Keratoconus is a deterioration of the cornea whose cause is unknown, resulting in gradual bulging from the normal round shape to a cone shape. This condition causes decreased visual acuity. It is frequently discovered during adolescence.

Keratoconus is more common in contact lens wearers and people with nearsighted eyes. Some researchers believe that allergies may play a role.

The earliest symptom is subtle blurring of vision that is not correctable with glasses. (Vision is generally correctable to 20/20 with gas-permeable contact lenses.)

Keratoconus can usually be diagnosed with slit-lamp examination of the cornea. Early cases may require corneal topography, a test that involves making a stereo image that gives a topographic map of the curvature of the cornea.

When keratoconus is advanced, the cornea may be thinner in areas. This can be measured with a painless test called pachymetry.

Treatment

Contact lenses are the primary treatment and are satisfactory treatment for most patients with keratoconus. Severe cases may require corneal transplantation. We also use Intacs in several of our patients using the IntraLase laser to form the channels.

In most cases vision can be corrected with gas-permeable contact lenses. Where corneal transplantation is needed, results are usually good after a long recovery period.