Abstract
BACKGROUND: To compare the distribution characteristics of corneal biomechanics and tomographic parameters for different corneal diameter (CD) in Chinese patients. METHODS: A retrospective cohort study of 403 consecutive patients without ectasia who underwent binocular corneal refractive surgery and were followed up for more than 2 years. All patients underwent a preoperative corneal tomography using Pentacam and corneal biomechanics using Corvis-ST. RESULTS: Significant differences were observed in the Stiffness parameter at first applanation (SP-A1), Ambrosio relational thickness to the horizontal profile (ARTh), Belin/Ambrosio enhanced ectasia total deviation index (BAD-D), Corvis Biomechanical Index (CBI), and Tomographic and Biomechanical Index (TBI) indicators among the CD ≤ 11.0 mm, 11.0 mm < CD ≤ 11.5 mm, 11.5 mm < CD < 12.0 mm, and CD ≥ 12.0 mm groups (all P < 0.05). CD was negatively correlated with BAD-D, CBI, and TBI (r = -0.475, -0.269 and − 0.237, all P < 0.05); Multiple linear regression analysis showed that TBI was negatively correlated with CD, SP-A1, and ARTh (R(2) = 0.12, p<0.001). CONCLUSIONS: CD may correlated with the biomechanical results, where smaller CD is often associated with higher BAD, CBI, and TBI values. CD-specific thresholds for biomechanical indices may reduce overdiagnosis of keratoconus in small corneas.