PubMed ID: 21149788
Author(s): Kushner BJ. Incomitant strabismus: does extraocular muscle form denote function? Arch Ophthalmol. 2010 Dec;128(12):1604-9. doi: 10.1001/archophthalmol.2010.301. PMID 21149788
Journal: Archives Of Ophthalmology (Chicago, Ill. : 1960), Volume 128, Issue 12, Dec 2010
The paradigm that an “underacting” extraocular muscle is always atrophic or hypoplastic and that an overacting extraocular muscle should always be enlarged leads to inconsistencies with clinical observations. These include findings of “overacting” inferior oblique muscles, superior rectus muscle overaction or contracture syndrome, and normal extraocular muscle diameters in patients with apparent superior oblique muscle palsy, among other clinical entities. These inconsistencies can be reconciled if one accepts the possibility that extraocular muscle contractile activity may reflect a change in neural input to an anatomically normal muscle or that muscle contractile activity may be altered by shifts in fiber type and distribution within a normal-sized muscle. This remodeling may result from vergence adaptation or from any change in neural stimulus to the muscle. There is substantial evidence to suggest that both of these theoretical possibilities may likely occur.