Purchase this article with an account.
Richard Wasicky, Farzad Ziya-Ghazvini, Roland Blumer, Julius–Robert Lukas, Robert Mayr; Muscle Fiber Types of Human Extraocular Muscles: A Histochemical and Immunohistochemical Study. Invest. Ophthalmol. Vis. Sci. 2000;41(5):980-990.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
purpose. To classify muscle fibers of human extraocular muscle (hEOM) and to
compare them to previous studies on hEOM, as well as to nonhuman EOM
classification schemes and skeletal muscle fiber types.
methods. Muscle fibers cut in different muscle planes were followed on
consecutive cross sections and typed with regard to their oxidative
profile in combination with their myosin–immunohistochemical
results. Three zones were observed. In the global layer three muscle fiber types
were observed: global layer singly innervated granular fibers,
79.4 ± 8.1 μm (perimeter [values at midmuscle region] ± SD);
59%; global layer singly innervated coarse fibers (80.3 ± 10.8μ
m; 21%); and global layer multiply innervated muscle fibers
(4.1 ± 9.7 μm; 21%). Two muscle fiber types were detected in
the orbital layer: orbital layer singly innervated muscle fibers
(54.1 ± 8.5 μm; 83%) and orbital layer multiply innervated
muscle fibers (53.5 ± 7.6 μm; 17%). Three muscle fiber types
were differed in the marginal zone: marginal zone singly innervated
muscle fibers (83.1 ± 15.8 μm; 56%), marginal zone multiply
innervated low oxidative muscle fibers (84.4 ± 23.3 μm; 7%),
and marginal zone multiply innervated high oxidative muscle fibers
(88.4 ± 14.5 μm; 37%). Coexpressions of developmental myosin
heavy chain isoforms and fast myosin heavy chain isoform were detected
mainly in the marginal zone.
conclusions. hEOMs resemble mammalian EOM with regard to their organization.
However, in addition to an inner global layer and an orbital layer an
external marginal zone was described for the first time in hEOM in the
This PDF is available to Subscribers Only