Keratoconus is a vision disorder affecting the cornea, or clear front covering of the eye. The shape and curvature of the cornea are vital to clear vision, as light passes through the front of the eye and is focused on the retina. Corneas with keratoconus are abnormally shaped or curved and unable to properly focus light on the retina. The result is blurry or distorted vision, as well as other symptoms.
Causes
A normal, healthy cornea is round and shaped like a basketball. When light enters the eye, the cornea is responsible for focusing it on the retina, which sends information to the brain to interpret. A cornea affected by keratoconus starts to thin and bulge into a conical shape. Keratoconus can progress for 10 to 20 years, gradually worsening and distorting vision.
Experts believe that genetics may be to blame for most cases of keratoconus. The disease has also been linked to eye injuries; certain eye conditions such as retinitis pigmentosa, retinopathy of prematurity (ROP) and vernal keratoconjunctivitis; and medical conditions such as Ehlers-Danlos syndrome and Down syndrome.
Symptoms
In addition to blurry, distorted vision, keratoconus symptoms include the following:
- sensitivity to light
- glare
- mild eye irritation
- frequent changes in eye prescription
- inability to wear contact lenses
In rare, serious cases, keratoconus can cause sudden corneal swelling and scarring. The cornea protrudes until a tiny crack forms and as the crack heals, scar tissue develops in its place. This process causes severe visual distortion and blurring.
Diagnosis and Treatment
Keratoconus is diagnosed through an eye examination. Instruments like a slit lamp and tests such as corneal topography may be used to diagnose different forms of the disease. Additional testing, such as keratometry or computerized corneal mapping, may be performed to identify the cornea’s shape.
Once diagnosis is confirmed, there are a few ways to treat keratoconus. Treatment usually depends on the stage and severity of the disease. In mild forms of early keratoconus, eyeglasses may provide sufficient visual correction. As the disease worsens, rigid contact lenses may be recommended to evenly refract light entering the eye for clear vision.
Another treatment option for keratoconus is the placement of Intacs, small implants that reshape the cornea so it can do its job properly. These FDA-approved devices flatten a steep cornea affected by keratoconus. Or, a procedure called collagen cross-linking can also help improve keratoconus. Collagen cross-linking uses a combination of special eye drops and a laser to strengthen the collagen fibers of the cornea. By strengthening the fibers, corneal cross-linking can flatten or stiffen a protruding cornea.
If these treatments do not provide adequate improvement and keratoconus becomes advanced, a corneal transplant may be the best option. This is used in 10 to 20 percent of keratoconus cases.
Talk to Our Eye Doctors about Keratoconus
If you are experiencing troubling visual symptoms, contact our team of eye doctors today to schedule a consultation. We can identify the problem affecting your vision and explain the available treatment options.