New approach in strabismus surgery in high myopia

Krzizok, Thomas; Kaufmann, Herbert J.; Traupe, Horst

doi:10.1136/bjo.81.8.625

Cited by 83 publications

(71 citation statements)

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“…12,13 Extreme pulley heterotopy is associated with esotropia and hypotropia in axial high myopia, the "heavy-eye syndrome." [14][15][16] The most common forms of human strabismus are horizontal, concomitant eso-and exotropia. Concomitant strabismus means that the degree of misalignment is the same regardless of horizontal gaze direction, although "A" and "V" patterns of variation with vertical gaze are typically associated with the most common forms in humans.…”

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confidence: 99%

Horizontal Rectus Muscle Anatomy in Naturally and Artificially Strabismic Monkeys

Narasimhan

Tychsen

Poukens³

et al. 2007

Invest. Ophthalmol. Vis. Sci.

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Purpose-Structural abnormalities of extraocular muscles (EOMs) or their pulleys are associated with some forms of human strabismus. This experiment was conducted to investigate whether such abnormalities are associated with artificial or naturally occurring strabismus in monkeys.Methods-Binocular alignment and grating visual acuities were determined in 10 monkeys representing various species using search coil recording and direct observations. Four animals were orthotropic, two had naturally occurring "A"-pattern esotropia, two had concomitant and one had "V"-pattern esotropia artificially induced by alternating or unilateral occlusion in infancy, and one had "A"-pattern exotropia artificially induced by prism wear. After euthanasia, 16 orbits were examined by high-resolution magnetic resonance imaging (MRI) in the quasicoronal plane. Paths and sizes of horizontal rectus EOMs were analyzed quantitatively in a standardized coordinate system. Whole orbits were then serially sectioned en bloc in the quasicoronal plane, stained for connective tissue, and compared with MRI. Nerve and EOM features were analyzed quantitatively.Results-Quantitative analysis of MRI revealed no significant differences in horizontal rectus EOM sizes or paths among orthotropic or naturally or artificially strabismic monkeys. Histologic examination demonstrated no differences in EOM size, structure, or innervation among the three groups, and no differences in connective tissues in the pulley system. The accessory lateral rectus (ALR) EOM was present in all specimens, but was small, inconsistently located, and sparsely innervated. Characteristics of the ALR did not correlate with strabismus.Conclusions-Major structural abnormalities of horizontal rectus EOMs and associated pulleys are unrelated to natural or artificial horizontal strabismus in the monkeys studied. The ALR is unlikely to contribute to horizontal strabismus in primates. However, these findings do not exclude a possible role of pulley abnormalities in disorders such as cyclovertical strabismus.Before the development of quantitative models of extraocular biomechanics, 1-3 it was believed sufficient to describe orbital anatomy by cadaveric measurements of extraocular It has subsequently emerged that the rectus and inferior oblique EOMs of humans and monkeys do indeed have highly structured soft pulleys that regulate EOM pulling directions. 7-10 The pulleys act as functional origins of the rectus EOMs. 11 Rectus EOMs travel through their respective pulleys, which imply that the pulleys must lie along the EOM paths. Many cases of human incomitant cyclovertical strabismus are associated with displacement of one or more rectus EOM pulleys. "A" and "V" patterns of incomitance in strabismic patients consistently match those predicted by computational simulation based on measured pulley locations, suggesting that pulley heterotopy caused the strabismus. 12,13 Extreme pulley heterotopy is associated with esotropia and hypotropia in axial high myopia, the "heavy-eye syndrome." 14-1...

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confidence: 99%

Horizontal Rectus Muscle Anatomy in Naturally and Artificially Strabismic Monkeys

Narasimhan

Tychsen

Poukens³

et al. 2007

Invest. Ophthalmol. Vis. Sci.

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“…Many surgical procedures have been defined in order to stabilize eyes with squint due to high myopia [4][5][6][7][8]. Two types of surgical procedures are preferred in general.…”

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confidence: 99%

“…Krzizok et al [8] used magnetic resonance imaging as an examination method in patients with high myopia. Inferior displacement of the LR muscle was detected in all 9 cases.…”

Section: Discussionmentioning

confidence: 99%

Partial Modification of the Yamada Technique in Myopic Strabismus Fixus Treatment: Case Presentation

Gündüz¹,

Kütükde²,

Doğanay³

2015

Med-Science

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“…Wenn diese Ansätze aufgrund eines langen Auges überdehnt und/oder instabil werden, verändert sich die Ausrichtung der Zugvektoren der Augenmuskeln: Die Zugrichtung folgt einem Kreis und entspricht der kürzesten Strecke auf einer Kugeloberfläche. In Folge ist der Bulbus nicht mehr von einem symmetrischen Muskelkonus umgeben; meistens weichen der M. rectus lateralis und der M. rectus superior auseinander [77], sodass das Auge in einer auffälligen Einwärts-und Abwärtsschielstellung steht. Seltener sind auch Fälle von Exotropie beschrieben worden [132].…”

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