Keratoconus is degenerative condition affecting the cornea – the front transparent window at the front of the eye. The condition causes a thinning to the cornea, this causes the shape of the cornea to change to a pointed, more conical shape. As a result, vision becomes blurry and patients usually notice treaks or increases in haloes – particularly at night.
Keratoconus affects 1 in 1000 people and usually affects people of Asian decent.
How is it Best Detected?
Earliest detection is possible with a combination of corneal topography, corneal pachymetry and aberrometry. Corneal topography measures thousands of points on the cornea to accurately calculate the shape of the cornea. Cornea pachymetry enables our Optometrists to calculate the thickness of the cornea. Finally, aberrometry allows our practitioner to measure subtle optical errors responsible to streaks and haloes.
Our keratoconus consultations will allow us to monitor the progression of the condition in order to advise you on the best treatment options.
If you are not having any difficulties with your vision in glasses then the sensible choice is to keep wearing an up-to-date glasses prescription. However, most keratoconic patients cannot see sufficently well in spectacles due to the irregular shape of the cornea.
The best option is then to wear precisely designed keratoconus contact lenses. There can be soft lenses but the most effective lenses are rigid lenses. Rigid gas permeable lenses are also availble in a number of designs and our Optometrists will deteermine the best design during your specialist contact lens consultation.
Our practice is not restricted to using any particular brand, In fact, we able to fit the following types:
Soft Contact Lenses
Ideal for early keratoconus where there is no significant corneal irregularity. Soft lenses are comfortable and offer a great deal of flexibility. As they flex on the eye the cannot accurately correct the irregular shape.
Hybrid Contact Lenses
Ideal for moderate keratoconus where rigid lenses are not tolerated. The outer skirt of the lens is soft (to provide comfort) and the centre is made from a rigid lens material (to correct the corneal irregularity).
Corneal GP Lenses
These are rigid lenses that sit on the cornea. They provide better vision correction than soft lenses. RGP lenses are suitable for moderate to advanced keratoconus. These are probably the most commonly fitted lens.
Semi / Mini Scleral
Semi and mini scleral lenses are gas permeable and rigid. They are comfortable and provide excellent vision. Suitable for moderate and highly advanced keratoconus. See our post on KeraFit lenses.
Can Keratoconus be Stabilised?
If we find that your keratoconus is changing, then we will recommend that you have corneal cross linking treatment. This treatment is available on the NHS. We will arrange a referral (either through the NHS or privately). Corneal cross linking is not suitable for everyone. If your keratoconus has advanced to a stage where the cornea is too thin, then treatment may not be possible.
Corneal Cross Linking (CXL) has been shown to stop the progression of keratoconus in 90% of patients.
Options without Contact Lenses
When contact lenses cannot be tolerated and vision in glasses is reduced, Intra Corneal Ring Segments or ICRS (sometimes referred to as INTACS) may be an option.
Small, thin semi-circular rings are inserted into a small channel created within the cornea. The rings cause the cornea to flatten. They can be used to improve cone centration and lower astigmatism and myopia. After ICRS treatment many patients are able to better tolerate contact lenses.