The influence of intraocular pressure on wavefront aberrations in patients undergoing laser-assisted in situ...

To investigate the effect of intraocular pressure (IOP) on wavefront aberrations in the anterior cornea, the internal optics, and the whole eye for myopic patients undergoing laser-assisted in situ keratomileusis (LASIK) surgery.

Fifty-seven myopic subjects were tested for wavefront aberrations in the anterior corneal surface and the whole eye using a corneal topographer and a wavefront analyzer, respectively, pre- and post-LASIK. The IOP and central corneal thickness (CCT) were measured with a noncontact tonometer and a pachymeter, respectively. Pre- and postoperative wavefront aberrations were compared, and the correlation between changes in the Zernike aberrations and the IOP was statistically tested.

The mean root mean square (RMS) values of the higher-order aberrations (HOAs) were significantly increased in the anterior cornea, the internal optics, and the whole eye. The mean RMS values for a majority of Zernike terms were significantly increased, and systematic increases in the spherical aberrations were found in both the cornea and the whole eye. The spherical aberrations after LASIK were significantly correlated to the IOP (r = 0.59, P < 0.01, for oculus dexter [OD, right eye] and r = 0.49, P < 0.01, for oculus sinister [OS, left eye] in the cornea; r = 0.38, P < 0.01, for OD and r = 0.46, P < 0.01, for OS in the whole eye).

IOP contributes to LASIK-induced HOAs, particularly spherical aberrations. To control the HOAs after LASIK, a new algorithm should include the IOP as a variable for laser surgery.