healthy patients with a broad spectrum of IOP values. Methods: This prospective, observational study recruited 113 healthy individuals. Each patient underwent IOP evaluation via GAT, Nidek NT-510 and Corvis ST. Difference in mean in IOP readings was assessed by one-way repeated-measures analysis of variance (ANOVA).Tonometer intermethod agreement was assessed by the Bland-Altman method. The difference between the four IOP measurements was correlated against corneal (CCT) and age with Pearson's correlation test. Results: IOP-Corvis showed the highest values (16.59 ± 3.08 mmHg),followed by IOP-NCT (16.05 ± 3.43 mmHg), IOP-GAT (15.62 ± 3.08 mmHg) and bIOP-Corvis (15.10 ± 2.67 mmHg).There were statistically significant differences in IOP measurements among all the ANOVA pairwise comparisons except between IOP-GAT and bIOP-Corvis (p = 0.07),as well as between IOP-GAT and IOP-NCT (p = 0.25). Bland Altman analysis revealed a notable bias (all p < 0.05) among IOP-GAT and bIOP-Corvis, IOP-GAT and IOP-Corvis, IOP-GAT and IOP-NCT, bIOP-Corvis and IOP-Corvis, bIOP-Corvis and IOP-NCT,IOP-Corvis and IOP-NCT of 0.51, -0.97, -0.43, -1.49, -0.95, 0.53 mmHg respectively. We observed a strong correlation of the difference between bIOP-Corvis and IOP-Corvis with CCT and patient age. Conclusion: Compared with GAT and Nidek NT-510, the Corvis-derived IOPs were recorded either the highest as IOP-Corvis or the lowest as bIOP-Corvis. Even if the differences among the tonometers were relatively small, the IOP values obtained with the Corvis ST, NCT and GAT were not interchangeable.
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Affiliation(s)
- Efthymios Karmiris
- Department of Ophthalmology, 251 Hellenic Airforce General Hospital, Athens, Greece
| | | | - Panos S Gartaganis
- Department of Ophthalmology, 251 Hellenic Airforce General Hospital, Athens, Greece
| | - Styliani Totou
- Department of Ophthalmology, 251 Hellenic Airforce General Hospital, Athens, Greece
| | | | - Andreas Patelis
- Department of Ophthalmology, 251 Hellenic Airforce General Hospital, Athens, Greece
| | - Ioannis Giannakis
- Department of Ophthalmology, 251 Hellenic Airforce General Hospital, Athens, Greece
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Jung Y, Suh H, Moon JI. Differential impact of prostaglandin analogues on agreement of intraocular pressure measurements obtained by Goldmann applanation, rebound, and noncontact tonometry. BMC Ophthalmol 2021; 21:436. [PMID: 34915877 PMCID: PMC8680149 DOI: 10.1186/s12886-021-02211-y] [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: 09/01/2021] [Accepted: 12/06/2021] [Indexed: 11/29/2022] Open
Abstract
Background To evaluate the effect of topical prostaglandin analogues on agreement of IOP measurements obtained by Goldmann applanation tonometry (GAT), rebound tonometry (RBT), and noncontact tonometry (NCT) in eyes with primary open- angle glaucoma (POAG). Methods Intraocular pressure measurements were obtained using GAT, RBT, and NCT in patients with POAG with or without prostaglandin analogues. The agreement between each tonometry was analysed using Bland-Altman analyses in those with or without prostaglandin analogues. The effect of average IOP on IOP differences was also evaluated. Results Among a total of 86 subjects included in the study, 44 patients were using prostaglandin analogues. The difference in IOP measured by GAT and RBT was marginally greater in those with (GAT-RBT: − 0.94 ± 1.63 mmHg) prostaglandin analogues than in those without (− 0.33 ± 1.22 mmHg, P = 0.06). The difference in IOP measured by GAT and NCT was significantly greater in the prostaglandin group (GAT-NCT: 2.40 ± 2.89 mmHg) than in the group without prostaglandin analogues (0.41 ± 1.63 mmHg, P < 0.01). While there was no significant relationship between the average of all tonometries and the difference between tonometries in those without prostaglandin analogues, both RBT and NCT underestimated IOP relative to GAT at higher IOP in those using prostaglandin analogues. Conclusion Intraocular pressure measured by RBT and NCT was similar to that measured by GAT in those without prostaglandin analogues. RBT overestimated and NCT underestimated IOP compared to GAT in those using prostaglandin analogues.
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Affiliation(s)
- Younhea Jung
- Department of Ophthalmology, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Hyun Suh
- Department of Ophthalmology, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea
| | - Jung Il Moon
- Department of Ophthalmology, Yeouido St. Mary's Hospital, College of Medicine, The Catholic University of Korea, Seoul, Republic of Korea.
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Yasukura Y, Miki A, Maeda N, Koh S, Nishida K. Effect of Prostaglandin Analogues on Corneal Biomechanical Parameters Measured With a Dynamic Scheimpflug Analyzer. J Glaucoma 2021; 30:996-1000. [PMID: 34086611 DOI: 10.1097/ijg.0000000000001895] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2020] [Accepted: 04/19/2021] [Indexed: 11/26/2022]
Abstract
PRCIS Treatment with topical prostaglandin analogues (PGAs) induces increased corneal compliance in glaucoma eyes measured with a dynamic Scheimpflug analyzer. PURPOSE The purpose of this study was to evaluate the effect of topical PGAs on the corneal biomechanical properties. METHODS We retrospectively studied the biomechanical parameters of 31 eyes of 19 consecutive patients with glaucoma measured using a dynamic Scheimpflug analyzer (Corvis ST) before and after initiation of treatment with topical PGAs. No patients had a history of glaucoma treatment before the study and no other antiglaucoma medication was used during the study period. Nine biomechanical parameters were evaluated before and 61.6±28.5 days (range: 21 to 105 d) after initiation of the treatment. The changes in the corneal biomechanical parameters before and after treatment were analyzed using multivariable models adjusting for intraocular pressure and central corneal thickness. The Benjamini-Hochberg method was used to correct for multiple comparison. RESULTS In multivariable models, PGA treatment resulted in shorter inward applanation time (P=0.016, coefficient=-0.151) and larger deflection amplitude (P=0.023, coefficient=0.055), peak distance (P=0.042, coefficient=0.131), and deformation amplitude ratio at 1 mm (P=0.018, coefficient=0.028). These associations consistently indicated increased corneal compliance (deformability) after PGA treatment. CONCLUSION Topical PGAs resulted in greater corneal compliance, suggesting that the changes in the corneal biomechanical properties may lead to overestimation of the intraocular pressure-lowering effects.
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Affiliation(s)
| | - Atsuya Miki
- Departments of Ophthalmology
- Innovative Visual Science, Osaka University Graduate School of Medicine
| | | | - Shizuka Koh
- Departments of Ophthalmology
- Innovative Visual Science, Osaka University Graduate School of Medicine
| | - Kohji Nishida
- Departments of Ophthalmology
- Integrated Frontier Research for Medical Science Division, Institute for Open and Transdisciplinary Research Initiatives, Osaka University, Suita, Osaka Prefecture, Japan
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Schlesener BN, Leonard BC, Miller PE, Kass PH, Hollingsworth SR, Cooper AE, Maggs DJ. Comparison of intraocular pressures estimated by rebound and applanation tonometry in dogs with lens instability: 66 cases (2012-2018). J Am Vet Med Assoc 2021; 259:1025-1031. [PMID: 34647480 DOI: 10.2460/javma.259.9.1025] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVE To compare intraocular pressures (IOPs) estimated by rebound and applanation tonometry for dogs with lens instability. ANIMALS 66 dogs. PROCEDURES Medical records of dogs examined between September 2012 and July 2018 were reviewed for diagnoses of anterior (ALL) or posterior (PLL) lens luxation or lens subluxation. RESULTS Estimates of IOP obtained with rebound and applanation tonometry significantly differed from each other for all types of lens instability considered collectively (mean ± SE difference between tonometric readings, 8.1 ± 1.3 mm Hg) and specific types of lens instability considered individually (mean ± SE difference between tonometric readings: ALL, 12.8 ± 2.5 mm Hg; PLL, 5.9 ± 1.7 mm Hg; subluxation, 2.8 ± 0.8 mm Hg). Median (range) differences between rebound and applanation tonometer readings for dogs with ALL was 5 mm Hg (-9 to 76 mm Hg), with PLL was 3 mm Hg (-1 to 19 mm Hg), and with lens subluxation was 3 mm Hg (-9 to 18 mm Hg). In eyes with ALL, rebound tonometer readings exceeded applanation tonometer readings on 44 of 60 (73%) occasions. CONCLUSIONS AND CLINICAL RELEVANCE Rebound tonometry yielded higher estimates of IOP than did applanation tonometry in eyes with ALL and with all types of lens luxation considered collectively. Estimates of IOP in eyes with lens instability should ideally be obtained with both rebound and applanation tonometers. Veterinarians with only one type of tonometer should interpret results for dogs with lens instability concurrent with physical examination findings.
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Karimi A, Razaghi R, Girkin CA, Downs JC. Ocular biomechanics due to ground blast reinforcement. COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2021; 211:106425. [PMID: 34598082 PMCID: PMC8577623 DOI: 10.1016/j.cmpb.2021.106425] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 09/14/2021] [Indexed: 05/24/2023]
Abstract
BACKGROUND AND OBJECTIVE Bomb blast injuries exerts a shearing force on the air-tissue interfaces, causing devastating ocular injury from the blast wave. Improvised explosive devices (IEDs) are usually placed at different heights from the ground to induce more severe injury through ground blast reinforcement (GBR). However, there is still a lack of knowledge of the role of GBR and IED height from the ground on ocular biomechanics, and how they can affect the intraocular pressure (IOP) in the eye. This study aimed to estimate the IOP due to frontal IED explosion at different heights from the ground using a fluid-structure interaction model with and without GBR effects. METHODS A 2 kg IED was placed within 5 m of the victim at 5 different heights from the ground, including 0, 0.42, 0.85, 1.27, and 1.70 m. Two different blast formulations were used to simulate the IED explosion: (a) spherical airburst, with no amplification of the initial shock wave due to interaction with the ground-surface, and (b) hemispherical surface-burst, where the initial blast wave is immediately reflected and reinforced by the ground (GBR). RESULTS Results revealed that the blast wave due to GBR reaches to the skull prior to the IED blast itself. The GBR also reached to the skull ∼ 0.6 ms earlier when the IED was on the ground compared to the height of 1.70 m. The highest and lowest IOPs of ∼ 17,000 and ∼ 15,000 mmHg were observed at the IED heights of 1.70 and 0 m from the ground considering GBR. However, when the role of the GBR is ignored, IOP of ∼ 9,000 mmHg was observed regardless of the IED height from the ground. The deformation in the apex of the cornea was higher when considering the GBR (∼ 0.75 cm) versus no GBR (∼ 0.65 cm). Considering GBR led to higher stresses and strains in the sclera. CONCLUSIONS When the role of GBR was ignored, the results showed similar patterns and magnitudes of stresses and deformations in the skull and eye regardless of the height of the IED from the ground, which was not the case when GBR was considered. The findings of this study suggest the critical role of GBR in ocular blast simulations.
