Abstract
The extraocular muscles of dystrophic mouse strain Re-129 dy/dy were studied in combined phase and electron microscopy. Changes in fiber morphology were found which are similar to those described in dystrophic human and mouse peripheral musculature, i.e., changes in fiber diameter, alterations in the cellular organelles, including mitochondria, sarcoplasmic reticulum, nuclei, sarcolemma, and lipid concentrations. Insofar as these changes were comparable to those reported in human extraocular muscle dystrophy (dystrophic ophthahnoplegia, progressive ocular muscular dystrophy, and oculopharyngeal muscular dystrophy), mouse extraocular muscle would seem to be a good model for the study of oculomotor dystrophy.