High-resolution magnetic resonance imaging of the normal extraocular musculature

Ettl, Armin; Kramer, Josef; Daxer, Albert; Koornneef, L.

doi:10.1038/eye.1997.207

Cited by 43 publications

(18 citation statements)

References 11 publications

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“…The connective tissue system of the superior orbit may have similar 'pulley-like' and supporting functions for the levator muscle [8,11].…”

Section: Discussionmentioning

confidence: 99%

“…A steep slope of the levator muscle aponeurosis and therefore 'force-saving' lid elevation is achieved by a deflection of the LPS at its culmination point [8,11], which may be due to the unique architecture of the connective tissue system of the superior orbit, i.e. the superior transverse ligament and transverse superior fascial expansion in connection with the radial suspensory septa [12].…”

Section: Discussionmentioning

confidence: 99%

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Dynamic Magnetic Resonance Imaging of the Levator palpebrae superioris Muscle

Ettl

Daxer²,

Priglinger³

et al. 1998

Ophthalmic Res

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The relationship between upper lid elevation (h) and shortening (s) of the levator palpebrae superioris muscle (LPS) has an influence on the dose-response relationship in ptosis surgery. In order to investigate the relationship between upper lid elevation and shortening of the LPS, parasagittal T₁-weighted MR images of the orbit were obtained in healthy subjects with the eye in down- and upgaze. The position of the upper lid margin and the length of the LPS were measured in the images in down- and upgaze and the amount of h and s was determined. For a mean (± SD) vertical upper lid elevation of 15 ± 1 mm, the mean (± SD) shortening of the LPS muscle was 21 ± 3 mm (n = 4). The mean ratio of h:s was calculated to be 1:1.4, which means that the levator muscle must contract by 1.4 cm in order to achieve a lid elevation of 1 cm. Therefore, the force of the LPS which is necessary to lift the upper eyelid can be smaller than the lid-closing force. This strongly suggests a physiological mechanism which reduces the muscle force necessary for lifting the upper eyelid.

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“…The connective tissue system of the superior orbit may have similar 'pulley-like' and supporting functions for the levator muscle [8,11].…”

Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Dynamic Magnetic Resonance Imaging of the Levator palpebrae superioris Muscle

Ettl

Daxer²,

Priglinger³

et al. 1998

Ophthalmic Res

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“…In addition to extraocular muscle insertion on the globe and levator palpebrae muscle insertion into the upper eyelid, an extraordinary connective tissue system in the orbit has attracted the attention of various authors (Lemke et al, 1990;Lemke, 1991;Ettl et al, 1996Ettl et al, , 1997Clark et al, 1998;Demer, 2002;Kono et al, 2002). Delicate fine connective tissue called Tenon's capsule or fascia bulbi, encloses the eyeball.…”

Section: Discussionmentioning

confidence: 98%

“…Lueder et al (1998) described the intraoperative discovery of an anomalous muscle that had been seen previously in scans, but which was interpreted as a large blood vessel. Nevertheless, currently, precise identification of even fine structures, such as the levator aponeurosis, Muller's muscle, and components of the connective tissue system, is possible by modern MRI devices fitted with high resolution equipment (Ettl et al, 1997;Hoffmann et al, 1998;Demer, 2002).…”

Section: Introductionmentioning

confidence: 99%

Levator palpebrae superioris muscle in human fetuses: Anatomical findings and their clinical relevance

2005

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Accessory medial muscular bellies of the levator palpebrae superioris muscle and broad lateral insertion of its aponeurosis into tissue near the lacrimal gland have been reported as rare variations in adults. The anatomy of this muscle was studied in orbits of ten human fetuses between the 5th and 10th months of gestation. In each of the dissected orbits, the levator palpebrae superioris muscle had a broad lateral insertion into the capsule of the lacrimal gland or the periorbita, in this period of development. In addition, medial accessory muscles of the levator or singular muscle fibers within fibrous bands that inserted near the trochlear region and the medial portion of the upper eyelid were present in 70% of the fetuses, either unilaterally or bilaterally. These findings demonstrate new unreported aspects of levator palpebrae superioris development and morphology. Our findings suggest that an initial broad anterior primary anlage of the muscle is followed by secondary atrophy of lesser used marginal portions of this muscle, which are replaced by delicate connective tissue. These findings might force new considerations about diagnostic and therapeutic approaches to congenital mobility disorders of the levator palpebrae superioris muscle, such as blepharoptosis or eyelid retraction. The clinical relevance of our results are discussed along with a review of the embryogenesis of extraocular muscles and soft tissue of the orbit.

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“…Similar to the extraocular rectus muscles [2,3], the LPS also courses in a curved path and culminates a few millimeters cranial to the surface of the globe [4][5][6] (fig. 1).…”

Section: Introductionmentioning

confidence: 99%

Is Whitnall’s Ligament Responsible for the Curved Course of the Levator palpebrae superioris Muscle?

et al. 1998

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Background and Purpose: The levator palpebrae superioris (LPS) muscle courses anteriosuperiorly to culminate cranial to the posteriosuperior surface of the globe from where it courses anterioinferiorly to the tarsal plate. Whitnall’s superior transverse ligament (STL) has been suggested to suspend the LPS at its culmination. If this was the case, one would expect the STL to be located near the culmination of the LPS. In order to elucidate this functional aspect of the STL, the spatial relation of the STL to the LPS muscle is investigated in this study. Methods: Surface coil MRI in an oblique sagittal plane along the optic nerve was performed in 6 orbits from 3 human cadavers in which the STL was marked with synthetic material. Results: The MR images showed that in human cadaver specimens the STL is situated in the anterior descending portion of the LPS. Conclusion: This result suggests that the STL does not suspend the LPS at its culmination and is therefore not responsible for the curved course of the muscle.

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High-resolution magnetic resonance imaging of the normal extraocular musculature

Cited by 43 publications

References 11 publications

Dynamic Magnetic Resonance Imaging of the Levator palpebrae superioris Muscle

Dynamic Magnetic Resonance Imaging of the Levator palpebrae superioris Muscle

Levator palpebrae superioris muscle in human fetuses: Anatomical findings and their clinical relevance

Is Whitnall’s Ligament Responsible for the Curved Course of the Levator palpebrae superioris Muscle?

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