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Affiliation(s)
- Alireza Karimi
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, 1670 University Boulevard, VH 390A, Birmingham, AL 35294, United States.
| | - Reza Razaghi
- Research Department, Heel of Scene Ltd., 2 Chome-12-3 Honmachi, Shibuya City, Tokyo, Japan.
| | - Christopher A Girkin
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, 1670 University Boulevard, VH 390A, Birmingham, AL 35294, United States.
| | - J Crawford Downs
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, 1670 University Boulevard, VH 390A, Birmingham, AL 35294, United States.
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Liu Y, Yang T, Yu J, Li M, Li J, Yan H. Creation of a New Explosive Injury Equipment to Induce a Rabbit Animal Model of Closed Globe Blast Injury via Gas Shock. Front Med (Lausanne) 2021; 8:749351. [PMID: 34631761 PMCID: PMC8495021 DOI: 10.3389/fmed.2021.749351] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Accepted: 08/25/2021] [Indexed: 11/13/2022] Open
Abstract
To establish a rabbit animal model of closed globe blast injury with an application of self-developed explosive injury equipment, we tend to explore the anatomic and pathological changes of eyes under different gas pressure. The device comprises of high-pressure air source compression pump, air channel, and gas shock. There were 36 healthy bluish blue rabbits exposed to one of five blast pressures (500, 1,000, 1,500, 2,000, and 5,000 Kpa). Slit lamp microscope, B-mode ultrasonography, fundus photography, optical coherence tomography (OCT), and intraocular pressure (IOP) examination were performed at 0-, 1-, 3-, and 7-days post exposure, while gross histopathology was assessed with H&E stain at 7 days. The contralateral eyes and non-blast exposed rabbits were used as controls. Definitive evidence of closed globe blast injury was obtained. Corneal edema and hyphema were observed in the models under all pressures with no full-thickness globe injury, or lens rupture, as the severity was pressure independent. There was no obvious retinal abnormality on B ultrasound or OCT scan, while light vitreous hemorrhage, commotio retinae, and heavy retinal pigmentation presented on one eye, respectively, in the eyes exposed to 5,000 Kpa. Increased retinal thickness with disorganizations on the retinal ganglion cell (RGC) layer and RGC apoptosis in groups under higher pressure (>500 Kpa). IOP of injured eyes were statistically decreased at day 1 and 7 post injury (p < 0.05). Conclusively, the rabbit animal model induced by self-developed equipment could mimic the clinical features of closed ocular blast injury successfully that was feasible and easy to operate. This will be a new rabbit animal model for investigating mechanisms and new therapeutic interventions of closed globe blast injury in the future.
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Affiliation(s)
- Yuanyuan Liu
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin Medical University, Tianjin, China
| | - Tiantian Yang
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin Medical University, Tianjin, China
| | - Jinguo Yu
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin Medical University, Tianjin, China
| | - Mengxuan Li
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin Medical University, Tianjin, China
| | - Jianan Li
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin Medical University, Tianjin, China
| | - Hua Yan
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin Medical University, Tianjin, China
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Min JS, Min BM. Clinical Outcomes of Laser Asymmetric Keratectomy to Manage Postoperative Adverse Effects–A Retrospective Clinical Trial. Open Ophthalmol J 2021. [DOI: 10.2174/1874364102115010171] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Background:
Laser asymmetric keratectomy reduces the regional asymmetry of corneal thickness.
Objective:
We aimed to describe the clinical outcomes of laser asymmetric keratectomy keratectomy with laser refractive surgery performed to resolve the adverse effects following ophthalmic surgeries.
Methods:
We compared the preoperative and postoperative outcomes and complaints of blurring after performing laser asymmetric keratectomy with laser refractive surgery in 24 eyes of 16 patients with a deviation sum in corneal thickness in four directions >80 µm. Laser asymmetric keratectomy with laser refractive surgery, with full integration of the Vision Up software, was used to analyze the corneal thickness deviation, employed selective laser ablation to create central symmetry on the thicker cornea to reduce regional asymmetry of corneal thickness, simultaneously correcting the refractive power and myopic shift. The pre-and postoperative clinical and topographic findings were analyzed.
Results:
The patients’ age was 37.57±22.30 (range, 23–65) years. The follow-up period was 16.56±3.23 months. The spherical equivalent (p=0.026), sphere (p=0.022), uncorrected distance visual acuity (LogMAR, p=0.045), blurring score (p=0.000), central corneal thickness (p=0.024), sum of deviations in corneal thickness in four directions (p=0.02), distance between the maximum posterior elevation and visual axis (p=0.04), and kappa angle (p=0.031), significantly decreased postoperatively. The efficiency and safety indices were 0.96±0.11 and 1.00, respectively. There was no myopic regression or blurred vision postoperatively.
Conclusion:
Performing laser asymmetric keratectomy with laser refractive surgery improved corneal symmetry and visual acuity and reduced blurring.
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Tzamalis A, Tsiampali C, Prousali E, Mataftsi A, Ziakas N, Kynigopoulos M. Reliability of Refraction, Keratometry, and Intraocular Pressure Measurements with an Automated All-in-one Device. Optom Vis Sci 2021; 98:1169-1176. [PMID: 34620780 DOI: 10.1097/opx.0000000000001781] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
SIGNIFICANCE This study explores the reliability of TonoRef II (Nidek, Tokyo, Japan), which represents a simple tool to obtain rapid refractometry and tonometry measurements. The present device demonstrates very high repeatability of refraction and intraocular pressure (IOP) readings as compared with subjective measurements and a higher concordance of IOP readings to Goldmann application tonometry (GAT). PURPOSE This study aimed to evaluate the repeatability of measurements acquired with the Autorefractometer/Keratometer/Tonometer TonoRef II and assess their agreement to subjective measurements and readings of other established devices. METHODS In a cross-sectional study, 54 eyes of 54 healthy subjects were enrolled. Each subject underwent five measurements with the TonoRef II, three measurements with the Canon RK-F1 Autorefractor Keratometer (Canon Europe NV, Amstelveen, the Netherlands), three IOP measurements with the Canon TX-F Noncontact Tonometer (Canon Inc., Tokyo, Japan), three measurements with GAT, and a thorough subjective refraction. Repeatability coefficient (r), intraclass correlation coefficient (ICC), and Bland-Altman plots were used to evaluate repeatability of readings and agreement to the subjective values. RESULTS TonoRef II showed high repeatability (ICC >0.9) in all parameters tested (sphere, r = 0.157; cylinder, r = 0.196; IOP, r = 2.653). A strong correlation was found between TonoRef and Canon instruments (P < .001 in all parameters). Mean differences and limits of agreement (mean ± 1.96 standard deviation) were -0.01 ± 0.69 D, -0.11 ± 0.7 D, and 2.1 ± 3.4 mmHg for sphere, cylinder, and IOP, respectively. Both autorefractors achieved a very good to excellent agreement to the values obtained with the subjective refraction for most of the parameters tested, without any significant difference to each other (P > .05). Intraocular pressure measurements of TonoRef II showed higher agreement to the GAT values compared with those obtained with the Canon tonometer (ICC, 0.9114 and 0.7002, respectively; P < .001). CONCLUSIONS Intraocular pressure and refraction readings acquired with TonoRef II demonstrate very high repeatability and agreement to the subjective measurements. Regarding IOP evaluation, TonoRef II shows higher concordance to GAT compared with another established noncontact tonometer.
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Affiliation(s)
| | - Chara Tsiampali
- 2nd Department of Ophthalmology, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Efthymia Prousali
- 2nd Department of Ophthalmology, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Asimina Mataftsi
- 2nd Department of Ophthalmology, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
| | - Nikolaos Ziakas
- 2nd Department of Ophthalmology, Papageorgiou General Hospital, Aristotle University of Thessaloniki, Thessaloniki, Greece
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Bronte-Ciriza D, Birkenfeld JS, de la Hoz A, Curatolo A, Germann JA, Villegas L, Varea A, Martínez-Enríquez E, Marcos S. Estimation of scleral mechanical properties from air-puff optical coherence tomography. BIOMEDICAL OPTICS EXPRESS 2021; 12:6341-6359. [PMID: 34745741 PMCID: PMC8548012 DOI: 10.1364/boe.437981] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Revised: 08/15/2021] [Accepted: 08/15/2021] [Indexed: 05/11/2023]
Abstract
We introduce a method to estimate the biomechanical properties of the porcine sclera in intact eye globes ex vivo, using optical coherence tomography that is coupled with an air-puff excitation source, and inverse optimization techniques based on finite element modeling. Air-puff induced tissue deformation was determined at seven different locations on the ocular globe, and the maximum apex deformation, the deformation velocity, and the arc-length during deformation were quantified. In the sclera, the experimental maximum deformation amplitude and the corresponding arc length were dependent on the location of air-puff excitation. The normalized temporal deformation profile of the sclera was distinct from that in the cornea, but similar in all tested scleral locations, suggesting that this profile is independent of variations in scleral thickness. Inverse optimization techniques showed that the estimated scleral elastic modulus ranged from 1.84 ± 0.30 MPa (equatorial inferior) to 6.04 ± 2.11 MPa (equatorial temporal). The use of scleral air-puff imaging holds promise for non-invasively investigating the structural changes in the sclera associated with myopia and glaucoma, and for monitoring potential modulation of scleral stiffness in disease or treatment.
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Affiliation(s)
- David Bronte-Ciriza
- Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
- CNR - IPCF, Istituto per i Processi Chimico-Fisici, Messina, Italy
- Co-first authors
| | - Judith S Birkenfeld
- Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
- Co-first authors
| | - Andrés de la Hoz
- Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
| | - Andrea Curatolo
- Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
- International Centre for Translational Eye Research, Warsaw, Poland
- Institute of Physical Chemistry, Polish Academy of Sciences, Warsaw, Poland
| | - James A Germann
- Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
| | - Lupe Villegas
- Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
| | - Alejandra Varea
- Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
| | - Eduardo Martínez-Enríquez
- Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
| | - Susana Marcos
- Instituto de Óptica "Daza de Valdés", Consejo Superior de Investigaciones Científicas (IO-CSIC), Madrid, Spain
- Center for Visual Science, The Institute of Optics, Flaum Eye Institute, University of Rochester, NY 14642, USA
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Qiao X, Chen D, Huo H, Tang M, Tang Z, Dong Y, Liu X, Fan Y. Full-field strain mapping for characterization of structure-related variation in corneal biomechanical properties using digital image correlation (DIC) technology. MEDICINE IN NOVEL TECHNOLOGY AND DEVICES 2021. [DOI: 10.1016/j.medntd.2021.100086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022] Open
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Simcoe MJ, Khawaja AP, Hysi PG, Hammond CJ. Genome-wide association study of corneal biomechanical properties identifies over 200 loci providing insight into the genetic etiology of ocular diseases. Hum Mol Genet 2021; 29:3154-3164. [PMID: 32716492 PMCID: PMC7645703 DOI: 10.1093/hmg/ddaa155] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2020] [Revised: 06/02/2020] [Accepted: 07/14/2020] [Indexed: 12/19/2022] Open
Abstract
Corneal hysteresis and corneal resistance factor are parameters that reflect the dynamic biomechanical properties of the cornea and have been shown to be biomarkers of corneal disease. In this genome-wide association study of over 100 000 participants, we identified over 200 genetic loci, all but eight novel, significantly associated with either one or both of these traits. In addition to providing key insights into the genetic architecture underlying normal corneal function, these results identify many candidate loci in the study of corneal diseases that lead to severe visual impairment. Additionally, using Mendelian randomization, we were able to identify causal relationships between corneal biomechanics and intraocular pressure measurements, which help elucidate the relationship between corneal properties and glaucoma.
