Risk Factors for Stereoacuity Impairment in Intermittent Exotropia: Results from a Nationwide Korean Study

Area of Science:

• Ophthalmology
• Strabismus Research
• Binocular Vision

Background:

• Intermittent exotropia (IXT) is a common strabismus affecting binocular vision.
• Stereoacuity, a key component of visual function, can be impaired in IXT patients.
• Identifying factors influencing stereoacuity is crucial for effective management.

Purpose of the Study:

• To identify clinical factors associated with stereoacuity impairment in patients with intermittent exotropia (IXT).
• To investigate the influence of perinatal, refractive, motor, and sensory parameters on stereoacuity in IXT.

Main Methods:

• A nationwide cross-sectional study of 5,385 Korean patients with IXT was conducted (Korean Intermittent Exotropia Multicenter Study - KIEMS).
• Stereoacuity was assessed using Titmus and Randot stereotests.
• Multivariable logistic regression identified predictors, including anisometropia and Worth 4 Dot (W4D) categories.

Main Results:

• Anisometropia (≥1.5 D) was strongly linked to poor Titmus stereoacuity (OR=4.707).
• Good distance and near fusion control were protective factors for Titmus stereoacuity.
• Prematurity and low birth weight were not independently associated with stereoacuity.

Conclusions:

• Anisometropia and fusion control are significant predictors of stereoacuity in IXT.
• Preserving fusion control and correcting anisometropia are vital for maintaining binocular visual function in IXT patients.