The cornea is a clear, dome-shaped window at the front of the eye. It focuses light into the eye. Keratoconus is when the cornea thins out and bulges like a cone. Changing the shape of the cornea brings light rays out of focus. As a result, vision becomes blurry and distorted, making daily tasks like reading more difficult. The cause of keratoconus is poorly understood. In some cases, it appears to be genetic and in others, it is strongly associated with eye allergies and excessive eye rubbing. Keratoconus often starts during the teenage years with gradual progression. The eyes are usually affected unequally. The vision symptoms slowly get worse over a period of about 10 to 20 years. The condition usually stabilises around the age of 30 years. The management of keratoconus is a three-pronged plan. The first is to control environmental factors such as eye rubbing, the second is to arrest progression and last to improve vision.
Collagen cross linking is a treatment to stop the progression of ectatic corneal disease, such as keratoconus. It is successful in more than 90% of cases. The treatment is recommended for patients whose corneal shape is getting worse on repeated scans, indicating that their keratoconus is getting worse. The treatment only increases the strength of the cornea and so it will still be necessary to use spectacles or contact lenses after the procedure to improve vision. The procedure is done as a day case at the hospital.