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Affiliation(s)
- Mark J Simcoe
- Department of Ophthalmology, Kings College London, London, UK, SE1 7EH.,Department of Twins Research and Genetic Epidemiology, Kings College London, London, UK, SE1 7EH.,Institute of Ophthalmology, University College London, London, United Kingdom, EC1V 9EL
| | - Anthony P Khawaja
- NIHR Biomedical Research Centre, Moorfields Eye Hospital NHS Foundation Trust and UCL Institute of Ophthalmology, London, UK, EC1V 2PD.,Department of Public Health and Primary Care, Institute of Public Health, University of Cambridge School of Clinical Medicine, Cambridge, UK, CB1 8RN
| | - Pirro G Hysi
- Department of Ophthalmology, Kings College London, London, UK, SE1 7EH.,Department of Twins Research and Genetic Epidemiology, Kings College London, London, UK, SE1 7EH.,Institute of Child Health, University College London, London, United Kingdom, WC1N 1EH
| | - Christopher J Hammond
- Department of Ophthalmology, Kings College London, London, UK, SE1 7EH.,Department of Twins Research and Genetic Epidemiology, Kings College London, London, UK, SE1 7EH
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Kyei S, Assiamah F, Kwarteng MA, Gboglu CP. The Association of Central Corneal Thickness and Intraocular Pressure Measures by Non-Contact Tonometry and Goldmann Applanation Tonometry among Glaucoma Patients. Ethiop J Health Sci 2021; 30:999-1004. [PMID: 33883845 PMCID: PMC8047243 DOI: 10.4314/ejhs.v30i6.18] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Background The aim of this study was to determine whether Central Corneal Thickness (CCT) is associated with intraocular pressure measurement (IOP) with a Non-contact tonometer and the Goldmann applanation tonometer in glaucoma patients. Materials and Methods The study involved two hundred and thirty-two eyes of clinically diagnosed glaucoma patients receiving care at a referral facility. IOP measurements were obtained using both the Non-Contact Tonometer (NCT) and Goldmann Applanation Tonometer (GAT). The association between age, ethnicity, and CCT, as well as CCT on the measures of NCT and GAT, were analyzed. Results There were 64(55.2%) males and 52 (44.8%) females and their ages ranged from 18 to 85 years (mean age = 47.72; SD ± 15.75 years). There was a weak positive correlation between the CCT and NCT findings in the right eye (r = 0.19, n = 116, p < 0.05) and in the left eye (r = 0.25, n = 116, p < 0.05). However, there was no correlation between CCT and GAT measurements. Age had a significant correlation with CCT while gender and ethnicity had no significant correlation. Conclusion The study found a significant association between CCT and NCT. However, there was no significant association between CCT and GAT. CCT had an association with age but independent of gender and ethnicity since there was no significant relationship between these variables.
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Affiliation(s)
- Samuel Kyei
- Department of Optometry and Vision Science, School of Allied Health Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana.,Department of Optometry, Faculty of Science and Engineering, Bindura University of Science Education, Bindura, Zimbabwe
| | - Frank Assiamah
- Department of Optometry and Vision Science, School of Allied Health Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana
| | - Michael Agyemang Kwarteng
- Department of Optometry, Faculty of Science and Engineering, Bindura University of Science Education, Bindura, Zimbabwe.,Discipline of Optometry, College of Health Sciences, University of KwaZulu-Natal, South Africa
| | - Cynthia Pakyennu Gboglu
- Department of Optometry and Vision Science, School of Allied Health Sciences, College of Health and Allied Sciences, University of Cape Coast, Cape Coast, Ghana
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Xu Y, Ye Y, Chong IT, Chen Z, Xu J, Yang Y, Yu K, Lam DCC, Yu M. A Novel Indentation Assessment to Measure Corneal Biomechanical Properties in Glaucoma and Ocular Hypertension. Transl Vis Sci Technol 2021; 10:36. [PMID: 34459861 PMCID: PMC8411863 DOI: 10.1167/tvst.10.9.36] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
Purpose To evaluate the ability of the new in vivo corneal indentation device (CID) to measure corneal biomechanical properties. Methods and Results In total, 186 eyes from 46 healthy subjects, 107 patients with primary open-angle glaucoma, and 33 patients with ocular hypertension were enrolled in a cross-sectional study. Measurements were performed using corneal visualization Scheimpflug technology (Corvis ST) and the CID. The deformation amplitude (DA), inward applanation time, inward applanation velocity (A1V), outward applanation time (A2T), outward applanation velocity (A2V), highest concavity time, DA ratio, max inverse radius (MIR), integrated radius, and stiffness parameter A1 were included as Corvis ST parameters, and stiffness and modulus were included as CID parameters. Associations between the Corvis ST and CID parameters and correlations between central corneal thickness and corneal biomechanical parameters were analyzed. The stiffness was significantly correlated with all the Corvis ST parameters (P < 0.05). The modulus was significantly correlated with the DA, A1V, A2T, A2V, highest concavity time, and MIR (P < 0.05). The DA, inward applanation time, A1V, A2T, A2V, DA ratio, MIR, integrated radius, and stiffness parameter A1 values and both CID-derived values were significantly correlated with central corneal thickness (P < 0.05). Conclusions Parameters derived from the CID and Corvis ST demonstrated agreement in the measurement of corneal biomechanical properties. The stiffness and modulus can characterize in vivo corneal biomechanical properties. Translational Relevance Agreeing with the Corvis ST regarding the assessment of corneal biomechanical properties, the CID can be a novel clinical tool for biomechanical evaluation of the cornea.
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Affiliation(s)
- Yunzhi Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yiming Ye
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Iok Tong Chong
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Zidong Chen
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Jiangang Xu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Yangfan Yang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Keming Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - David C C Lam
- Department of Mechanical and Aerospace Engineering, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong
| | - Minbin Yu
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
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Xu J, Li R, Xu H, Yang Y, Zhang S, Ren T. Recent progress of continuous intraocular pressure monitoring. NANO SELECT 2021. [DOI: 10.1002/nano.202100137] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Affiliation(s)
- Jiandong Xu
- Institute of Microelectronics Tsinghua University Beijing 100084 China
- Beijing National Research Center for Information Science and Technology (BNRist) Tsinghua University Beijing 100084 China
| | - Ruisong Li
- Department of Electrical Engineering and Computer Science and Department of Bioengineering College of Engineering University of California Berkeley California 94720 USA
| | - Haokai Xu
- Institute of Microelectronics Tsinghua University Beijing 100084 China
- Beijing National Research Center for Information Science and Technology (BNRist) Tsinghua University Beijing 100084 China
| | - Yi Yang
- Institute of Microelectronics Tsinghua University Beijing 100084 China
- Beijing National Research Center for Information Science and Technology (BNRist) Tsinghua University Beijing 100084 China
| | - Sheng Zhang
- Shenzhen International Graduate School Tsinghua University Shenzhen 518055 China
| | - Tian‐Ling Ren
- Institute of Microelectronics Tsinghua University Beijing 100084 China
- Beijing National Research Center for Information Science and Technology (BNRist) Tsinghua University Beijing 100084 China
- Center for Flexible Electronics Technology Tsinghua University Beijing 100084 China
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Risk Factors for the Structural Progression of Myopic Glaucomatous Eyes with a History of Laser Refractive Surgery. J Clin Med 2021; 10:jcm10112408. [PMID: 34072378 PMCID: PMC8198199 DOI: 10.3390/jcm10112408] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2021] [Revised: 05/25/2021] [Accepted: 05/27/2021] [Indexed: 11/25/2022] Open
Abstract
As laser refractive surgeries (LRS) have been widely performed to correct myopia, ophthalmologists easily encounter patients with glaucoma who have a history of LRS. It is well known that intraocular pressure (IOP) in eyes with glaucoma is not accurate when measured using Goldmann applanation tonometry. However, risk factors for glaucoma progression, particularly those associated with measured IOP, have rarely been studied. We analysed data for 40 patients with a history of LRS and 50 age-matched patients without a history of LRS. Structural progression was defined as significant changes in thickness in the peripapillary retinal nerve fibre layer as identified using optical coherence tomography event-based guided progression analysis. Risk factors were determined via Cox regression analysis. Disc haemorrhage (DH) was associated with glaucoma progression in both the non-LRS group and LRS group (hazard ratio (HR): 4.650, p = 0.012 and HR: 8.666, p = 0.019, respectively). However, IOP fluctuation was associated with glaucoma progression only in the LRS group (HR: 1.452, p = 0.023). Our results show that DH was a significant sign of progression in myopic glaucoma eyes. When treating patients with myopia and glaucoma, IOP fluctuation should be monitored more carefully, even if IOP seems to be well controlled.
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Wang M, Berdahl J, McCafferty S. Corneal Crosslinking Biomechanics Evaluated by a Novel and Easily Implemented Differential Tonometry Method. Curr Eye Res 2021; 46:1614-1620. [PMID: 34039182 DOI: 10.1080/02713683.2021.1916039] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Purpose: Evaluate potential corneal biomechanical changes following corneal crosslinking (CXL) by paired differential tonometry intraocular pressure (IOP) measurements with a Goldmann tonometer (GAT) prism and corneal compensating, correcting applanation tonometry surface (CATS) prism.Methods: IOP was measured prospectively on 23 unique eyes undergoing CXL for keratoconus with a GAT using a standard flat GAT prism and a curved corneal error correcting CATS prism before treatment and at 2 weeks, 2 months and 6 months after treatment. Concurrent measurements of central corneal thickness (CCT) and corneal hysteresis (CH) were completed.Results: Paired IOP measurements with standard GAT and corneal correcting CATS prisms indicated a significant sustained relative increase in the differential IOP between the two prisms after CXL (p = .002,0.051,0.062). CH initially decreased at two weeks post-CXL then returned to sustained pre-op levels (p = .033,0.20,0.20). CCT progressively decreased following CXL (p = .005).Discussion: Differential tonometry between standard GAT and corneal biomechanical compensating CATS prisms indicates findings consistent with increased corneal rigidity following CXL and may demonstrate a simple and sensitive method for measurement of relative corneal biomechanical changes due to pharmacologic agents and procedures.
