Morphology of Extraoccular Muscles in Case of Strabismus

Anna Valaine, Anna Augule, Māra Pilmane, Sandra Valeina

Research output: Chapter in Book/Report/Conference proceedingChapterpeer-review

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Strabismus is a common disorder of children and adults that affects up to 4% of general population. The aim of the present study was to describe the morphologic changes in human strabismic extraoccular muscle.
The histopathological study was conducted on 15 patients with strabismus. Tissues were processed
for IGF-1, IGFR-1, TGF-β1, NGFR and PGP 9.5 by means of biotin-streptavidin immunohistochemistry.
In all specimens, atrophic degenerative changes were observed. The muscle fibers were heterogeneous in shape, size and colour. A chronic persistent perivascular inflammation with lymphocyte predominance, but also presence of neutrophils was observed, as well as neoangiogenesis. Also new myotube formation was detected. Numerous to moderate numbers of TGF-β1 positive endothelial cells and fibroblasts were observed. VEGF was seen in endothelium in moderate numbers. IGF-1 was seen occasionally in endothelial and smooth muscle cells. Occasional IGFR1 positive endothelial, inflammation cells and connective tissue cells were observed. Numerous to moderate number of PGP 9.5 positive nerve fibers were seen in nerve bundles, among muscle fibers and endothelial cells. NGFR positive perivascular nerve fibers were mostly seen in low to moderate appearance.
Occasional to few numbers of structures positive for IGF-1 and its receptor indicate possible
disturbances in muscle fiber growth and regeneration in extraocular muscles in case of strabismus.
Moderate to numerous numbers of TGF-β1 positive structures indicate the continuing regeneration of
connective tissue and blood vessels in strabismus affected muscle. Notable numbers of VEGF positive
endothelial cells simultaneously to the sclerotic blood vessels and neoangiogenesis proves the tissue
ischemia in strabismus affected eye muscle. Presence of PGP 9.5 continuing nerve fibers excludes
innervation disorder in strabismus affected eye muscle.
Original languageEnglish
Title of host publicationRīga Stradiņš University Collection of Scientific Papers 2013
Subtitle of host publicationResearch articles in medicine & pharmacy
Place of PublicationRīga
PublisherRīgas Stradiņa universitāte
ISBN (Print)978-9984-793-43-6
Publication statusPublished - 2014

Publication series

NameCollection of Scientific Papers
PublisherRīga Stradiņš University
ISSN (Print)1691-497X


  • strabismus
  • growth factors
  • extraoccular muscles

Field of Science*

  • 3.1 Basic medicine
  • 3.2 Clinical medicine

Publication Type*

  • 3.2. Articles or chapters in other proceedings other than those included in 3.1., with an ISBN or ISSN code


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