The lens in the eye focuses images onto the retina. However, it may be displaced from its normal position in which case it is called ectopia lentis, or simply a dislocated lens. It may follow trauma or internal eye infections but it may also occur as an isolated condition secondary to gene mutations.
In this condition, the lens is often displaced from birth but this may be missed until loss of vision is evident. Vision is highly variable depending upon the amount of lens dislocation. In this rare condition of isolated (without systemically associated abnormalities) ectopia lentis, there is no other disease of the eye such as glaucoma, clouding of the cornea, or retinal detachments. Amblyopia or ‘lazy eye’ may, however, occur.
This is an autosomal recessive condition in which both parents are normal but each contributes a single mutation and the presence of both in the offspring is responsible for the disorder. Such carrier parents can expect that on average one in four of their children will have dislocated lenses.
The diagnosis is made from a complete eye examination. It should be made early, preferably in infancy, since the obstruction to good vision can cause a ‘lazy eye’ or amblyopia. The dislocated lens may be surgically removed but this should be considered only when vision cannot be corrected with glasses or contact lenses. Only a few families have been reported and so far no other eye disease has been noted. However, it is well known that dislocated lenses are often associated with increased risk of glaucoma and retinal detachments and it is suggested that patients with this condition should have periodic evaluations throughout their lives. The prognosis for a normal life is excellent.