Abstract
Purpose: :
Objective measurement of the central and peripheral visual acuity may be useful in the evaluation of the vision rehabilitation. We developed an interactive visual acuity measurement program with high-definition projector and iterative acuity chart.
Methods: :
1920 x 1080 pixeled, high-definition projector was used to visualize the acuity chart. Minimum discernable and minimum separable visual acuity were evaluated by simple dot and Landolt C ring respectively. Visual acuity in the points of 1, 1.5, 2, 2.5, 3, 6, 9 and 15 degrees from the center were evaluated. Among those points, 1, 3 and 15 degree points were defined as main points, and the others as subsidiary points. Main point visual acuity were measured by using pseudorandom sequences and five consecutive, iterative decision making. With this value, subsidary point visual acuities were checked by three consecutive, iterative decision making. Joystick and buttons were provided to the examinee for giving answers.
Results: :
Distribution graphs of visual acuity according to the distance from the center to the periphery could be obtained in minimum discernable and minimum separable acuity check, and this matches the cone cell distribution of the retina.
Conclusions: :
The central and peripheral visual acuity could be measured like conventional visual field evaluation by the proposed method. This method might be useful for the evaluation of the retinal prosthesis, especially for localising and measuring vision enhancement by the small-sized retinal stimulator.
Keywords: visual acuity • vision and action • visual fields