Excimer Laser Surgery: Biometrical Iris Eye Recognition with Cyclorotational Control Eye Tracker System

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Surgery

Background:

• Astigmatism correction during refractive surgery requires precise alignment.
• Intraoperative patient rotation (cyclotorsion) can negatively impact refractive outcomes.
• Dynamic rotational tracking aims to compensate for cyclotorsion during laser ablation.

Purpose of the Study:

• To evaluate the clinical importance of intraoperative dynamic rotational tracking in Excimer laser correction for astigmatism.
• To compare the refractive outcomes and re-treatment rates between patients with and without cyclorotational control.

Main Methods:

• A prospective comparative study involving two groups of patients undergoing corneal refractive laser surgery.
• Cyclotorsion was measured using iris image comparison between upright and supine positions.
• Group 1 received cyclorotational control, while Group 2 received standard X-Y control.

Main Results:

• Significant differences were observed in mean postoperative cylinder refraction between the groups (p < 0.05).
• The mean cyclotorsion was 3.75° (SD 3.1°), with a range of -14.9° to +12.6°.
• Re-treatment rates were significantly lower in the cyclorotational control group (2.2%) compared to the X-Y control group (8.2%) (p < 0.01).

Conclusions:

• Intraoperative dynamic rotational tracking enhances the predictability and quality of refractive outcomes in LASIK surgery.
• Implementing cyclorotational control significantly reduces the need for postoperative re-treatments.
• Dynamic rotational tracking is crucial for optimizing astigmatism correction in laser refractive surgery.