Distance Stereotest using a 3D Monitor for Adult Subjects

Jongshin Kim¹, Hee Kyung Yang^1,2, Youngmin Kim³, Byoungho Lee³, Jeong-Min Hwang^1,2

¹Department of Ophthalmology, Seoul National University College of Medicine
²Department of Ophthalmology, Seoul National University Bundang Hospital
³School of Electrical Engineering, Seoul National University

Purpose: We developed a new distance stereotest with a broad range of disparities and compact intervals, using a 3-dimensional monitor-based stereotest (distance 3D stereotest). By using this 3D stereotest, we evaluated normative data, validity, and test-retest reliability.
We also measured the maximum horizontal disparity that can be fused with disparity vergence to determine the largest measurable disparity of true stereopsis.

Design: Observational case series

Methods: Sixty-four normal adult subjects (23–39 years) were recruited. Contour-based circles (crossed disparity 5000–20 arcsec; Microsoft Visual Studio C++ 6.0) were generated on a 3D monitor (46-inch stereoscopic display) using polarization glasses and presented to subjects with normal binocularity at 3 m. While the position of the stimulus changed among 4 possible locations, the subjects were instructed to press the corresponding position of the stimulus on a keypad. The results with the new distance 3D stereotest were compared with the distance Randot stereotest.

Results: The results of the distance 3D and the distance Randot stereotests were identical in 64% and within one disparity level in 97% of normal adults. Scores obtained with the two tests showed a statistically significant correlation (r = 0.324, p = 0.009). The half width of the 95% limit of agreement was 0.47 log arcsec (1.55 octaves) using the distance 3D stereotest - similar to or better than that obtained with conventional distance stereotests. The maximum binocular disparity that can be fused with vergence was 1828 ± 794 arcsec (range 4000–500).

Conclusion: The distance 3D stereotest showed good concordance with the distance Randot stereotest and relatively good test-retest reliability, supporting the validity of the new distance 3D stereotest. The normative data set obtained from the present study can serve as a useful reference for quantitative assessment of a wide range of binocular sensory abnormalities.