Keratoconus can be diagnosed through a routine eye exam. Your eye doctor will review your medical and family history and conduct various tests to check for vision problems and changes in the shape of your cornea. Some common tests to diagnose keratoconus include:
Eye refraction: This test measures your eyes to check for vision problems. You may be asked to look through a device that contains wheels of different lenses (phoropter) or a hand-held instrument (retinoscope) to help judge which combination gives you the sharpest vision.
Slit-lamp examination: This test uses a vertical beam of light and a low-powered microscope to view your eye. Your doctor evaluates the shape of your cornea and looks for other potential problems in your eye.
Keratometry: This test focuses a circle of light on your cornea and measures the reflection to determine the basic shape of your cornea.
Computerized corneal mapping: This test uses special photographic tests, such as corneal tomography and corneal topography, to record images and create a detailed shape map of your cornea. Corneal tomography can also measure the thickness of your cornea. Corneal tomography can often detect early signs of keratoconus before the disease is visible by slit-lamp examination.