Cyclotorsion measurement in laser refractive surgery

Area of Science:

• Ophthalmology
• Refractive Surgery
• Ophthalmic Optics

Background:

• Astigmatism axis changes can impact refractive surgery outcomes.
• Cyclotorsion, or rotational eye movement, is a potential factor influencing surgical precision.

Purpose of the Study:

• To investigate the occurrence and significance of cyclotorsion in eyes undergoing laser refractive surgery.
• To compare astigmatism measurements in seated versus supine positions.

Main Methods:

• A comparative observational study analyzed 104 eyes from 61 patients who had laser refractive surgery.
• Astigmatism axis was measured in the seated position using Schwind's ORK-CAM and compared to measurements taken in the supine position via the Schwind Amaris® laser system.
• Incyclotorsion and excyclotorsion were quantified, with negative and positive values, respectively.

Main Results:

• The maximum recorded excyclotorsion was +7.7 degrees, and the maximum incyclotorsion was -11.0 degrees.
• The mean cyclotorsion (excyclo or incyclo) was 2.74 degrees (standard deviation 2.30 degrees).
• No statistically significant difference (p=0.985) was found in the astigmatism axis between seated and supine positions.

Conclusions:

• Clinically significant cyclotorsion was observed in 36.5% of eyes undergoing laser correction.
• Despite no statistically significant difference between positions, a notable percentage of patients exhibited substantial eye rotation.