Keratoconus: treatment, symptoms, causes and corneal cross-linking

Moorfields says that in most cases vision can be improved. Early on, this usually means spectacles or soft contact lenses, and as the disease progresses hard contact lenses are often required. In very advanced cases, where contact lenses no longer work, a corneal transplant may be needed to restore vision.

Moorfields explains that in the past up to about 20% of patients needed a transplant at some point in their life, but corneal cross-linking now allows doctors to intervene early to stop vision loss.

Moorfields describes corneal cross-linking (CXL) as a treatment that prevents keratoconus getting worse. The surface layer of the cornea is gently brushed clear, riboflavin (vitamin B2) drops are applied for at least 10 minutes, and ultraviolet light is then shone for 8 minutes. The light and riboflavin react to create cross links that make the cornea stiffer. It is done as a day case under anaesthetic drops, with no needles or injections, and a soft contact lens is placed on the eye as a bandage until the follow-up visit.

Moorfields says CXL is successful in more than 90% of cases, and that it does not cure keratoconus but locks in the shape the cornea has at the time of treatment. After treatment you will still need glasses or contact lenses. Some people get an improvement in shape and vision, which Moorfields calls a bonus.

Moorfields says the eye will be sore for a few days, vision is often hazy at first and most patients can return to work after one week. It says CXL is safe, but there is a small chance (less than 3%) of reduced vision afterwards.

Moorfields lists worsening vision causing frequent changes to prescription, blurring or clouding of vision, and sensitivity and glare from bright lights. It says early stages can be detected by a local optometrist, and that vision is often unaffected in the very early stages.

The change in shape affects focus, causing short sight (myopia) and astigmatism. In advanced cases some patients develop scarring in the cornea, which can make sight blurred by reducing the light entering the eye.

Moorfields says a small number of patients may experience a sudden, painful loss of vision if fluid from the eye enters a very thin cornea, called hydrops, which settles with time.

Moorfields says the exact cause remains unknown, though both genetic and environmental factors are believed to have an impact. It estimates that around 1 in 10 people with keratoconus have a first-degree family member also affected, but says it is not typically considered an inherited disease.

It says keratoconus occurs more commonly in people with certain allergic conditions, including asthma and eczema, and is more likely to develop in non-Caucasian ethnicity groups. It says the latest research shows keratoconus is much more common than previously thought, although many cases are mild.

Moorfields says that after CXL, evidence shows more than 90% of patients remain stable, but you are monitored for a total of five years. At its stable monitoring clinic, appointments include a vision test and a series of eye scans, and if results are stable you are written to with the details of your next appointment. After about five years of stable results you are discharged back to your community optometrist.

For people not yet treated, Moorfields runs an early keratoconus clinic to diagnose and monitor those with keratoconus to see if they are progressing, using corneal scans, vision tests and spectacle prescription. If a change occurs, it says patients can normally be listed for CXL within a few weeks.

Keratoconus is usually first suspected by a community optometrist, who refers on to a hospital eye service for corneal scans and consideration of cross-linking. Hospital services monitor those who need it and treat progression on the NHS.

Moorfields states that treatment is also available privately, either self-funded or through private medical insurance. Contact lens fitting for keratoconus is often specialist work, and it is reasonable to ask which lens type suits your stage.