TABLE 28.2 DIFFERENTIAL DIAGNOSIS OF STRABISMUS a Neurogenic palsies III Cranial nerve palsy (partial or complete) IV Cranial nerve palsy VI Cranial nerve palsy Traumatic extraocular muscle palsy Myasthenia gravis Internuclear ophthalmoplegia Skew deviation Restrictive strabismus Orbital wall fracture Orbital hemorrhage, tumor, infection, or abscess Thyroid eye disease Nonthyroid extraocular muscle infiltration (e.g., metastasis) Orbital cellulites Nonneurogenic nonrestrictive strabismus Idiopathic childhood strabismus Strabismus caused by refractive errors (e.g., accommodative esotropia) Sensory strabismus (unilateral visual loss) a Not listed in order of frequency