Clinical and Histological Study of Extraocular Muscle in Congenital Fibrosis Syndrome

ABSTRACT

The authors analyzed 8 cases of the patients with congenital fibrous syndrome for clinical and histological study. In addition we observed the histological findings for the relationship between the clinical manifestations and fibrosis of the muscles and the cause of the fibrosis. All of the patients had hypotropia and 7 of whom had bilateral tendency, six patients showed exotropia and two patines showed esotropia. Associated ocular problems were amblyopia (88%), ptosis (88%), nisometropia (50%) and nystagmus (62%). The most common abnormal head posture was chin up position (88%). There were improvement of abnormal head position in six patients but no change of abnormal head posture in two patients after operation. In histological study the muscle fiber showed generalized degeneration. Clumping of the nuclei of the muscle fiber was replaced by many nuclei of the fibroblasts in light microscopy. The authors observed the proliferation of the collagen fibers among the fibroblastic nuclei and amorphous diffuse particle stained by lightred color in the intercellular space. In electron microscopy the premature collagen fibers appeared among amorphous particles and some particles had close relationship with collagen fibers. From these findings, it would appear that formation of the collagen fiber occurs in extraocular space and degenerated myofibrils are responsible for the formation of the collagen fiber, and abnormal head posture results from fibrosis of muscle fiber and ptosis.