The use of dynamic magnetic resonance in the diagnosis of ocular motility disorders.

UNLABELLED: Dynamic Magnetic Resonance (dMRI) of the extraocular muscles is based on performing a number of short sequences, while the patient fixates consecutive points placed in different positions of gaze. PURPOSE: To check the relation between dMRI findings and the results of clinical examination in patients with various types of strabismus. MATERIALS AND METHODS: We have selected three patients with lateral rectus palsy, superior rectus palsy and inferior rectus restriction from the group, in which we have performed dMRI. We have taken measures of the affected muscles shape, sectional area and volume. The results were related with the clinical examination. RESULTS: The measurements obtained with use of dMRI reflect the actual state of the affected muscle as seen on the Hess screen. The limitation of the muscles action is represented by a lack of increase in the sectional area and volume in respective gaze intervals. The restriction of the muscle affects its shape by pulling it towards the place of entrapment. CONCLUSIONS: Data acquired by means of dMRI correspond to the clinical findings and allow a quantitative analysis of the degree of muscle weakness. Defining the extent of the morphological changes in extraocular muscles, related with long-lasting paralysis, let us make an informed decision regarding further treatment.