Software-based assessment of postoperative rotation of toric intraocular lens.

A specially designed grid and software used to assess the postoperative rotation of a toric intraocular lens (IOL) are described. Postoperatively, a digital retroillumination image of the patient is taken and this image is superimposed on the grid. The software determines the center of the IOL. A prominent episcleral vessel is identified, and the axis of the toric IOL and the episcleral vessel are documented using the grid. These values act as references for aligning the images taken during the follow-up period.