Spherical aberration yielding optimum visual performance: Evaluation of intraocular lenses using adaptive optics simulation
Received 6 November 2008; received in revised form 18 January 2009; accepted 25 February 2009.
Purpose
To evaluate the influence of spherical aberration on contrast sensitivity using adaptive optics.
Setting
Vision Science and Advanced Retinal Imaging Laboratory, Department of Ophthalmology & Vision Science, University of California, Davis Medical Center, Sacramento, California, USA.
Methods
Contrast sensitivity at 8 cycles per degree was evaluated using an adaptive optics system that permitted aberrations to be measured with a Hartmann-Shack wavefront sensor and controlled by a 109 actuator continuous-surface deformable mirror that was at a plane conjugate to the observer's pupil. Vertical Gabor patches were viewed through a 6.3 mm diameter pupil conjugate aperture. Contrast sensitivity was measured with the deformable mirror set to produce 1 of 5 spherical aberration profiles (−0.2 to +0.2 μm). Contrast sensitivity over the range of spherical aberration was fitted with a polynomial function.
Results
Three subjects (age 21 to 24 years) participated. The measured total mean spherical aberration resulting from the spherical aberration profiles produced by the deformable mirror was between −0.15 μm and +0.25 μm. The peak contrast sensitivity of this function for the 3 subjects combined occurred at +0.06 μm of spherical aberration. The peak contrast sensitivity was also achieved with positive spherical aberration for each subject's data fitted individually (mean 0.09).
Conclusion
There was intersubject variability in the measurements; however, the mean visual performance was best with the introduction of a small positive spherical aberration.
From the University of California Davis Eye Center, Department of Ophthalmology & Vision Science, University of California, Davis Medical Center, Sacramento, California, USA
Corresponding author: John S. Werner, UC Davis Eye Center, Department of Ophthalmology & Vision Science, University of California–Davis Medical Center, 4860 Y Street, Suite 2400, Sacramento, California 95817, USA.
No author has a financial or proprietary interest in any material or method mentioned.
Supported by the National Institute on Aging (grant AG04058), National Institutes of Health, Bethesda, Maryland, USA, and Alcon Laboratories, Fort Worth, Texas, USA.
ABSTRACT