Age-related changes in the orbital pulley array of older Japanese adults with acquired exotropia

Purpose: To evaluate age-related changes in the orbital pulley array using magnetic resonance imaging (MRI) in older Japanese adults with acquired exotropia (XT) compared with young healthy participants (YHP).
Methods: In this retrospective cross-sectional case series, MRI images of 30 eyes from fifteen patients (age ≥ 60 years) with distance XT and no high myopia were compared with those of 14 eyes from seven YHP. Rectus muscle (RM) pulley positions relative to the globe center were assessed. The lateral rectus muscle–superior rectus (LR–SR) band was evaluated for rupture.
Results: Mean age of patients with XT was 73.7 ± 5.5 years. Compared with YHP, patients with XT showed significant inferior displacement of the lateral rectus (LR) pulley (–3.6 ± 1.2 mm vs. − 2.0 ± 1.1 mm, p < 0.01) and temporal displacement of the superior rectus (SR) pulley (–0.4 ± 1.2 mm vs. − 1.6 ± 0.8 mm, p < 0.01). No significant differences were observed in medial rectus or inferior rectus pulley positions. Inferior LR pulley displacement correlated with inferior SR pulley displacement (r = 0.41, p = 0.03), whereas no significant relationship was observed between LR pulley position and MR or IR pulley position. Rupture of the LR–SR band was observed in 24 orbits (80.0%).
Conclusion: Older Japanese adults with XT exhibit localized pulley displacement and LR–SR band rupture. These structural changes differ from the global sagging observed in sagging eye syndrome and may contribute to the pathogenesis of acquired exotropia in older adults.

This version of the article has been accepted for publication, after peer review (when applicable) and is subject to Springer Nature’s AM terms of use, but is not the Version of Record and does not reflect post-acceptance improvements, or any corrections. The Version of Record is available online at: http://dx.doi.org/10.1007/s00417-026-07315-z

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