Single Stage Surgical Outcomes for Large Angle Intermittent Exotropia

Area of Science:

• Ophthalmology
• Strabismus Surgery
• Pediatric Ophthalmology

Background:

• Intermittent exotropia, particularly large-angle deviations, presents unique surgical challenges.
• Few studies have specifically evaluated surgical outcomes for large-angle intermittent exotropia (>60 prism diopters).

Purpose of the Study:

• To assess the efficacy of single-stage surgical interventions for large-angle intermittent exotropia.
• To identify potential risk factors influencing surgical success in these patients.

Main Methods:

• Retrospective review of 40 patients with exodeviations >60 PD treated at Zhongshan Ophthalmic Center.
• Analysis of pre- and post-operative ocular motility, alignment, binocular vision, and complications.
• Comparison of outcomes between two-muscle and three-muscle surgical procedures based on deviation magnitude.

Main Results:

• Orthophoria (within 8 PD) achieved in 77.5% of patients; under-correction (15%) and over-correction (7.5%) were noted.
• Success rates decreased to 30% when considering both ocular alignment and binocular vision.
• No significant difference in success rates between two- and three-muscle surgeries; temporary abduction deficits occurred in 7 patients.

Conclusions:

• Single-stage two- and three-muscle surgeries are effective for managing large-angle intermittent exotropia, yielding favorable alignment.
• While anatomical success is high, functional success (including binocular vision) is lower, indicating areas for improvement.
• No significant risk factors for poor outcomes were identified in this cohort.