Duchenne and Becker Muscular Dystrophy
These two are the most common of muscular dystrophies, and both of them are caused due to mutation of the dystrophin gene. Dystrophin is needed for muscular fibers to maintain their strength. Dystrophin gene also plays a role in the normal working of specific brain centers, retinal pigment, and extra-ocular musculature.
As the MD progresses,it affects almost every muscle of our body, and in later stages person dies due to the failure of cardio-respiratory apparatus. However, amazingly due to the different morphology of muscles involved in the eye movement, they are not affected much. In fact, till now most of the people in medical community used to think that in Duchenne and Becker muscular dystrophies all movements of the eye are fully preserved. Nevertheless, latest and more advanced research has shown that though saccadic eye movements are more or less retained, however, there is some degree of impairment (1).
As dystrophin is also abundant in brain synapses and retina, studies have been done regarding the effect of dystrophin gene mutation on the eyesight. It seems that though there is little impairment of the functioning of the retina in these disorders, vision is more or less preserved, and these changes have little clinical significance (2).