What are the symptoms? Reduced clarity of vision: An eye test will reveal increased astigmatism (spectacle prescription needed when the eye is more rugby ball shaped rather than spherical). The vision worsens as the astigmatism becomes more irregular and spectacles become less effective. What are the causes? The cornea becomes stretched and thin near its centre and bulges resulting in increased short-sight, astigmatism and distorted vision. Keratoconus is often associated with atopic conditions (asthma, eczema, hayfever) and can be made worse if the eyes are itchy and rubbed a lot. It can be associated with other conditions, such as Down syndrome or it can have a genetic cause and affect other members of the family. How is it diagnosed? It is diagnosed using a slit lamp (special microscope) and with corneal topography (surface mapping) which shows the irregular corneal contour. How is it treated? People with early or mild keratoconus can often manage with spectacles or soft contact lenses but if it is more advanced, rigid contact lenses are usually necessary to improve the vision. Contact lenses do not slow down the rate of progression but they provide good vision while being worn. If the eyes are itchy, eye rubbing should be avoided and if necessary, treatment such as antiallergy eye drops or medication should be used. As well as correcting the vision, regular topography scans (corneal mapping) should be carried out. If the keratoconus is becoming worse, a treatment called corneal cross-linking (CXL) may be advisable. CXL is a procedure where the cornea is treated with riboflavin (Vitamin B2) eye drops and ultraviolet light in order to strengthen it and slow down or halt the changes. However, CXL is not suitable for everyone and it may not prevent keratoconus from progressing. In a small percentage of cases, where keratoconus is advanced and contact lenses are either not tolerated or do not improve the vision sufficiently, the cornea may need to be replaced surgically with a corneal transplant or graft. Contact lenses are frequently needed after a corneal transplant to achieve good vision. Inheritance patterns and prenatal diagnosis Inheritance patternsThe causes of keratoconus are thought to be a combination of environmental and genetic, the latter being multi-factorial. Many cases are sporadic but some are known to be familial. Prenatal diagnosisNot applicable. Is there support? Keratoconus Self Help and Support Group Tel: 020 8993 4759Email: firstname.lastname@example.org Website: keratoconus-group.org.uk A Registered Charity in England and Wales No. 1057629. It provides information and support for people with Keratoconus in the UK. The Group organises regular meetings for members, holds a bi-annual conference, raises money for research and works to raise awareness of the condition. Group details last updated October 2019.