purpose: we report an unusual case of trabecular carcinoid of the ovary with orbital involvement. methods: we encountered a 49-year-old woman with a complaint of bilateral proptosis. ocular examination revealed severe bilateral proptosis and signs of corneal exposure. orbital ct scan showed massive enlargement of extraocular muscles and optic nerve compression. the patient medical history showe...

PURPOSE Clinical data indicate that extraocular muscles have different susceptibilities for some orbital immune disorders depending on their anatomic location. The resident immunocompetent cells may be important mediators in the local pathogenesis of such disorders so the distribution of these cells was studied in extraocular muscles obtained from normal human donors. For comparison skeletal mu...

PURPOSE To evaluate contrast enhancement of normal extraocular muscles in the orbit. METHODS Noncontrast and contrast-enhanced T1-weighted images of the orbit were acquired using a fat-suppression MR technique in eight patients with no orbital disease. Contrast enhancement of 64 extraocular muscles was evaluated and compared with that of 16 temporal muscles. RESULTS Compared with temporal m...

OBJECTIVE Establish criteria for the diameters of normal extraocular muscles using computerized tomography in a Thai population. MATERIAL AND METHOD Diameters of extraocular muscles (medial, lateral, superior complex, and inferior rectus) were calculated for 200 patients on coronal direction of screening paranasal sinuses. The effects of age and sex were also analyzed. RESULT Normal ranges ...

The extraocular muscles are one of few skeletal muscles that are structurally and functionally intact in Duchenne muscular dystrophy. Little is known about the mechanisms responsible for differential sparing or targeting of muscle groups in neuromuscular disease. One hypothesis is that constitutive or adaptive properties of the unique extraocular muscle phenotype may underlie their protection i...

As described in Chapter 4, the extraocular muscles perform two functions: optostatic and optokinetic. The optostatic function requires that the muscles maintain a state of postural tonicity; the optokinetic function requires that quick, tetanic contractions be performed. These two contradictory functions are served by two different sets of muscles in the skeletal muscle system. Eye muscles, how...

PURPOSE Extraocular muscles show specific adaptations to fulfill the metabolic demands imposed by their constant activity. One aspect that has not been explored is the availability of substrate for energy pathways in extraocular muscles. In limb muscles, glucose enters by way of GLUT1 and GLUT4 transporters in a process regulated by insulin and contractile activity to match metabolic supply to ...

Extraocular motoneurons resist degeneration in diseases such as amyotrophic lateral sclerosis. The main objective of the present work was to characterize the presence of neurotrophins in extraocular motoneurons and muscles of the adult rat. We also compared these results with those obtained from other cranial motor systems, such as facial and hypoglossal, which indeed suffer neurodegeneration. ...

The M lines are structural landmarks in striated muscles, necessary for sarcomeric stability and as anchoring sites for the M isoform of creatine kinase (CK-M). These structures, especially prominent in fast skeletal muscles, are missing in rodent extraocular muscle, a particularly fast and active muscle group. In this study, we tested the hypotheses that 1). myomesin and M protein (cytoskeleta...

PURPOSE The constant activity of the extraocular muscles is supported by abundant mitochondria. These organelles may enhance energy production by increasing the content of respiratory complexes. The authors tested the hypothesis that extraocular muscle mitochondria respire faster than do mitochondria from limb muscles because of the higher content of respiratory complexes. METHODS Inner mitoc...