Analysis of Asphericity and Corneal Longitudinal Spherical Aberration of 915 Chinese Myopic Adult Eyes

Abstract

Purpose

To analyze the corneal asphericity, longitudinal spherical aberration (LSA), and related factors in Chinese myopic adult eyes.

Methods

This was a retrospective study of myopic adult patients. The corneal asphericity and LSA were measured at 3.0, 4.0, 5.0, 6.0, and 7.0 mm diameter apertures using corneal tomography. Age and refractive power were recorded for correlation analysis.

Results

In total, 531 females and 384 males were included. At the above five diameter settings the corneal asphericity values (Q) of the anterior surface were −0.09±0.21, −0.14±0.16, −0.15±0.13, −0.17±0.11, and −0.20±0.11, and those of the posterior surface were 0.23±0.49, 0.06±0.29, −0.01±0.22, −0.07±0.16, and −0.08±0.15, respectively. The anterior corneal LSA values at these diameters were 0.39±0.19, 0.63±0.27, 0.97±0.36, 0.90±0.30, and 0.83±0.29 D, respectively and the whole corneal values were 0.26±0.20, 0.44±0.27, 0.70±0.36, 0.66±0.30, and 0.59±0.28 D, respectively. Corneal asphericity and peripheral LSA showed no or weak correlation with age or spherical equivalent (all r < 0.2).

Conclusion

Corneal anterior and posterior Q values in myopia patients are negatively correlated with corneal diameter. Corneal anterior and whole corneal LSA increased significantly with diameter up to 5 mm, then decreased slightly with diameter. Corneal asphericity and peripheral LSA showed very weak or no correlation with age or spherical equivalent.

Clinical Trial Registration Number

ChiCTR1800015985.

Keywords:

• wavefront aberration
• asphericity
• longitudinal spherical aberration
• myopia

Abbreviations

LSA, longitudinal spherical aberration; ZZ IOL, Zhang & Zheng IOL; RMS, root mean square; BCVA, best corrected visual acuity; CCT, corneal central thickness; SE, spherical equivalent; HOA, higher order aberration.

Ethics Approval and Informed Consent

The study was approved by the institutional review board at each participating site and by the ethics committee of Hangzhou MSK Eye Hospital. The data are anonymous, confidential and the study was in compliance with the Declaration of Helsinki, so the requirement for informed consent was waived.

Acknowledgments

This work was supported by the Zhejiang Province Medical and Health Science and Technology Project (2018267858).

Disclosure

All authors declare that they have no conflicts of interest in this work.