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Asphericity analysis using corneal wavefront and topographic meridional fits
Samuel Arba-Mosquera1, Jesús Merayo-Lloves, Diego de Ortueta
1University of Valladolid, Instituto de Oftalmobiologia Aplicada, Refractive Surgery and Quality of Vision, Valladolid, E-47004 Spain. sarbamo@cofis.es
Journal of Biomedical Optics
|May 13, 2010
Summary
Calculating corneal asphericity using corneal wavefront aberrations provides a more accurate 3-D fit than 2-D topographic meridians, especially for hyperopic refractive surgery.
Area of Science:
- Ophthalmology
- Optometry
- Biomedical Optics
Background:
- Corneal asphericity is a critical parameter in refractive surgery planning.
- Accurate calculation of corneal asphericity is essential for predicting surgical outcomes.
- Existing methods based on corneal topography may not fully represent the 3-D corneal surface.
Purpose of the Study:
- To evaluate a method for calculating corneal asphericity and its changes after refractive surgery.
- To compare the accuracy of corneal asphericity calculation using corneal wavefront aberrations versus corneal topography.
- To assess the predictability of refractive outcomes based on these calculation methods.
Main Methods:
- Retrospective analysis of 60 eyes (30 myopic, 30 hyperopic) undergoing refractive surgery.
- Preoperative and 3-month postoperative corneal topography and corneal wavefront analyses.
- Laser ablation using an aberration-free profile for a 6-mm corneal diameter.
Main Results:
- Corneal asphericity calculated from wavefront aberrations offers a more accurate 3-D fit than 2-D topographic meridians.
- A stronger correlation between postoperative and predicted asphericity was found using wavefront data, particularly for hyperopic treatments.
- Induction of corneal spherical aberrations correlated with achieved defocus correction.
Conclusions:
- Corneal wavefront aberrations provide higher fidelity for calculating postoperative corneal asphericity compared to topographic meridians.
- Hyperopic refractive surgery outcomes show greater accuracy in prediction when using wavefront-based asphericity calculations.
- Wavefront analysis offers a superior method for assessing corneal asphericity in refractive surgery.
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