Keratoconus is a progressive eye disease in which the normally round cornea thins and begins to bulge into a cone-like shape. This cone shape deflects light as it enters the eye on its way to the light-sensitive retina, causing distorted vision.
Keratoconus can occur in one or both eyes and often begins during a person’s teens or early 20s.
New research suggests the weakening of the corneal tissue that leads to keratoconus may be due to an imbalance of enzymes within the cornea. This imbalance makes the cornea more susceptible to oxidative damage from compounds called free radicals, causing it to weaken and bulge forward.
Signs and Symptoms
- Irregular shaped cornea
- Distored and blurred vision
- Light sensitivity
In the mildest form of keratoconus, eyeglasses or soft contact lenses may help. But as this progresses, glasses and soft contacts no longer provide adequate vision correction.
Treatments for moderate and advanced keratoconus include:
Gas permeable contact lenses.
If eyeglasses or soft contact lenses cannot control keratoconus, then rigid gas permeable (RGP or GP) contact lenses are usually the preferred treatment.
ClearKone hybrid contact lenses.
(SynergEyes Inc., Carlsbad, Calif.) These hybrid contact lenses combine a highly oxygen-permeable rigid center with a soft peripheral “skirt.” The ClearKone version was designed specifically for keratoconus and vaults above the eye’s cone shape for increased comfort.
Topography-guided conductive keratoplasty.
While more study is needed, early results of a small study involving topography-guided conductive keratoplasty (CK) show this procedure might help smooth irregularities in the corneal surface.
This treatment uses energy from radio waves, applied through tiny probes, to reshape the eye’s surface. A topographic “map” created through imaging of the eye’s surface helps create individualized treatment plans.
A corneal transplant may be needed when vision cannot be corrected satisfactorily using other procedures such as contact lenses and glasses, or if painful swelling cannot be relieved by medications. A corneal transplant, also known as a corneal graft, or as a penetrating keratoplasty, involves the removal of the central portion called a button (see left photo) of the diseased cornea and replacing it with clear healthy donor button.