Parts of the Visual System Affected

Mobius Syndrome

Parts of the visual system affected

Reduction in blinking mechanism, decrease in tear production and greater frequency of corneal erosions.

Comprehensive description

Moebius syndrome is a rare neurological disorder that is present at birth. It is congenital and stable. Moebius syndrome is a condition in which the facial nerve is underdeveloped, causing paralysis or weakness of the muscles of the face. Other nerves to the facial structures may also be underdeveloped. Moebius syndrome has been called "life without a smile" because the paralysis of the facial muscles, the most constant feature, leads to the physical inability to form a smile even when happy feelings are experienced. Individuals with Moebius syndrome may also have abnormalities of their limbs, chest muscles, and tongue. The chance of mental retardation appears to be increased in people with Moebius syndrome, but most people with the disorder have normal intelligence.

Moebius syndrome is extremely rare and does not seem to affect any particular ethnic group more than others.

Effects of the condition on the visual system

The lack of lateral ocular movements results in greater head turns in order to see to the sides. Additionally, there is a reduction in the blinking mechanism which causes dry eyes and an increase in the frequency of eye infections. Furthermore, because of the cranial nerve anomaly there is also a decrease in tear production and an increase in blepheritis. Often these patients experience a decrease in vision because of the dry eye condition and greater frequency of corneal erosions.

Common treatments

There is no specific course of treatment for Moebius syndrome. Infants may require feeding tubes or special bottles to maintain sufficient nutrition. Surgery may correct crossed eyes and improve limb and jaw deformities. Physical and speech therapy often improves motor skills and coordination, and leads to better control of speaking and eating abilities. Plastic reconstructive surgery may be beneficial in some individuals. Nerve and muscle transfers to the corners of the mouth have been performed to provide limited ability to smile.

From a surgical perspective, it is possible to assist these children in several ways through muscle transplantation. Support can be provided for the lower lip resulting in improvement in speech particularly sounds such as P and B that require the lips to be placed together. Mouth closure protects the teeth and gums. Last but not least, muscle transplantation can animate the face and create a smile.

Anticipated functional implications of the condition

Intellectual development of children with Moebius Syndrome usually fits into the normal range. However, because of their lack of facial expression, speech difficulties, drooling and unusual eye movements, they are often mistakenly categorized as mentally deficient. As there is no foundation for this characterization, it is imperative that they be integrated into the normal school system and given the opportunities of any child with normal intelligence. Only in this way, can the child reach his or her full potential

Numerous problems may affect the child with Moebius syndrome. As a newborn, feeding problems may be so severe as to lead to failure to thrive and the need for a gastrostomy. Any squint or strabismus may be amenable by surgery at a very early age. As a preschooler, the absence of facial expression begins to become an issue. The children are often interpreted as being dull, disinterested or simply rude. This may have enormous implications for psycho-social development. Because of the lack of support normally provided to the lower lip by the facial musculature, drooling and the inability to produce bilabial sounds, such as B and P, also become significant issues. It is here that muscle transplantation can be very helpful. With proper positioning, tension and innervation, lower lip support can be provided, thus helping with drooling and bilabial speech as well as facilitating a simulated smile. Being able to smile is very helpful in allowing the child to demonstrate facial emotions even though they may not be completely spontaneous or normal.

References:

Geneva Foundation for Medical Education and Research. (2011, May 12). Retrieved from http://www.gfmer.ch/genetic_diseases_ v2/gendis_detail_list.php?cat3=1707

National Institute of Neurological Disorders and Stroke. (2011, June 23). Retrieved from http://www.ninds.nih.gov/disorders/mo bius/moebius.htm

Smile-Surgery.com. (n.d.) Retrieved from http://smile-surgery.com/moebius.html

Developed by Jerry Mullins