Use of a six-dimensional eye-tracker in corneal laser refractive surgery with the SCHWIND AMARIS TotalTech laser

To evaluate intraoperative six-dimensional (6D) eye movements and postoperative outcomes among aberrated eyes that underwent LASIK treatments with 6D eye-tracking using the SCHWIND AMARIS platform (SCHWIND eye-tech-solutions).

Thirty-four patients (58 eyes) were enrolled in the study. Standard examinations and pre-and postoperative wavefront analyses with the Ocular Wavefront Analyzer (SCHWIND eye-tech-solutions) were performed. Treatments were planned using the Custom Ablation Manager and ablations (aspheric ablation [35 eyes] and ocular wavefront [23 eyes]) were performed using the SCHWIND AMARIS TotalTech laser. Laser in situ keratomileusis flaps were cut using the LDV femtosecond laser (Ziemer Group) in all cases. Eye movements were evaluated in terms of cyclotorsion, rolling, and axial movements. Clinical outcomes were evaluated in terms of predictability, refractive outcome, safety, wavefront aberration, and contrast sensitivity.

Registration rate was 100% for cyclotorsion, and 90% for rolling and axial movements. Static cyclotorsion was within ±4° in 69% of eyes. Dynamic cyclotorsion was within ±2° in 72% of eyes. Z-movement was within ±0.5 mm in 69% of eyes. At 3-month follow-up, 70% of eyes were within ±0.25 diopters (D) of emmetropia. Mean defocus was -0.12±0.17 D and astigmatism was 0.15±0.25 D. Corrected distance visual acuity improved in 19% of eyes.

Laser in situ keratomileusis with active compensation of 6D eye-movements with a 6D eye-tracker using the SCHWIND AMARIS is safe, predictable, and yields excellent outcomes. Refraction and higher order aberrations were reduced to subclinical values postoperatively without applying additional nomograms.