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H. P. Apple, J. M. Miller, E. M. Harvey, C. E. Clifford-Donaldson, T. K. Green; Simplified Laptop Testing Protocol for Radial Hyperacuity. Invest. Ophthalmol. Vis. Sci. 2010;51(13):5281.
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© ARVO (1962-2015); The Authors (2016-present)
Both strabismic amblyopes1 and children with unilateral deprivation amblyopia2 show elevated thresholds for radial hyperacuity in the amblyopic eye. However, these stimuli are not readily available for use in most clinical or research settings. The goal of the present project is to develop a laptop computer program to allow controlled presentation of radial hyperacuity stimuli for determination of threshold performance.
A MATLAB computer program was developed to allow presentation of circular D4 radial stimuli 1-4. The program generates trials containing four circular stimuli as described by Hess and Wang, one of which is radially modulated (the target). This allows 4AFC testing. The program accepts control from an operator through a numeric keypad, allowing the operator to specify position of the target, magnitude of modulation of the target, and presence or absence of stimuli (blanking of the screen). The operator uses a pre-printed data collection form that ensures balance of target position, with stopping rules that are well-defined in advance.
The MATLAB program provides the examiner flexibility of stimulus size, modulation, and presentation location and the ability to use alternative algorithms to most efficiently determine threshold.
The MATLAB program and associated data collection sheet allow integration of radial hyperacuity testing in the same setting and with the same equipment as computerized visual acuity testing. Alternative presentation strategies, including the ATS protocol, can be readily incorporated into testing because of the flexibility offered by manual stimulus position and modulation selection. The MATLAB program and data collection sheet are freely available from the authors.1 Hess RF, Wang Y-Z, Demanins R, Wilkinson F, Wilson HR: A deficit in strabismic amblyopia for global shape detection. Vis Res 1999b;39:901-14.2 Jeffrey BG , Wang Y-Z, Birch EE: Altered global shape discrimination in deprivation amblyopia. Vis Res 2004;44:167-77.3 Hess RF, Wang Y-Z, Dakin SC: Are judgements of circularity local or global? Vis Res 1999a;39:4354-60.4 Wilkinson F, Wilson HR, Habak C: Detection and recognition of radial frequency patterns. Vis Res 1998;38:3555-68.
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