KERATOCONUS
Keratoconus (literally, conical cornea) is a thinning of the central zone of the cornea, the front surface of the eye. The normal pressure within the eye makes the thinner area of the cornea bulge forward slightly.
Keratoconus is an inherited disorder that occurs in about one in 3 000 people. It is a recessive condition requiring genetic factors to be inherited from both parents, so the chances of the children of a person with keratoconus also having the condition are low (around one in 50).
Keratoconus usually becomes apparent between the ages of 10 and 25 years. It is sometimes associated with other conditions such as allergies, infantile eczema, asthma, reduced night vision, double jointedness and, in rare instances, with occasional short bouts of chest pain.
Because keratoconus is a genetic condition, it cannot be treated with drugs but glasses and contact lenses can give good vision and surgery can be used to treat severe cases. Keratoconus does not cause blindness.
Interestingly, about 60 percent of people with keratoconus go on to tertiary education, compared with 15 per cent of the population as a whole.
The initial symptom of keratoconus is blurred vision, which is caused by shortsightedness and astigmatism. These are caused by the cornea changing shape as it bulges forward and often they are indistinguishable from shortsightedness and astigmatism caused by other factors. At this stage, good vision generally can be obtained with spectacles.
As keratoconus progresses, the shape of the cornea becomes irregular and it is not possible to correct the vision with spectacles alone. In such cases, rigid contact lenses can be used to provide good vision. The contact lenses essentially provide a new, regular front surface for the eye, eliminating the distortions caused by the keratoconus.
Image taken from: www.eyerobics.com.au/keratoconus.html
Advanced Keratoconus
Image taken from: www.sparklingvision.com.hk/Eng/oh-Eng.htm
A rigid gas permeable contact lens is used to correct the irregular corneal shape. Some people will get excellent vision compared to glasses in the later stages of the disease. Urban Eyewear has the latest equipment to manage keratoconic contact lens fittings and our highly trained optometrists will be able to fit RGP contact lenses.
Image taken from: centrumdigital.com/.../keratoconus.html
Because the cornea continues to change shape, it is important that people with keratoconus have regular examinations to ensure that their contact lenses fit correctly. A poorly-fitting contact lens can cause abrasions and scarring.
In about 85 per cent of cases of keratoconus, the condition gradually stabilises by the age of 35 years, although exceptions are always possible. In the remaining 15 per cent, the condition progresses and vision and tolerance to contact lenses may deteriorate. For members of this group, a corneal graft may be necessary.
A corneal graft or keratoplasty is an operation in which the thinned area of the cornea is removed and replaced by normal tissue transplanted from a donor cornea. Corneal grafting is used only when all other methods for correcting vision have failed to provide good vision. The success rate for corneal grafts is extremely high although most people will still need to wear glasses or contact lenses.
Corneal Topography
At Urban Eyewear, we have the latest equipment to diagnose and treat Keratoconus. Computerised corneal topography is a three dimensional imaging process used to map the surface power of the cornea. The data points gathered are then digitised and analysed by sophisticated computer software. The result is a detailed map of the corneal curvature much like a topographical map of land.
* Some of the above information was provided by the Optometrists Association Australia
See the section on ou'r technology' for more information on corneal topography.
Trial to shine a light on eye damage
A new treatment based on a good dose of light and vitamin B2 promises to save the eyesight of thousands of Australians.
The treatment will be welcome news for the estimated 10,000 Australians with keratoconus, a degenerative disease that can lead to blindness.
The State Government will help fund a clinical trial of the procedure at the Royal Victorian Eye and EarHospital over the next 12 months.
Tanya Wilkinson is part of a procedure that could save eyesight. Photo: Joe Castro
Keratoconus is a weakness in the corneas — the front surface of the eyes — and over time these thin and distort, gradually impairing vision. It usually affects teenagers and until now there has been no treatment other than corneal transplants for the most severe cases.
The new procedure involves removing the "skin" of the eye, applying drops of riboflavin (vitamin B2) and exposing the eye to UVA light to strengthen the cornea. It will not improve eyesight but it will prevent further deterioration — and stave off blindness.
Tanya Wilkinson, a 26-year-old travel agent from Langwarrin, is an enthusiastic candidate for the clinical trial. Diagnosed with the condition as a child, Mrs Wilkinson was legally blind in her left eye by the time she was 21 years old. She had a corneal transplant but her right eye continues to deteriorate, raising the spectre of another risky operation.
However, the new treatment could provide a simpler, safer alternative — something Mrs Wilkinson welcomes not only for herself, but for any children she may have. "It will be great for my children because if they do get the disease … they will have another option," she said.
The trial will be led by Christine Wittig who pioneered the procedure in Germany over the past five years. Her tests on 250 patients have a 100 per cent success rate and there were no long-term complications, she said.
In Melbourne, 100 patients will take part in the randomised trial and the hospital expects the procedure to be generally available next year.
It is hoped the procedure will relieve the pressure on waiting lists for corneal transplants, which come second only to kidney transplant lists nationwide.
About 300 corneal transplants are performed in Victoria each year, half of which are for patients with keratoconus.
* Article taken from The Age Company Ltd, 2006
Groundbreaking eye treatment could replace surgery
April 17, 2006 - 11:26AM
A simple treatment using Vitamin B2 and ultraviolet light could replace major corneal transplant surgery for Australian patients in a revolutionary eye treatment trial.
Scientists believe the procedure will save the eyesight of up to 50,000 Australians with the degenerative eye disease keratoconus. Keratoconus sufferers experience a progressive cone-like distortion of the normally round-shaped cornea, which can initially be corrected with glasses or contact lenses but can lead to blindness and the need for a corneal transplant.
But the new treatment can stop the disease by strengthening the cornea to prevent it changing shape.
German doctor Christin Wittig is in Australia to complete the randomised trial involving 100 patients at Melbourne's Royal Victorian Eye and EarHospital over the next year.
Dr Wittig said about 250 patients had undergone the procedure in Germany in the past five years.
It had stopped the progression of the disease in all, and none had suffered serious complications.
"It treats the cause of the disease, not just the symptoms, and stops patients undergoing major surgery, so it's a pretty big step forward really," Dr Wittig said.
She said it was most effective in the early stages of the disease because it could not reverse the deterioration of the cornea.
The treatment involves scraping a layer of skin off the patient's eye, applying Vitamin B2, also called riboflavin, using an eye dropper and exposing the cornea to a measured dose of UVA light.
The light activates the B2 to produce oxygen radicals, which begin a chemical reaction that binds and cross-links collagen fibres in the cornea and thereby strengthen it, Dr Wittig said.
She said the procedure had much less impact on patients' lives than a corneal transplant, was cheaper and quicker and could easily be taken to regional areas.
She said the procedure had much less impact on patients' lives than a corneal transplant, was cheaper and quicker and could easily be taken to regional areas.
Melbourne travel agent Tanya Wilkinson, 26, who has suffered keratoconus since she was 10, had a corneal transplant in her left eye in 2001.
The disease still affects Mrs Wilkinson's right eye, and she could need a second transplant within seven years. She said she preferred the new procedure because a transplant required 18 months of post-operative care and could be rejected. "It's a great prospect," she said.
Corneal Unit head Dr Grant Snibson said if the trial appeared successful after six months, and the hospital received ethics committee approval, it would offer the procedure to other patients.
Keratoconus is estimated to occur in one in every 400 to 2,000 Australians and usually begins between the ages of eight and 45.
More than 1,200 corneal transplants are performed in Australia every year. | 
