Vertical fusional vergence (VFV) normally compensates for slight vertical heterophorias. We employed magnetic resonance imaging to clarify extraocular muscle contributions to VFV induced by monocular two-prism diopter (1.15°) base-up prism in 14 normal adults. Fusion during prism viewing requires monocular infraduction. Scans were repeated without prism, and with prism shifted contralaterally. ...

INTRODUCTION Endoscopic sinus surgery can result in serious extraocular muscle dysfunction. The medial rectus muscle is more frequently affected than other extraocular muscles. METHODS A transconjunctival subperiosteal medial orbitotomy was successful in retrieving a partially extirpated medial rectus muscle after endoscopic sinus surgery. RESULTS A previous attempt to localize this muscle ...

Purpose To investigate changes in volumes of extraocular muscle (EOM) compartments in unilateral superior oblique (SO) palsy using magnetic resonance imaging (MRI). Methods High-resolution, surface-coil MRI was obtained in 19 patients with unilateral SO palsy and 19 age-matched orthotropic control subjects. Rectus EOMs and the SO were divided into two anatomic compartments for volume analysis...

A midline experimental lesion separating the medial longitudinal fasciculi at and below the level of the abducens nuclei without damaging either fasciculus at the level of the nuclei has produced defects of ocular motility resembling those of clinical internuclear ophthalmoplegia. Electromyographic recordings during lateral gaze demonstrate: (1) lack of inhibition of the lateral rectus muscle i...

OBJECTIVE To evaluate the success rate of surgical corrections of constant and intermittent exotropias. STUDY DESIGN A case series. PLACE AND DURATION OF STUDY Al-Ibrahim Eye Hospital, Karachi, from July 2011 to December 2012. METHODOLOGY Patients having primary exotropia (deviation 15 - 45 prism diopters [PD]) were included. Patients with either constant exotropia or basic intermittent e...

Purpose: Consecutive exotropia is a frequent consequence of surgery for convergent strabismus that may develop at differing rates postoperatively. Several surgical options on horizontal recti have been proposed, but none report a clearly standardized amount of surgery. The present study provides further results of the medial rectus muscle advancement. Methods: Twenty-eight patients, age ranged ...

BACKGROUND AND PURPOSE To report on the outcomes of treating children with a persistent esotropia with an injection of botulinum toxin in a medial rectus muscle. PATIENTS AND METHODS The medical records were reviewed of all children at one institution with a persistent esotropia after bilateral medial rectus recessions and bilateral lateral rectus resections then treated with a botulinum toxi...

PURPOSE The goal of this study was to determine whether the medial rectus muscles of patients with a history of medial rectus underaction or overaction show alterations in the process of satellite cell activation when compared with normal age-matched control muscles. METHODS Medial rectus muscles were obtained with consent from adult patients undergoing surgical resection due to medial rectus...

To the Editors: Ocular motility problems related to congenital abnormalities of the extraocular muscles are rare. Such congenital abnormalities may present in a spectrum from accessory additional rectus muscles to the absence of extraocular muscles.1-5 Absence of one or more extraocular muscles is a rare condition usually seen in association with craniofacial syndromes. We present a case of bil...

Received: 25.12.2013; Revised: 25.03.2014; Accepted: 14.05.2014 Fig. 1: MRI shows enlarged hyperintense extraocular muscles (left superior rectus, inferior rectus and medial rectus) retinal vein or artery occlusion. Ocular tonometry showed intraocular pressure of 18 mm Hg. Magnetic resonance imag ing (MRI) showed en larged hyperintense extraocular muscles (left superior rectus, inferior rectus ...