ESCRS presentation “Adaptive Optics Correction of Post-LASIK Aberrations”

During the 2007 annual meeting of the ESCRS, Dr. Nguyen Khoa presented his results in evaluating the visual effects of correcting higher-order aberrations in post-LASIK patients using Imagine Eyes' crx1. Click the "read more" link to view the full abstract.

Optical correction of post-LASIK wavefront aberrations using adaptive optics

Jean-Luc Nguyen Khoa1, Laurent Vabre2 1 Hôpital Foch, Suresnes, France, 2 Imagine Eyes, Orsay, France

Purpose

The objective of this study was to evaluate the visual effects of correcting higher-order wavefront aberrations in post-LASIK patients.

Method

Ten patients were selected according to the following main criteria: myopic LASIK surgery performed at least three month before the experiment, myopia before surgery of more than 2.5D, age between 18 and 40. A crx1 adaptive optics simulator (Imagine Eyes, France) was used to measure visual acuity in the subjects' right eyes in two configurations: 1) the adaptive optics device was set to compensate for the eye's spherical defocus and astigmatism; 2) the device corrected all ocular wavefront aberrations up to the 5^th order. We measured the patients' monocular visual acuity through both optical configurations using the Freiburg Acuity Test software (Prof. Michael Bach, Germany) running on a laptop computer. We connected this system to the micro-display target located inside the crx1 simulator and generated sequences of Landolt C optotypes under a luminance of 50 cd/m2. The tests were conducted in a randomized order and each measurement was repeated twice. All experiments were conducted in natural pupil conditions under dim room illumination. An artificial pupil in the adaptive optics device limited the pupil diameter to 5.5 mm.

Results

The higher-order wavefront aberrations measured in the patients' eyes ranged between 0.18 and 1.16 µm RMS. The average monocular visual acuity was 0.24 LogMAR with the sphero-cylinder correction. Visual acuity improved up to 0.08 LogMAR in average when higher-order aberrations were corrected by the adaptive optics system. The observed difference was statistically significant (Wilcoxon test, p<0.05).

Conclusion

The correction of higher-order wavefront aberrations in post-LASIK eyes may enhance their monocular visual acuity by more than one chart line.