Patient-Specific Eye Models for Intraocular Lens Power Calculation in Irregular Corneas

Abstract

AbstractIntraocular lens (IOL) power calculation is normally performed using theoretical Gaussian formulas. Paraxial calculation renders clinically acceptable outcomes in normal eyes with regular corneal shape and optics but leads to refractive error whenever the cornea is irregular in terms of anterior surface shape or anterior to posterior curvature proportions. The most prevalent conditions are keratoconus, keratoplasty, or corneas that have undergone refractive surgery, especially with old techniques. In this chapter, a more robust calculation methodology is proposed based on a three-dimensional model of the cornea constructed from tomographic data. Optical calculations are done by exact ray tracing, overcoming the limitations of the paraxial constraints and managing adequately the effect of higher-order aberrations. Image quality metrics that correlates with subjective vision will be used as a target to determine the best IOL sphere and cylinder power.