To diagnose keratoconus, your eye doctor (ophthalmologist or optometrist) will review your medical and family history and conduct an eye exam. He or she may conduct other tests to determine more details regarding the shape of your cornea. Tests to diagnose keratoconus include:
- Eye refraction. In this test your eye doctor uses special equipment that measures your eyes to check for vision problems. He or she may ask you to look through a device that contains wheels of different lenses (phoropter) to help judge which combination gives you the sharpest vision. Some doctors may use a hand-held instrument (retinoscope) to evaluate your eyes.
- Slit-lamp examination. In this test your doctor directs a vertical beam of light on the surface of your eye and uses a low-powered microscope to view your eye. He or she evaluates the shape of your cornea and looks for other potential problems in your eye.
- Keratometry. In this test your eye doctor focuses a circle of light on your cornea and measures the reflection to determine the basic shape of your cornea.
- Computerized corneal mapping. Special photographic tests, such as optical coherence tomography and corneal topography, record images of your cornea to create a detailed shape map of your cornea's surface. The tests can also measure the thickness of your cornea.
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 many people, the cornea will become stable after a few years. If you have this type, you likely won't experience severe vision problems or require further treatment.
In some people with keratoconus, the cornea becomes scarred or wearing contact lenses becomes difficult. In these cases, surgery might be necessary.
- Eyeglasses or soft contact lenses. Glasses or soft contact lenses can correct blurry or distorted vision in early keratoconus. But people frequently need to change their prescription for eyeglasses or contacts as the shape of their corneas change.
- Hard contact lenses. Hard (rigid, gas permeable) contact lenses are often the next step in treating progressing keratoconus. Hard lenses may feel uncomfortable at first, but many people adjust to wearing them and they can provide excellent vision. This type of lens can be made to fit your corneas.
- Piggyback lenses. If rigid lenses are uncomfortable, your doctor may recommend "piggybacking" a hard contact lens on top of a soft one.
- Hybrid lenses. These contact lenses have a rigid center with a softer ring around the outside for increased comfort. People who can't tolerate hard contact lenses may prefer hybrid lenses.
- Scleral lenses. These lenses are useful for very irregular shape changes in your cornea in advanced keratoconus. Instead of resting on the cornea like traditional contact lenses do, scleral lenses sit on the white part of the eye (sclera) and vault over the cornea without touching it.