Eye trackers may improve optical and visual outcomes

The use of active eye tracking appears to improve both optical and visual outcomes but did not affect the refractive outcome after laser refractive surgery, according to Michael Mrochen, PhD, and colleagues from the department of ophthalmology at the University of Zurich, Switzerland.

In a paper published in the July issue of the Journal of Cataract & Refractive Surgery, physicians performed laser refractive surgery — both photorefractive keratectomy and LASIK — for myopia and myopic astigmatism in 40 eyes. In 20 eyes, the ablation was centered on the entrance pupil using the eye tracking capability of a commercially available system. During laser treatment in the remaining 20 eyes assigned to the non-tracker group, the surgeon manually performed the centration. Preop, 1 month and 3 months postop, patients had standard ophthalmic exams and wavefront analyses.

Postoperatively the authors found visual acuity was significantly better in patients treated with the eye tracker. The increase in coma-like and spherical aberrations was significantly smaller in these patients than in those in the non-tracker group. The refractive outcome was not significantly different in sphere and cylinder.