Effects of axial length and corneal curvature on corneal biomechanics in elderly population / 国际眼科杂志(Guoji Yanke Zazhi)

ABSTRACT

AIM:To explore the corneal biomechanical properties of the elderly with different axial length ( AL) and corneal curvature by corneal visualization Scheimpflug Technology ( Corvis ST) .?METHODS: Cross - sectional study. A total of 161 patients ( 297 eyes ) undergoing phacoemulsification were collected in this study. They were divided into 22-24mm, 24-26mm, more than 26mm groups according to axial length ( 190 eyes, 54 eyes and 53 eyes, respectively). Those of whom axial length was 22-24mm and the corneal curvature was 42-44D were divided into male and female groups ( 44 eyes and 49 eyes, respectively). Those of whom axial length was 22-24mm were divided into 42-44D group, more than 44D group according to corneal curvature ( 88 eyes, 102 eyes, respectively ) . Corvis ST was used to measure the biomechanical parameters of the cornea. The differences in the parameters between different groups were analyzed using the independent-samples t test or one-way analysis of variance and correlation analyses were performed using Pearson correlation analysis.?RESULTS:When comparing the corneal biomechanical parameters, no statistically significant differences were found between male and female groups (P>0. 05). The first applanation length and second applanation length among different corneal curvatures were statistically significant (P<0. 05). There was statistical significance on the difference of the second applanation velocity, deformation amplitude, central cornea thickness, intraocular pressure in different AL groups (P<0. 05). The axial length was positively correlated with deformation amplitude, intraocular pressure ( r=0. 429, 0. 278; P < 0. 001 ), but there was negative linear correlation between the patient's axial length and central cornea thickness, the second applanation velocity ( r=-0. 291, -0. 415;P<0. 001).?CONCLUSION: The corneal curvature and ocular axial length may be the factors affecting the corneal biomechanical characteristics. The longer axial length, the thinner corneal thickness, the more easily the corneal is deformed, and with the increase of the axial length, intraocular pressure also increases.