Keratoconus is a condition affecting the cornea of the eye. This is the clear front surface of the eye. 'Keratoconus' literally means 'conical cornea' and describes a cornea that has thinned and distorted into a cone shape. As this is the major focussing surface of the eye this distortion affects your vision.
The incidence of keratoconus is approximately 1 in 2000 and often begins during puberty. It tends to progress slowly and then stabilises, although the degree of progression is different for each individual. The cornea may also become scarred over time.
The symptoms of early keratoconus are generally much the same as that of someone needing glasses - objects appear out of focus and blurred. The difference is that when you visit your optometrist to have your eyes tested, spectacle lenses often do not allow sharp focus, even with the best possible lenses in front of your eyes.
If we suspect you have keratoconus, we will test you using an instrument called a topographer. This will show us a 'map' of your cornea and highlight any areas that are distorted. There are different types of keratoconus and this 'mapping' gives us as much information as possible so we know how best to treat it.
There is no treatment that will cure keratoconus but it can be successfully managed. We mainly concentrate on improving the distorted vision, and quite often the most successful way to do this is to use Rigid Gas Permeable (RGP) contact lenses. As the name suggests, these have a rigid structure unlike the more common Soft contact lenses which are very flexible. The rigid contact lens can 'vault' over the cornea creating a smooth, uniform surface which enables the eye to focus better.
In very severe cases of keratoconus, a corneal transplant may be considered. This is usually recommended in cases where the cornea has become very scarred and is no longer clear in the centre. If this occurs, contact lenses no longer help as the scarring will physically obstruct good vision.
There is also a relatively new procedure called corneal collagen cross-linkage. This is performed by an Ophthalmologist and requires local anaesthesia. It involves the application of Riboflavin drops to the eye and then exposing it to ultraviolet light. This aims to stabilise the cornea and so prevent further changes to its shape.