[Histological and ultrastructural studies of extraocular muscle proprioceptor in concomitant strabismus]

To investigate the morphological change of extraocular muscle proprioceptor (EMP) in concomitant strabismus and study its pathogenesis.

The samples were obtained from the extraocular muscles of patients with concomitant strabismus and enucleated eyeballs. After being stained, the samples were examined under light microscopy (LM) and transmission electron microscopy (TEM) to count the number of the mitochondria in each sample in an area of 4,000 mm(2) of the axon under the same amplification.

Under light microscopy, at the myotendinous junction of the extraocular muscle, the EMP nerve fibers were ended at the initial site or the bilateral sides of a nearby single extrafusal fiber. Under electron microscopy, the general architecture of the receptors in concomitant strabismus was completely disorganized. The nerve component in them had disappeared. The number of the mitochondria in 4,000 mm(2) of the axon in the experimental group was significantly lower than that in the control group (P < 0.05).

The results indicate that in concomitant strabismus, the reception and transmission of proprioceptive information are abnormal, and the morphological EMP disturbance plays an important role in the pathogenesis of concomitant strabismus.