Purpose: To conduct longitudinal, intrapatient comparisons of aspherical and spherical silicone intraocular lenses (IOL) of the same material and platform in patients undergoing bilateral cataract surgery.
Design: Prospective, randomized study.
Methods: Sixty-two eyes of 31 patients were randomized to receive a silicone aspherical IOL (Tecnis Z9000; AMO Inc, Santa Ana, California, USA) in 1 eye and a silicone spherical IOL (CeeOn 911A; AMO Inc) in the other eye. Best spectacle-corrected visual acuity (BSCVA); corneal and ocular wavefront aberrations; contrast sensitivity under photopic (180 lux), intermediate (75 lux), and scotopic (15 lux) illumination; amount of IOL decentration and tilt; and degree of posterior capsular opacification were measured at 1, 3, 6, and 12 months after surgery. All-distance visual acuity (VA) was measured 3 months after surgery.
Results: There were no significant differences between IOLs with regard to BSCVA, amount of IOL decentration and tilt, degree of posterior capsule opacification, and all-distance VA at any point after surgery. Regarding corneal wavefront aberrations, there was no difference in third- and fourth-order root mean square (RMS). In ocular wavefront aberrations, aspherical IOLs showed significantly lower fourth-order RMS (P < .001) than spherical IOLs throughout the study, but not in third-order RMS. Contrast sensitivity under photopic and mesopic conditions was not different between IOLs, but contrast sensitivity under scotopic conditions was significantly better with aspherical IOLs than with spherical IOLs (P < .01) at all measurement points.
Conclusions: The silicone aspherical IOL (Tecnis Z9000; AMO Inc) significantly reduced ocular spherical aberration and improved scotopic contrast sensitivity, and these results were consistent through the 1-year follow-up.