Childhood-, adult-onset strabismus may arise from different mechanisms

This study examined the differences in etiology and type of pulley abnormalities in children and adults with strabismus, and found that defects in children are probably congenital while adult-onset defects are often due to age-related changes.

The author examined magnetic resonance imaging from a prospective study that included 95 patients with pulley heteropy, of whom 56 had childhood-onset pattern strabismus, and compared this with published data from a separate study conducted by the same research group on 28 patients aged 69 ± 12 years who had sagging eye syndrome and age-matched normal controls with no strabismus.

He found that patients with childhood-onset strabismus had intact lateral rectus–superior rectus band ligaments and straight extraocular muscle paths but exhibited pulley array A pattern–associated incyclorotation or V pattern–associated excyclorotation.

Patients with sagging eye syndrome exhibited blepharoptosis, superior sulcus defect and inferolateral displacement of rectus pulleys with elongation of extraocular muscles that followed curved paths. Symmetrical lateral rectus pulley sag was associated with divergence paralysis esotropia; asymmetrical sag > 1 mm was associated with cyclovertical strabismus. Both lateral rectus resection and medial rectus recession were used to treat divergence paralysis esotropia, and partial vertical rectus tenotomy treated cyclovertical strabismus.

The author concludes that childhood-onset pulley abnormalities are associated with A- or V-pattern strabismus, and external anatomical features suggest that these pulley defects are probably congenital, while adult-onset pulley defects commonly result from age-related tissue involution and external features, such as adnexal laxity.