Keratoconus occurs when the clear part at the front of the eye, which we call the cornea, starts to weaken and become progressively thinner. This causes it to develop a cone-like bulge and become irregular in shape. This usually develops in your mid to late teens or early twenties and often stabilises in mid- thirties. The incidence can vary depending on ethnicity but can be anything from 1 in 500 to 1 in 2000. In a small percentage of people there can be a family history of the condition, and there can be a link to people who have atopic conditions such as asthma, eczema and hay-fever. It is thought that it may be linked to eye rubbing which often occurs in people with allergies. It usually occurs in both eyes but can occasionally occur in one eye.
The symptoms can include reduced vision and distortion of vision, frequent changes in prescription, especially increased astigmatism, and increased sensitivity to light.
Current research shows that there are tiny fibres within the cornea that are responsible for maintaining the shape of the cornea. When these fibres become weak, due to an imbalance of enzymes, the cornea starts to bulge and become more cone shaped.
In the early stages Keratoconus can be managed with spectacles, as the condition progresses, it becomes more difficult to correct with spectacles and contact lenses give a better level of vision. Newer treatments are available now, particularly in the earlier stages, and if the condition is progressing. This is known as collagen cross linking which helps to strengthen the cornea and stabilise the condition. Other treatments are available such as INTACS which are small clear plastic arc shaped implants which are inserted into the cornea as part of a minimally invasive procedure, to create a regular shape. In advanced keratoconus a corneal graft may be required although nowadays with advent of collagen cross linking, the need for a corneal graft is reducing as this aims to halt the progression.