[Small Incision Lenticule Extraction (SMILE) for correction of myopic astigmatism]

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Surgery

Background:

• Myopic astigmatism presents a significant challenge in refractive surgery.
• Small Incision Lenticule Extraction (SMILE) is an advanced laser vision correction procedure.
• Astigmatism correction requires precise surgical techniques for optimal visual outcomes.

Purpose of the Study:

• To evaluate the efficacy, stability, safety, and predictability of SMILE for moderate and high myopic astigmatism.
• To assess outcomes at 1 day and 3 months postoperatively.
• To introduce a method for manual detection and compensation of cyclotorsion during SMILE.

Main Methods:

• Retrospective analysis of 164 eyes from 114 patients undergoing SMILE for myopic astigmatism (≥1.5 D).
• Manual compensation of cyclotorsion by aligning corneal marks to the reticule after suction activation.
• Postoperative assessment of visual acuity and refractive outcomes at 1 day and 3 months.

Main Results:

• High predictability for spherical equivalent (SE) correction: 87% within ±0.50 D and 98% within ±1.00 D at 3 months.
• Excellent predictability for cylinder correction: 96.3% within ±1.00 D, with mean postoperative cylinder of -0.3±0.39 D.
• Significant visual acuity improvement: 91% achieved uncorrected distance visual acuity (UDVA) of 8/10 or better, with 22% gaining a line of vision.

Conclusions:

• SMILE is a predictable and safe surgical option for correcting astigmatism.
• Manual cyclotorsion compensation can improve astigmatic correction accuracy with SMILE.
• The technique shows promise for managing moderate to high astigmatism.