Characterization of anterior corneal high-order wavefront aberrations and correlations with astigmatism in Chinese elderly subjects

This study aimed to investigate the distribution of total high-order aberrations (HOAs) Z3±1, Z40, and Z3±3 of anterior cornea and their correlations to astigmatism. In addition, the relationship between different axes of astigmatism and Z3−1 or Z31 was analyzed. The HOAs in the central 6-mm zone of the cornea were measured with an iTrace wavefront analyzer in 556 cataractous eyes at the Tianjin Eye Hospital in China. Simulated keratoscope readings (Sim k) were also measured with the analyzer. The corneal total HOAs Z3±1, Z40 and Z3±3 exhibited a non-normal distribution. Significant correlations were found between the topographic-simulated keratometric power (ΔSim k) with the axis at 180° ± 5° and absolute value of Z3−1 (P = 0.008), the ΔSim k with the axis at 90° ± 5° and absolute value of Z31 (P < 0.001), and the ΔSim k and total HOAs (P < 0.001), Z3±1 (P < 0.001), and Z3±3 (P < 0.001). No significant correlation was found between ΔSim k and Z40 (P = 0.404). In conclusion, corneal astigmatism with the axis near the horizontal position was mainly associated with the value of Z3−1. Corneal astigmatism with the axis near the vertical position was mainly related to the value of Z31. HOAs except Z40 are correlated with astigmatism.