What is congenital fibrosis of the extraocular muscles?
Congenital fibrosis of extraocular muscles (CFEOM), also known as congenital fibrosis syndrome, is a non-progressive genetic disorder affecting the movement of the eyes. It is generally characterised by ophthalmoplegia, i.e., inability to move the eyes. It may be present with or without droopy eyelids (ptosis). CFEOM includes about eight types of strabismus (eyes do not align properly when looking towards an object) syndrome viz. CFEOM1A, CFEOM1B, CFEOM2, CFEOM3A, CFEOM3B, CFEOM3C, Tukel syndrome, and CFEOM3 with polymicrogyria (abnormal brain development prior to birth). However, these manifest in a similar manner.
What are its main signs and symptoms?
Individuals with this disorder experience the following symptoms:
- Inability to move eyes in certain directions
- Droopy eyelids (only in some cases)
- Eyes fixed in abnormal positions, mostly in downward position
These symptoms do not progress with time. Individuals with CFEOM3A may also have facial weakness, intellectual, and social disability, Kallmann syndrome, and paralysis of the vocal cord. Individuals with Tukel syndrome have missing and webbed toes and fingers, along with the disorder of eye movement.
What are its main causes?
It is a hereditary disease caused by the defective gene transferred from the parent to the child.
How is it diagnosed and treated?
A thorough examination of your eye is performed to diagnose this syndrome. It may be confused with some other eye disorders like chronic progressive external ophthalmoplegia, isolated congenital ptosis, isolated third nerve palsy, and congenital myasthenic syndrome. The various factors that are considered during diagnosis are:
- The range of motion of the eyes
- Ocular misalignment
- Eyeball retraction
- Eye-opening size (palpebral fissure)
- Eye movement in the vertical direction
The diagnosis of the subtype is based on the specific eye movement details.
The treatment can be divided into various steps as follows:
- Management of the refractive errors by using glasses or lenses. Corneal lubrication has also proved to be helpful in treating the manifestations.
- Preventing the secondary complications: Amblyopia therapy is provided to prevent the loss of eyesight.
- Routine eye examination with an ophthalmoscope
- Examinations of family members at risk can help in early diagnosis and management of the condition. It will also aid in preventing other associated complications.