Keratoconus is a condition which causes reduced vision due to a more extreme degree of astigmatism (where the front of the eye is shaped a little like a rugby ball as opposed to a football). Keratoconus is derived from the Greek words: kerato, meaning cornea, and konos, meaning cone. The cornea becomes distorted with a cone-shaped bulge.
Keratoconus affects approximately 1 in 2000 of the population, presenting mainly in the late teens or early 20s and remains the commonest indication for corneal transplantation in this age group.
Progression of the condition depends on many factors but includes the age at the time of the onset. The earlier the onset, the faster keratoconus progresses.
The condition almost always affects both eyes, with one eye usually more affected than the other.
What causes Keratoconus?
The precise cause of Keratoconus is unknown. We do however, know that there are several risk factors for its development. These include: hereditary factors, excessive eye rubbing, certain underlying disorders such as Downs Syndrome. Affected patients often suffer from allergic eye disease. Keratoconus can be managed with a variety of techniques including the following:
1. Spectacles in the early stages of the disorder
2. Hard contact lenses when spectacles are no longer helpful
3. Corneal collagen cross linking (CXL) with Riboflavin which increases the strength of the cornea to prevent progression of the keratoconus
4. Intrastromal rings (Intacs)
5. Corneal transplantation – deep anterior lamellar keratoplasty (DALK) or full thickness penetrating keratoplasty (PK) for more advanced stages.
The main treatment that Face & Eye recommends for keratoconus is Accelerated Collagen Cross-Linking (KXL).
This is a technique which uses an intense ultraviolet light (UVA) source and a photosensitising chemical (Riboflavin) to create increased linkages (cross-linking) between the cornea’s collagen fibres. This technique has been shown to be extremely successful in arresting the progression of (i.e. stabilising) the condition and occasionally even producing small improvements.