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Maria Vinas, Carlos Dorronsoro, Veronica Gonzalez, Daniel Cortes, Susana Marcos; . Invest. Ophthalmol. Vis. Sci. 2015;56(7 ):1358.
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© ARVO (1962-2015); The Authors (2016-present)
Multifocal vision corrections are increasingly used solutions to correct for presbyopia, by producing different foci for different distances. We will evaluate the effect of multi-zone multifocal designs (angular & radial, 2-4 zones) on vision, in the presence and absence of natural aberrations.
Perceived visual quality was tested on 8 subjects (age:29±2; spherical error:-1.32±1.00D) with 6 segmented multifocal designs simulated by a phase-only reflective spatial light modulator. A custom-developed Adaptive Optics (AO) system, including a Hartmann-Shack sensor and an electromagnetic deformable mirror, was used to measure and correct the eye’s aberrations (HOA). Light source from a supercontinuum laser was used for wavefront sensing (827nm) and to back-illuminate (555nm) a static natural visual stimulus. The multifocal phase designs had 2 to 4 zones of progressive power (0 to +3D) in either radial or angular configurations. In a psychophysical paradigm the subject judged the better perceived image (first or second) from pairs of images viewed through different multifocal patterns (a total of 240 pairs, randomly presented), providing a weighted response (±10, 5 & 1). The experiment was performed under natural HOA and under AO-correction. Patterns were graded according to the weighted perceived visual quality responses for far vision. The optical quality of each eye (with/without HOA) with each multifocal pattern was calculated in terms of Visual Strehl (VS).
85.76% of the perceptual responses were statistically significant (p<0.05; i.e. higher than chance). On average, radial profiles provided better perceived quality (495±59) than angular profiles (-468±61). However, in the presence of HOA, 2 subjects consistently scored higher the angular patterns, a trend that disappeared upon HOA correction. With HOA correction there was a statistically significant correlation (p<0.05) between optical quality (VS) and perceived quality (scores) in 6/8 subjects. There was a trend for 2-zone patterns to provide better quality (perceived & optical) than 3 and 4 zones, which was statistically significant (p<0.05) with HOA correction.
Visual simulation with AO allows identifying the optimal multifocal correction for a patient and the effects of interactions of the natural aberrations. Aberrations play a significant role in perceived visual quality across different multifocal patterns.
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