Z-VIEW ABERROMETER MEASUREMENTS OF WAVEFRONT AND ACCOMMODATION

Title Z-VIEW ABERROMETER MEASUREMENTS OF WAVEFRONT AND ACCOMMODATION
Author, Co-Author Jason Cole, Dorothy Win-Hall, Adrian Glasser
Topic
Year
2006
Day
Program Number
065394
Room
Affiliation
University of Houston, College of Optometry
Abstract PURPOSE: Objective tests for accommodation are clinically important and are typically performed with autorefractors. However, aberrometers may be useful as well. This study evaluated the capability of the Z-View aberrometer (ZV) to measure aberrations and accommodation in young subjects in comparison with baseline aberrations measured with the iTrace aberrometer (IT) and accommodation measured with the Grand Seiko WR-5100K autorefractor (GS).

METHODS: 15 subjects, ages 21-32 years old (mean 23.7±2.8), participated. Subjects were either emmetropic or distance-corrected with contact lenses. For all testing, subjects viewed a distant, back-illuminated letter chart with one eye. The viewing eye was measured and the fellow eye occluded. Baseline wavefronts were measured with the IT and the ZV. Accommodation was measured in response to 0-5D increasing stimulus amplitudes with the GS using negative trial lenses and with the ZV using optical defocusing. The ZV prototype accommodation software was run in automated mode on seven subjects and in automated and manual modes on eight subjects.

RESULTS: For distance viewing, Bland-Altman analysis showed agreement in the wavefront data for the IT and ZV. There was no systematic difference in RMS error for low order aberrations. In response to a 5.00D accommodative stimulus, the GS measured 4.23±0.64D and the ZV measured 3.85±0.33D in manual mode and in another group of subjects, the GS measured 4.01±0.41D and the ZV measured 4.09±0.57D in automated mode. Although slight differences were noted between the two instruments and the two ZV modes, these were not statistically significant.

CONCLUSIONS: The ZV and IT show good agreement in measuring wavefront aberrations. Likewise, the ZV and GS were comparable in measuring accommodation objectively. Furthermore, when the ZV software was run in manual mode, fewer bad readings occurred for the accommodation test than in automated mode. The ZV is a suitable instrument for measuring aberrations and objective accommodation.
Affiliation of Co-Authors University of Houston, College of Optometry, University of Houston, College of Optometry
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