Objective Analysis of Reading Ability Using an Eye Tracker in Intermittent Exotropia

Area of Science:

• Ophthalmology
• Vision Science
• Clinical Research

Background:

• Intermittent exotropia is a common strabismus condition.
• Reading ability can be affected by visual conditions.
• Objective measurement of reading performance in intermittent exotropia is needed.

Purpose of the Study:

• To analyze reading ability in patients with intermittent exotropia using eye-tracking technology.
• To determine the impact of clinical characteristics of intermittent exotropia on reading speed.
• To compare reading speed between intermittent exotropia patients and normal controls.

Main Methods:

• Compared reading speed (letters per second) in 25 intermittent exotropia patients and 25 age-matched controls (≥13 years, best-corrected visual acuity ≥20/25).
• Utilized eye-tracking to measure fixation disparity during reading tasks.
• Evaluated correlations between reading speed and clinical features of intermittent exotropia.

Main Results:

• Intermittent exotropia patients demonstrated significantly slower reading speeds (6.1 LPS) than controls (6.8 LPS).
• Clinical measures like deviation angle did not significantly correlate with reading speed.
• Fixation disparity scores from eye tracking showed a significant negative correlation with reading speed (r=-0.458, p=0.028).

Conclusions:

• Reading speed is impaired in individuals with intermittent exotropia compared to controls.
• Objective fusional control scores, measured via eye tracking, are the primary correlate of reading speed deficits in this population.