Distance stereotesting using vision test charts for intermittent exotropia.

Area of Science:

• Ophthalmology
• Vision Science
• Pediatric Ophthalmology

Background:

• Intermittent exotropia (IXT) is a common childhood strabismus characterized by outward deviation of the eyes.
• Accurate assessment of stereoacuity is crucial for evaluating the severity and control of IXT.
• Current methods for measuring distance stereoacuity may have limitations in objectively quantifying IXT control.

Purpose of the Study:

• To evaluate the effectiveness of the System Chart SC-1600 Pola (SC) test in assessing distance stereoacuity.
• To determine if the SC test can serve as an objective measure for evaluating intermittent exotropia (IXT).
• To compare the SC test's performance against established stereotests and ocular alignment scores.

Main Methods:

• Stereoacuity was measured in 28 children with IXT and 25 controls using the SC test and the distance Randot stereotest.
• Near stereoacuity was assessed with the Titmus stereotest.
• Ocular alignment control was quantified using the revised Newcastle Control Score (NCS), and correlations were analyzed using Spearman's test.

Main Results:

• The SC test demonstrated significantly better distance stereoacuity compared to the distance Randot stereotest in both IXT patients and controls (P<0.001).
• A significant positive correlation was found between SC test scores and both distance and total NCS scores (r s=0.49, P=0.004).
• No significant correlation was observed between NCS scores and the distance Randot or Titmus stereotest scores.

Conclusions:

• Distance stereoacuity measured by the SC test appears to be a sensitive and objective indicator of IXT control.
• The SC test shows promise as a valuable tool for clinical assessment of intermittent exotropia.
• The SC test's correlation with NCS suggests its utility in objectively monitoring treatment outcomes for IXT.