Influence of Extrinsic and Intrinsic Parameters on Myopic Correction in Small Incision Lenticule Extraction.

Area of Science:

• Ophthalmology
• Refractive Surgery
• Corneal Surgery

Background:

• Small Incision Lenticule Extraction (SMILE) is a popular refractive surgery procedure.
• Understanding factors influencing SMILE outcomes is crucial for patient satisfaction.

Purpose of the Study:

• To evaluate how extrinsic and intrinsic parameters affect outcomes in eyes with myopia or myopic astigmatism after SMILE.
• To identify key predictors of refractive outcomes in SMILE procedures.

Main Methods:

• Multicenter retrospective chart review of 2,564 eyes across three private centers.
• Analysis of postoperative spherical equivalent refraction using univariate and multilinear correlations.
• Assessment of seasonal variations using a sine fit model.

Main Results:

• Higher corrections and younger age correlated with relative undercorrections.
• Female patients showed relative overcorrections compared to males.
• Systematic undercorrection of -0.40 D observed; seasonal variations present.

Conclusions:

• Patient age, gender, and planned correction significantly impact SMILE refractive outcomes.
• A system-universal, age, and gender-dependent adjustment could optimize SMILE results.
• Center-specific adjustments are necessary for other parameters and seasonal variations.