David P Piñero1, Pedro Ruiz-Fortes2, Rafael J Pérez-Cambrodí3, Verónica Mateo4, Alberto Artola2. 1. Ocular Surface and Cornea Unit, Department of Ophthalmology, Oftalmar, Hospital Internacional Medimar, Alicante, Spain; Foundation for the Visual Quality (FUNCAVIS, Fundación para la Calidad Visual), Alicante, Spain; Department of Optics, Pharmacology and Anatomy, University of Alicante, Spain. Electronic address: david.pinyero@ua.es. 2. Ocular Surface and Cornea Unit, Department of Ophthalmology, Oftalmar, Hospital Internacional Medimar, Alicante, Spain. 3. Ocular Surface and Cornea Unit, Department of Ophthalmology, Oftalmar, Hospital Internacional Medimar, Alicante, Spain; Foundation for the Visual Quality (FUNCAVIS, Fundación para la Calidad Visual), Alicante, Spain. 4. Department of Optics, Pharmacology and Anatomy, University of Alicante, Spain.
Abstract
PURPOSE: To define a range of normality for the vectorial parameters Ocular Residual Astigmatism (ORA) and topography disparity (TD) and to evaluate their relationship with visual, refractive, anterior and posterior corneal curvature, pachymetric and corneal volume data in normal healthy eyes. METHODS: This study comprised a total of 101 consecutive normal healthy eyes of 101 patients ranging in age from 15 to 64 years old. In all cases, a complete corneal analysis was performed using a Scheimpflug photography-based topography system (Pentacam system Oculus Optikgeräte GmbH). Anterior corneal topographic data were imported from the Pentacam system to the iASSORT software (ASSORT Pty. Ltd.), which allowed the calculation of the ocular residual astigmatism (ORA) and topography disparity (TD). Linear regression analysis was used for obtaining a linear expression relating ORA and posterior corneal astigmatism (PCA). RESULTS: Mean magnitude of ORA was 0.79 D (SD: 0.43), with a normality range from 0 to 1.63D. 90 eyes (89.1%) showed against-the-rule ORA. A weak although statistically significant correlation was found between the magnitudes of posterior corneal astigmatism and ORA (r=0.34, p<0.01). Regression analysis showed the presence of a linear relationship between these two variables, although with a very limited predictability (R(2): 0.08). Mean magnitude of TD was 0.89D (SD: 0.50), with a normality range from 0 to 1.87D. CONCLUSION: The magnitude of the vector parameters ORA and TD is lower than 1.9D in the healthy human eye.
PURPOSE: To define a range of normality for the vectorial parameters Ocular Residual Astigmatism (ORA) and topography disparity (TD) and to evaluate their relationship with visual, refractive, anterior and posterior corneal curvature, pachymetric and corneal volume data in normal healthy eyes. METHODS: This study comprised a total of 101 consecutive normal healthy eyes of 101 patients ranging in age from 15 to 64 years old. In all cases, a complete corneal analysis was performed using a Scheimpflug photography-based topography system (Pentacam system Oculus Optikgeräte GmbH). Anterior corneal topographic data were imported from the Pentacam system to the iASSORT software (ASSORT Pty. Ltd.), which allowed the calculation of the ocular residual astigmatism (ORA) and topography disparity (TD). Linear regression analysis was used for obtaining a linear expression relating ORA and posterior corneal astigmatism (PCA). RESULTS: Mean magnitude of ORA was 0.79 D (SD: 0.43), with a normality range from 0 to 1.63D. 90 eyes (89.1%) showed against-the-rule ORA. A weak although statistically significant correlation was found between the magnitudes of posterior corneal astigmatism and ORA (r=0.34, p<0.01). Regression analysis showed the presence of a linear relationship between these two variables, although with a very limited predictability (R(2): 0.08). Mean magnitude of TD was 0.89D (SD: 0.50), with a normality range from 0 to 1.87D. CONCLUSION: The magnitude of the vector parameters ORA and TD is lower than 1.9D in the healthy human eye.
Authors: David P Piñero; Rafael J Pérez-Cambrodí; Roberto Soto-Negro; Pedro Ruiz-Fortes; Alberto Artola Journal: Graefes Arch Clin Exp Ophthalmol Date: 2015-09-07 Impact factor: 3.117
Authors: Samira Heydarian; Sara Sardari; Zahra Heidari; Abbas Ali Yekta; Hadi Ostadimoghaddam; Mehdi Khabazkhoob Journal: J Curr Ophthalmol Date: 2020-12-12