Health Tips

Not only eyes are the window to the soul, they’re also a body part with intricate structures. In a normal eye, the cornea has a perfect structure that functions like a window that controls and focuses the entry of light into the eye. However, in a condition known as keratoconus, the cornea develops into a ‘weird’ shape that may affect vision and cause sensitivity to light and glare.

Signs and symptoms of keratoconus

Signs and symptoms of keratoconus may change as the disease progresses. They include:

• Blurred or distorted vision

• Increased sensitivity to bright light and glare, which can cause problems with night driving

• A need for frequent changes in eyeglass prescriptions

• Sudden worsening or clouding of vision

Differences between a normal eye and keratoconus

In a normal eye, the cornea is supposed to shape like a dome. However, keratoconus causes the cornea to thin out and gradually bulge outward into a cone shape:

Image credit: Mayo Clinic

This seemingly small change in the shape of the cornea can actually have a huge impact on a person’s vision. Patients may present with blurry vision or a sudden decrease in visual acuity. 

While the exact cause is unknown, it was found that in keratoconus, the collagen content in the cornea is lower compared to normal cornea. The scientists looked closer and found that the molecular structure of the collagen in a keratoconic cornea also demonstrates abnormality. The corneal thinning seen in keratoconus is possibly the result of a degradation process that results in the loss of structural elements of the cornea, much like a poorly built buildings:

Keratoconus usually affects both eyes, though it often affects one eye more than the other. It generally begins to affect people between the ages of 10 and 25. The condition may progress slowly for 10 years or longer.

Treatment of keratoconus

In the early stages of keratoconus, you might be able to correct vision problems with glasses or corrective contact lenses. A large portion of patients with keratoconus can be managed with contact lenses for an extended period of time. 

However, as the disease progresses, corrective lenses may be difficult to fit and require frequent changes due to progressive nearsightedness and irregular astigmatism. A therapy known as collagen cross-linking is recommended for managing progressive keratoconus.

Collagen cross-linking

Collagen cross-linking is a procedure that uses riboflavin drops, ultraviolet light, and a photosensitizer to strengthen bonds in the cornea. This helps to stop or slow down the progression of keratoconus.

Corneal transplant

Corneal transplant, also known as keratoplasty, is the only option in the advanced stage of keratoconus. Approximately 10 to 15 percent of patients with keratoconus will require keratoplasty. Good news is, this procedure has a very high success rate among patients with keratoconus.

A word from DOC2US

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Cover image credit: Photo by Brands&People on Unsplash

Written by

Ms Joyce Toh