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Tatara S, Maeda F, Tsukahara Y, Handa T, Yaoeda K. Intrasession and Intersession Variabilities of Intraocular Pressure Measured by Noncontact Tonometer in Normal Volunteers. Clin Ophthalmol 2021; 15:4507-4512. [PMID: 34848943 PMCID: PMC8627315 DOI: 10.2147/opth.s342014] [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: 09/30/2021] [Accepted: 11/09/2021] [Indexed: 11/23/2022] Open
Abstract
Purpose Intraocular pressure (IOP) measured using a noncontact tonometer is evaluated by performing multiple measurements because IOP is affected by the ocular pulse. We investigated the relationship between value fluctuations in multiple measurements during noncontact tonometer measurements and cardiac rate. Materials and Methods Forty-two healthy subjects were included and IOP was measured using a noncontact tonometer. The measurement was performed three times each for the right eye and the left eye, for a total of six times. Blood pressure and cardiac rate were measured at the same time as the IOP measurement. Using repeated-measures analysis of variance, we examined whether the measured IOP and cardiac rate fluctuate throughout the day over the course of 4 days. Results There was a fluctuation in the IOP in a sequence only on day 1 of the four measurement days (P < 0.001). The IOP on day 1 tended to be high for the first and second measurements (P = 0.0111–0.0015). Systolic blood pressure and diastolic blood pressure did not fluctuate over the 4 days (P = 0.6247 and 0.7132), but cardiac rate was high only on day 1 (P = 0.0276). Conclusion The IOP on day 1 tended to be high in the first and second measurements. The IOP measured on days 2–4 did not fluctuate during the sequence of measurements. The cardiac rate measured at the same time as the IOP was high only on the first day.
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Affiliation(s)
- Shunya Tatara
- Department of Orthoptics and Visual Sciences, Faculty of Medical Technology, Niigata University of Health and Welfare, Niigata, Japan.,Department of Vision Science, Faculty of Sensory and Motor Control, Kitasato University Graduate School of Medical Science, Sagamihara, Kanagawa, Japan
| | - Fumiatsu Maeda
- Department of Orthoptics and Visual Sciences, Faculty of Medical Technology, Niigata University of Health and Welfare, Niigata, Japan.,Field of Orthoptics and Visual Sciences, Major in Medical and Rehabilitation Sciences, Niigata University of Health and Welfare Graduate School, Niigata, Japan
| | | | - Tomoya Handa
- Department of Vision Science, Faculty of Sensory and Motor Control, Kitasato University Graduate School of Medical Science, Sagamihara, Kanagawa, Japan.,Orthoptics and Visual Science, Department of Rehabilitation, School of Allied Health Sciences, Kitasato University, Sagamihara, Kanagawa, Japan
| | - Kiyoshi Yaoeda
- Field of Orthoptics and Visual Sciences, Major in Medical and Rehabilitation Sciences, Niigata University of Health and Welfare Graduate School, Niigata, Japan.,Department of Ophthalmology, Yaoeda Eye Clinic, Nagaoka, Niigata, Japan.,Division of Ophthalmology and Visual Sciences, Niigata University Graduate School of Medical and Dental Sciences, Niigata, Japan
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Intraocular pressure measurement after corneal transplantation. Surv Ophthalmol 2019; 64:639-646. [DOI: 10.1016/j.survophthal.2019.02.011] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2018] [Revised: 02/20/2019] [Accepted: 02/25/2019] [Indexed: 11/20/2022]
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Pagoulatos DD, Kapsala ZG, Makri OE, Georgalas IG, Georgakopoulos CD. Comparison of intraocular pressure using Goldmann applanation tonometry versus non-contact tonometry in eyes with high-viscosity silicone oil. Eur J Ophthalmol 2019; 30:494-499. [PMID: 30832494 DOI: 10.1177/1120672119833556] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND To compare intraocular pressure (IOP) measurements using Goldmann applanation tonometer (GAT) and air tonometer (non-contact tonometry [NT]) in vitrectomized eyes with high-viscosity silicone oil tamponade, as well as in normal eyes. PATIENTS AND METHODS In this prospective comparative study, 32 eyes with silicone oil tamponade of high viscosity (5700 CS) and 32 normal fellow eyes were included. IOP was measured by GAT and air tonometer 30 ± 12 days after vitrectomy, while measurements of central corneal thickness (CCT) were also obtained. RESULTS In eyes with silicone oil, IOP was 20.09 ± 4.91 mmHg and 16.75 ± 3.86 mmHg using contact tonometer and air tonometer, respectively (p < 0.0001). In normal eyes, IOP was 16.41 ± 2.15 mmHg and 16.31 ± 2.49 mmHg using the same tonometry techniques and this difference was not statistically significant (p = 0.598). In addition, no significant correlation was detected between IOP measurements using both techniques and age, gender, CCT, and type of lens. CONCLUSIONS It seems that GAT overestimates IOP in eyes with high-viscosity silicone oil compared with NT, while both IOP measurement techniques in normal eyes provide similar values. Further assessment of available IOP measurement methods could possibly establish the most accurate technique for IOP estimation in vitrectomized eyes with silicone oil tamponade.
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Affiliation(s)
| | - Zoi G Kapsala
- Department of Ophthalmology, School of Medicine, University of Crete, Heraklion, Greece
| | - Olga E Makri
- Department of Ophthalmology, School of Medicine, University of Patras, Rio, Greece
| | - Ilias G Georgalas
- 1st Ophthalmology Department, National and Kapodistrian University of Athens, Athens, Greece
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Hashemi H, Khabazkhoob M, Nabovati P, Yazdani N, Ostadimoghaddam H, Shiralivand E, Derakhshan A, Yekta A. Distribution of IOP measured with an air puff tonometer in a young population. J Curr Ophthalmol 2018; 30:35-41. [PMID: 29564406 PMCID: PMC5859631 DOI: 10.1016/j.joco.2016.11.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 11/06/2016] [Accepted: 11/06/2016] [Indexed: 11/25/2022] Open
Abstract
Purpose To determine the normal range of intraocular pressure (IOP) in the young and its association with certain corneal parameters using a non-contact device. Methods Subjects were selected from students of Mashhad University of Medical Sciences through stratified sampling. All participants had visual acuity testing, corneal imaging, a comprehensive slit-lamp examination by an ophthalmologist, and IOP measurement using a non-contact air-puff tonometer. Results Of the 1280 invitees, 1073 (83.8%) participated, and 1027 were eligible. Mean IOP was 16.38 mmHg [95% confidence interval (CI): 16.22–16.53] in the total sample, 16.14 mmHg (95% CI: 15.84–16.45) in men, and 16.48 mmHg (95% CI: 16.31–16.66) in women. There was a significant IOP difference between myopes and emmetropes (P = 0.031). Based on the multiple linear regression model, IOP associated directly with age and central corneal thickness (CCT), and inversely with corneal diameter, spherical equivalent (SE), and keratoconus. Based on standardized coefficients of the regression model, CCT and SE had the strongest association with IOP. Conclusions In the present study, we demonstrated the IOP distribution in a young population using a non-contact method. CCT and SE were strongly associated with IOP.
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Affiliation(s)
- Hassan Hashemi
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Mehdi Khabazkhoob
- Department of Medical Surgical Nursing, School of Nursing and Midwifery, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
| | - Payam Nabovati
- Noor Ophthalmology Research Center, Noor Eye Hospital, Tehran, Iran
| | - Negareh Yazdani
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Hadi Ostadimoghaddam
- Refractive Errors Research Center, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
| | - Ehsan Shiralivand
- Noor Research Center for Ophthalmic Epidemiology, Noor Eye Hospital, Tehran, Iran
| | - Akbar Derakhshan
- Khatam-al-Anbia Hospital, Mashhad University of Medical Sciences, Mashhad, Iran
| | - AbbasAli Yekta
- Department of Optometry, School of Paramedical Sciences, Mashhad University of Medical Sciences, Mashhad, Iran
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Lafaut AS, Van Malderen L, Zeyen T. Is Pulse Synchronized Pneumotonometry More Reproducible than Routine Pneumotonometry and More in Agreement with Goldmann Applanation Tonometry? Eur J Ophthalmol 2018; 17:178-82. [PMID: 17415689 DOI: 10.1177/112067210701700205] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Purpose This study compared the variability of intraocular pressure (IOP) measurements taken with pulse synchronized pneumotonometry (PNT) and with routine PNT (without pulse synchronization) and evaluated the