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Updated: Mar 24, 2026
Comparison of Three Clinical Stereoscopic Methods for Measuring Binocular Visual Function During Amblyopic Treatment in Unilateral Amblyopia
Published on: September 27, 2024
Quantification of Stereopsis in Patients with Impaired Binocularity
Sang Beom Han1, Hee Kyung Yang, Jonghyun Kim
1*MD †BS ‡PhD Department of Ophthalmology, Kangwon National University Hospital, Kangwon National University Graduate School of Medicine, Chuncheon, Republic of Korea (SBH); Department of Ophthalmology, Seoul National University Bundang Hospital, Seoul National University College of Medicine, Seongnam, Republic of Korea (HKY, J-MH); School of Electrical Engineering, Seoul National University, Seoul, Republic of Korea (JK, KH, BL).
Purpose:
To quantify stereopsis at distance resulting from binocular fusion in patients with impaired binocular vision using a three-dimensional (3-D) display stereotest.
Methods:
A total of 68 patients (age range, 6 to 85 years) with strabismus (40 esotropes and 28 exotropes) whose stereoacuity could not be measured with the near and distance Randot stereotests were included. Contour-based circles with a wide range of crossed horizontal disparities (2500 to 20 arcsec) displayed on a 3-D monitor were presented to subjects at 3 m. Between the patients who had stereoacuity of at least 2500 arcsec and those with no measurable stereoacuity, parameters including age, sex, best-corrected visual acuity, spherical equivalent refractive error, Worth 4 dot test results, and type and angle of deviation were compared.
Results:
Stereoacuity at distance of 2500 arcsec or better was detected in 25 (63%) of 40 esotropes, and 16 (57%) of 28 exotropes, although stereoacuity of 800 arcsec or better was found only in two (5%) esotropes and one (4%) exotrope. Patients with stereopsis were significantly younger (19.3 ± 16.9 years) than those with no measurable stereopsis (31.5 ± 26.4 years) (p = 0.040). There were no significant differences in best-corrected visual acuity, presence of amblyopia >20/100, spherical equivalent refractive error, type of deviation, deviation angle, sex, and Worth 4 dot test results between these groups.
Conclusions:
Stereopsis at distance resulting from binocular fusion that cannot be measured with conventional stereoacuity tests may be preserved in patients with impaired binocular vision. The 3-D display stereotest can be useful for quantifying stereopsis at distance resulting from binocular fusion.
