Purchase this article with an account.
V. Fernandez-Sanchez, N. Lopez-Gil, L. N. Thibos, R. Montés-Micó; Objective Measurement of the Amplitude of Accommodation From Optical Quality Metrics Applied to Wavefronts Outcomes. Invest. Ophthalmol. Vis. Sci. 2010;51(13):793.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
To obtain objective measurement of the monocular amplitude of accommodation by using different optical quality metrics and to compare the results with those obtained using three standard subjective methods.
32 optical quality metrics were used to find the refractive state and accommodation response of 180 eyes for subjects with ages between 20 and 58 years. The metrics were applied to a set of wavefront error measurements obtained over the full diameter of the natural pupil when a stimulus approached to the eye in steps of 0.5 D. Target vergence covered the full range of accommodation, so each metric-derived measures of refractive state provided an objective measure of the amplitude of accommodation for each subject. Three different subjective methods were used to find the subjective amplitude of accommodation: minus lenses, push-up and a custom made Badal optometer.
Subjective amplitude of accommodation was not significantly different for Badal optometer and minus lenses methods, but push-up gave a mean increase of 23%. All objective methods showed smaller amplitude of accommodation than the subjective ones by an amount that varied from 0.2 to 1.1 D. In particular, the smallest difference between subjective and objective results was 0.3 D based on a metric for the volume under the OTF. The change of spherical aberration during accommodation produces differences in the objective amplitude of accommodation up to 2.5 D depending on the metric used.
Subjective amplitude of accommodation overestimates the objective one for all the metrics tested due to effect of depth of field in the subjective measurements, especially at the near point where the pupil is constricted. The change of spherical aberration during accommodation increases the amplitude of accommodation objectively and subjectively.
This PDF is available to Subscribers Only