Effect of decentration and tilt on the image quality of aspheric intraocular lens designs in a model eye.
OBJECTIVE
To determine the impact of decentration and tilt on the imaging quality of aspheric intraocular lens (IOL) designs in a schematic model eye.


METHODS
Institute of Medical Physics, University of Erlangen-Nuremberg, Erlangen, Germany.


METHODS
A model eye was used to calculate the impact of misalignment on the imaging quality of 6 IOL designs. The crystalline lens in the model eye was replaced with IOL designs with 22.0 diopters nominal refractive power, and the anterior chamber depth (ACD) was set to the estimated ACD value provided by the manufacturer. The retinal position was optimized for the best image quality. The IOLs were decentered up to +/-1.0 mm and tilted up to +/-5 degrees relative to the line of sight. At each position, the modulation transfer function was recorded with 3.0 mm and 4.5 mm pupil diameters. The results between the IOL designs and those of the phakic model eye were then compared.


RESULTS
Aberration-correcting IOLs were very sensitive to decentration and tilt. However, the impact of misalignment depended on IOL design. Aberration-free IOLs showed less sensitivity within a wide range of displacement but provided better results than the spherical IOL.


CONCLUSIONS
Overall, modern aspheric IOLs provided better imaging quality than conventional spherical IOL designs. Aberration-free IOLs were less sensitive to decentration and tilt than aberration-correcting IOLs but provided better image quality than spherical IOLs. Aberration-correcting IOLs have the potential to provide diffraction-limited imaging quality when perfectly aligned.
Eppig
Timo
T
Medical Optics Research Group, Institute of Medical Physics, University of Erlangen-Nuremberg, and the Max Planck Research School for Optics and Imaging, Erlangen, Germany. timo.eppig@imp.uni-erlangen.de
Scholz
Katja
K
Löffler
André
A
Messner
Arthur
A
Langenbucher
Achim
A
D000818:Animals; D005548:Foreign-Body Migration / Q000503:physiopathology*; D007910:Lenses, Intraocular; D051379:Mice; D008954:Models, Biological; D055620:Optical Phenomena; D011474:Prosthesis Design; D019591:Pseudophakia / Q000503:physiopathology*; D012029:Refraction, Ocular / Q000502:physiology; D014792:Visual Acuity / Q000502:physiology*