Artifacts in fusion and stereopsis testing based on red/green dichoptic image separation

Area of Science:

• Ophthalmology
• Vision Science
• Clinical Optometry

Background:

• Binocular vision testing is crucial for diagnosing conditions like amblyopia and strabismus.
• Red/green anaglyph stereotests, such as the TNO test and Worth 4-Dot test, are commonly used.
• Potential artifacts in these tests may affect diagnostic accuracy.

Purpose of the Study:

• To investigate the potential for artifacts introduced by the red/green format in binocular vision testing.
• To evaluate the impact of reversing red/green lens positions on test results.
• To determine if this reversal technique can improve diagnostic reliability.

Main Methods:

• Administered the TNO stereotest to anisometropic amblyopia patients.
• Administered the Worth 4-Dot test to strabismus patients.
• Performed both tests twice, reversing the red/green lens orientation between administrations.

Main Results:

• 12 of 15 anisometropic amblyopia patients showed a stereo acuity difference of 2:1 or more.
• 18 of 89 strabismus patients altered their Worth 4-Dot fusion/suppression status upon lens reversal.
• Seven strabismic patients exhibited discrepancies between red/green and achromatic tests, indicating a reversal effect.

Conclusions:

• The red/green anaglyph format can introduce artifacts in binocular vision testing.
• Reversing lens positions between repeated tests can prevent misinterpretation of binocular status.
• This modified testing approach may provide valuable diagnostic information for visual disorders.