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Affiliation(s)
- Mingwu Wang
- Ophthalmology, Cornea Associates, Tucson, Arizona, USA
| | - John Berdahl
- Ophthalmology, Vance Thompson Vision, Sioux Falls, South Dakota, USA
| | - Sean McCafferty
- Ophthalmology, Arizona Eye Consultants, Tucson, Arizona, USA
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van den Bosch JJON, Pennisi V, Invernizzi A, Mansouri K, Weinreb RN, Thieme H, Hoffmann MB, Choritz L. Implanted Microsensor Continuous IOP Telemetry Suggests Gaze and Eyelid Closure Effects on IOP-A Preliminary Study. Invest Ophthalmol Vis Sci 2021; 62:8. [PMID: 33956052 PMCID: PMC8107486 DOI: 10.1167/iovs.62.6.8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Accepted: 03/15/2021] [Indexed: 11/24/2022] Open
Abstract
Purpose To explore the effect of gaze direction and eyelid closure on intraocular pressure (IOP). Methods Eleven patients with primary open-angle glaucoma previously implanted with a telemetric IOP sensor were instructed to view eight equally-spaced fixation targets each at three eccentricities (10°, 20°, and 25°). Nine patients also performed eyelid closure. IOP was recorded via an external antenna placed around the study eye. Differences of mean IOP between consecutive gaze positions were calculated. Furthermore, the effect of eyelid closure on gaze-dependent IOP was assessed. Results The maximum IOP increase was observed at 25° superior gaze (mean ± SD: 4.4 ± 4.9 mm Hg) and maximum decrease at 25° inferonasal gaze (-1.6 ± 0.8 mm Hg). There was a significant interaction between gaze direction and eccentricity (P = 0.003). Post-hoc tests confirmed significant decreases inferonasally for all eccentricities (mean ± SEM: 10°: -0.7 ± 0.2, P = 0.007; 20°: -1.1 ± 0.2, P = 0.006; and 25°: -1.6 ± 0.2, P = 0.006). Eight of 11 eyes showed significant IOP differences between superior and inferonasal gaze at 25°. IOP decreased during eyelid closure, which was significantly lower than downgaze at 25° (mean ± SEM: -2.1 ± 0.3 mm Hg vs. -0.7 ± 0.2 mm Hg, P = 0.014). Conclusions Our data suggest that IOP varies reproducibly with gaze direction, albeit with patient variability. IOP generally increased in upgaze but decreased in inferonasal gaze and on eyelid closure. Future studies should investigate the patient variability and IOP dynamics.
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Affiliation(s)
| | - Vincenzo Pennisi
- Department of Ophthalmology, University Hospital Magdeburg, Germany
| | - Azzurra Invernizzi
- Laboratory for Experimental Ophthalmology, University of Groningen, University Medical Center Groningen, Groningen, The Netherlands
- Cognitive Neuroscience Center, Department of Biomedical Sciences of Cells & Systems, University Medical Center Groningen, Groningen, The Netherlands
| | - Kaweh Mansouri
- Glaucoma Research Center, Montchoisi Clinic, Swiss Visio, Lausanne, Switzerland
- Department of Ophthalmology, University of Colorado, Denver, Colorado, United States
| | - Robert N. Weinreb
- Hamilton Glaucoma Center, Viterbi Family Department of Ophthalmology and Shiley Eye Institute, University of California, San Diego, La Jolla, California, United States
| | - Hagen Thieme
- Department of Ophthalmology, University Hospital Magdeburg, Germany
| | - Michael B. Hoffmann
- Department of Ophthalmology, University Hospital Magdeburg, Germany
- Center for Behavioral Brain Sciences, Magdeburg, Germany
| | - Lars Choritz
- Department of Ophthalmology, University Hospital Magdeburg, Germany
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Scott JA, Roberts CJ, Mahmoud AM, Jain SG. Evaluating the Relationship of Intraocular Pressure and Anterior Chamber Volume With Use of Prostaglandin Analogues. J Glaucoma 2021; 30:421-427. [PMID: 33149104 DOI: 10.1097/ijg.0000000000001736] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 10/24/2020] [Indexed: 11/26/2022]
Abstract
PRCIS In this prospective study, naive prostaglandin use in primary open-angle glaucoma was associated with scleral biomechanical alteration and intraocular pressure (IOP) measuring errors. PURPOSE The purpose of this study is to determine the effects of naïve use of prostaglandin analogues (PGA) on IOP and anterior chamber volume (ACV), as well as investigate how PGAs might affect corneal and scleral stiffness and their impact on ocular rigidity. MATERIALS AND METHODS This study was a prospective study of 21 recently diagnosed open-angle glaucoma patients (33 eyes) initiating medical therapy with a topical prostaglandin eye drop. Corneal morphologic and biomechanical parameters as well as IOP were measured at 3 visits over a 4-month period with the following equipment: Pentacam, Corvis ST, Ocular Response Analyzer, Goldmann applanation tonometry (GAT) and Pascal dynamic contour tonometry. RESULTS The study demonstrated a significant decrease in mean IOP with initiation of PGA in all 4 tonometers (P<0.0001). The greatest change in IOP occurred in the first 4 weeks of treatment (P<0.0001). The mean ACV showed a significant decrease at visit 2 (P<0.02) and visit 3 (P<0.04) compared with baseline visit 1. However, there was a paradoxical increase in ACV in 37% of eyes at visit 2, despite a significant mean reduction in IOP by GAT and dynamic contour tonometry.The IOP/ACV ratio at visit 1 significantly predicted the reduction in respective measures of IOP, as well as scleral stiffness measured by stiffness parameter-highest concavity. CONCLUSION In clinical practice, GAT may not be the most appropriate tonometer for measuring IOP in PGA treated eyes due the measurement errors from ocular biomechanical alteration. The IOP/ACV ratio could potentially serve as a new diagnostic parameter to determine the likelihood of PGA treatment success.
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Affiliation(s)
| | - Cynthia J Roberts
- Departments of Ophthalmology & Vision Sciences
- Biomedical Engineering, Havener Eye Institute, The Ohio State University Wexner Medical Center, Columbus, OH
| | - Ashraf M Mahmoud
- Departments of Ophthalmology & Vision Sciences
- Biomedical Engineering, Havener Eye Institute, The Ohio State University Wexner Medical Center, Columbus, OH
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Abstract
Glaucoma is the second cause of irreversible blindness in the world. Intraocular pressure (IOP) is a recognized major risk factor for the development and progression of glaucomatous damage. Goldmann applanation tonometry (GAT) is internationally accepted as the gold standard for the measurement of IOP. The purpose of this study was to search for correlations between Goldmann tonometry and corneal mechanical properties and thickness by means of in vitro tests. IOP was measured by the Goldmann applanation tonometer (GIOP), and by a pressure transducer inserted in the anterior chamber of the eye (TIOP), at increasing pressure levels by addition of saline solution in the anterior chamber of enucleated pig eyes (n = 49). Mechanical properties were also determined by inflation tests. The GAT underestimated the real measurements made by the pressure transducer, with most common differences in the range 15–28 mmHg. The difference between the two instruments, highlighted by the Bland–Altman test, was confirmed by ANOVA, normality tests, and Mann–Whitney’s tests, both on the data arranged for infusions and for the data organized by pressure ranges. Pearson correlation tests revealed a negative correlation between (TIOP-GIOP) and both corneal stiffness and corneal thickness. In conclusion, data obtained showed a discrepancy between GIOP and TIOP more evident for softer and thinner corneas, that is very important for glaucoma detection.
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76
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Min JS, Min BM. A Novel Approach to Enhancement Linked Laser Asymmetric Keratectomy Using Semi-Cylindrical Ablation Pattern in Patients with Myopic Regression After Laser Refractive Surgery. Clin Ophthalmol 2021; 15:1751-1758. [PMID: 33935491 PMCID: PMC8080158 DOI: 10.2147/opth.s306636] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2021] [Accepted: 04/09/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose We aimed to introduce a new technique to reduce regional asymmetry of corneal thickness by assessing its effectiveness in four patients with myopic regression after laser refractive surgery (LRS). Patients and Methods Four patients (four eyes) with myopic regression after LRS were included in this study. A new technique of enhancement with laser epithelial keratomileusis-linked laser asymmetric keratectomy using semi-cylindrical ablation pattern (E-LAK-SCAP) with full integration of the Vision-Up software for analyzing the corneal thickness deviation can be used to create central symmetry by blocking laser ablation on the thin cornea. It reduces the regional asymmetry of the corneal thickness, thus improving corneal symmetry and correcting the refractive power and myopic shift due to E-LAK-SCAP. We measured refraction, visual acuity, intraocular pressure (IOP), central corneal thickness (CCT), corneal irregularities in the 3.0mm, and 5.0 zones on Orbscan maps, the sum of corneal thickness deviations in four directions (SUM), distance between the maximum posterior elevation (best-fit-sphere [BFS]) and the visual axis (DISTANCE), and angle kappa before and after LRS and E-LAK-SCAP. Blurring scores were measured before and after E-LAK-SCAP. Results The uncorrected far visual acuity (LogMAR) increased after LRS and E-LAK-SCAP. SUM (µm) increased after LRS in three cases, but decreased in all four cases after E-LAK-SCAP. DISTANCE increased after LRS, but decreased after E-LAK-SCAP. The spherical equivalent, CCT, decreased after LRS and E-LAK-SCAP. Blurring scores decreased after E-LAK-SCAP, and angle kappa was similar before and after LRS, but decreased after E-LAK-SCAP. IOP was similar before and after both LRS and E-LAK-SCAP. Conclusion E-LAK-SCAP improved corneal symmetry by reducing the SUM and DISTANCE, showing good postoperative visual acuity, and blurring was reduced postoperatively. There was no myopic regression in the one-year postoperative period.
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Affiliation(s)
- Ji Sang Min
- Kim's Eye Hospital, Division of Cornea, Cataract, and Refractive Surgery, Konyang University School of Medicine, Seoul, South Korea
| | - Byung Moo Min
- Woori Eye Clinic, Department of Ophthalmology, Yonsei University School of Medicine, Daejon, South Korea
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Changes in corneal thickness after vitrectomy-Implications for glaucoma practice. PLoS One 2021; 16:e0249945. [PMID: 33882075 PMCID: PMC8059830 DOI: 10.1371/journal.pone.0249945] [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: 12/02/2020] [Accepted: 03/26/2021] [Indexed: 12/01/2022] Open
Abstract
Purpose To evaluate changes in central corneal thickness (CCT) following vitrectomy. Methods All consecutive old and new patients referred to glaucoma services for possible secondary glaucoma after vitrectomy and who had undergone corneal pachymetry between July 2013 to June 2020, were included. The eye that developed elevated intraocular pressure (IOP) and was diagnosed clinically as glaucoma after vitrectomy, was labelled as the “affected” eye. The contralateral eye of the patient with normal IOP and no history of vitrectomy was labelled as the “control” eye. The difference in CCT in the affected eye and the contralateral control eye (ΔCCT) and CCT were compared between different age groups. Correlation of CCT in the affected eye with age, diagnosis, type of surgery done, lens status and pre-existing glaucoma was done using multivariate regression analysis. Results Of 127 eyes of 120 patients (M:F = 85:35), the average CCT in the affected eye was significantly higher than the unaffected contralateral control eye (p<0.0001). The ΔCCT in eyes presenting at an age <25 years was higher (median 582, 497–840) than those that presented later (median 518, 384–755), p <0.0001, with maximum ΔCCT seen in eyes that had undergone vitrectomy at age<12 years. The CCT in the affected eye was significantly higher in aphakic eyes (588±81.6 microns) than in pseudophakic eyes (552±79.03 microns), p = 0.03. On multivariate analysis, age<25 years remained as a significant influencer of CCT in the affected eye (β = -1.7, p<0.001, R2 = 28.3%). Conclusions Young age group<25 years are more prone to corneal remodelling and CCT changes after vitrectomy.
