Characterization of Corneal Biomechanics Using CORVIS ST Device in Different Grades of Myopia in a Sample of Middle Eastern Ethnicity

Abstract

Esraa El-Mayah, Ahmed Saad Albalkini, Omar A Barrada Ophthalmology Department, Kasr Alainy School of Medicine, Cairo University, Cairo, EgyptCorrespondence: Esraa El-Mayah, Kasr Alainy School of Medicine, University, Ophthalmology Department, Elmanyal, Cairo, 11562, Egypt, Tel [phone], Email [email protected]: To characterize corneal biomechanical properties using the CORVIS-ST device in myopic individuals.Methods: This prospective cross-sectional study included patients with myopia. Our study included 154 eyes of 154 myopic patients aged between 18 and 40 years, with stable refraction for at least 2 years. A full ophthalmological examination and corneal tomography were performed using a Pentacam HR device. Corneal biomechanical parameters were assessed using the CORVIS-ST device in mild, moderate, severe, and extreme myopia groups.Results: Statistically significant differences were observed in the DA ratio (p = 0.033), SP-A (p=0.009), CBI (p=0.041), SSI (p=0.000), and Peak distance (p = 0.032). In correlation with different Corvis ST biomechanical variables, SE was found to be correlated with DA ratio(r=− 0.191, p=0.018), SP-A(r=0.199, p=0.013) and SSI(r=− 0.336, p=0.000), while in multiple regression analysis, SE was found to be independently correlated with SSI and peak distance(p=0.036,0.038 respectively) while the grade of myopia was found to be independently correlated with SP-A(p=0.034).Conclusion: SSI, Peak distance, and SP-A were independently related to SE and myopia grade, confirming the hypothesis that eyes with higher myopia are more deformable and less stress resistant.Keywords: corneal biomechanics, myopia, high myopia, CORVIS, scheimpflug, Middle Eastern, stress-strain index

Keywords

• corneal biomechanics
• myopia
• high myopia
• corvis
• schimflug
• middle eastern
• stress strain index