scholarly journals Neuroanatomical Structures in Extraocular Muscles and Their Potential Implication in the Management of Strabismus

Author(s):  
Jan Richard Bruenech
2021 ◽  
pp. 117-127

Keywords: extraocular muscles, oculomotor anomalies, sensory receptors, strabismus Key points: • Human extraocular muscles contain neural structures important for the development and maintenance of binocular vision. • Strabismus and other oculomotor anomalies may be attributable to developmental delay or acquired dysfunctions associated with these structures. • Treatment options and their potential implications are discussed.


Author(s):  
Asish C. Nag ◽  
Lee D. Peachey

Cat extraocular muscles consist of two regions: orbital, and global. The orbital region contains predominantly small diameter fibers, while the global region contains a variety of fibers of different diameters. The differences in ultrastructural features among these muscle fibers indicate that the extraocular muscles of cats contain at least five structurally distinguishable types of fibers.Superior rectus muscles were studied by light and electron microscopy, mapping the distribution of each fiber type with its distinctive features. A mixture of 4% paraformaldehyde and 4% glutaraldehyde was perfused through the carotid arteries of anesthetized adult cats and applied locally to exposed superior rectus muscles during the perfusion.


Author(s):  
Bruce R. Pachter

Diabetes mellitus is one of the commonest causes of neuropathy. Diabetic neuropathy is a heterogeneous group of neuropathic disorders to which patients with diabetes mellitus are susceptible; more than one kind of neuropathy can frequently occur in the same individual. Abnormalities are also known to occur in nearly every anatomic subdivision of the eye in diabetic patients. Oculomotor palsy appears to be common in diabetes mellitus for their occurrence in isolation to suggest diabetes. Nerves to the external ocular muscles are most commonly affected, particularly the oculomotor or third cranial nerve. The third nerve palsy of diabetes is characteristic, being of sudden onset, accompanied by orbital and retro-orbital pain, often associated with complete involvement of the external ocular muscles innervated by the nerve. While the human and experimental animal literature is replete with studies on the peripheral nerves in diabetes mellitus, there is but a paucity of reported studies dealing with the oculomotor nerves and their associated extraocular muscles (EOMs).


1962 ◽  
Vol 41 (3) ◽  
pp. 474-480 ◽  
Author(s):  
Otto Wegelius ◽  
E. J. Jokinen

ABSTRACT In all previous investigations on experimental exophthalmos, heterologous thyrotrophic pituitary extracts have been used. These protein hormones stimulate antihormone formation in the test animals. Cortisone has been reported to effectively block antibody formation. In addition, it has been shown to potentiate TSH-induced exophthalmos in guinea-pigs. With rabbits as test animals, the hexosamine content of the orbital tissues was determined and used as an index of exophthalmos development and at the same time the antibody titres in the sera were followed. TSH injections for six weeks led to a highly significant accumulation of hexosamine in the retrobulbar connective tissue and in the extraocular muscles, i. e. an increase of up to 400% as compared with the control animals. At the same time a significant rise in antihormonal titres was detectable in the sera. Concomitant treatment with cortisone brought about an equal or higher accumulation of hexosamine but significantly lower antibody titres. The known opposite peripheral actions of TSH and cortisone can be reconciled with the synergy in producing experimental exophthalmos by attributing the synergetic action of cortisone to the blocking of antihormone formation. If less antihormones are produced, the effect of TSH is enhanced. Our experiments do not provide direct proof for this hypothesis. High hexosamine values in the orbit and low antihormone titres in the serum are, however, concomitant phenomena.


Sign in / Sign up

Export Citation Format

Share Document