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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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Franco S, Lira M. Biomechanical properties of the cornea measured by the Ocular Response Analyzer and their association with intraocular pressure and the central corneal curvature. Clin Exp Optom 2021; 92:469-75. [DOI: 10.1111/j.1444-0938.2009.00414.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Affiliation(s)
- Sandra Franco
- Physics Department (Optometry), University of Minho, Portugal E‐mail:
| | - Madalena Lira
- Physics Department (Optometry), University of Minho, Portugal E‐mail:
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Wong Y, Lam AK. Influence of corneal astigmatism, corneal curvature and meridional differences on corneal hysteresis and corneal resistance factor. Clin Exp Optom 2021; 94:418-24. [DOI: 10.1111/j.1444-0938.2011.00591.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Affiliation(s)
- Yin‐zhi Wong
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China. E‐mail:
| | - Andrew Kc Lam
- School of Optometry, The Hong Kong Polytechnic University, Hong Kong SAR, China. E‐mail:
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Min JS, Min BM. Comparison of outcomes of laser refractive surgery (LRS) alone and LRS with laser asymmetric keratectomy in patients with myopia: A retrospective study. Medicine (Baltimore) 2021; 100:e25366. [PMID: 33832118 PMCID: PMC8036046 DOI: 10.1097/md.0000000000025366] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 03/11/2021] [Indexed: 01/05/2023] Open
Abstract
To compare and analyze the postoperative 1-year outcomes of laser refractive surgery (LRS) alone vs LRS with laser asymmetric keratectomy (LAK), in patients with myopia, for preventing and resolving LRS complications.This retrospective study compared the preoperative and 1-year postoperative outcomes between the control and comparison groups using a sum of deviations in corneal thickness in 4 directions >80 μm. The control group included 41 patients with myopia (41 eyes) who underwent LRS. The comparison group included 33 patients (33 eyes) who received LAK-linked LRS. Age, spherical equivalent (SE), sphere, cylinder, uncorrected distance visual acuity (UDVA), pupil size, kappa angle, central corneal thickness, corneal irregularity in the 3.0 mm zone on Orbscan maps (SUM), distance between the maximum posterior elevation (best-fit-sphere) and the visual axis (DISTANCE), postoperative blurring scores, frequency of postoperative myopic regression, and efficiency index were compared.Preoperative age (P = .198), SE (P = .686), sphere (P = .562), cylinder (P = .883), UDVA (P = .139), pupil size (P = .162), kappa angle (P = .807), central corneal thickness (P = .738), corneal irregularity (P = .826), SUM (P = .774), and DISTANCE (P = .716) were similar between the 2 groups. The 1-year postoperative SE (P = .024), sphere (P = .022), corneal irregularity (P = .033), SUM (P = .000), DISTANCE (P = .04), blurring scores (P = .000), and frequency of postoperative myopic regression (P = .004) were significantly decreased in the comparison group compared to the control group. UDVA (P = .014) and the efficiency index (P = .035) were higher in the comparison group.LAK with LRS improved corneal symmetry by reducing the SUM and DISTANCE. UDVA and efficiency index were also improved and blurring and myopic regression were reduced postoperatively.
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Affiliation(s)
- Ji Sang Min
- Kim's Eye Hospital, Division of Cornea,Cataract, and Refractive Surgery. Konyang University School of Medicine. Youngdeungpo-gu, Seoul
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82
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Shin H, Seo H, Chung WG, Joo BJ, Jang J, Park JU. Recent progress on wearable point-of-care devices for ocular systems. LAB ON A CHIP 2021; 21:1269-1286. [PMID: 33704299 DOI: 10.1039/d0lc01317j] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/14/2023]
Abstract
The eye is a complex sensory organ that contains abundant information for specific diseases and pathological responses. It has emerged as a facile biological interface for wearable healthcare platforms because of its excellent accessibility. Recent advances in electronic devices have led to the extensive research of point-of-care (POC) systems for diagnosing and monitoring diseases by detecting the biomarkers within the eye. Among these systems, contact lenses, which make direct contact with the ocular surfaces, have been utilized as one of the promising candidates for non-invasive POC testing of various diseases. The continuous and long-term measurement from the sensor allows the patients to manage their symptoms in an effective and convenient way. Herein, we review the progress of contact lens sensors in terms of the materials, methodologies, device designs, and target biomarkers. The anatomical structure and biological mechanisms of the eye are also discussed to provide a comprehensive understanding of the principles of contact lens sensors. Intraocular pressure and glucose, which are the representative biomarkers found in the eyes, can be measured with the biosensors integrated with contact lenses for the diagnosis of glaucoma and diabetes. Furthermore, contact lens sensors for various general pathologies as well as other ocular diseases are also considered, thereby providing the prospects for further developments of smart contact lenses as a future POC system.
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Affiliation(s)
- Haein Shin
- Nano Science Technology Institute, Department of Materials Science and Engineering, Yonsei University, Seoul, 03722, Republic of Korea.
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Niemczyk M, Danielewska ME, Kostyszak MA, Lewandowski D, Iskander DR. The effect of intraocular pressure elevation and related ocular biometry changes on corneal OCT speckle distribution in porcine eyes. PLoS One 2021; 16:e0249213. [PMID: 33770135 PMCID: PMC7997020 DOI: 10.1371/journal.pone.0249213] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2020] [Accepted: 03/14/2021] [Indexed: 11/21/2022] Open
Abstract
The aim of this study was to evaluate the influence of increase in intraocular pressure (IOP) and cooccurring changes in ocular biometry parameters on the corneal optical coherence tomography (OCT) speckle distribution in ex-vivo experiments on porcine intact eyes. Twenty-three eyeballs were used in the inflation test where IOP in the anterior chamber was precisely set from 10 mmHg to 40 mmHg in steps of 5 mmHg and where eye biometry was utilized (IOL Master 700). To assess the influence of the duration of the experiment on the OCT speckle statistics, the second experiment was performed with 10 eyeballs at the constant IOP of 15 mmHg. Based on the OCT scans of central cornea (Copernicus REVO), spatial maps of the scale parameter (a) and the shape parameter (v) of the gamma distribution speckle model were estimated. The means of both parameters for each spatial map were computed within the 2 mm of the central stroma. Both distributional parameters statistically significantly varied with IOP and time (one way repeated measures ANOVA, all p-values < 0.001). The a parameter revealed a faster statistically significant increase in IOP up to 25 mmHg, regardless of time. Central corneal thickness (CCT), the anterior chamber depth, and the mean equivalent spherical power varied significantly with IOP, whereas CCT and axial length changed statistically significantly with time. Statistically significant correlation was found between CCT and the a parameter, after removing IOP as a confounding factor (r = -0.576, p < 0.001). The parameters of the gamma distribution can be used not only for identifying IOP induced changes in the optical scattering within the corneal stroma, but also in corneal geometry. The approach of corneal speckle analysis could be potentially utilized for an indirect and noninvasive assessment of some properties of corneal stroma.
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Affiliation(s)
- Marcela Niemczyk
- Department of Biomedical Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Monika E. Danielewska
- Department of Biomedical Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Malgorzata A. Kostyszak
- Department of Biomedical Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - Daniel Lewandowski
- Department of Mechanics, Materials and Biomedical Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland
| | - D. Robert Iskander
- Department of Biomedical Engineering, Wroclaw University of Science and Technology, Wroclaw, Poland
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Agreement of Corrected Intraocular Pressure Values Between Corvis ST and Pentacam in Patients With Keratoconus, Subclinical Keratoconus, and Normal Cornea. Cornea 2021; 40:1426-1432. [PMID: 33734163 DOI: 10.1097/ico.0000000000002707] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2020] [Accepted: 01/18/2021] [Indexed: 11/27/2022]
Abstract
PURPOSE To analyze the agreement of corrected intraocular pressure (IOP) values between Corvis ST (ΔIOP1) and Pentacam (ΔIOP2) in patients with keratoconus (KC), subclinical KC (sub-KC), and normal cornea. METHODS In total, 235 eyes were divided into KC, sub-KC, and control groups. Differences in ΔIOP1 (biomechanically corrected IOP minus uncorrected IOP) and ΔIOP2 (central corneal thickness-corrected amounts of IOP) were analyzed within and among groups. Topographical and biomechanical differences were compared among the 3 groups. Factors affecting differences between ΔIOP1 and ΔIOP2 were analyzed. Agreement analysis of ΔIOP2 and ΔIOP1 was performed by Bland-Altman plots for all 3 groups. RESULTS Mean ΔIOP1 was highest in the KC group (1.23 ± 0.84 mm Hg), followed by sub-KC and control groups (all P < 0.05). Deformation amplitude ratio at 2 mm (DA-2 mm), integrated radius, stiffness parameter at first applanation, and Corvis biomechanical index values significantly differed between sub-KC and control groups. The differences between ΔIOP1 and ΔIOP2 were affected by stiffness parameter at first applanation, after adjusting for central corneal thickness and age, in all 3 groups. The lowest agreement between ΔIOP2 and ΔIOP1 was observed in the KC group (mean difference: 1.90 mm Hg; 95% limit of agreement ranged from -0.2 to 3.9 mm Hg). CONCLUSIONS Among the 3 groups in this study, the KC group exhibited the worst consistency between ΔIOP2 and ΔIOP1. For the sub-KC and control groups, corrected IOP values derived by Pentacam were similar to Corvis ST. Ophthalmologists should carefully consider the mechanical properties of eyes with KC during IOP management.
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85
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An Intraocular Pressure Measurement Technique Based on Acoustic Radiation Force Using an Ultrasound Transducer: A Feasibility Study. SENSORS 2021; 21:s21051857. [PMID: 33799942 PMCID: PMC7961774 DOI: 10.3390/s21051857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 03/02/2021] [Accepted: 03/03/2021] [Indexed: 11/16/2022]
Abstract
High intraocular pressure (IOP) is one of the major risk factors for glaucoma, and thus accurate IOP measurements should be performed to diagnose and treat glaucoma early. In this study, a novel technique for measuring the IOP based on acoustic radiation force was proposed, and its potential was experimentally demonstrated. The proposed technique uses the acoustic radiation force to generate axial displacement on the ocular surface while simultaneously measuring the degree of deformation. In order to verify that the ocular displacement induced by the acoustic radiation force is related to the IOP, the experiment was conducted by fabricating a 5 MHz single element transducer and gelatin phantoms with different stiffness values. Our experimental results show that there is a close relationship between the ocular displacement by the acoustic radiation force and the IOP obtained by a commercial tonometer. Therefore, the proposed acoustic radiation force technique can be a promising candidate for measuring the IOP.
