Binocular Stereopsis With Random Dot Stereogram
The random dot stereogram is printed in red and green. There are a number of images. The first image in the
front is used to check whether the stereopsis of both eyes is qualitative. The corresponding stereopsis sharpness
will be marked below the next several images, including 800 ″, 400 ″, 200 ″, 100 ″, 60 ″, 40 ″ and other quantitative
images, which are used to check the stereopsis of both eyes quantitatively.
Operation steps:
① During the examination, the patient shall wear matching red and green glasses and place the random dot
stereogram at 40cm in front of his eyes for examination. If the patient has ametropia, they should wear corrective
glasses, and then wear red and green glasses on the outside of the corrective glasses.
② Qualitative examination: judge whether there is binocular stereopsis. Let the patient observe the first binocular
stereopsis qualitative examination chart and identify the hidden graphics. If the graphics can be described, it is
proved that there is binocular stereopsis. If not, it is proved that there is no binocular stereopsis.
③ Quantitative examination: measure the stereoacuity of both eyes with quantitative chart. Let the patient
recognize the hidden figures in the quantitative examination chart from the picture with the largest stereoscopic
acuity until the figure can not be recognized. Record the corresponding stereoscopic acuity under the last
recognizable picture as the stereoscopic acuity of the patient's eyes.
In the binocular stereoscopic examination of amblyopic patients, Titmus stereoscopic examination chart and
random dot stereogram are convenient to carry and examine, and are widely used. However, the Titmus
stereogram contains a single eyeliner, which is easy to remember and has poor repeatability. Patients with
anisometropia and small angle strabismus can generally pass the examination, with high false negative rate and
poor accuracy. Compared with the Titmus stereogram, the random point stereogram does not have any single
eyeliner, and the binocular disparity is cleverly hidden in a disordered mess, just like the cipher diagram, which
can not be guessed at all, and can accurately measure the advanced overall binocular stereovision, but it is not
applicable to some patients who are too young, because it is impossible to describe what the pattern is.
Therefore, it is common for young amblyopic patients to use Titmus stereogram for binocular stereoscopic
examination.
