Study finds iris registration of little to no benefit in LASIK

The authors of this retrospective nonrandomized study compared six-month outcomes of patients who underwent LASIK with or without iris registration technology. They concluded that wavefront-guided LASIK with the VISX STAR S4 CustomVue laser system is safe, effective and predictable - independent of registration status. 

One surgeon performed LASIK on 239 myopic eyes of 142 patients at one location during a one-year period. All eligible patients were scheduled for VISX CustomVue LASIK with iris registration, a noninvasive automated technology that compensates for cyclotorsion by referencing multiple points found in the natural iris pattern and compensates for centroid shift by referencing the pupil center to the outer iris boundary. These points are matched to the corresponding points in the patient's eye during surgery. Iris registration was successful in 121 eyes, and these eyes were assigned to the iris registration group. The 118 eyes in which iris registration was not successful were assigned to the noniris registration group.

After six months, results were similar in the iris registration and noniris registration eyes for mean logMAR UCVA (0.00 versus -0.01), the percentage with UCVA of 20/20 or better (79 versus 78 percent) and the percentage within 0.50 D of emmetropia (92 versus 90 percent). There were also no significant differences between the two groups in astigmatism correction or induction of higher order aberrations.

Financial Disclosures
Dr. Stahl is a consultant for Alcon Laboratories, Inc., and Bausch & Lomb Surgical.