0521779407-19 CUNY1086/Karliner 0 521 77940 7 June 6, 2007 17:50
Strabismus 1379■Exotropia
➣1. pontine lesions may cause paralytic exotropia – look to see
whether each eye fully adducts.- craniofacial disorders may cause true exotropia.
- High myopia also may cause exotropia that can be corrected
with glasses.
■Vertical strabismus (hypertropia)
■Myasthenia gravis may mimic any sort of strabismus. Skew devia-
tion is coirritant hypertropia seen in patients with brainstem dis-
ease. Causes of true vertical strabismus are 4th nerve palsy, Graves
disease, blowout fracture, double elevator palsy (congenital fibrosis
of inferior rectus muscle), orbit tumor.
■Amblyopia
➣Diagnosed when decreased visual acuity occurs with normal eye.
Differential includes strabismus, anisometropia (unequal refrac-
tive error), and occlusion (e.g., congenital cataracts).
management
What to Do First
■Rule out neurologic cause-sixth nerve palsy, papilledema. Assess
visual acuity and start treating amblyopia.General Measures
■Measure severity of strabismus, measure refraction to see whether
glasses are indicated.specific therapy
■For congenital esotropia, usually surgery. First treat amblyopia and
refractive error.
■For accommodative esotropia, treat with glasses first for hyperopia.
If still esotropia, surgery. Manage amblyopia as necessary.
■For exotropia, first try over-minus with glasses to induce accom-
modative convergence. May need surgery.
■For vertical strabismus, surgery when uncomfortable or double
vision can’t be managed with glasses and prism. For adults, adjusta-
ble suture technique may improve outcome.Side Effects & Contraindications
■Rate of reoperation at least 1/3 for congenital esotropia. Surgery may
overcorrect esotropia or exotropia. Surgical complications include
conjunctival cyst, change in eyelid position (especially for vertical
strabismus surgery), endophthalmitis (rare).