What is it?

Keratoconus is a condition that affects the cornea, the clear front surface of the eye. The cornea becomes thinner and more cone-shaped over time, instead of having a rounder curve. The change of shape causes blurred and distorted vision in the early stages, whilst in the late stages there can be an increase in blurred and distorted vision, poor night vision, halos and ghosting around lights. 

The number of people affected with keratoconus varies across studies and countries with between 1 in 375 and 1 in 1,750. Keratoconus is most common in people of Asian heritage.

A cartoon of a person's eye in profile sowing the cornea as cone-shaped instead of round.

The cornea becomes cone-shaped in keratoconus

  • Causes

    We don't fully understand what causes keratoconus. We know that genetic factors play a role and that some people have a family history of the condition and are more likely to develop it. But even so it's hard to predict who in the family might be affected. Individuals usually begin to experience the first symptoms of the condition in their teens or 20s.

    Keratoconus can develop in people that have no other illnesses or health conditions or it may occur more frequently in individuals who have other genetic conditions such as Down syndrome, Marfan syndrome and Leber congenital amaurosis and individuals with asthma and eczema.

  • Symptoms

    Keratoconus usually starts in teenage years with increasing short-sightedness (myopia) and astigmatism.

    Keratoconus in the early stages of the condition may cause blurred or distorted vision. Other symptoms include frequent changes in eye glass prescription, increased sensitivity to bright lights, double vision and halos around bright lights. The condition will eventually lead to further short-sightedness. Keratoconus rarely leads to permanent vision loss. Although 15-20% of those with keratoconus ultimately require corneal transplant surgery – which has risks.

    It’s important to be assessed by an ophthalmologist early on as there are new treatments available that can stop keratoconus progressing.
  • Treatments

    Treatments for keratoconus aim to improve vision. Glasses or soft contact lenses help in the early stages but if the condition gets worse, custom-made contact lenses may be needed.

    Corneal transplant surgery may be needed for advanced cases. This involves removing the damaged cornea and replacing it with a healthy one from a donor. Other types of surgery may also be possible, such as corneal implants, where a plastic ring is inserted into the cornea to help flatten the shape.

    A treatment called ‘collagen cross-linking’ can stop keratoconus from progressing. A solution of vitamin B2 (riboflavin) is applied to the eye and then activated with UV-A light. Together they cause the fibers of the cornea to cross-link, strengthening the tissue of the cornea.

    Collagen cross-linking is only recommended where the shape of the cornea is continuing to deteriorate and the cornea is still of sufficient thickness. See an ophthalmologist to find out if cross-linking is needed.
  • Research

    There are several options for treating keratoconus but they may not always be right for an individual or may not be successful for some people. So it's important to understand more about what causes keratoconus to develop better treatments. We also need research to improve the way we detect the condition.

    Read our research projects


  • Personal stories

    Elizabeth Keell was diagnosed with keratoconus in 1995.

    Elizabeth began to struggle seeing the board at school and started to develop severe headaches and reluctantly booked an eye test.

    At the opticians they could tell there was a huge deterioration in Elizabeth’s sight and she needed glasses. Wearing the glasses Elizabeth was still struggling with her sight and was referred to a hospital for further testing. Following this she was diagnosed with the condition

    Elizabeth said: “I was shocked with my diagnosis because I didn’t really know what it was and I wasn’t sure what was going to happen.”

    Currently Elizabeth’s vision is okay but her left eye is deteriorating much faster than her right eye. She has been recommended to have a cornea transplant, however Elizabeth is extremely hesitant to have this procedure. Although she understands if the deterioration continues this will be her only option.

    Elizabeth is still under the care of the same ophthalmologist at the hospital, who has been through her fight for sight journey.

    Elizabeth said: “Eye research is so important to me, because I have two small children and if it is a genetic disease, it could be likely that one of my daughters may develop keratoconus. So it’s crucial to find new less invasive treatments that can help save people’s sight.”

  • Clinical trials

    You could play an important part in eye research by being a participant in clinical research study that may benefit many people. You could even help shape clinical research by becoming more actively involved and having a say. Patients, carer, or anyone with an interest can help.

    What are clinical trials

    Clinical trials are research studies that find out if a medical strategy, treatment, or device is safe and effective for humans. They are a key research tool for improving medical knowledge and patient care. The people who carry out research are mostly the same doctors and healthcare professionals who treat people. Their aim is to find better ways of treating patients and keeping people healthy.

    Taking part

    Here are some ways to find out about research projects and clinical trials that you can get involved in.

    UK Clinical Trials Gateway

    The UK Clinical Trials Gateway run by the National Institute for Health Research (NIHR) provides easy to understand information about clinical research trials running in the UK, and gives to a large range of information about these trials. It is designed to enable patients and clinicians to locate and contact trials of interest. Visit their website and select the eye condition that you are interested in.

    NIHR Clinical Research Network Portfolio

    The NIHR Clinical Research Network Portfolio is a database of high-quality clinical research studies in England, Northern Ireland, Scotland and Wales. Within this the Ophthalmology Specialty Group supports a national portfolio of research studies in ophthalmology and the vision sciences. See their website for details.

    If you wish to join a trial it is always best to discuss this with your doctor or clinical team first.

Last updated November 2017
Approved by Prof Colin Willoughby, University of Liverpool

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