(1) In acquired SO palsy, torsional diplopia occurs as a result of weakened intorsional effect and the greater extorsional effect of the inferior oblique
c) There is overaction of all muscles in the left eye except medial rectus and inferior oblique
The levator palpebrae superioris, pupillary sphincter muscle, and four extraocular muscles (the superior rectus, inferior rectus, medial rectus, and inferior oblique
muscles) are innervated by the oculomotor nerve.
It exists in complex with multiple independent subnuclei, controlling the superior, inferior, and medial rectus muscle, inferior oblique
muscle, levator palpebrae superioris muscle, and sphincter pupillae, respectively.
A 3-year, 8-month-old female patient underwent disinsertion of right inferior oblique
and general anesthesia and following the diagnosis of "right superior oblique muscle paralysis." During the first postoperative month, the patient's mother found her eye showed a restricted up-gaze and limited inferior turn (Figure 3(a)), and swelling of the lower right eyelid was also evident due to the massive size of the cyst.
There was enhancement and thickening of the left inferior oblique
muscle measuring 8.31 mm.
Patel, "Intramuscular hemangioma of the inferior oblique
: a rare cause of extraocular muscle enlargement," JAMA Ophthalmology, vol.
They innervate superior rectus, inferior rectus, medial rectus and inferior oblique
muscle, and levator palpebrae muscle.
Bilateral inferior oblique
weakening procedure is planned to enable fusional amplitudes and improve horizontal alignment.
Table 1: Extraocular examination of left eye Extraocular muscle Function Movement of left eye Medial rectus Adduction Absent Superior rectus Elevator in abduction Absent Inferior rectus Depressor in abduction Absent Inferior oblique
Elevator in adduction Absent Superior oblique Depressor in adduction Present but not full Lateral rectus Abduction Absent
Elevation defective in upgaze both in abduction and adduction (revealing right superior rectus and right inferior oblique
Cranial nerve III (CN III) innervates the superior, inferior, medial recti and the inferior oblique