Biometry of the anterior segment of the eye in unilateral high myopia patients

Abstract

Objective To investigate the biometric properties of the anterior segment of high myopia eyes, and to determine if there are differences in the ocular biometry of eyes with high myopia and low to moderate refractive errors. Methods Twenty-three patients [aged from 8 to 49 years, mean age (24.1±12.4)years]with unilateral high myopia (-6.00 diopters or more) were recruited for the paired study. Fellow eyes with low to moderate refractive errors (within -5.75 diopters) were used as a control group. Anisometropia was (8.73±4.73)D (range from 1.62 D to 16.75 D). The central comeal thickness and axial length (AL) were measured with A-scan ultrasonography and corneal curvature (mean curvature of the maximum and minimum meridian curvature of the central cornea), corneal asphericity (Q value within 30 degrees), corneal astigmatism、anterior chamber depth (ACD), anterior chamber angle (ACA) and anterior chamber volume (ACV) were measured with a Pentacam. Statistical analysis was performed with SPSS software for Windows (version 15.0). A paired t-test was used to evaluate the differences in the parameters between the two eyes and linear correlation was used to describe the correlation between the two variables. A P value of 0.05). Spherical equivalent was positively correlated to AL in the high myopia group and control group (r=0.662, P<0.01; r=0.618, P<0.01, respectively). However, this value was not correlated to the corneal curvature radius (CR) in either group (high myopia group r=0.287, P=0.196, control group r=0.261, P=0.240). Conclusion There are no significant differences in the biometric properties of the anterior segment of the eye between high myopia and low to moderate refractive errors. The AL is the main biometric parameter related to high myopia. Key words: Myopia; Ocular biometry; Corneal asphericity; Comeal curvature; Axial length; Anterior chamber length; Anterior chamber volume