Tukezban Huseynova1, George O Waring2, Cynthia Roberts3, Ronald R Krueger4, Minoru Tomita5. 1. Shinagawa LASIK Center, Chiyoda-ku, Tokyo, Japan. 2. Medical University of South Carolina, Storm Eye Institute, Charleston, South Carolina. 3. The Ohio State University, Columbus, Ohio. 4. Cleveland Clinic Cole Eye Institute, Cleveland, Ohio. 5. Shinagawa LASIK Center, Chiyoda-ku, Tokyo, Japan; Department of Ophthalmology, Wenzhou Medical College, Wenzhou, China. Electronic address: tomita@shinagawa-lasik.com.
Abstract
PURPOSE: To evaluate corneal biomechanical deformation response using Ocular Response Analyzer (ORA) and Corvis ST data. DESIGN: Prospective observational case-control study. METHODS: A total of 1262 eyes of 795 patients were enrolled. Three groups were established, according to the corneal compensated intraocular pressure (IOPcc): Group I (10-13 mm Hg), Group II (14-17 mm Hg), and Group III (18-21 mm Hg). Each group included 3 subgroups, based on central corneal thickness (CCT): Subgroups 1 (465-510 μm), 2 (510-555 μm), and 3 (555-600 μm). In addition, similar groups of CCT were divided into subgroups of IOPcc. Corneal hysteresis (CH) and corneal resistance factor (CRF) were derived from ORA. The parameters of highest concavity with the parameters of first and second applanation were recorded from Corvis ST. RESULTS: CH and CRF, applanation 1 time, and radius of curvature at highest concavity showed significant differences between CCT subgroups for each IOPcc group (P < .0001). CH, applanation 1 and 2 time, and applanation 2 velocity, as well as deformation amplitude (DA), showed significant differences by IOP subgroups for all CCT groups. IOPcc is correlated negatively with CH (r = -0.38, P < .0001). There are positive correlations of IOPcc with applanation 1 time, applanation 2 velocity, and radius and negative correlations with applanation 2 time (r = -0.54, P < .0001), applanation 1 velocity (r = -0.118, P < .0001), and DA (r = -0.362, P < .0001). CONCLUSION: ORA and Corvis ST parameters are informative in the evaluation of corneal biomechanics. IOP is important in deformation response evaluation and must be taken into consideration.
PURPOSE: To evaluate corneal biomechanical deformation response using Ocular Response Analyzer (ORA) and Corvis ST data. DESIGN: Prospective observational case-control study. METHODS: A total of 1262 eyes of 795 patients were enrolled. Three groups were established, according to the corneal compensated intraocular pressure (IOPcc): Group I (10-13 mm Hg), Group II (14-17 mm Hg), and Group III (18-21 mm Hg). Each group included 3 subgroups, based on central corneal thickness (CCT): Subgroups 1 (465-510 μm), 2 (510-555 μm), and 3 (555-600 μm). In addition, similar groups of CCT were divided into subgroups of IOPcc. Corneal hysteresis (CH) and corneal resistance factor (CRF) were derived from ORA. The parameters of highest concavity with the parameters of first and second applanation were recorded from Corvis ST. RESULTS: CH and CRF, applanation 1 time, and radius of curvature at highest concavity showed significant differences between CCT subgroups for each IOPcc group (P < .0001). CH, applanation 1 and 2 time, and applanation 2 velocity, as well as deformation amplitude (DA), showed significant differences by IOP subgroups for all CCT groups. IOPcc is correlated negatively with CH (r = -0.38, P < .0001). There are positive correlations of IOPcc with applanation 1 time, applanation 2 velocity, and radius and negative correlations with applanation 2 time (r = -0.54, P < .0001), applanation 1 velocity (r = -0.118, P < .0001), and DA (r = -0.362, P < .0001). CONCLUSION: ORA and Corvis ST parameters are informative in the evaluation of corneal biomechanics. IOP is important in deformation response evaluation and must be taken into consideration.
Authors: Brecken J Blackburn; Shi Gu; Matthew R Ford; Vinícius de Stefano; Michael W Jenkins; William J Dupps; Andrew M Rollins Journal: Invest Ophthalmol Vis Sci Date: 2019-01-02 Impact factor: 4.799
Authors: Allan Luz; Bernardo Lopes; Katie M Hallahan; Bruno Valbon; Bruno Fontes; Paulo Schor; William J Dupps; Renato Ambrósio Journal: Am J Ophthalmol Date: 2015-12-29 Impact factor: 5.258