Clinical study for the undercorrection factor in intermittent exotropia.

Area of Science:

• Ophthalmology
• Strabismology
• Surgical Outcomes

Background:

• Intermittent exotropia (X(T)) surgery is technically straightforward but prone to recurrence.
• Undercorrection is a significant cause of X(T) surgical failure.
• Identifying factors influencing undercorrection is crucial for improving surgical success rates.

Purpose of the Study:

• To investigate the factors associated with surgical undercorrection in patients with intermittent exotropia (X(T)).

Main Methods:

• A cohort of 199 X(T) patients undergoing lateral rectus recession or combined recession-resection surgery was analyzed.
• Patients were categorized based on their angle of deviation (≥9 prism diopters [PD] vs. ≤8 PD or orthophoria) one year post-surgery.
• Preoperative factors and initial postoperative overcorrection were compared between groups.

Main Results:

• Initial postoperative overcorrection was significantly higher in patients who did not develop undercorrection (Group 2) compared to those who did (Group 1).
• Factors including age of onset, age at surgery, strabismus duration, preoperative deviation, dissociated vertical deviation, amblyopia, anisometropia, and vertical strabismus did not significantly influence undercorrection.
• The angle of deviation in the early postoperative period was the most critical factor identified.

Conclusions:

• The angle of deviation observed immediately after surgery is the most significant predictor of long-term surgical success in intermittent exotropia (X(T)).
• Focusing on achieving appropriate initial overcorrection is paramount for preventing recurrence in X(T) surgery.