Visual Psychophysics / Physiological Optics - ARVO

ARVO 2013 Annual Meeting Abstracts by Scientific Section/Group – Visual Psychophysics / Physiological OpticsProgram Number: 4261 Poster Board Number: B0298Presentation Time: 8:30 AM - 10:15 AMThe Dynamic Accommodative Response with the Binocular openfieldautorefractor and a Movable Real TargetShinji Arai 1 , Hiroshi Uozato 1, 2 , Masakazu Hirota 1 . 1 Department ofVisual Science, Kitasato University Graduate School of MedicalSciences, Kanagawa, Japan; 2 Department Orthoptics and VisualSciences, Kitasato University School of Allied Health Science,Kanagawa, Japan.Purpose: To evaluate the dynamic characteristic of accommodationin the open field and real target using new device WMT-1Methods: Fourteen volunteers (6 men and 8 women; mean ±standard deviation age, 23.9 ± 4.0 years; range, 19 to 33 years)participated in our study. All subject had a visual acuity 20/20 orbetter and normal ocular health. Each subject’s accommodativeresponse was measured by target moving system WMT-1 (GrandSeiko Co., Ltd, Hiroshima, Japan) dynamically. The WMT-1 is a newdevice that is connected to the WAM-5500 open-field autorefractor.It can move a target optionally from 0.2 to 1.0 meter and measurerefraction every 0.2 second. We made shape of the cross as a visualtarget, displayed it in iPad (Apple Inc., Cupertino, CA).We evaluated three difference movements that had been programmedon the WMT-1.First, the constant diopter triangle drive. Second, constant velocitytriangle drive. Third, diopter sin drive. We measured dynamicallyaccommodative response in visual target distance from 1.0 meter to0.2 meter. We compared maximum quantity of accommodativeresponse and among three movements.Results: The maximum quantity of accommodative response ofDiopter Sin Drive became larger than Constant Velocity TriangleDrive (p < 0.05, Scheffe test). However, statistical significantlydifference was not found to other comparison.Accommodative response related to movement of visual target.Conclusions: We could measure dynamic characteristic ofaccommodation in the open field and real target using the WMT-1.The accommodation is evaluated at a definite point conventionally.The WMT-1 is useful to evaluate the dynamic characteristic ofaccommodation, because it can measure not only maximum quantityof accommodative response but also process of accommodativeresponse.Alistair P. Curd, Karen M. Hampson, Edward Mallen. BradfordSchool of Optometry and Vision Science, University of Bradford,Bradford, United Kingdom.Purpose: To investigate whether suppression of the accommodationresponse (AR) would be observed when a dioptric stimulusperformed a step-change, followed by an inverted step-change withinthe latency time for AR. Results would be relevant to models ofaccommodation and nearwork.Methods: A monocular adaptive optics apparatus displayed a targetto participants, and accommodation was recorded using a Shack-Hartmann wavefront sensor. A deformable mirror rapidly changedthe dioptric stimulus provided by the target. The baseline vergence ofthe target was −2D at the eye. An initial step-change in the stimuluswas followed by a second, inverted step, before the stimulus returnedto the baseline. Initial steps were of 1D or 2D in either direction;intervals between the steps ranged from 0.05s to 0.5s. The stimulussettings were randomised in order. The six participants (aged 21-26)observed every stimulus condition five times, through their dominanteye. A Badal optometer arrangement was used to eliminate a size cueand audible cues from the system were masked with auditory inputthrough headphones. Timings of the first change in the stimulus wererandomised.Results: Whether accommodation was responding to the first orsecond change in the stimulus affected the peak AR (p