It stands to reason that there will be a relationship between muscular disease and eye focusing problems, since the eye is a muscle and can be affected as well.
One of the most common of the muscular diseases, which affect the eye, is muscular dystrophy. There are several different types of this disease, including one called oculopharyngeal muscular dystrophy, which is actually a weakening of the eye muscle itself.
Other neuromuscular diseases which show problems with the patient’s ability to focus properly; include myotonic muscular dystrophy (MMD), myasthenia gravis (MG), congenital myasthenic syndromes, and mitochondrial disorders.
All of these conditions are characterized by what is considered weak levators. The levator palpebrae superioris muscle is the one that lifts the upper eyelid. When the levators are weak, it results in a drooping of the eye, or the eyelid. This will in turn have an impact on the ability to focus properly.
This problem can sometimes be corrected with surgery, but in some cases such as with myasthenic disorders (including congenital myasthenic syndromes, which are genetic – or autoimmune myasthenia gravis, which is the result of an immune-system attack on muscle cells), the patient is treated with certain medications in the hope that the eye problem will clear up, which it often does.
Anyone suffering from a muscular disease will usually suffer from weakness in one or both eye muscles, so the ability to focus will be compromised. In the case of some diseases, like Leigh’s syndrome, which is a mitochondrial muscle disorder that can affect the visual system, one of the problems associated with the disease itself is nystagmus. This is characterized by a constant shifting back and forth of the eyes, which can move very rapidly. Sometimes the optic nerve can atrophy, or begin to shrink, which will also lead to a decrease in vision in these types of diseases.
Those who are suffering from a muscle disease will want to try performing exercises to strengthen the eye muscles, which may be able to help with the problems they are having focusing.
Whatever the causes, there is often a link between muscular disease and eye focusing problems, whether it be due to the disease process itself, or in relation to a symptom of the disease. Depending on the muscular disease in question, there may be ways to try and improve the eye’s ability to focus — either through surgery or another treatment option. It is important to discuss options with a doctor, because treatments will depend on the severity of the disease and the type of muscular disease that is present.