Keratoconus is a condition that affects the front window of the eye, the cornea.
The cornea is usually relatively flat and strong, but in keratoconus, weakening occurs and the cornea takes up a shape which is thinner and more pointed as a result.
The change in shape causes a change in the way the light is focused on the retina. The image becomes scattered and so the vision is blurred. Because the onset of keratoconus is so slow, it rarely carries any symptoms in Down's syndrome until the moderate stages. These symptoms might be poor distance vision, holding reading materials closely, eye rubbing, or sensitivity to light.
It is particularly important that these symptoms are investigated in any young person with Down's syndrome who is in their teens or twenties, as this is usually the time that keratoconus can progress more rapidly.
A new treatment for keratoconus now exists, if the condition is picked up early and before the cornea becomes too thin. Because the normal Down's syndrome cornea is 15% thinner to begin with, monitoring keratoconus is particularly important in this group of young people.
Some people have keratoconus and do not require any surgical treatment, but wear contact lenses or glasses to improve vision in stable keratoconus. They are likely to be very short-sighted and yet still have some blurry vision and sensitivity to light.
Stephanie Campbell is particularly interested in the reasons why keratoconus seems much more common in people who have Down's syndrome than in people who don't. Her research studies aim to characterise a map of the typical Down's syndrome cornea, so that optometrists and doctors can pick up early keratoconus more easily.
Collagen is the building block of skin, and surprisingly, also the building block of the eye. The special arrangement of collagen in the eye is what allows it to be transparent, and particularly strong. Stephanie studies the collagen in a model of Down's syndrome, and its impact upon sight, in order to try and understand the underlying disease process.
Ultimately, the aim of this work is to make treatment of this condition more effective, and help protect the sight of young people with keratoconus so that they do not require corneal transplants later in life.