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86
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Yeh SJ, Chen KH, Kuang TM, Liu CJL, Chen MJ. Comparison of the iCare, Tono-Pen, non-contact airpuff, and Goldmann applanation tonometers in eyes with corneal edema after penetrating keratoplasty. J Chin Med Assoc 2021; 84:320-325. [PMID: 33587519 DOI: 10.1097/jcma.0000000000000476] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022] Open
Abstract
BACKGROUND To compare the utility of the iCare, Tono-Pen, and non-contact airpuff (NCT) tonometers with the Goldmann applanation tonometer (GAT) for measuring intraocular pressure (IOP) in patients with corneal edema after penetrating keratoplasty (PKP) and to assess the effects of central corneal thickness (CCT) and corneal curvature (CC) on IOP measurements. METHODS Thirty-two eyes of 27 patients with corneal edema after PKP due to corneal abnormalities and 43 control eyes of 30 patients with normal corneas were recruited. Before IOP measurements, all patients underwent a baseline examination, including auto-refraction, keratometry, slit lamp biomicroscopy, and CCT measurement. IOP was measured using the devices in the same order: first the NCT, followed by the iCare, Tono-Pen, and GAT. The differences between the iCare, Tono-Pen, NCT, and GAT were calculated with repeated-measures analysis of variance. The Bland-Altman method was used to assess the agreement between the iCare, Tono-Pen, and NCT versus the GAT. The influences of CCT and CC on IOP measurement were evaluated by correlation analysis using Pearson's correlation coefficient. RESULTS Mean IOP measurements were significantly higher with the NCT and Tono-Pen than with the GAT in the PKP and control groups. When compared with GAT, iCare showed significantly higher IOP readings in the control group, but the IOP readings did not differ between the iCare and GAT in the PKP group. Poor agreement was noted between the NCT and GAT in both groups. The Tono-Pen showed clinically acceptable agreement with GAT in control eyes and poor agreement in PKP eyes. The agreement between the iCare and GAT appeared to be clinically acceptable in both groups. Correlation analysis of the results from control eyes showed that the IOP measurements with the GAT and NCT were weakly related to CCT and moderately correlated with CC. The iCare IOP readings were weakly correlated with CCT and CC. CONCLUSION In the PKP group, the NCT and Tono-Pen significantly overestimated IOP, whereas the iCare IOP readings were similar to those obtained using the GAT. Poor agreement was noted between the NCT and GAT as well as between the Tono-Pen and GAT, but the iCare showed clinically acceptable agreement with GAT. In normal corneas, the GAT, NCT, and iCare were affected by CCT and CC. The iCare tonometer was less affected by corneal edema than were the NCT and the Tono-Pen. The iCare appears to be a useful device for IOP measurement in eyes with corneal edema after PKP.
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Affiliation(s)
- Shih-Jung Yeh
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
| | - Ko-Hua Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- School of Meidicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
| | - Tung-Mei Kuang
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- School of Meidicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
| | - Catherine Jui-Ling Liu
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- School of Meidicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
| | - Mei-Ju Chen
- Department of Ophthalmology, Taipei Veterans General Hospital, Taipei, Taiwan, ROC
- School of Meidicine, National Yang Ming Chiao Tung University, Taipei, Taiwan, ROC
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Chong J, Dupps WJ. Corneal biomechanics: Measurement and structural correlations. Exp Eye Res 2021; 205:108508. [PMID: 33609511 DOI: 10.1016/j.exer.2021.108508] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Revised: 02/09/2021] [Accepted: 02/12/2021] [Indexed: 02/02/2023]
Abstract
The characterization of corneal biomechanical properties has important implications for the management of ocular disease and prediction of surgical responses. Corneal refractive surgery outcomes, progression or stabilization of ectatic disease, and intraocular pressure determination are just examples of the many key clinical problems that depend highly upon corneal biomechanical characteristics. However, to date there is no gold standard measurement technique. Since the advent of a 1-dimensional (1D) air-puff based technique for measuring the corneal surface response in 2005, advances in clinical imaging technology have yielded increasingly sophisticated approaches to characterizing the biomechanical properties of the cornea. Novel analyses of 1D responses are expanding the clinical utility of commercially-available air-puff-based instruments, and other imaging modalities-including optical coherence elastography (OCE), Brillouin microscopy and phase-decorrelation ocular coherence tomography (PhD-OCT)-offer new opportunities for probing local biomechanical behavior in 3-dimensional space and drawing new inferences about the relationships between corneal structure, mechanical behavior, and corneal refractive function. These advances are likely to drive greater clinical adoption of in vivo biomechanical analysis and to support more personalized medical and surgical decision-making.
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Affiliation(s)
- Jillian Chong
- Cleveland Clinic Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA
| | - William J Dupps
- Cleveland Clinic Cole Eye Institute, Cleveland Clinic, Cleveland, OH, USA; Dept. of Ophthalmology, Cleveland Clinic Lerner College of Medicine of Case Western Reserve Univ, Cleveland, OH, USA; Dept. of Biomedical Engineering, Lerner Research Institute and Case Western Reserve Univ, Cleveland, OH, USA.
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88
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Konstantinidis A, Panagiotopoulou EK, Panos GD, Sideroudi H, Mehmet A, Labiris G. The Effect of Antiglaucoma Procedures (Trabeculectomy vs. Ex-PRESS Glaucoma Drainage Implant) on the Corneal Biomechanical Properties. J Clin Med 2021; 10:jcm10040802. [PMID: 33671167 PMCID: PMC7922603 DOI: 10.3390/jcm10040802] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2021] [Revised: 02/09/2021] [Accepted: 02/13/2021] [Indexed: 11/03/2022] Open
Abstract
The aim of this study is to investigate the effect of two antiglaucoma procedures, namely trabeculectomy and Ex-PRESS mini-shunt insertion on the biomechanical properties of the cornea. This is a prospective study. Thirty patients (30 eyes) were included in the study. Nineteen eyes had an Ex-PRESS shunt inserted (Group 1) and 11 had trabeculectomy (Group 2). The examination time points for both groups were one to three weeks preoperatively and at month 1, 6, and 12 postoperatively. Corneal biomechanical properties (corneal hysteresis (CH) corneal resistance factor (CRF)) were measured with the Ocular Response Analyzer (ORA). In group 1, CH was significantly increased at 6 and 12 months compared to baseline values. Corneal hysteresis was also higher at 1 month postoperatively, but this increase did not reach statistical significance. In group 2, the CH was significantly increased at all time points compared to the preoperative values. CRF decreased at all time points postoperatively compared to the preoperative values in both groups. The difference (preoperative values to postoperative values at all time points) of the CH and CRF between the two groups was also compared and no significant differences were detected between the two surgical techniques. Trabeculectomy and the EX-PRESS mini-shunt insertion significantly alter the corneal biomechanical properties as a result of the surgical trauma and the presence of the shunt in the corneal periphery. When compared between them, they affect the corneal biomechanical properties in a similar way.
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89
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The Relationship Between Corneal Hysteresis and Progression of Glaucoma After Trabeculectomy. J Glaucoma 2021; 29:912-917. [PMID: 32555063 DOI: 10.1097/ijg.0000000000001581] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE The purpose of this study was to investigate the association of corneal hysteresis (CH) measured with Ocular Response Analyzer on the progression of glaucoma after trabeculectomy. MATERIALS AND METHODS Twenty-four eyes of 19 patients with primary open-angle glaucoma underwent trabeculectomy. A series of visual fields (Humphery Field Analyzer 24-2 SITA-standard) were measured starting after 6 months after trabeculectomy (4.2±5.0 y, mean±SD). The mean total deviation (mTD) of the 52 test points were calculated. In addition, the mTD was divided into the following areas: central area (within central 10 degrees), superior area and inferior area: mTDcentre, mTDsuperior, and mTDinferior, respectively. The relationship between each area's progression rate of mTD and the 7 variables of baseline age, central corneal thickness, baseline mTD, mean intraocular pressure (IOP), SD of IOP divided by the mean IOP, the difference between baseline IOP obtained before the initiation of any treatment, mean IOP, and CH were analyzed using the linear mixed model, and the optimal model was selected using the model selection method with the second ordered Akaike Information Criterion. RESULTS In the optimal model for mTD progression rate, only CH was selected with the coefficient of 0.11. The optimal model for the mTDcentre progression rate included mean IOP with the coefficient of -0.043 and CH with the coefficient of 0.12, and that for mTDinferior included only CH with the coefficient of 0.089. There was no variable selected in the optimal model for the mTDsuperior progression rate. CONCLUSION CH is a useful measure in the management of glaucoma after trabeculectomy.
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90
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Krolo I, Mihaljevic B, Kasumovic A, Bagatin F, Ravlic MM, Herman JS. Rebound Tonometry over Soft Contact Lenses. Acta Inform Med 2021; 28:185-189. [PMID: 33417647 PMCID: PMC7780781 DOI: 10.5455/aim.2020.28.185-189] [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] [Indexed: 11/19/2022] Open
Abstract
Introduction: Goldmann applanation tonometry (GAT) is named as a gold standard for intraocular pressure (IOP) measurement. Aim: To assess the accuracy of intraocular pressure (IOP) measurements using rebound tonometry over hydrogel and silicone hydrogel contact lenses (CLs) of different powers. Methods: This study included 117 eyes of 61 patients (12 male, 49 female), all habitual wearers of hydrogel and silicone hydrogel CLs, and none previously diagnosed with glaucoma, ocular hypertension or anterior surface disease. Five IOP measurements were taken over each eye using a rebound tonometer (Icare): with soft CLs in situ and then repeated without CLs. Lens power ranged from -9.50 to +10.00 spherical diopters and to a maximum of -0.75 cylinder diopters. Results: A significant positive correlation was found between IOP measurements with and without CLs. The difference between IOP measurements with (mean 20.74±5.19 mmHg) and without (mean 18.79±4.36 mmHg) CLs was found to be 1.95 mmHg (P <0.01). Statistical analysis was performed using the paired t-test and a correlation coefficient was calculated (r = 0.59; P <0.001). We have observed that increase in central corneal thickness (CCT) correlates positively with increase of measurement error of rebound tonometry (r = 0.43; P <0.001). Conclusion: We have shown good reliability of IOP measurements over CLs of different materials and thickness profiles while using rebound tonometer which makes it a feasible and accurate method for clinical purposes.
