Digital overlay technique for documenting toric intraocular lens axis orientation

Purpose: To describe a digital overlay technique for documenting toric intr aocular lens (IOL) axis alignment. Setting: Jules Stein Eye Institute and the Department of Ophthalmology, Uni versity of California at Los Angeles School of Medicine, Los Angeles, Calif ornia, USA. Methods: Digital overlay imaging was used to evaluate the alignment of Staa r 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 an alysis of digitally scanned retroillumination photographs. A stock digital image of a Staar AA4203TF toric IOL was super-imposed on corneal topography images to document IOL alignment with the steep corneal meridian. Results: Digital overlay images demonstrated that 3 IOLs in the sample grou p 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 estima tions were 3 to 18 degrees different from that determined by this technique . Conclusion: Digital overlay imaging of correctly oriented toric IOLs on com puterized corneal topography maps represents an intuitive, accurate, and vi sually appealing method of documenting toric IOL axis alignment. J Cataract Refract Surg 2000; 26:1496-1504 (C) 2000 ASCRS and ESCRS.