Wavefront aberration and its association with intraocular pressure and central corneal thickness in myopic eyes

To investigate the association between intraocular pressure (IOP), central corneal thickness (CCT), or both and wavefront aberrations in the anterior cornea and the whole eye in myopia.

Wenzhou Medical College, Wenzhou, Zhejiang, China.

Seventy myopic subjects were tested with a Humphrey corneal topographer for wavefront aberrations in the anterior corneal surface and with a wavefront aberration-supported cornea ablation wavefront analyzer (Complete Ophthalmic Analysis System, Carl Zeiss Meditec) for wavefront aberrations in the whole eye. The IOP and CCT were measured with a noncontact Canon tonometer and a Tomey pachymeter, respectively. Relationships between the wavefront aberrations and the IOP and CCT were analyzed.

Four corneal Zernike aberrations were significantly correlated with the IOP, including defocus (Z4) (r = 0.36, P<.01 for right eye; r = 0.31, P<.05 for left eye), y-axis coma (Z7) (r = 0.32, P<.05 for right eye), spherical aberration (Z12) (r = 0.34, P<.02 for both eyes), and secondary astigmatism (Z13) (r = -0.35, P<.01 for right eye; r = -0.37, P<.01 for left eye). In the whole eye, 3 Zernike aberrations were significantly correlated with IOP: trefoil (Z6) (r = 0.31, P<.05 for right eye), spherical aberration (Z12) (r = 0.34, P<.02 for right eye; r = 0.30, P<.05 for left eye), and secondary astigmatism (Z13) (r = -0.45, P<.01 for right eye; r = -0.30, P<.05 for left eye). However, only a single Zernike aberration (Z11) was significantly correlated with CCT (r = -0.29, P<.05 for right eye).

Intraocular pressure was associated with wavefront aberrations in both the cornea and the whole eye, and its association was not limited to symmetrical aberrations but included asymmetric higher-order aberrations as well. In contrast, CCT was very weakly associated with wavefront aberrations.