Evidence Supporting Extraocular Muscle Pulleys: Refuting the Platygean View of Extraocular Muscle Mechanics

Overview

Journal J Pediatr Ophthalmol Strabismus

Specialties Ophthalmology
Pediatrics

Date 2006 Oct 7

PMID 17022164

Citations 7

Authors

Joseph L Demer

Affiliations

Soon will be listed here.

Abstract

Background: Late in the 20th century, it was recognized that connective tissue structures in the orbit influence the paths of the extraocular muscles and constitute their functional origins. Targeted investigations of these connective tissue "pulleys" led to the formulation of the active pulley hypothesis, which proposes that pulling directions of the rectus extraocular muscles are actively controlled via connective tissues.

Purpose: This review rebuts a series of criticisms of the active pulley hypothesis published by Jampel, and Jampel and Shi, in which these authors have disputed the existence and function of the pulleys.

Methods: This article reviews published evidence for the existence of orbital pulleys, the active pulley hypothesis, and physiological tests of the active pulley hypothesis. Magnetic resonance imaging in a living subject and histological examination of a human cadaver directly illustrate the relationship of pulleys to extraocular muscles.

Results: Strong scientific evidence is cited that supports the existence of orbital pulleys and their role in ocular motility. The criticisms of the hypothesis have ignored mathematical truisms and strong scientific evidence.

Conclusions: Actively control led orbital pulleys play a fundamental role in ocular motility. Pulleys profoundly influence the neural commands required to control eye movements and binocular alignment. Familiarity with the anatomy and physiology of the pulleys is requisite for a rational approach to diagnosing and treating strabismus using emerging methods. Conversely, approaches that deny or ignore the pulleys risk the sorts of errors that arise in geography and navigation from incorrect assumptions such as those of a flat ("platygean") earth.

Citing Articles

The biomechanical significance of pulley on binocular vision.

Guo H, Gao Z, Chen W Biomed Eng Online. 2017; 15(Suppl 2):137.

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Extraocular Muscles Tension, Tonus, and Proprioception in Infantile Strabismus: Role of the Oculomotor System in the Pathogenesis of Infantile Strabismus-Review of the Literature.

Schiavi C Scientifica (Cairo). 2016; 2016:5790981.

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Minimally invasive surgery for thyroid eye disease.

Naik M, Nair A, Gupta A, Kamal S Indian J Ophthalmol. 2015; 63(11):847-53.

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Complex tropomyosin and troponin T isoform expression patterns in orbital and global fibers of adult dog and rat extraocular muscles.

Bicer S, Reiser P J Muscle Res Cell Motil. 2013; 34(3-4):211-31.

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Postnatal changes in the developing rat extraocular muscles.

Moncman C, Andrade M, Andrade F Invest Ophthalmol Vis Sci. 2011; 52(7):3962-9.

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