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Affiliation(s)
- Iva Krolo
- Department of Ophthalmology, University Hospital Center Sestre milosrdnice, Zagreb, Croatiaa
| | - Boze Mihaljevic
- Department of Ophthalmology, University Hospital Center Sestre milosrdnice, Zagreb, Croatiaa
| | - Aida Kasumovic
- Department of Ophthalmology, University Hospital Center Sestre milosrdnice, Zagreb, Croatiaa
| | - Freja Bagatin
- Department of Ophthalmology, University Hospital Center Sestre milosrdnice, Zagreb, Croatiaa
| | - Maja Malenica Ravlic
- Department of Ophthalmology, University Hospital Center Sestre milosrdnice, Zagreb, Croatiaa
| | - Jelena Skunca Herman
- Department of Ophthalmology, University Hospital Center Sestre milosrdnice, Zagreb, Croatiaa
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91
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Gedde SJ, Vinod K, Wright MM, Muir KW, Lind JT, Chen PP, Li T, Mansberger SL. Primary Open-Angle Glaucoma Preferred Practice Pattern®. Ophthalmology 2021; 128:P71-P150. [DOI: 10.1016/j.ophtha.2020.10.022] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 10/20/2020] [Indexed: 12/17/2022] Open
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92
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Puri V, Sethi A, Waikar S. Correlation of corneal hysteresis and central corneal thickness with intraocular pressure measured by ocular response analyzer and goldmann applanation tonometer. JOURNAL OF MARINE MEDICAL SOCIETY 2021. [DOI: 10.4103/jmms.jmms_94_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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93
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Weng CC, Chen PY, Chou D, Shih CC, Huang CC. High Frequency Ultrasound Elastography for Estimating the Viscoelastic Properties of the Cornea Using Lamb Wave Model. IEEE Trans Biomed Eng 2020; 68:2637-2644. [PMID: 33306463 DOI: 10.1109/tbme.2020.3044066] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
OBJECTIVE Estimating the elasticity distribution in the cornea is important because corneal elasticity is usually influenced by corneal pathologies and surgical treatments, especially for early corneal sclerosis. Because the thickness of the cornea is typically less than 1 mm, high-resolution ultrasound elastography as well as the Lamb wave model is required for viscoelastic property estimation. In the present study, an array high-frequency ultrasound (HFUS) elastography method based on ultrafast ultrasound imaging was proposed for estimating the viscoelastic properties of porcine cornea. METHODS The elastic wave was generated by an external vibrator, after which the wave propagation image was obtained using a 40-MHz array transducer. Viscoelasticity estimation was performed by fitting the phase velocity curve using the Lamb wave model. The performance of the proposed HFUS elastography system was verified using 2-mm-thick thin-layer gelatin phantoms with gelatin concentrations of 7% and 12%. Ex vivo experiments were carried out using fresh porcine cornea with artificial sclerosing. RESULTS Experimental results showed that the estimated elasticity was close to the standard value obtained in the phantom study when the Lamb wave model was used for elasticity measurement. However, the error between the standard elasticity values and the elasticity values estimated using group shear wave velocity was large. In the ex vivo eyeball experiments, the estimated elasticities and viscosities were respectively 9.1 ± 1.3 kPa and 0.5 ± 0.10 Pa·s for a healthy cornea and respectively 15.9 ± 2.1 kPa and 1.1 ± 0.12 Pa·s for a cornea with artificial sclerosis. A 3D HFUS elastography was also obtained for distinguishing the region of sclerosis in the cornea. CONCLUSION The experimental results demonstrated that the proposed HFUS elastography method has high potential for the clinical diagnosis of corneal diseases compared with other HFUS single-element transducer elastography systems.
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94
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Founti P, Bunce C, Khawaja AP, Doré CJ, Mohamed-Noriega J, Garway-Heath DF. Risk Factors for Visual Field Deterioration in the United Kingdom Glaucoma Treatment Study. Ophthalmology 2020; 127:1642-1651. [DOI: 10.1016/j.ophtha.2020.06.009] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2019] [Revised: 06/01/2020] [Accepted: 06/04/2020] [Indexed: 12/30/2022] Open
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95
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Qassim A, Mullany S, Abedi F, Marshall H, Hassall MM, Kolovos A, Knight LSW, Nguyen T, Awadalla MS, Chappell A, Schulz AM, Galanopoulos A, Agar A, Healey PR, Hewitt AW, Graham SL, Landers J, Casson RJ, Siggs OM, Craig JE. Corneal Stiffness Parameters Are Predictive of Structural and Functional Progression in Glaucoma Suspect Eyes. Ophthalmology 2020; 128:993-1004. [PMID: 33245936 DOI: 10.1016/j.ophtha.2020.11.021] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 10/28/2020] [Accepted: 11/18/2020] [Indexed: 11/17/2022] Open
Abstract
PURPOSE To investigate corneal stiffness parameters (SPs) as predictors of future progression risk in glaucoma suspect eyes. DESIGN Prospective, longitudinal study. PARTICIPANTS Three hundred seventy-one eyes from 228 primary open-angle glaucoma suspects, based on optic disc appearance, with normal baseline Humphrey Visual Field (HVF; Carl Zeiss Meditec) results. METHODS Baseline corneal SPs were measured using Corvis ST (Oculus Optikgeräte GmbH). Participants were followed up every 6 months with clinical examination, HVF testing, and OCT. The baseline SP at first applanation (SP-A1) and highest concavity predicted the prospective outcome measures. MAIN OUTCOME MEASURES Structural progression was measured by the OCT rate of thinning of the retinal nerve fiber layer (RNFL) and ganglion cell-inner plexiform layer (GCIPL). Functional progression was assessed by permutation analysis of pointwise linear regression criteria on HVF testing. RESULTS Stiffness parameters correlated positively with central corneal thickness (CCT), which was adjusted for in all analyses. A higher SP-A1, suggestive of a stiffer cornea, was associated with a faster rate of RNFL thinning (P < 0.001), synergistic with thinner CCT (P = 0.004) over a mean follow-up of 4.2 years. Eyes with higher SP-A1 and thinner CCT (thin and stiff corneas) showed accelerated RNFL thinning by 0.72 μm/year relative to eyes with lower SP-A1 and thicker CCT (95% confidence interval [CI], 0.17-1.28; P = 0.011) and were at 2.9-fold higher likelihood of fast RNFL progression of more than 1 μm/year (95% CI, 1.4-6.1; P = 0.006). Consistent results also were observed with GCIPL thinning. Furthermore, a higher SP-A1 was associated with a greater risk of visual field progression (P = 0.002), synergistic with thinner CCT (P = 0.010). Eyes with higher SP-A1 and thinner CCT were at 3.7-fold greater risk of visual field progression relative to eyes with thicker CCT and lower SP-A1 (95% CI, 1.3-10.5; P = 0.014). CONCLUSIONS Glaucoma suspect eyes with higher corneal SPs and lower CCT, suggestive of thin and stiff corneas, are at greater risk of progression. Corneal SPs seem to act synergistically with CCT as risk factors for glaucoma progression.
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Affiliation(s)
- Ayub Qassim
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia.
| | - Sean Mullany
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Farshad Abedi
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Henry Marshall
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Mark M Hassall
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Antonia Kolovos
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Lachlan S W Knight
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Thi Nguyen
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Mona S Awadalla
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Angela Chappell
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Angela M Schulz
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - Anna Galanopoulos
- South Australian Institute of Ophthalmology, Royal Adelaide Hospital, Adelaide, Australia
| | - Ashish Agar
- Department of Ophthalmology, Prince of Wales Hospital, Randwick, Australia
| | - Paul R Healey
- Centre for Vision Research, Westmead Institute for Medical Research, University of Sydney, Sydney, Australia
| | - Alex W Hewitt
- Menzies Institute for Medical Research, University of Tasmania, Hobart, Australia
| | - Stuart L Graham
- Faculty of Medicine and Health Sciences, Macquarie University, Sydney, Australia
| | - John Landers
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Robert J Casson
- South Australian Institute of Ophthalmology, University of Adelaide, Adelaide, Australia
| | - Owen M Siggs
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
| | - Jamie E Craig
- Department of Ophthalmology, Flinders University, Flinders Medical Centre, Bedford Park, Australia
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96
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Liu G, Rong H, Pei R, Du B, Jin N, Wang D, Jin C, Wei R. Age distribution and associated factors of cornea biomechanical parameter stress-strain index in Chinese healthy population. BMC Ophthalmol 2020; 20:436. [PMID: 33143686 PMCID: PMC7607623 DOI: 10.1186/s12886-020-01704-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 10/23/2020] [Indexed: 12/15/2022] Open
Abstract
Background To investigate the new cornea biomechanical parameter stress-strain index (SSI) in Chinese healthy people and the factors associated with SSI. Methods A total of 175 eyes from 175 participants were included in this study. Axial length was measured with the Lenstar LS-900. Pentacam measured curvature of the cornea and anterior chamber volume (ACV). Cornea biomechanical properties assessments were performed by corneal visualization Scheimpflug technology (Corvis ST). Student’s t-test, one-way ANOVA, partial least square linear regression (PLSLR) and linear mixed effects (LME) model were used in the statistical analysis. Results The mean (±SD) SSI was 1.14 ± 0.22 (range, 0.66–1.78) in all subjects and affected by age significantly after age of 35 (P < 0.05). In LME models, SSI was significantly associated with age (β = 0.526, P < 0.001), axial length (AL) (β = − 0.541, P < 0.001), intraocular pressure (IOP) (β = 0.326, P < 0.001) and steepest radius of anterior corneal curvature (RsF) (β = 0.229, P < 0.001) but not with ACV, biomechanical corrected intraocular pressure (bIOP), flattest radius of anterior corneal curvature (RfF) or central corneal thickness (CCT) (P > 0.05 for each). Conclusions SSI increased with age after the age of 35. In addition to age, SSI was positively correlated with RsF and IOP, while negatively correlated with AL.
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Affiliation(s)
- Guihua Liu
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Postal address: 251 Fukang Road, Nankai District, Tianjin, China.,Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Postal address: 251 Fukang Road, Nankai District, Tianjin, China
| | - Hua Rong
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Postal address: 251 Fukang Road, Nankai District, Tianjin, China.,Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Postal address: 251 Fukang Road, Nankai District, Tianjin, China
| | - Ruxia Pei
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Postal address: 251 Fukang Road, Nankai District, Tianjin, China.,Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Postal address: 251 Fukang Road, Nankai District, Tianjin, China
| | - Bei Du
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Postal address: 251 Fukang Road, Nankai District, Tianjin, China.,Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Postal address: 251 Fukang Road, Nankai District, Tianjin, China
| | - Nan Jin
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Postal address: 251 Fukang Road, Nankai District, Tianjin, China.,Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Postal address: 251 Fukang Road, Nankai District, Tianjin, China
| | - Di Wang
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Postal address: 251 Fukang Road, Nankai District, Tianjin, China.,Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Postal address: 251 Fukang Road, Nankai District, Tianjin, China
| | - Chengcheng Jin
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Postal address: 251 Fukang Road, Nankai District, Tianjin, China.,Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Postal address: 251 Fukang Road, Nankai District, Tianjin, China
| | - Ruihua Wei
- Tianjin International Joint Research and Development Centre of Ophthalmology and Vision Science, Postal address: 251 Fukang Road, Nankai District, Tianjin, China. .,Eye Institute and School of Optometry, Tianjin Medical University Eye Hospital, Postal address: 251 Fukang Road, Nankai District, Tianjin, China.
