Higher-order aberrations and best-corrected visual acuity in Native American children with a high prevalence of astigmatism

Abstract

Purpose To determine whether higher-order aberrations (HOAs) in children from a highly astigmatic population differ from population norms and whether HOAs are associated with astigmatism and reduced best-corrected visual acuity. Methods Subjects were 218 Tohono O’odham Native American children 5–9 years of age. Noncycloplegic HOA measurements were obtained with a handheld Shack-Hartmann sensor (SHS). Signed (z06s to z14s) and unsigned (z06u to z14u) wavefront aberration Zernike coefficients Z(3,−3) to Z(4,4) were rescaled for a 4 mm diameter pupil and compared to adult population norms. Cycloplegic refraction and best-corrected logMAR letter visual acuity (BCVA) were also measured. Regression analyses assessed the contribution of astigmatism (J0) and HOAs to BCVA. Results The mean root-mean-square (RMS) HOA of 0.191 ± 0.072 μm was significantly greater than population norms (0.100 ± 0.044 μm. All unsigned HOA coefficients (z06u to z14u) and all signed coefficients except z09s, z10s, and z11s were significantly larger than population norms. Decreased BCVA was associated with astigmatism (J0) and spherical aberration (z12u) but not RMS coma, with the effect of J0 about 4 times as great as z12u. Conclusions Tohono O’odham children show elevated HOAs compared to population norms. Astigmatism and unsigned spherical aberration are associated with decreased acuity, but the effects of spherical aberration are minimal and not clinically significant.

Ocular Refraction at Birth and Its Development During the First Year of Life in a Large Cohort of Babies in a Single Center in Northern Italy

“…However, persistent infantile astigmatism is associated with increased astigmatism and myopia during school years (30)(31)(32)(33). In this case, our data do not match those obtained by Miller et al (34), who found that elevated higher-order aberrations to astigmatism and unsigned spherical aberration were minimal and not clinically significant in native American children. It is possible that this difference is due to ethnic differences between our study cohort from Italy and cohorts from other nations or regions.…”

Correlations of Corneal Spherical Aberration with Astigmatism and Axial Length in Cataract Patients

“…We used multiple regression analyses to identify the factors associated with corneal SAs. It was no surprise to find that astigmatism did not contribute to either the anterior or total corneal SA in the regression models because Miller et al reported that they observed no association between elevated astigmatism and SA [32]. The negative coefficients for axial length in the regression were consistent with the decreasing trend in SA values as the axial length increased in patients with astigmatism of 1-2 D (axial length < 20 mm was omitted from the analysis because the population was small).…”

<p>Contributions of Anterior Corneal and Ocular Residual Astigmatism to Autorefraction Astigmatism in a Myopic Adult Sample</p>

“…1 The prevalence of astigmatism (>1.00 D) varies over a wide range through the different studies, from 17% to 63%. 2 – 7…”

“…1 The prevalence of astigmatism (>1.00 D) varies over a wide range through the different studies, from 17% to 63%. [2][3][4][5][6][7] The origin of ocular astigmatism is not always purely corneal. 8 Two components of astigmatism can be individually measured: autorefraction astigmatism (ARA) and anterior corneal astigmatism (ACA), which arises from the anterior corneal surface.…”