Keratoconus

Keratoconus is a condition of the cornea that causes it to thin and develop a cone-shaped bulge. It causes blurred vision and can produce sensitivity to light. Its prevalence varies among populations and can be as high as 1.2% in Europeans.

Keratoconus usually begins to develop between the late teens and thirties, and most commonly affects both eyes.

The causes are unknown, although genetic and environmental factors are involved in its development. It is estimated that about 1 in 10 people have a family history of keratoconus and the environmental risk factors described to date are:

• Rubbing the eyes vigorously on a regular basis.
• Presence of ocular allergies.
• Having certain conditions such as retinitis pigmentosa, Down syndrome, Ehlers-Danlos syndrome, Marfan syndrome, hay fever and asthma.

Keratoconus usually affects both eyes, although it can produce different symptoms in both eyes. Symptoms appear progressively and among the most common are:

• Blurred vision
• Slightly distorted vision where straight lines may appear crooked or wavy.
• Increased sensitivity to light
• Redness or swelling of the eyes
• Aggravation of nearsightedness and/or astigmatism
• Poorly fitting contact lenses

There are no effective measures to prevent the onset of keratoconus, although controlling ocular allergies and avoiding rubbing the eyes may help prevent its aggravation. Once it has developed, contact lenses are the main treatment, although they do not stop the progression of the condition. The only effective surgical treatment to date is corneal transplantation.