EXTRAOCULAR MUSCLE DYSFUNCTION IN MYOPATHIES

Abstract

The distinct histological and neurophysiological features of extraocular muscles form the basis for their extremely specialized and accurate function. This contributes to either their characteristic vulnerability, or their resilience to particular neuromuscular disorders, depending on the underlying pathophysiological mechanism.
The present review focusses on both common and rare myopathies that present with extraocular muscle dysfunction as a core symptom (such as mitochondrial myopathies, oculopharyngeal muscular dystrophy, orbital myositis and dysthyroid Graves’ orbitopathy) or involve eye movements to a lesser degree, while skeletal muscle weakness predominates the phenotype.
Lastly, contemporary non-invasive neuroimaging and electrophysiological techniques used for diagnosis and quantification of extraocular muscle dysfunction will be discussed.