Keratoconus, progressive eye disease
WHAT IS KERATOCONUS?
KERATOCONUS LITERALLY means a cone-shaped cornea. The cornea (the clear front portion of the eye) becomes thin and protrudes. This abnormal shape can cause severe distortion of vision.
WHAT CAUSES KERATOCONUS?
Research indicates that keratoconus may be caused by an excess of enzymes that break down the proteins in the corneal surface. Keratoconus appears to run in families. The condition happens more often in people with certain allergic eye conditions. The condition could be related to chronic eye rubbing. Most often though, there is no eye injury or disease that explains why the eye starts to change. Keratoconus usually starts in the teenage years but it can begin in childhood or in people over 30 years of age. The changes in the shape of the cornea can happen quickly or may occur over several years. Keratoconus is more common than thought and is often not diagnosed until in the advanced stages.
WHAT ARE THE SYMPTOMS OF KERATOCONUS?
Blurred vision, distortion, glare, light-sensitivity and corneal irritation are among the early signs. As the disease progresses and the cornea steepens and scars, the visual distortion will increase. The changes can stop at any time or they can continue for decades. In most people both eyes are eventually affected although not always to the same extent. To confirm if you have keratoconus your eye exam will include the measurement of the shape of the cornea. This can be done by using various instruments, one of which is a corneal topographer.
HOW IS KERATOCONUS TREATED?
Glasses may be sufficient in the early stages of keratoconus but contact lenses are needed when the cornea becomes so misshapen that glasses are no longer effective. In some cases, the corneal shape becomes even too distorted for contact lenses to help. Scarring may develop, causing the vision to be cloudy. At this stage, a corneal transplant is usually needed.
Corneal transplantation is a major surgical procedure and carries certain risks. There is, however, a relatively new treatment for keratoconus called Corneal Collagen Crosslinking with riboflavin.
A procedure developed in Europe in the late 1990s, Corneal Collagen Crosslinking has now proven itself in international clinical studies and is approved throughout the European Union for the treatment of keratoconus or other corneal ectasias. It was approved by Health Canada in 2008 and is currently undergoing investigation by the FDA in the USA.
Corneal Collagen Crosslinking with riboflavin causes the formation of normal chemical links between the collagen protein strands in the cornea. This strengthens the cornea, making it more rigid and can stop the keratoconus from progressing. The treatment may even cause the keratoconus to reverse to some extent. Corneal Collagen Crosslinking may prevent the need for contact lenses if performed early on. Even where contact lenses are already needed, Corneal Collagen Crosslinking can eliminate the need for corneal transplantation. No other treatment for keratoconus can offer these benefits.
WHO IS A SUITABLE CANDIDATE FOR CORNEAL COLLAGEN CROSSLINKING?
Anyone with progressive keratoconus is potentially suitable. Patients with advanced keratoconus or whose vision is already spoiled by scarring will usually not be good candidates for the procedure. The earlier the treatment is done the better, but Crosslinking can still be beneficial decades after keratoconus has begun to develop.
It is an outpatient procedure and is extremely safe.
Based on the available data, Corneal Collagen Crosslinking offers a treatment for a disease that currently has no real treatment except corneal transplantation. This treatment has been available in Jamaica for the past two years.