Eye Health and Keratoconus
How Is Keratoconus Diagnosed?
Keratoconus changes vision in two ways:
- As the cornea changes from a ball shape to a cone shape, the smooth surface becomes slightly wavy. This is called irregular astigmatism.
- As the front of the cornea expands, vision becomes more nearsighted. That is, only nearby objects can be seen clearly. Anything too far away will look like a blur.
An eye doctor may notice symptoms during an eye exam. You may also mention symptoms that could be caused by keratoconus. These include:
- Blurred vision
- Double vision when looking with just one eye
- Objects both near and far looking distorted
- Bright lights looking like they have halos around them
- Lights streaking
- Seeing triple ghost images
To be sure you have keratoconus, your doctor needs to measure the curvature of the cornea. There are several different ways this can be done.
One instrument, called a keratometer, shines a pattern of light onto the cornea. The shape of the reflection tells the doctor how the eye is curved. There are also computerized instruments that make three-dimensional "maps" of the cornea.
How Is Keratoconus Treated?
Treatment usually starts with new eyeglasses. If eyeglasses don't provide adequate vision, then contact lenses, usually rigid gas permeable contact lenses, may be recommended. With mild cases, new eyeglasses can usually make vision clear again. Eventually, though, it will probably be necessary to use contact lenses or seek other treatments to strengthen the cornea and improve vision.
A cornea transplant can be used to treat advanced keratoconus when good vision cannot be obtained with any other means. This involves removing the center of the cornea and replacing it with a donor cornea that is stitched into place.