Cyclophoria refers to the tendency of one or both eyes to deviate nasally or temporally at the 12 o'clock position of the cornea. The balance of the superior and inferior oblique muscles usually maintains normal eye alignment, but patients may experience eye strain due to excessive tension in these muscles.

bubble_chart Etiology

1. Insufficiency of the superior oblique muscle or overaction of the inferior oblique muscle can cause excyclophoria. Overaction of the superior oblique muscle or insufficiency of the inferior oblique muscle can cause incyclophoria.

2. In oblique astigmatism, when fixating on horizontal and vertical lines, a tilt equivalent to the oblique axis of astigmatism may occur, causing the eye to rotate. If the strength of the superior and inferior oblique muscles cannot overcome the tilt of the retinal image induced by oblique astigmatism, optical cyclophoria may result.

bubble_chart Clinical Manifestations

Symptoms such as headache, eye pain, and nausea.

bubble_chart Treatment Measures

Myogenic cyclodeviation can be treated surgically. For excyclodeviation caused by superior oblique muscle insufficiency or inferior oblique muscle overaction, the ipsilateral inferior oblique muscle can be incised or recessed. For cyclodeviation caused by superior oblique muscle overaction or inferior oblique muscle insufficiency, the ipsilateral superior oblique muscle can be partially incised.