Expanding depth of focus by modifying higher-order aberrations induced by an adaptive optics visual simulator
Received 9 December 2008; received in revised form 18 April 2009; accepted 8 May 2009.
Purpose
To evaluate the impact of higher-order aberrations on depth of focus using an adaptive optics visual simulator.
Setting
Refractive Surgery Department, Cole Eye Institute, Cleveland Clinic, Cleveland, Ohio, USA.
Methods
An adaptive optics simulator was used to optically introduce individual aberrations in eyes of subjects with a 6.0 mm pupil under cycloplegia (coma and trefoil, magnitudes ±0.3 μm; spherical aberration, magnitudes ±0.3, ±0.6, ±0.9 μm). A through-focus response curve was assessed by recording the percentage of Sloan letters at a fixed size identified at various target distances. The subject's ocular depth of focus and center of focus were computed as the half-maximum width and the midpoint of the through-focus response curve.
Results
The dominant eyes of 10 subjects were evaluated. The simulation of positive or negative spherical aberration had the effect of enhancing depth of focus and resulted in linearly shifting of the center of focus by 2.6 diopters (D)/μm of error. This increase in depth of focus reached a maximum of approximately 2.0 D with 0.6 μm of spherical aberration and became smaller when the aberration was increased to 0.9 μm. Trefoil and coma appeared to neither shift the center of focus nor significantly modify the depth of focus.
Conclusion
The introduction of both positive and negative spherical aberration using adaptive optics technology significantly shifted and expanded the subject's overall depth of focus; simulating coma or trefoil did not produce such effects.
From Cole Eye Institute (Rocha, Krueger), Cleveland Clinic, Cleveland, Ohio, USA; Imagine Eyes (Vabre, Chateau), Orsay, France; Federal University of São Paulo (Rocha), São Paulo, Brazil
Corresponding author: Karolinne Maia Rocha, MD, PhD, 1701 East 12th Street, 21R, Cleveland, Ohio 44114, USA.
Drs. Chateau and Vabre are employees of Imagine Eyes. No other author has a financial or proprietary interest in any material or method mentioned.
Presented at the XXVI Congress of the European Society of Cataract & Refractive Surgeons, Berlin, Germany, September 2008.
ABSTRACT