Congenital Fibrosis of the Extraocular Muscles
Congenital fibrosis of the extraocular muscles (CFEOM), or congenital fibrosis syndrome, is a group of rare congenital disorders in which EOM restriction is present and fibrous tissue replaces these muscles. Some forms have been noted to be inherited, usually as an autosomal dominant trait but occasionally in an autosomal recessive fashion. Cases of CFEOM involve developmental defects of cranial nerve nuclei and of the nerves themselves, resulting in dysinnervation and abnormal structure of the EOMs.
Depending upon the type of CFEOM, there may be various combinations of esotropia with limited abduction, exotropia with limited adduction, limited elevation with chin-up head position, and ptosis.
Strabismus fixus involves the horizontal rectus muscles, usually the medial rectus muscles, causing severe esotropia. The condition is usually sporadic and can be acquired late.
Vertical retraction syndrome affects the superior rectus muscle and causes inability to depress the eye.
Diagnosis of CFEOM depends on finding limited voluntary motion with restriction, which is usually severe and can be confirmed with forced duction testing. The congenital onset is important in distinguishing the syndrome from thyroid eye disease.
Surgery for CFEOM is difficult and requires release of the restricted muscles (ie, weakening procedures). Fibrosis of the adjacent tissues may be present as well. A good surgical result aligns the eyes in primary position, but full ocular rotations cannot be restored and the outcome is unpredictable.
Sener EC, Taylan Sekeroglu H, Ural O, Oztürk BT, Sanaç AS. Strabismus surgery in congenital fibrosis of the extraocular muscles: a paradigm. Ophthalmic Genet. 2014;35(4):208–225.
Excerpted from BCSC 2020-2021 series: Section 10 - Glaucoma. For more information and to purchase the entire series, please visit https://www.aao.org/bcsc.