Effect of Q-Value Individualized CLEAR Kerato-refractive Lenticule Extraction Profile on Corneal Asphericity, Spherical Aberration, and Optical Zone Stability

Refractive surgery enhances visual performance by reshaping the cornea; however, preserving its natural asphericity is essential to minimizing induced optical aberrations. This study aims to evaluate the effect of Corneal Lenticule Extraction for Advanced Refractive Correction (CLEAR) on corneal asphericity, spherical aberration (SA) and effective optical zone (EOZ). Sixty eyes of 30 patients underwent refractive correction for myopia or compound myopic astigmatism with the CLEAR application, which considers individual Q-value to preserve corneal asphericity. Three months postoperatively, the uncorrected distance visual acuity (UDVA) was − 0.02 ± 0.06 LogMAR, the corrected distance visual acuity (CDVA) was − 0.04 ± 0.05 LogMAR and the manifest spherical equivalent refraction (MRSE) was 0.00 ± 0.34 D. The Q-value increased from − 0.13 ± 0.09 to 0.01 ± 0.27, resulting in an oblate shift of 0.14 ± 0.25 from the preoperative state. The preoperative SA was 0.24 ± 0.06 µm, remaining stable at 0.24 ± 0.13 µm postoperatively. The planned optical zone of 6.50 mm resulted in an achieved EOZ of 5.93 ± 0.40 mm, a mean reduction of -0.57 ± 0.40 mm. Myopia and compound myopic astigmatism correction with CLEAR therefore resulted in minimal positive shift in Q-value, limited EOZ reduction, and no overall induction of spherical aberration.