February 28th is Rare Disease Day

The cornea is the clear, dome-shaped window at the front of the eye. It focuses light into the eye, Keratoconus is when the cornea thins out and bulges like a cone. Changing the shape of the cornea brings light rays out of focus. As a result, vision is blurry and distorted, making daily tasks like reading or driving difficult.
 

What Causes Keratoconus?

Doctors do not know for sure why people have keratoconus. In some cases, it appears to be genetic (passed down in families). About 1 out of 10 people with keratoconus have a parent who has it too. Keratoconus is also associated with:
 

• eye allergies
   

• excessive eye rubbing
   

• connective tissue disorders like Marfan Syndrome and Ehlers-Danlos Syndrome
   

Keratoconus often starts when people are in their late teens to early 20s. The vision symptoms slowly get worse over a period of about 10 to 20 years.
 

Keratoconus Symptoms

Early Stages
 

• mild blurring of vision
   

• slightly distorted vision, where straight lines look bent or wavy
   

• increased sensitivity to light and glare
   

• eye redness or swelling
   

Later Stages
 

• more blurry and distorted vision
   

• increased nearsightedness or astigmatism (when your eye cannot focus as well as it should). As a result, you may need new eyeglass prescriptions often.
   

• not being able to wear contact lenses. They may no longer fit properly and they are uncomfortable.
  
   

Keratoconus usually takes years to go from early to late stage. For some people, though, keratoconus can get worse quickly. The cornea can swell suddenly and start to scar. When the cornea has scar tissue, it loses its smoothness and becomes less clear. As a result, vision grows even more distorted and blurry.

How is Keratoconus Treated?

Keratoconus treatment depends on symptoms. When symptoms  are mild, vision can be corrected with eyeglasses. Later, special hard contact lenses may be required to help keep vision in proper focus. 

Here are other ways to treat advanced keratoconus:
 

• Intacs. This is a small, curved device that an opthalmologist surgically puts in the cornea. Intacs help flatten the curvature of the cornea to improve vision.
   

• Collagen cross-linking. UV light and eye drops are used to strengthen the cornea. Doing this helps to flatten or stiffen the cornea, keeping it from bulging further. 
   

• Corneal transplant. When symptoms are severe, opthalmologist may replace all or part of the diseased cornea with healthy donor cornea tissue.