1. A Comparison of the Corrected Intraocular Pressure Obtained by the Corvis ST and Reichert 7CR Tonometers in Glaucoma Patients
- Author
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Yoshitaka Nakao, Satoshi Okimoto, and Yoshiaki Kiuchi
- Subjects
Intraocular pressure ,genetic structures ,Eye Diseases ,Scheimpflug principle ,lcsh:Medicine ,Glaucoma ,Cornea ,0302 clinical medicine ,Mathematical and Statistical Techniques ,Measurement device ,Medicine and Health Sciences ,030212 general & internal medicine ,lcsh:Science ,Multidisciplinary ,Infrared Radiation ,Physics ,Electromagnetic Radiation ,Classical Mechanics ,Deformation ,medicine.anatomical_structure ,Physical Sciences ,Regression Analysis ,Engineering and Technology ,Anatomy ,Statistics (Mathematics) ,Research Article ,medicine.medical_specialty ,Ocular Anatomy ,Equipment ,Research and Analysis Methods ,03 medical and health sciences ,Ocular System ,Ophthalmology ,medicine ,Ocular structure ,Statistical Methods ,Intraocular Pressure ,Measurement Equipment ,Measurement method ,Damage Mechanics ,business.industry ,lcsh:R ,Goldmann Applanation Tonometer ,Biology and Life Sciences ,medicine.disease ,eye diseases ,030221 ophthalmology & optometry ,Eyes ,lcsh:Q ,sense organs ,business ,human activities ,Head ,Mathematics - Abstract
The purpose of the study was to investigate the accuracy of two corrected intraocular pressure (IOP) measurements by Corvis Scheimpflug Technology (CST)-IOPpachy and by corneal-compensated IOP (IOPcc) using the Reichert 7CR (7CR) tonometers. We also investigated the effects of corneal anatomical and structural parameters on the IOP measurements. The participants included 90 primary open-angle glaucoma patients. We assessed the IOP measurements, obtained by the CST, 7CR, and Goldmann applanation tonometer (GAT), using a paired t-test with Bonferroni correction, Bland-Altman plots, and multiple regression analyses. The 7CR-IOPcc gave the highest value (15.5 ± 2.7 mmHg), followed by the 7CR-IOPg (13.7 ± 3.1 mmHg), GAT-IOP (13.6 ± 2.2 mmHg), CST-IOP (10.3 ± 2.6 mmHg), and CST-IOPpachy (9.7 ± 2.5 mmHg). The values of CST-IOPpachy were significantly lower than those obtained by the other IOP measurement methods (all, p < 0.01). The values of 7CR-IOPcc were significantly higher than those obtained by the other IOP measurement methods (all, p < 0.01). Bland-Altman plots showed a mean difference between the GAT-IOP and the other IOP measurements (CST-IOP, CST-IOPpachy, 7CR-IOPg, and 7CR-IOPcc), which were -3.20, -3.82, 0.14, and 2.00 mmHg, respectively. The widths of the 95% limits of agreement between all pairs of IOP measurements were greater than 3 mmHg. With the exception of the 7CR-IOPcc, all of the IOP variations were explained by regression coefficients involving gender, average corneal curvature, and central corneal thickness. The IOP values obtained by the GAT, CST, and 7CR were not interchangeable. Each new IOP measurement device that was corrected for ocular structure had its own limitations.
- Published
- 2017