Familial ectopia lentis (FEL) or Isolated ectopia lentis (IEL) is a rare condition that can begin at any age. IEL causes lens dislocation when the lens of the eye is not in the right place. Light enters the eye and passes through the lens. The lens focuses light to the retina. The retina is at the back of the eye and sends information to the brain. This information tells the person what he/she sees. Lens dislocation causes light to not focus on the retina correctly which will cause a person with IEL to not see clearly.
The lens is held in place in the eye by zonular fibers. Someone with IEL will not have as many zonular fibers as they should, causing lens dislocation. The severity of lens dislocation will be different for each person with IEL. The more dislocated the lens is, the worse vision will be. Lens dislocation can get worse with time, causing vision to worsen. Some people with IEL also have other eye conditions.
Familial ectopia lentis is when IEL is passed down from parents to their children through genes. Genes are segments of DNA that act as the body’s instruction manual. DNA is a “code” made up of small parts called nucleotides. A gene mutation is when one or more nucleotides in the DNA “code” that makes up a gene is changed. FEL can be caused by a mutation in two different genes: ADAMTSL4 or FBN1. FEL is inherited in an autosomal dominant or autosomal recessive pattern. In an autosomal dominant pattern, the child has to inherit one changed copy of the FBN1 gene from one parent to have FEL. In an autosomal recessive pattern, both parents pass down a mutated ADAMTSL4 gene to the child for the child to have FEL.
Someone can be diagnosed with FEL with genetic tests either before or after birth. Treatment includes surgery, the use of contact lenses, or prosthetic (man-made) lenses. If you or a family member has been diagnosed with FEL, talk to your doctor about the most current treatment options.