agreement between PNT and Goldmann applanation tonometry (GAT). Methods In this prospective study, 148 eyes from 78 patients were enrolled. Patients were randomized into two groups. In the first group (A), the sequence of measurements was pulse synchronized PNT, routine PNT, and GAT. In the second group (B), the sequence of measurements was routine PNT, pulse synchronized PNT, and GAT. The mean of three measurements was averaged for PNT and GAT. All the measurements were performed by the same investigator, who was masked to GAT measurements. The mean IOP measurements and intrapatient standard deviations among the three tonometers were compared using analysis of variance measurement. Bland & Altman plots were used to assess the agreement between PNT and GAT. Results The variability of IOP measurements taken with pulse synchronized PNT was significantly lower than with routine PNT in both groups (1.2±0.7 vs 1.3±0.7 mmHg in group A and 1.1±0.9 vs 1.3±1.0 mmHg in group B [p<0.001], respectively). PNT measurements with and without pulse synchronization were on average ±2 mmHg higher than GAT measurements in both groups (p<0.001). The 95% limits of agreement between PNT and GAT varied between −3.8 and 8.5 mmHg. Conclusions Pulse synchronized PNT gives more reproducible measurements than routine PNT. The agreement between PNT and GAT is poor. (Eur J Ophthalmol 2007; 17: 178–82)
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Affiliation(s)
- A-S Lafaut
- Department of Ophthalmology, University Hospitals Leuven, 3000 Leuven, Belgium
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Cheng J, Kong X, Xiao M, Sun X. Twenty-four-hour pattern of intra-ocular pressure in untreated patients with primary open-angle glaucoma. Acta Ophthalmol 2016; 94:e460-7. [PMID: 26843038 DOI: 10.1111/aos.12963] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2015] [Accepted: 11/24/2015] [Indexed: 11/26/2022]
Abstract
PURPOSE To investigate and compare the 24-hr intra-ocular pressure (IOP) pattern among different severities of glaucomatous optic neuropathy (GON) together with different subtypes of primary open-angle glaucoma (POAG). METHODS The IOPs of untreated patients with POAG were measured every 2 hrs over a 24-hr period. Subjects were divided into mild, moderate and severe groups according to the glaucoma staging system 2. The two POAG subtypes, normal tension glaucoma (NTG) and hypertension glaucoma (HTG) were classified according to peak IOP values throughout the 24-hr period. The 24-hr IOP curves were obtained based on the average IOP value at each time-point. The mean, peak, trough and fluctuation of IOP together with the diurnal-to-nocturnal IOP change were calculated and compared among different groups. RESULTS A total of 160 POAG patients (84 NTG and 76 HTG) were enrolled in the study. Generally, IOP decreased in the diurnal period and increased progressively during the nocturnal period, with peak IOP occurring from 2:00 AM to 10:00 AM. The average IOP values at all time-points were significantly higher in the mild group compared to the moderate and severe groups (p < 0.05). Compared with the NTG subjects, the IOP parameters including mean, peak, trough and fluctuation were significantly higher in the HTG subjects (p < 0.001), and IOP increased more predominantly in the HTG subtype during the nocturnal period. CONCLUSIONS There was some regularity in the 24-hr IOP pattern in POAG, but different severities of GON and different subtypes might present different characteristics. Other non-IOP factors may lead to pathological IOP fluctuation and could be correlated with GON.
