Peripheral refraction validity of the Shin-Nippon SRW5000 autorefractor


PURPOSE: To investigate the operation of the Shin-Nippon/Grand Seiko autorefractor and whether higher-order aberrations affect its peripheral refraction measurements. METHODS: Information on instrument design, together with parameters and equations used to obtain refraction, was obtained from a patent. A model eye simulating the operating principles was tested with an optical design program. Effects of induced defocus and astigmatism on the retinal image were used to calibrate the model eye to match the patent equations. Coma and trefoil were added to assess their effects on the image. Peripheral refraction of a physical model eye was measured along four visual field meridians with the Shin-Nippon/Grand Seiko autorefractor SRW-5000 and a Hartmann-Shack aberrometer, and simulated autorefractor peripheral refraction was derived using the Zernike coefficients from the aberrometer. RESULTS: In simulation, the autorefractor's square image was changed in size by defocus, into rectangles or parallelograms by astigmatism, and into irregular shapes by coma and trefoil. In the presence of 1.0 D oblique astigmatism, errors in refraction were proportional to the higher-order aberrations, with up to 0.8 D sphere and 1.5 D cylinder for ±0.6 μm of coma or trefoil coefficients with a 5-mm-diameter pupil. For the physical model eye, refraction with the aberrometer was similar in all visual field meridians, but refraction with the autorefractor changed more quickly along one oblique meridian and less quickly along the other oblique meridian than along the horizontal and vertical meridians. Simulations predicted that higher-order aberrations would affect refraction in oblique meridians, and this was supported by the experimental measurements with the physical model eye. CONCLUSIONS: The autorefractor's peripheral refraction measurements are valid for horizontal and vertical field meridians, but not for oblique field meridians. Similar instruments must be validated before being adopted outside their design scope.

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Divisions: College of Health & Life Sciences > School of Optometry > Optometry & Vision Science Research Group (OVSRG)
College of Health & Life Sciences > School of Optometry > Optometry
College of Health & Life Sciences
College of Health & Life Sciences > School of Optometry > Vision, Hearing and Language
Additional Information: This is a non-final version of an article published in final form in Osuagwu, U. L., Suheimat, M., Wolffsohn, J. S., & Atchison, D. A. (2016). Peripheral refraction validity of the Shin-Nippon SRW5000 autorefractor. Optometry and Vision Science, 93(10).
Uncontrolled Keywords: Shin-Nippon/Grand Seiko autorefractor,higher-order aberrations,Hartmann-Shack aberrometer,COAS-HD aberrometer,peripheral refraction
Publication ISSN: 1538-9235
Last Modified: 08 Jul 2024 07:25
Date Deposited: 12 Sep 2016 12:35
PURE Output Type: Article
Published Date: 2016-10
Published Online Date: 2016-08-17
Accepted Date: 2016-04-09
Submitted Date: 2015-11-24
Authors: Osuagwu, Uchechukwu Levi
Suheimat, Marwan
Wolffsohn, James S. (ORCID Profile 0000-0003-4673-8927)
Atchison, David A.



Version: Accepted Version

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