Embodiments of the present invention provide methods and systems for determining an ablation treatment for an eye of a patient. The systems and method may involve determining an ellipsoid shape corresponding to an anterior corneal surface of the patients eye. The ellipsoid shape may include an anterior portion, a major axis, and an apex, where the major axis intersects the anterior portion at the apex. The systems and method may also involve determining a tilted orientation of the eye, such as when the patient fixates on a target during a laser ablation procedure. The systems and method may further involve determining the ablation treatment based on the ellipsoid shape and/or the tilted orientation.
