Monofixation syndrome

From Wikipedia, the free encyclopedia
  (Redirected from Microtropia)
Jump to: navigation, search
Monofixation syndrome
Classification and external resources
Specialty neurology
ICD-10 H50.4
ICD-9-CM 378.34
DiseasesDB 33536
eMedicine article/1199953

Monofixation syndrome (MFS) (also: microtropia or microstrabismus) is an eye condition defined by less-than-perfect binocular vision.[1] It is defined by a small angle deviation with suppression of the deviated eye and the presence of binocular peripheral fusion.[2] That is, MFS implies peripheral fusion without central fusion.

Aside the manifest small-angle deviation ("tropia"), subjects with MFS often also have a large-angle latent deviation (phoria). Their stereoacuity is often in the range of 3000 to 70 arcsecond, and a small central suppression scotoma of 2 to 5 deg.[3]

A rare condition, MFS is estimated to affect only 1% of the general population. There are three distinguishable forms of this condition: primary constant, primary decompensating, and consecutive MFS. It is believed that primary MFS is a result of a primary sensorial defect, predisposing to anomalous retinal correspondence.[4]

Secondary MFS is a frequent outcome of surgical treatment of congenital esotropia.[2] A study of 1981 showed MFS to result in the vast majority of cases if surgical alignment is reached before the age of 24 months and only in a minority of cases if it is reached later.[5]

MFS was first described by Marshall Parks.[3]


  1. ^ "Monofixation Syndrome: eMedicine Ophthalmology". 
  2. ^ a b Guthrie ME, Wright KW (September 2001). "Congenital esotropia". Ophthalmol Clin North Am. 14 (3): 419–24, viii. doi:10.1016/S0896-1549(05)70239-X. PMID 11705141. 
  3. ^ a b Kenneth Weston Wright; Peter H. Spiegel (January 2003). Pediatric Ophthalmology and Strabismus. Springer Science & Business Media. p. 174. ISBN 978-0-387-95478-3. 
  4. ^ Lang J. "Microtropia". Int Ophthalmol. 6: 33–6. PMID 6826290. 
  5. ^ M.R. Ing (1961). "Early surgical alignment for congenital esotropia". Transactions of the American Ophthalmological Society (79): 625–663.  Cited according to: Myron Yanoff; Jay S. Duker; James J. Augsburger (2009). Ophthalmology. Elsevier Health Sciences. p. 1323. ISBN 0-323-04332-1.