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Affiliation(s)
- Jingyi Cheng
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital; Shanghai Medical College of Fudan University; Shanghai China
- Key Laboratory of Myopia; Ministry of Health (Fudan University); Shanghai China
- Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University); Shanghai China
| | - Xiangmei Kong
- Department of Ophthalmology and Visual Science, Eye, Ear, Nose and Throat Hospital; Shanghai Medical College of Fudan University; Shanghai China
- Key Laboratory of Myopia; Ministry of Health (Fudan University); Shanghai China
- Shanghai 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, Ear, Nose and Throat Hospital; Shanghai Medical College of Fudan University; Shanghai China
- Key Laboratory of Myopia; Ministry of Health (Fudan University); Shanghai China
- Shanghai Key Laboratory of Visual Impairment and Restoration (Fudan University); Shanghai China
- State Key Laboratory of Medical Neurobiology; Institutes of Brain Science; Fudan University; Shanghai China
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Abstract
Foreword It gives me pleasure to introduce the 4th edition of the EGS Guidelines. The Third edition proved to be extremely successful, being translated into 7 languages with over 70000 copies being distributed across Europe; it has been downloadable, free, as a pdf file for the past 4 years. As one of the main objectives of the European Glaucoma Society has been to both educate and standardize glaucoma practice within the EU, these guidelines were structured so as to play their part. Glaucoma is a living specialty, with new ideas on causation, mechanisms and treatments constantly appearing. As a number of years have passed since the publication of the last edition, changes in some if not all of these ideas would be expected. For this new edition of the guidelines a number of editorial teams were created, each with responsibility for an area within the specialty; updating where necessary, introducing new diagrams and Flowcharts and ensuring that references were up to date. Each team had writers previously involved with the last edition as well as newer and younger members being co-opted. As soon as specific sections were completed they had further editorial comment to ensure cross referencing and style continuity with other sections. Overall guidance was the responsibility of Anders Heijl and Carlo Traverso. Tribute must be made to the Task Force whose efforts made the timely publication of the new edition possible. Roger Hitchings Chairman of the EGS Foundation www.eugs.org The Guidelines Writers and Contributors Augusto Azuara Blanco Luca Bagnasco Alessandro Bagnis Keith Barton Christoph Baudouin Boel Bengtsson Alain Bron Francesca Cordeiro Barbara Cvenkel Philippe Denis Christoph Faschinger Panayiota Founti Stefano Gandolfi David Garway Heath Francisco Goni Franz Grehn Anders Heijl Roger Hitchings Gabor Hollo Tony Hommer Michele Iester Jost Jonas Yves Lachkar Giorgio Marchini Frances Meier Gibbons Stefano Miglior Marta Misiuk-Hojo Maria Musolino Jean Philippe Nordmann Norbert Pfeiffer Luis Abegao Pinto Luca Rossetti John Salmon Leo Schmetterer Riccardo Scotto Tarek Shaarawy Ingeborg Stalmans Gordana Sunaric Megevand Ernst Tamm John Thygesen Fotis Topouzis Carlo Enrico Traverso Anja Tuulonen Ananth Viswanathan Thierry Zeyen The Guidelines Task Force Luca Bagnasco Anders Heijl Carlo Enrico Traverso Augusto Azuara Blanco Alessandro Bagnis David Garway Heath Michele Iester Yves Lachkar Ingeborg Stalmans Gordana Sunaric Mégevand Fotis Topouzis Anja Tuulonen Ananth Viswanathan The EGS Executive Committee Carlo Enrico Traverso (President) Anja Tuulonen (Vice President) Roger Hitchings (Past President) Anton Hommer (Treasurer) Barbara Cvenkel Julian Garcia Feijoo David Garway Heath Norbert Pfeiffer Ingeborg Stalmans The Board of the European Glaucoma Society Foundation Roger Hitchings (Chair) Carlo E. Traverso (Vice Chair) Franz Grehn Anders Heijl John Thygesen Fotis Topouzis Thierry Zeyen The EGS Committees CME and Certification Gordana Sunaric Mégevand (Chair) Carlo Enrico Traverso (Co-chair) Delivery of Care Anton Hommer (Chair) EU Action Thierry Zeyen (Chair) Carlo E. Traverso (Co-chair) Education John Thygesen (Chair) Fotis Topouzis (Co-chair) Glaucogene Ananth Viswanathan (Chair) Fotis Topouzis (Co-chair) Industry Liaison Roger Hitchings (Chair) Information Technology Ingeborg Stalmans (Chair) Carlo E. Traverso (Co-chair) National Society Liaison Anders Heijl (Chair) Program Planning Fotis Topouzis (Chair) Ingeborg Stalmans (Co-chair) Quality and Outcomes Anja Tuulonen (Chair) Augusto Azuara Blanco (Co-chair) Scientific Franz Grehn (Chair) David Garway Heath (Co-chair)
