JUL 30, 2012
This study examined visual quality in aspheric aberration-correcting IOLs and spherical IOLs using an adaptive optics visual simulator. While tilt and decentration affected visual quality with both types of IOLs, this impact was greater with aberration-correcting IOLs.
The results also suggest that aberration-correcting and spherical IOLs provide comparable visual quality when centered in eyes in which the corneal higher-order aberrations are those of the average human cornea. The authors found that residual spherical aberration slightly improved depth of focus and tolerance to defocus, which is in agreement with the results of previous studies.
Ten subjects (10 eyes) participated in the study. The authors used the crx1 adaptive optics visual simulator to simulate the wavefront aberration pattern of two commercially available aspheric aberration-correcting IOLs (Acrysof IQ SN60WF and Tecnis ZA9003) and two spherical IOLs (Akreos Adapt and Triplato) in five situations: centered, decentered 0.2 mm and 0.4 mm, and tilted 2 degrees and 4 degrees.
When the IOLs were centered, there were no differences in visual acuity between the four IOLs at any contrast. Among the aberration-correcting IOLs, the Tecnis ZA9003 IOL was the most sensitive to decentration and the Acrysof IQ SN60WF IOL the most sensitive to tilt. The impact of tilt and decentration on visual quality with the two spherical IOLs was comparable.
The authors say that the advantages of aspheric IOLs over spherical IOLs could be limited, canceled or even turned into a disadvantage if the IOL decenters or tilts.