Optimizing measurement of subjective amplitude of accommodation with defocus curves


PURPOSE: To determine whether letter sequences and/or lens-presentation order should be randomized when measuring defocus curves and to assess the most appropriate criterion for calculating the subjective amplitude of accommodation (AoA) from defocus curves. SETTING: Eye Clinic, School of Life & Health Sciences, Aston University, Birmingham, United Kingdom. METHODS: Defocus curves (from +3.00 diopters [D] to -3.00 D in 0.50 D steps) for 6 possible combinations of randomized or nonrandomized letter sequences and/or lens-presentation order were measured in a random order in 20 presbyopic subjects. Subjective AoA was calculated from the defocus curves by curve fitting using various published criteria, and each was correlated to subjective push-up AoA. Objective AoA was measured for comparison of blur tolerance and pupil size. RESULTS: Randomization of lens-presentation order and/or letter sequences, or lack of, did not affect the measured defocus curves (P>.05, analysis of variance). The range of defocus that maintains highest achievable visual acuity (allowing for variability of repeated measurement) was better correlated to (r = 0.84) and agreed best with ( 0.50 D) subjective push-up AoA than any other relative or absolute acuity criterion used in previous studies. CONCLUSIONS: Nonrandomized letters and lens presentation on their own did not affect subjective AoA measured by defocus curves, although their combination should be avoided. Quantification of subjective AoA from defocus curves should be standardized to the range of defocus that maintains the best achievable visual acuity.

Publication DOI: https://doi.org/10.1016/j.jcrs.2008.04.031
Divisions: Life & Health Sciences > Optometry
Life & Health Sciences > Ophthalmic Research Group
Life & Health Sciences
Life & Health Sciences > Vision, Hearing and Language
Additional Information: NOTICE: this is the author’s version of a work that was accepted for publication in Journal of cataract and refractive surgery. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Gupta, N, Wolffsohn, JSW & Naroo, SA, 'Optimizing measurement of subjective amplitude of accommodation with defocus curves', Journal of cataract and refractive surgery, vol 34, no. 8 (2008) DOI http://dx.doi.org/10.1016/j.jcrs.2008.04.031
Uncontrolled Keywords: eye clinic,United Kingdom,Birmingham,Aston University,School of Life & Health Sciences,Ophthalmology
Full Text Link:
Related URLs: http://www.scop ... tnerID=8YFLogxK (Scopus URL)
PURE Output Type: Article
Published Date: 2008-08
Published Online Date: 2008-07-23
Authors: Gupta, Navneet
Wolffsohn, James S. W. ( 0000-0003-4673-8927)
Naroo, Shehzad A. ( 0000-0002-6373-7187)



Version: Accepted Version

| Preview

Export / Share Citation


Additional statistics for this record