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Affiliation(s)
- Alireza Mashaghi
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Jiaxu Hong
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Sunil K Chauhan
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
| | - Reza Dana
- Schepens Eye Research Institute, Massachusetts Eye and Ear Infirmary, Harvard Medical School, Boston, Massachusetts, USA
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Resende AF, Yung ES, Waisbourd M, Katz LJ. Monitoring intra ocular pressure in glaucoma: current recommendations and emerging cutting-edge technologies. EXPERT REVIEW OF OPHTHALMOLOGY 2015. [DOI: 10.1586/17469899.2015.1100539] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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Repeatability and reproducibility of measurements using a NT-530P noncontact tono/pachymeter and correlation of central corneal thickness with intraocular pressure. BIOMED RESEARCH INTERNATIONAL 2013; 2013:370592. [PMID: 24222904 PMCID: PMC3816021 DOI: 10.1155/2013/370592] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2013] [Revised: 08/30/2013] [Accepted: 09/03/2013] [Indexed: 11/17/2022]
Abstract
PURPOSE To investigate the repeatability and reproducibility of intraocular pressure (IOP) and central corneal thickness (CCT) measurements using a noncontact tono/pachymeter (NT-530P) and to assess the correlation of CCT with IOP. METHODS Forty-six eyes of healthy volunteers were measured by two examiners. Three consecutive measurements per eye were performed. Repeatability was assessed using the coefficient of variation, and reproducibility was assessed using Bland-Altman plots. Linear correlations were used to determine agreement between CCT and noncorrected IOP and CCT and corrected IOP, which was calculated using a formula built into the NT-530P. RESULTS The coefficient of variation for IOP was 6.4% and for CCT was 0.4%. The 95% limits of agreement between examiners were -0.17 ± 1.42 mmHg (range: -2.95 to 2.61 mmHg) for IOP, -0.93 ± 4.37 μ m (range: -9.50 to 7.64 μm) for CCT. The corrected IOP was significantly higher than the noncorrected IOP (P = 0.010.3). The noncorrected IOP significantly correlated with CCT (r = -0.4883, P = 0.0006). The corrected IOP showed no significant correlation with CCT (r = -0.0285, P = 0.8509). CONCLUSIONS NT-530P offered repeatability and reproducibility in both IOP and CCT measurements. The corrected IOP calculated using the NT-530P was independent of the CCT, suggesting that this IOP may be less influenced by the central corneal thickness.
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Kowalska MA, Kasprzak HT, Iskander DR. Comparison of high-speed videokeratoscopy and ultrasound distance sensing for measuring the longitudinal corneal apex movements. Ophthalmic Physiol Opt 2010; 29:227-34. [PMID: 19422553 DOI: 10.1111/j.1475-1313.2009.00648.x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Two different methods to measure binocular longitudinal corneal apex movements were synchronously applied. High-speed videokeratoscopy at a sampling frequency of 15 Hz and a custom-designed ultrasound distance sensor at 100 Hz were used for the left and the right eye, respectively. Four healthy subjects participated in the study. Simultaneously, cardiac electric cycle (ECG) was registered for each subject at 100 Hz. Each measurement took 20 s. Subjects were asked to suppress blinking during the measurements. A rigid headrest and a bite-bar were used to minimize undesirable head movements. Time, frequency and time-frequency representations of the acquired signals were obtained to establish their temporal and spectral contents. Coherence analysis was used to estimate the correlation between the measured signals. The results showed close correlation between both corneal apex movements and the cardiopulmonary system. Unraveling these relationships could lead to better understanding of interactions between ocular biomechanics and vision. The advantages and disadvantages of the two methods in the context of measuring longitudinal movements of the corneal apex are outlined.
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Affiliation(s)
- Malgorzata A Kowalska
- Institute of Physics, Wroclaw University of Technology, Wybrzeze Wyspianskiego 27, 50-370 Wrocław, Poland.
