Corneal high order aberrations in adults with myopia: correlations with myopic degree and keratometry

AIM: To investigate the corneal high order aberrations in adults with myopia and to study its correlations with myopic degree and keratometry. <p>METHODS: A total of 63 patients(126 eyes)from the ophthalmology department of our hospital were included in this study during May 2014 to June 2015. Visual acuity, intraocular pressure(IOP), diopter, slit lamp examination, central corneal thickness(CCT), funduscopic examination, corneal topography and corneal total higher order aberrations(THOAs)were recorded. Right eye was selected. According to the spherical equivalence(SE), 63 eyes were divided into two groups, the mild to moderate myopia group(M-M group, SE<-6.00D)and the high myopia group(H group, SE≥-6.00D). The correlations of corneal THOAs with diopter, keratometry, IOP and CCT were analyzed. Kolmogorov-Smirnov Test was used for normality test. Independent-samples t test was used for comparison between two groups. Pearson correlation analysis was for comparison between two continuous variables.<p>RESULTS: Z₄₄ was found a statistic difference between the M-M group and H group(<i>t</i>=2.51,<i>P</i>=0.02). IOP was negatively correlated with Z_5-3(<i>r</i>=-0.52,<i>P</i>=0.01), and CCT was positively correlated with Z_4-4(<i>r</i>=0.43,<i>P</i>=0.03)in H group. There was no correlation between higher order aberrations and SE in M-M group(all <i>P</i>>0.05)Total coma aberration(TCA)was negatively correlated with SE(<i>r</i>=-0.57,<i>P</i>=0.002)and spherical degree(Sph, <i>r</i>=-0.55,<i>P</i>=0.003)in H group. Z₄₀ was positively correlated with average K(AK)(M-M group:<i>r</i>=0.40,<i>P</i>=0.02. H group:<i>r</i>=0.55, <i>P</i>=0.03), K steep(K_s)(M-M group:<i>r</i>=0.39, <i>P</i>=0.02. H group:<i>r</i>=0.51, <i>P</i>=0.01)and K flat(K_f)(M-M group:<i>r</i>=0.40, <i>P</i>=0.02. H group:<i>r</i>=0.57, <i>P</i>=0.01)in both groups. Z₅₃was negatively correlated with K_s(<i>r</i>=-0.4,<i>P</i>=0.04)in H group. <p>CONCLUSION: The THOAs parameters are influenced by diopter and keratometry. TCA is negatively correlated with SE and Sph in patients with high myopia, and spherical aberration is positively correlated with keratometry