Histologic Study for Effect of Experimental Hematoma on Extraocular Muscle

ABSTRACT

This study was performed to evaluate the effect of hematoma which often occurred during the strabismus surgery on the extraocular muscles. We created focal hematomas around the superior rectus mascles of three dogs by rupture of the anterior ciliary artery. One, two and four weeks after formation of the hematoma respectively, we resected the superior rectus muscles 7mm in length at the site of previous hematoma and histopathologic examination with a light microscope was performed. We could not find any specific pathologic change in the muscular fiber in one week after surgery. But, focal degeneration of the muscle fiber was found in that of two weeks and diffuse degeneration in that of four weeks after surgery. However, any fibrotic lesion was not found. The muscle degeneration may be caused by the pressure of hematoma and ischemia due to small arterial occlusion.