Keratoconus
Keratoconus causes
Researchers believe keratoconus is probably caused by a combination of genetics and other factors such as ethnicity, age and gender. In other words, some people are genetically more likely to get it, but they might not actually develop keratoconus unless it’s triggered by something like rubbing your eyes or wearing contact lenses. Other people with different genes can rub their eyes or wear contact lenses and not develop keratoconus.³
Keratoconus can also be triggered by wearing contact lenses, or by conditions such as hay fever, eczema, allergic asthma, or sleep apnea.³
It affects people from all ethnic groups, although it may be more common in people of South Asian descent.² Keratoconus is more likely to develop in teenagers or young adults than in other age groups.³ If you’ve already got keratoconus, it’s likely to get worse until your mid-thirties. However, after this it can slow down or stop.²
Keratoconus is relatively rare and affects about 1 in 2000 people.² Because of the genetic link, you’re more likely to develop keratoconus if you have a family member with it.²
Living with keratoconus
Keratoconus can often be corrected by wearing glasses or contact lenses, especially in the early stages. As the cornea becomes more distorted over time, glasses and soft contact lenses may no longer help and you may need to wear hard contact lenses, also called rigid gas-permeable lenses. Some of these are shaped especially for people with keratoconus.² If you find hard contact lenses uncomfortable, there are options available including hybrid contact lenses, which have a hard centre with a soft outer ring. Soft contact lenses can also be worn under the hard contact lens to cushion your eye against it.²
If you have keratoconus and wear glasses or contact lenses to correct it, you may need to change your prescription more often than usual. This is because your cornea is thinner and more flexible, so it can change shape more quickly.²
If your keratoconus is getting worse, you will keep needing stronger lenses to correct it. This means they will be thicker, heavier and might distort your vision at the edges.² Another difficulty with wearing contact lenses for keratoconus is that you might be more likely to develop dry eye. This is a risk for anyone who wears contact lenses, but can be worse if you have keratoconus. This is because the uneven cornea makes it more difficult for your eyelids to spread tears across the surface of your eye evenly.² If you suffer from dry eye, you may be able to treat it with artificial tear eye drops.²