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AlMubrad TM, Ogbuehi KC. The effect of repeated applanation on subsequent IOP measurements. Clin Exp Optom 2008; 91:524-9. [PMID: 18651843 DOI: 10.1111/j.1444-0938.2008.00298.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND In studies aimed at assessing the accuracy and repeatability of non-contact tonometers, the order in which these tonometers and the Goldmann tonometer are used is usually randomised despite studies in the literature that demonstrate an ocular massage effect that occurs post-applanation but not after non-contact tonometry. The purpose of this study was to investigate the effect of repeated corneal applanation on subsequent assessments of IOP. METHODS Data were obtained from 65 left eyes of 65 young, oculovisual normals. Three sets of IOP measurements were obtained, one set with the Goldmann applanation tonometer and two with the Topcon CT80 non-contact tonometer (one set each before and after applanation with the Goldmann tonometer), in each one of two separate measurement sessions, one week apart. RESULTS The average (and SD) IOP measured with the Goldmann tonometer in the first session (14.8+/-2.9 mmHg) did not vary significantly from the IOP measured with the non-contact tonometer (pre-applanation) in both sessions or with the average Goldmann IOP in the second session. The bias (mean difference +/- SD) between methods was 0.3+/-1.4 mmHg and 0.4+/-1.4 mmHg, respectively, for the first and second sessions, with the CT80 (pre-applanation) recording the higher IOP in both sessions. The within-session repeatability coefficients were +/-2.3 mmHg, +/-2.6 mmHg, +/-2.1 mmHg and +/-2.0 mmHg for the CT80 (pre-applanation) in the first and second sessions, and the Goldmann tonometer in the first and second sessions, respectively. Test-retest repeatability coefficients were +/-2.8 mmHg and +/-2.5 mmHg for the CT80 (pre-applanation) and the Goldmann tonometer respectively. Post-applanation with the Goldmann tonometer, there was a statistically significant (p<0.05) reduction (1.5+/-1.2 mmHg in session 1) in the IOP measured with the non-contact tonometer in both sessions. CONCLUSION These results suggest that repeated corneal applanation leads to a statistically significant reduction in IOP on subsequent measurements.
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Affiliation(s)
- Turki M AlMubrad
- Department of Optometry and Vision Sciences, College of Applied Medical Sciences, King Saud University, Riyadh, Kingdom of Saudi Arabia
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Abstract
BACKGROUND The reliability of non-contact tonometers has been reported extensively in the literature. This study was designed to assess reliability of the new Topcon CT80 non-contact tonometer in normotensive subjects, using the Goldmann tonometer as the standard. METHODS The accuracy of the Topcon CT 80 non-contact tonometer was assessed by comparing its IOP assessments with those of the Goldmann applanation tonometer, on 60 right eyes of young healthy subjects with normal intraocular pressures. Each subject's intraocular pressure was assessed with each technique on two separate occasions, one week apart. The reliability of each technique was determined by the assessment of its inter-session repeatability using the Bland-Altman method. The 95 per cent limits of agreement for the two methods were also determined. RESULTS No statistically significant difference was found between the average intraocular pressures measured with the two techniques (p > 0.05). The inter-session repeatability indices for the two techniques did not differ significantly (p > 0.05). The mean difference in intraocular measurements between the two techniques was 0.2 +/- 1.5 mmHg (mean +/- SD) and the 95 per cent limits of agreement were -3.14 and +2.74 mmHg, with the non-contact tonometer returning higher readings than the Goldmann tonometer. CONCLUSION In this sample of normotensive subjects, the Topcon CT80 non-contact tonometer proved to be accurate and as reliable as the Goldmann tonometer in the assessment of intraocular pressure. Thus, it can be used as an objective clinical method for the assessment of normal intraocular pressure.
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Affiliation(s)
- Kelechi C Ogbuehi
- Department of Optometry and Vision Sciences, College of Applied Medical Sciences, Riyadh, Kingdom of Saudi Arabia.
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Brown KE, Congdon NG. Corneal structure and biomechanics: impact on the diagnosis and management of glaucoma. Curr Opin Ophthalmol 2006; 17:338-43. [PMID: 16900024 DOI: 10.1097/01.icu.0000233951.01971.5b] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
PURPOSE OF REVIEW Highlights recent studies relating to the impact of corneal structure and biomechanical properties on glaucoma evaluation and management. RECENT FINDINGS Central corneal thickness has been shown to play a role in the interpretation of intraocular pressure. Central corneal thickness has also been suggested as a glaucoma risk factor. The potential role of other corneal factors, such as stromal makeup, in the accurate measurement of intraocular pressure and the assessment of glaucoma risk remains to be determined. SUMMARY Improved understanding of central corneal thickness and corneal biomechanical properties may someday lead to a better understanding of glaucoma risk and its assessment.
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Affiliation(s)
- Kimberly E Brown
- Wilmer Eye Institute, Johns Hopkins University, Baltimore, Maryland 21287, USA.
