Related Experiment Videos
Aberrometric and Visual Outcomes Following Planned Axis Flip versus No Axis Flip During Toric Intraocular Lens
Alicia C Espinosa-Moreno1, Leire Irusteta-Jiménez1, Daniela Pulido-London1
1Anterior Segment Department, Instituto de Oftalmología Fundación Conde de Valenciana, Mexico City, Mexico.
Purpose:
To compare postoperative aberrometric and visual outcomes between eyes with and without a planned astigmatic axis flip after toric intraocular lens (IOL) implantation.
Setting:
Instituto de Oftalmologia Conde de Valenciana, Mexico City, Mexico.
Design:
Comparative observational study.
Methods:
This study included patients who underwent uneventful cataract surgery with toric IOL implantation to minimize residual astigmatism, eyes were classified into undercorrection without an axis flip and an overcorrection with an axis flip. Postoperative evaluation included uncorrected and best-corrected visual acuity, spherical equivalent refraction, and aberrometry using the Pentacam AXL Wave (Oculus Optikgeräte GmbH). Aberrometric parameters included total higher-order aberrations (HOA), coma, spherical aberration (SA), and trefoil. Intergroup comparisons were performed using independent-samples t-tests with Benjamini-Hochberg false discovery rate correction for multiple comparisons. Multivariate linear regression analyses were performed adjusting for age, sex, preoperative astigmatism magnitude and type, IOL model, and axial length. A p-value < 0.05 was considered statistically significant.
Results:
Eighty eyes of 80 patients were analyzed (mean age of 67.16 ± 11.49 years). There were no significant differences between planned axis flip and no-axis flip groups in uncorrected distance visual acuity (p = 0.628), best-corrected distance visual acuity (p = 0.685), or spherical equivalent refraction (p = 0.455). Total HOA, coma, and SA were comparable between groups (all p > 0.05). In contrast, the planned axis flip group demonstrated a higher trefoil aberration compared with the no-axis flip group (0.15 ± 0.06 µm vs 0.08 ± 0.09 µm; p < 0.001). Multivariate linear regression analysis confirmed that axis flip was independently associated with higher trefoil aberration (β = 0.075, 95% CI [0.038, 0.111]; p = 0.0001), with no significant associations found for any other aberrometric or visual outcome.
Conclusion:
Planned astigmatic axis flip during toric IOL implantation was not associated with differences in postoperative visual outcomes, despite a significant increase in trefoil aberration. These findings suggest that planned axis flip does not appear to compromise visual or aberrometric performance and may be considered among the available strategies to minimize residual astigmatism. Prospective studies incorporating functional vision metrics and longer follow-up are needed to confirm these findings.
