Keratoconus is a condition in which the cornea (the clear front of the eye) becomes thin and protrudes. Keratoconus literally means “conical cornea”. This abnormal shape can cause serious distortion of vision.
Research shows that Keratoconus may be due to an excess of enzymes that break down proteins at the corneal surface, causing the cornea to become thin and protrude.
The genetic inheritance of Keratoconus has not been clearly established. It appears that it covers a number of different genes. Relatives of someone affected by Keratoconus, may show small changes in the cornea. This indicates that Keratoconus probably has different genetic causes, that may ‘show itself’ in different ways.
Vigorous eye rubbing may contribute to the disease process. People with Keratoconus should avoid rubbing their eyes. This is sometimes very difficult because some allergies that cause itchy, irritated eyes, are more commonly associated with Keratoconus patients.
Blurring and distortion of vision are the earliest symptoms of Keratoconus. Symptoms usually occur in the late teens or early twenties. The disease will often progress slowly for 10 to 20 years, and then stop.
In the early stages, vision may be only slightly affected, causing glare, light sensitivity and irritation. Each eye may be affected in different ways. As the disease progresses and the cornea bulges, vision may become distorted.
A sudden decrease in vision can occur when the cornea swells suddenly. The swelling may persist for weeks or months, then slowly heals, after which it is gradually replaced by scar tissue.
Several studies have already demonstrated the effectiveness of this treatment. Most treated corneas showed increased stability, and improved vision.
One particular study showed that in a group of 64 eyes no patient scored worse than before surgery. On average, the improved vision without glasses was 1/10., and by wearing glasses it improved with an average of 1.5/10. On average, the patients were also 1.5 D less myopic, evidence that the cornea slightly flattens by the treatment.
It is important to understand that cross linking, unlike other laser therapies, will not completely correct nearsightedness, farsightedness or astigmatism. After the treatment, in most cases there is still a correction needed: usually hard contact lenses, sometimes only soft contact lenses or glasses. The advantage of this technique is that a corneal transplant, with its delayed healing process and ever-changing refraction, may be postponed or at best be avoided