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Queirós A, González-Méijome JM, Fernandes P, Jorge J, Almeida JB, Parafita MA. Non-contact tonometry synchronized with cardiac rhythm and its relationship with blood pressure. Ophthalmic Physiol Opt 2006; 26:384-91. [PMID: 16792738 DOI: 10.1111/j.1475-1313.2006.00374.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
PURPOSE The main objectives of this study were to determine the differences between non-synchronized intraocular pressure (IOP_N) and intraocular pressure readings synchronized with cardiac pulse and try to determine if these parameters are related to blood pressure values. METHODS One hundred and sixty-five right eyes from 165 volunteers (107 females, 58 males) aged from 19 to 73 years (mean +/- S.D., 29.93 +/- 11.17) were examined with the Nidek NT-4000, a new non-contact tonometer that allows the measurement of IOP synchronized with the cardiac rhythm. IOP measurements in the four different modes of synchronization were taken in a randomized order. Three measures of each parameter were taken and then averaged. The blood pressure was determined three times with a portable manometer and mean values of systolic and diastolic pressure and the pulse rate were computed. Mean arterial pressure (MAP) was determined as being 1/3 of systolic plus 2/3 of diastolic blood pressure. RESULTS The mean +/- S.D. values for the standard intraocular pressure (IOP_N: 14.76 +/- 2.86), intraocular pressure in the systolic instant or peak (IOP_P: 14.99 +/- 2.85), intraocular pressure in the middle instant between heartbeats or middle (IOP_M: 14.68 +/- 2.76), and intraocular pressure in the diastolic instant or bottom (IOP_B: 13.86 +/- 2.61) were obtained. The IOP_P was higher than the remaining values. A significant difference in mean IOP existed between IOP_B and the remaining modes of measuring (p < 0.05). Differences were statistically significant for all pair comparisons involving IOP_B. Arterial blood pressure values were systolic 125.5 +/- 14.22, diastolic 77.7 +/- 8.38 and MAP 93.64 +/- 9.44 mmHg. The pulse rate was 77.3 +/- 12.6 beats per minute. Except for the MAP (p = 0.025) there was no significant correlation between different IOP values and systolic or diastolic blood pressure, or pulse rate. CONCLUSIONS NT-4000 is able to differentiate IOP values when synchronized with the cardiac rhythm and those differences are expected to be within a range of +/-2.5 to +/- 3.0 mmHg. IOP_B seems to be the parameter whose value differs from the non-synchronized and the remaining synchronized parameters in a significant way. Other than a weak association with MAP, no significant correlation between IOP and BP was found. The measurements of IOP readings for the three modes are consistent with timings during the cardiac cycle and IOP pulse cycle.
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Affiliation(s)
- A Queirós
- Department of Physics (Optometry), School of Sciences, University of Minho, Braga, Portugal.
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Hoffmann EM, Pfeiffer N, Barleon L, Grus FH. Goldmann-Applanationstonometrie und dynamische Konturtonometrie. Ophthalmologe 2006; 103:317-20. [PMID: 16520991 DOI: 10.1007/s00347-006-1318-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
BACKGROUND The aim of the study was to compare intraocular pressure (IOP) measurements between Goldmann applanation tonometry (GAT) and dynamic contour tonometry (DCT) during product certification according to the international requirements for ophthalmic instruments (tonometers, ISO 8612:2001). METHODS The study included 160 eyes of 80 subjects. IOP measurements were performed four times consecutively on each instrument in randomized order. The difference of mean IOP measurements between GAT and DCT was analyzed. Furthermore, Bland and Altman analysis was performed to assess agreement between the instruments. RESULTS The mean difference between DCT and GAT IOP measurements was 0.30+/-2.18 mmHg. At low to normal IOP values of 7-16 mmHg and higher IOP values of > or =23 mmHg, the difference between DCT IOP measurements and GAT IOP measurements increased in the opposite direction (1.44+/-1.59 mmHg and -1.47+/-2.57 mmHg). The Bland and Altman analysis revealed a fixed bias of -0.4+/-2.0 mmHg. CONCLUSIONS The test tonometer DCT exceeds the requirements for the international standard for tonometers ISO 8612:2001. The results are valid for a central corneal thickness of 540+/-40 microm.
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