"The Cornea in WAGR Syndrome: Keeping the Window Clean"
Aniridia-associated Keratopathy is also called corneal pannus or corneal scarring. The cornea is the clear, dome-shaped covering at the front of the eye. In the
normal eye, it covers the area of the pupil and the iris, and is completely clear.
Keratopathy occurs when the cornea becomes cloudy and blood vessels begin forming over it. In Aniridia, keratopathy is thought to be the result of an insufficent number of specialized cells
called limbal cells. Located in an area of the eye called the Limbus, these cells help the cornea maintain its clear surface and recover from irritation or injury. Other abnormalities common
in the aniridic eye, such as "dry eye" and poor quality tears, may also play a role in keratopathy.
Diagram of the Eye
Illustration of Limbus
Any injury to the surface of the eye, such as eye infections or irritation from contact lenses, may worsen keratopathy. Eye surgery, and in some cases, treatment for glaucoma may also worsen
Keratopathy forms at the edges of the cornea first, then over time progresses inward toward the center of the cornea. As keratopathy progresses, vision is reduced because the cornea is no
Keratopathy occurs in more than 90 percent of individuals with Aniridia. It often begins in the first decade of life, but may not begin to affect vision until
Development of aniridia-associated keratopathy may be unavoidable. But the onset of this condition may be delayed or its progression slowed by
Avoiding the use of contact lenses unless therapeutic (such as bandage contacts for corneal abrasions)
Minimizing the number of eye surgeries, if possible
Early diagnosis and prompt treatment of eye infections
Frequent use of preservative-free, phosphate-free lubricant drops (artificial tears)
Avoiding the use of "VEGF antagonist" eyedrops, such as bevacizumab, ranibizumab, and pegatamib
Diagnosis and Treatment
Aniridia-associated Keratopathy is diagnosed by an eye doctor. Using a slit lamp (a high-powered microscope) the doctor can closely examine the surface of the cornea.
"Dry eye" may be the first symptom of Aniridia-associated Keratopathy. An ophthalmologist can measure the amount of moisture on the cornea, and this measurement can be an important tool for
detecting and monitoring the degree of dry eye in a patient with Aniridia.
Nonsurgical treatment of Aniridia-associated Keratopathy may include
Frequent lubrication with preservative-free artificial tear eyedrops and artificial tear gel. Recommendations include eyedrops with hyaluronic acid, semi-fluorinated alkanes,
and dexpanthenol ointment at night
Warm compresses and lid massage
Puntal plugs (small devices to block the tear ducts)
Low-dose, preservative-free, phosphate-free steroid eyedrops or low-dose Cyclosporine A eyedrops
Autologous serum eyedrops. These are eyedrops made from the patient's own blood. Red blood cells and clotting factors are removed, and the serum is diluted to produce a tear substitute
that contains growth factors and nutrients normally found in healthy tears
Amniotic membrane "patch" (used with a bandage contact lens) or amniotic membrane extract eyedrops
When Aniridia-associated Keratopathy has progressed to the point that functional vision is lost, a cornea transplant may be recommended. Unfortunately, cornea transplant alone almost always
results in regrowth of the keratopathy and failure of the transplant.
Success rates improve when the cornea transplant is combined with transplant of limbal stem cells. Unlike cornea transplant alone, transplant of limbal stem cells
require long-term use of medication to suppress the immune system and prevent rejection of the transplanted tissue.
An alternative treatment for late-stage (light perception only) Aniridia-associated Keratopathy is the Boston Keratoprosthesis or “KPro.” This device is an artificial
cornea. It may be an option for individuals who are not able to tolerate immunosuppressive drugs. The success rate for this device is low, but it is an option for those with blindness. The
Boston Keratoprosthesis requires permanent use of a contact lens and antibiotic eyedrops after the procedure. Glaucoma may occur before or after KPro but can be controlled in about 80 percent
The International WAGR Syndrome Association is working to stimulate research on Aniridia: