To describe a digital overlay technique for documenting toric intraocular lens (IOL) axis alignment.
Jules Stein Eye Institute and the Department of Ophthalmology, University of California at Los Angeles School of Medicine, Los Angeles, California, USA.
Digital overlay imaging was used to evaluate the alignment of Staar toric IOLs in 4 eyes of 3 patients who had regular corneal astigmatism at the time of cataract surgery. Lens axes were determined by computerized analysis of digitally scanned retroillumination photographs. A stock digital image of a Staar AA4203TF toric IOL was superimposed on corneal topography images to document IOL alignment with the steep corneal meridian.
Digital overlay images demonstrated that 3 IOLs in the sample group were within 5 degrees and 1 was within 20 degrees of the intended axis at the time of the final postoperative examination. Slitlamp lens axis estimations were 3 to 18 degrees different from that determined by this technique.
Digital overlay imaging of correctly oriented toric IOLs on computerized corneal topography maps represents an intuitive, accurate, and visually appealing method of documenting toric IOL axis alignment.