What is Keratoconus?
Keratoconus (also known as Pellucid) is a progressive non-inflammatory disorder that causes a characteristic thinning and cone-like steepening of the cornea. This steepening results in distortion of vision, increased sensitivity to glare and light and an associated reduction in visual acuity. These symptoms usually appear in the late teens and early twenties.
Keratoconus may progress for 10-20 years and then can slow or even stabilize. Each eye can be affected differently. This can result in a dramatic decrease in the ability to see clearly even with corrective lenses.
New research shows that Keratoconus is much more common today than it was in past. Years ago, Keratoconus occurred in 1 in 2000 people, now it is 1 in 500, a 400% increase. No one is sure why there was been such an increase in Keratoconus, but this is concerning.
As the cornea develops an irregular shape, symptoms include progressive nearsightedness, blurred vision and sensitivity to light and glare.
Frequent prescription changes to spectacles are often needed with every visit to the optometrist.
Patients also tend to excessively rub their eyes, have difficulty seeing at night and often get headaches.
The cause of the weakening is due to an imbalance of enzymes within the cornea itself that leads to high levels of damaging “reactive species” chemicals. Different types of reactive species include super-oxides, hydrogen peroxide, and nitric oxide. These substances essentially are free radicals that cause oxidative damage to the cornea.
Spectacles or soft contact lenses may be used to correct the mild short-sightedness and astigmatism in the early stages of keratoconus. As the disorder progresses and the cornea continues to thin and change shape, rigid gas permeable (RGP) contact lenses can be prescribed. The contact lenses must be carefully fitted and frequent checkups and lens changes may be needed to achieve and maintain adequate vision.
It is also possible to have a corneal graft, or transplant, where the cornea is removed and replaced with a healthy cornea from a donor eye. Results can be mixed and are often only performed in latter stages of the condition.
It is not uncommon to develop intolerance to RGP contacts characterized by foreign body sensations, light sensitivity, irritation, and discomfort. Corneal scarring occurs in more advanced cases and further reduces vision. Until now a corneal transplant (penetrating keratoplasty) was the only option available to advanced Keratoconus patients.
One method to stop the worsening of Keratoconus is with corneal crosslinking treatment.
Some patients take a “wait and see” approach with Keratoconus. The risk of waiting is that as the cornea continues to bulge out and get worse, the back layer of the cornea can rip open. When this happens to the progressively bulging cornea, the internal eye liquid rushes in and swells up the cornea the same way a dry sponge soaks up water and becomes very thick.
Corneal Collagen Crosslinking with Riboflavin is a groundbreaking treatment developed by Dr. Brian Boxer Wachler. The eye practitioner applies a solution rich with vitamins onto the eye and is stimulated with a special UV light. The procedure rebuilds weakened collagen and helps strengthen the cornea to halt progressive loss of vision, while preserving current vision.
