Keratoconus (ker-uh-toe-KOH-nus) occurs when your cornea — the clear, dome-shaped front surface of your eye — thins and gradually bulges outward into a cone shape.
A cone-shaped cornea causes blurred vision and may cause sensitivity to light and glare. Keratoconus usually affects both eyes and generally occurs in people ages 10 to 25. The condition may progress slowly for 10 years or longer.
Vision problems can be corrected with glasses or soft contact lenses early on in the condition. As keratoconus progresses, you may have to be fitted with rigid gas permeable contact lenses or other types of contact lenses. Advanced keratoconus may require a cornea transplant.
Signs and symptoms of keratoconus may change as the disease progresses. They include:
When to see a doctor
If you're considering laser-assisted in-situ keratomileusis (LASIK) eye surgery, make sure your doctor checks for signs of keratoconus before you proceed.
The cause of keratoconus is unknown.
Keratoconus may be associated with:
These factors can increase your chances of developing keratoconus:
In some situations, your cornea may swell quickly and cause sudden reduced vision and scarring of the cornea.
In advanced keratoconus, your cornea may become scarred, particularly where the cone forms. A scarred cornea causes worsening vision problems and may require corneal transplant surgery.
The effect of ongoing vision problems on your daily life also can lead to anxiety. However, finding ways to adapt to your condition can lessen anxiety.
Preparing for your appointment
If you're having difficulty with your vision, you'll likely start by seeing an eye doctor (ophthalmologist). If your eye doctor determines that you may need a cornea transplant, you may be referred to an ophthalmologist who has had special training in corneal surgery.
Because appointments can be brief and there's often a lot to talk about, it's a good idea to be prepared. Here's some information to help you get ready, and what to expect from your eye doctor.
What you can do
Your time with your doctor is limited, so preparing a list of questions will help you make the most of your time together. List your questions from most important to least important in case time runs out. For keratoconus, some basic questions to ask your doctor include:
In addition to the questions that you've prepared to ask your doctor, don't hesitate to ask questions during your appointment.
What to expect from your doctor
Tests and diagnosis
To diagnose keratoconus, your eye doctor (ophthalmologist) will review your symptoms and medical history and conduct a routine eye examination. Your eye doctor may conduct other tests to determine the exact shape of your cornea. Tests to diagnose keratoconus include:
Treatments and drugs
Treatment for keratoconus depends on the severity of your condition and how quickly the condition is progressing.
Mild to moderate keratoconus can be treated with eyeglasses or contact lenses. For most people, the cornea will become stable after a few years. You often won't experience severe vision problems and require further treatment.
In some people with keratoconus, however, the cornea becomes scarred or wearing contact lenses becomes difficult. In these cases, surgery might be necessary.
If you're using rigid or scleral contact lenses, make sure to have them fitted by an eye doctor with experience in treating keratoconus. You'll also need to have regular checkups and refittings because a poor-fitting hard contact lens can damage your cornea.
After having riboflavin drops applied to your cornea, you're exposed to ultraviolet A (UVA) light. The procedure strengthens the cornea to prevent further thinning or bulging. The treatment is still in the testing phase in the United States, and additional study is needed before it becomes widely available.
Last Updated: 2013-02-20
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