Keratoconus is a rare eye condition that alters the structure of the cornea, changing its gradual curve into a thinner and more conical shape. These changes affect the clarity of your vision and the condition can progress over time. The onset of Keratoconus is usually in adolescence.
Research suggests that it affects between 1 in 1000 and 1 in 3000 people – although there is difficulty pinning down the exact rate of occurrence because symptoms can overlap with other similar conditions.
SIGNS AND SYMPTOMS
Symptoms of keratoconus can include:
Slight blurring of vision.
Poor vision in low lit conditions, or when you are tired.
A halo or ‘ghost’ effect when looking at bright lights.
Sensitivity to light.
Many of these symptoms are common among different eye conditions, so it is essential to be evaluated by a specialist in order to diagnosis keratoconus or other complaints.
WHAT CAUSES KERATOCONUS?
There is no scientific consensus on what causes keratoconus, the fact that it occurs more frequently in certain ethnic groups – such as people from Asia – suggests the causes are genetic. Existing evidence would imply that there is less than a 10% chance of a family member of someone with keratoconus also being a sufferer. Considering the condition is also quite rare you are unlikely to have a family member who is affected.
There are also hypotheses that environmental factors can aggravate or bring on the condition – particularly vigorous rubbing of the eyes. Many sufferers also have allergies such as hay fever, asthma, or eczema – it may be this is what stimulates the need to rub the eyes or there may be another causal factor. Although these theories remain unproven, it is recommended to avoid persistent rubbing of your eyes.
HOW DO YOU TREAT KERATOCONUS?
There are various treatments for keratoconus depending on the severity. Although none of them can reverse the effects of the condition, they can help correct distorted vision. In extreme cases, surgery may be required.
Spectacles/contact lenses- Initially, these may be used to correct astigmatism or myopia caused by keratoconus, usually in the early stages when damage is limited.
Rigid Gas Permeable (RGP) Contact Lenses- These form a rigid material over the lens which replaces the distorted cone shape of the cornea with a smooth refracting surface.
Intrastromal corneal ring segments (INTACS)- These are small plastic rings that are inserted into the middle of the cornea’s many layers. They force the conical shape of the cornea to transform, flattening it out into its original, gradual curve.
Corneal Crosslinking (CXL)- A relatively new treatment, the point of which is to increase the rigidity of the cornea – it is only useful in stopping the deterioration of the cornea, once it becomes too thin CXL is no longer useful.
Corneal Transplant- In a minority of cases, keratoconus may become so severe that glasses or contact lenses cannot correct the distorted vision. A surgeon will graft a donor cornea to the existing eye tissue of the patient. Recovery takes around 1-2 months and according to the National Keratoconus Foundation, the success rate of surgery is 95% or greater when performed on an otherwise healthy eye.