Keratoconus can be a progressive eye disease in which the normally symetrical front window of the eye (cornea) thins and begins to bulge into a cone-like shape. This cone shape distorts images as it enters eye the image to the back of the eye (retina), causing distorted vision.
Patients with Keratoconus can occur in one or both eyes and often begins during a person’s teens or early 20s.
Keratoconus Symptoms and Signs
As the cornea becomes more irregular in shape, the eye gets more nearsightedness and the surface is irregular , creating additional problems with distorted and blurred vision. Glare and light sensitivity also may occur.
Often, keratoconic patients can not correct their vision using just their eyeglass prescription..
What Causes Keratoconus?
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.
Risk factors for oxidative damage and weakening of the cornea include a genetic predisposition, explaining why keratoconus often affects more than one member of the same family.
Keratoconus also is associated with overexposure to ultraviolet rays from the sun, excessive eye rubbing, a history of poorly fitted contact lenses and chronic eye irritation.
In the mildest form of keratoconus, eyeglasses or soft contact lenses may help. But as the disease progresses and the cornea thins and becomes increasingly more irregular in shape, glasses and regular soft contact lens designs no longer provide adequate vision correction.
Treatments for moderate and advanced keratoconus include:
Custom soft contact lenses. Recently, contact lens manufacturers have introduced custom soft contact lenses specially designed to correct mild-to-moderate keratoconus. These lenses are made-to-order based on detailed measurements of the person’s keratoconic eye(s) and may be more comfortable than gas permeable (GP) or hybrid contact lenses for some wearers.
For the mild keratoconus patients, gas permeable hard contact lenses has be a option for generations, providing good visual in low-contrast situations, and the soft toric lenses performed equally well in good lighting with comfort.
Gas Permeable lenses works well because it vaults over the cornea, replacing the irregular shape with a smooth, uniform refracting surface to improve vision.
“Piggybacking” contact lenses. As a patient’s keratoconus advances, sometimes the gas permeable contact lens continues to give good vision but can be uncomfortable,a “piggybacking” is applied, where two different types of contact lenses on the same eye. This involves placing a soft contact lens,, over the eye and then fitting a GP lens over the soft lens. This approach increases wearer comfort because the soft lens acts like a cushioning pad under the rigid GP lens.
Your eye care practitioner will monitor closely the fitting of “piggyback” contact lenses to make sure enough oxygen reaches the surface of your eye, which can be a problem when two lenses are worn on the same eye. However, most modern contacts — both GP and soft — typically have adequate oxygen permeability for a safe “piggyback” fit.
ClearKone® Lenses for Keratoconus
Remember when you had only two choices in contact lenses? “Hard” (GP) lenses provided good vision, but were often irritating and uncomfortable. Soft lenses offered good comfort, but couldn’t correct your vision problems. ClearKone was a technological breakthrough that made having to compromise a thing of the past. ClearKone hybrid contact lenses offer all the benefits of gas permeable (GP) and soft contact lenses without any of the disadvantages for an overall GREAT contact lens experience.