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Patterns of Nonlinearity in the Ratio of Stimulus Accommodative Convergence to Accommodation

Firth, A.Y., Leach , C.M., Griffiths , H.J. and Rennie, I.G. (1996) Patterns of Nonlinearity in the Ratio of Stimulus Accommodative Convergence to Accommodation. Middle East Journal of Ophthalmology, 4 (2). pp. 123-127.

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Background: This study disputes the assumption that the stimulus accommodative convergence to accommodation (AC/A) ratio is linear. Subjects and Methods: Accommodative convergence induced by minus lenses of varying power (-1.50 to -6.00DS, at intervals of 1.50DS) is measured on the Synoptophore in a group of 96 non-strabismic children aged 6 years 3 months to 11 years 2 months (mean 8.81 ± 1.43 years). Results: The mean AC/A ratios obtained with a stimulus to accommodation of 1.5D; 3.00D; 4.5D; 6.00D are 2.25 ± 1.47; 2.88 ± 1.15; 3.28 ± 1.02; 3.49 ± 0.85 respectively. Five patterns of change in AC/A ratio with stiumulus are described. Conclusion: Further studies in all age groups are necessary to investigate the non-linearity of the AC/A ratio over repeated measurements and the repeatability of the testing method.

Item Type: Article
Keywords: Convergence, accommodative convergence, AC/A ratio
Institution: The University of Sheffield
Academic Units: The University of Sheffield > Faculty of Medicine, Dentistry and Health (Sheffield) > School of Medicine (Sheffield) > Clinical Sciences Division North (Sheffield) > Department of Medicine (Sheffield)
Depositing User: Miss Alison Y Firth
Date Deposited: 06 Apr 2011 16:33
Last Modified: 27 Sep 2014 21:38
Status: Published
Publisher: Pan Arab Council of Ophthalmology
Refereed: Yes
URI: http://eprints.whiterose.ac.uk/id/eprint/42925

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