Study on the relationship of diopter, central corneal thickness, intraocular pressure and axial length in eyes with high myopia

Objective To investigate the relationship of diopter (spherical equivalent, SE), central corneal thickness(CCT), intraocular pressure(IOP) and axial length(AL) in eyes with high myopia. Methods A total of 211 eyes of 119 patients with high myopia from Apr.2016 to Aug. 2017 were enrolled. The patients were divided into two groups according to SE.There were 75 eyes of 43 patients in the high myopia group(group A) with the SE of(-7.44±0.79)D and 136 eyes of 76 patients in the hyperopic-emmetropia group (group B) with the SE of(-16.68±4.12)D.AL was measured with IOL Master system.The ocular response analyzer (ORA) measured corneal hysteresis and obtained the correlation parameter corneal compensated IOP. The CCT was measured with OCT.The relationship of SE, CCT, IOP and AL was analyzed. Results The AL values were(26.30±0.93)mm in group A and(30.03±2.03)mm in group B. The difference was statitically significant(F=226.972, P=0.000). IOP were(12.62±3.77)mmHg and(13.91±3.84)mmHg in two groups respectively.The difference was statistically significant(F=5.575, P=0.019). CCT were (549.77±33.29)μm and(541.61±30.35)μm in two groups, the difference was not significant (F=3.261, P=0.072). The SE was positively correlated with AL (r=0.862, P=0.000), and there was no correlation with CCT (r=0.091, P=0.186). The IOP was negatively correlated with diopter(r=-0.198, P=0.004)and positively correlated with AL(r=0.316, P=0.000). Conclusion There is a positive correlation between SE and AL and there is no correlation between SE and CCT in patients with highly myopic eyes.There is a negative correlation between IOP and SE, but a positive correlation between IOP and AL. Key words: Myopia, high; Pressure, intraocular; Length, axial; Thickness, central corneal