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97
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Yang Y, Ng TK, Wang L, Wu N, Xiao M, Sun X, Chen Y. Association of 24-Hour Intraocular Pressure Fluctuation With Corneal Hysteresis and Axial Length in Untreated Chinese Primary Open-Angle Glaucoma Patients. Transl Vis Sci Technol 2020; 9:25. [PMID: 33244445 PMCID: PMC7683862 DOI: 10.1167/tvst.9.12.25] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2020] [Accepted: 10/12/2020] [Indexed: 02/05/2023] Open
Abstract
PURPOSE The purpose of this study was to evaluate the association of 24-hour intraocular pressure (IOP) fluctuation with corneal biomechanics and ocular biometric parameters in Chinese patients with primary open angle glaucoma (POAG) before initial treatment. METHODS Forty-nine Chinese patients with POAG (98 eyes) were recruited in this study before start of any POAG treatment. The 24-hour IOP was measured with a 2-hour interval by a noncontact tonometer. Corneal biomechanical properties and biometric parameters were measured once during 8 AM to 6 PM before 24-hour IOP measurement. RESULTS The 24-hour IOP fluctuation was defined as the differences between the peak and trough IOP measurement and was significantly associated with axial length (AL) in the multivariate analysis. The POAG subjects with AL ≤ 26 mm had significantly larger 24-hour IOP fluctuation but lower corneal hysteresis, compared to those with AL > 26 mm. In addition, subgroup analysis showed that high tension glaucoma subjects had larger 24-hour IOP fluctuation and higher corneal resistance factor than patients with normal tension glaucoma. CONCLUSIONS This study revealed the association of 24-hour IOP fluctuation with office hour corneal biomechanical properties and AL in patients with POAG. Their contributions to IOP fluctuation should be considered in the risk analysis of glaucoma development and progression. TRANSLATIONAL RELEVANCE Ocular biometric parameters are related with 24-hour IOP fluctuation in patients with POAG, which is potentially helpful in explaining different progression patterns in different types of patients.
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Affiliation(s)
- Yaping Yang
- Department of Ophthalmology and Visual Science, Eye and Ear Nose Throat Hospital, Shanghai Medical College, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Ministry of Health, Fudan University, Shanghai, China
- Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Tsz Kin Ng
- Joint Shantou International Eye Center of Shantou University and The Chinese University of Hong Kong, Shantou University Medical College, Shantou, Guangdong, China
- Department of Ophthalmology and Visual Sciences, The Chinese University of Hong Kong, Hong Kong
| | - Li Wang
- Department of Ophthalmology and Visual Science, Eye and Ear Nose Throat Hospital, Shanghai Medical College, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Ministry of Health, Fudan University, Shanghai, China
- Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Na Wu
- Department of Ophthalmology and Visual Science, Eye and Ear Nose Throat Hospital, Shanghai Medical College, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Ministry of Health, Fudan University, Shanghai, China
- Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
| | - Ming Xiao
- Department of Ophthalmology, Shanghai Bei Zhan Hospital, Shanghai, China
| | - Xinghuai Sun
- Department of Ophthalmology and Visual Science, Eye and Ear Nose Throat Hospital, Shanghai Medical College, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Ministry of Health, Fudan University, Shanghai, China
- Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, China
| | - Yuhong Chen
- Department of Ophthalmology and Visual Science, Eye and Ear Nose Throat Hospital, Shanghai Medical College, Fudan University, Shanghai, China
- Key Laboratory of Myopia, Ministry of Health, Fudan University, Shanghai, China
- Key Laboratory of Visual Impairment and Restoration, Fudan University, Shanghai, China
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98
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Rahmati SM, Razaghi R, Karimi A. Biomechanics of the keratoconic cornea: Theory, segmentation, pressure distribution, and coupled FE-optimization algorithm. J Mech Behav Biomed Mater 2020; 113:104155. [PMID: 33125958 DOI: 10.1016/j.jmbbm.2020.104155] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2020] [Revised: 10/14/2020] [Accepted: 10/21/2020] [Indexed: 10/23/2022]
Abstract
Understanding of the corneal biomechanical properties is of high interest due to its potential application in the early diagnosis of keratoconus (KC). KC by itself is a non-inflammatory eye disorder causes corneal structural and/or compositional anomalies. The biomechanically weakened cornea is no longer able to preserve the normal shape of the cornea against the intraocular pressure (IOP) and gradually starts to bulge outward, invoking a conical shape and subsequent distorted vision. The most popular way to measure the in vivo corneal biomechanical properties is the CorVis-ST, which enables to analyze the dynamic response of the cornea under a temporary air puff pressure. However, the complications, such as the lack of knowledge on the accurate air-puff pressure distribution on the cornea's surface as a function of the distance from the apex of the cornea as well as the time, hinder us to have a reliable estimation of the cornea's mechanical parameters. This study aims to establish patient-specific geometries of the healthy and KC corneas and calculate the pressure distribution on the cornea's surface as a function of both the distance from the apex of the cornea and time, and thereafter, the viscoelastic mechanical properties of both the healthy and KC corneas using a coupled finite element (FE)-optimization algorithm. To do that, the dynamic deformation response of six healthy and six KC corneas were measured via CorVis-ST. The videos of the in vivo deformation of the corneas under the applied air puff pressure were segmented using our segmentation algorithm to determine the anterior and posterior curvatures of the corneas during the dynamic movement of the cornea. The FE model of the corneas were established using the segmented data and subjected to a negative (pre-stress), positive IOP, and air puff pressure while the floating boundary conditions were applied to the two ends of the corneas' FE models. The simulation results were imported into a loop of FE-optimization algorithm and analyzed until the deformation amplitude at the apex of the cornea reaches to its minimum difference compared to the clinical data by CorVis-ST. The results revealed that the pressure distributions found in the literature as a function of the distance from the apex of the cornea and time unable to provide satisfactory results. Therefore, the pressure distributions both as a function of the distance and time were optimized using our coupled FE-optimization algorithm and employed to estimate the viscoelastic properties of the healthy and KC corneas. The mean percentage error (MPE) of 8.45% and 10.79% were found for the healthy and KC corneas compared to the clinical data of CorVis-ST, respectively. The results also revealed a significantly higher short-time shear modulus for the KC (62.33 MPa) compared to the healthy (37.45 MPa) corneas while the long-time shear modulus of both the healthy and KC corneas were almost the same (4.01 vs. 3.91 MPa). The proposed algorithm is a noninvasive technique capable of accurately estimating the viscoelastic mechanical properties of the cornea, which can contribute to understand the mechanism of KC development and improve diagnosis and intervention in KC.
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Affiliation(s)
| | - Reza Razaghi
- Research Department, Heel of Scene Ltd., Tokyo, Japan; Basir Eye Health Research Center, Tehran, Iran.
| | - Alireza Karimi
- Department of Ophthalmology and Visual Sciences, University of Alabama at Birmingham, Birmingham, AL, United States.
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99
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Wu N, Chen Y, Yang Y, Sun X. The changes of corneal biomechanical properties with long-term treatment of prostaglandin analogue measured by Corvis ST. BMC Ophthalmol 2020; 20:422. [PMID: 33081750 PMCID: PMC7576693 DOI: 10.1186/s12886-020-01693-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2020] [Accepted: 10/12/2020] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND To investigate the corneal biomechanical changes in primary open angle glaucoma (POAG) patients treated with long-term prostaglandin analogue (PGA). METHODS One hundred eleven newly diagnosed POAG patients, including 43 high tension glaucoma (HTG) and 68 normal tension glaucoma (NTG), were measured by Corvis ST to obtain intraocular pressure (IOP), central corneal thickness (CCT) and corneal biomechanical parameters at baseline and at each follow-up visit after initiation of PGA treatment. The follow-up measurements were analyzed by the generalized estimate equation model with an exchangeable correlation structure. Restricted cubic spline was employed to estimate the dose-response relation between follow-up time and corneal biomechanics. RESULTS The mean follow-up time was 10.3 ± 7.02 months. Deformation amplitude (β = -0.0015, P = 0.016), the first applanation velocity (AV1, β = -0.0004, P = 0.00058) decreased and the first applanation time (AT1, β = 0.0089, P < 0.000001) increased statistically significantly with PGA therapy over time after adjusting for age, gender, axial length, corneal curvature, IOP and CCT. In addition, AT1 was lower (7.2950 ± 0.2707 in NTG and 7.5889 ± 0.2873 in HTG, P = 0.00011) and AV1 was greater (0.1478 ± 0.0187 in NTG and 0.1314 ± 0.0191 in HTG, P = 0.00002) in NTG than in HTG after adjusting for confounding factors. CONCLUSIONS Chronic use of PGA probably influences the corneal biomechanical properties directly, which is to make cornea less deformable. Besides, corneas in NTG tended to be more deformable compared to those in HTG with long-term treatment of PGA.
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Affiliation(s)
- Na Wu
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.,NHC Key Laboratory of Myopia (Fudan University); Key Laboratoy of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China.,Shanghai Key Laboratoy of Visual Impairment and Restoration, Shanghai, 200031, China
| | - Yuhong Chen
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China. .,NHC Key Laboratory of Myopia (Fudan University); Key Laboratoy of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China. .,Shanghai Key Laboratoy of Visual Impairment and Restoration, Shanghai, 200031, China.
| | - Yaping Yang
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.,NHC Key Laboratory of Myopia (Fudan University); Key Laboratoy of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China.,Shanghai Key Laboratoy of Visual Impairment and Restoration, Shanghai, 200031, China
| | - Xinghuai Sun
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China.,NHC Key Laboratory of Myopia (Fudan University); Key Laboratoy of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China.,Shanghai Key Laboratoy of Visual Impairment and Restoration, Shanghai, 200031, China.,State Key Laboratory of Medical Neurobiology, Institutes of Brain Science and Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China
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Gazzard G, Jayaram H, Roldan AM, Friedman DS. When gold standards change: time to move on from Goldmann tonometry? Br J Ophthalmol 2020; 105:1-2. [PMID: 32972917 DOI: 10.1136/bjophthalmol-2020-317112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2020] [Revised: 06/30/2020] [Accepted: 09/07/2020] [Indexed: 11/04/2022]
Affiliation(s)
- Gus Gazzard
- Glaucoma Service, Moorfields Eye Hospital, London, UK .,University College London Institute of Ophthalmology, London, UK
| | - Hari Jayaram
- University College London Institute of Ophthalmology, London, UK.,Glaucoma Service, Moorfields Eye Hospital NHS Foundation Trust, London, UK
| | - Ana M Roldan
- Glaucoma Service, Massachusetts Eye and Ear Infirmary, Boston, Massachusetts, USA
| | - David S Friedman
- Ophthalmology, Harvard University, Cambridge, Massachusetts, USA
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