We previously wrote about some of the recent developments in keratoconus management here. Collagen cross linking (CXL) is a wonderful addition to the keratoconus toolkit, and, when applied appropriately, can halt the disease in its tracks.
One of the most important aspects of diagnosing and managing keratoconus in young patients is prompt referral for CXL if there is any sign of progression of the disease.
Please note if you are over 25 years of age and have been advised to have CXL, please get a second opinion. After 25 we have found that keratoconus is less likely to progress and CXL is not without risk.
As the diagram shows, CXL builds links between the various collagen fibres of the cornea and makes it stronger.
CXL is widely available in Australia now but there are some new treatments in the pipeline. Still undergoing clinical trials, the following treatments may have the potential to stave off the need for a corneal graft in more patients.
Collagen cross linking combined with laser resurfacing
Very new is a procedure which combines collagen crosslinking with topographically-guided laser resurfacing. At this stage it is still experimental and only indicated in patients that have definitely failed in contact lenses and whose keratoconus is relatively mild to moderate. We believe, until this procedure has been established in the peer-reviewed literature to give safe and accurate outcomes, that mild to moderate keratoconus sufferers who can’t wear contact lenses are better off in glasses. Because the already thin cornea is thinned even more by the laser reshaping, this technique could be a fast-track to a corneal transplant. However, it may have a role to play as a last resort to try and avoid a corneal graft in a patient who has failed in contact lenses.
Keraflex is a new procedure for the treatment of keratoconus which is still under investigation. In this procedure, a single, low energy microwave pulse is used to shrink collagen fibres and thus flatten the cornea without removing any tissue – which is usually high risk in keratoconus. The treatment takes less than a second and is combined with an accelerated (less than three minutes) version of collagen cross linking to improve the stability of the cornea. This procedure is still undergoing trials but it is believed that it may ultimately help keratoconus sufferers with no alternative therapeutic options to avoid or at least delay progression to corneal transplant.
This procedure received significant press a few years ago, yet has not really made any inroads into the armatarium of the experienced corneal surgeons.
New corneal graft techniques
If all else fails and your only option is a corneal transplant, take comfort in the fact that there are some fabulous new transplant techniques available. A corneal graft should not be considered until it has been established that you cannot be successfully fitted with contact lenses – even by a contact lens specialist. But if you do find yourself going under the knife, the newer graft techniques are showing a lot of promise.
Lamellar grafts only replace some layers of the cornea, rather than the full thickness. This means no sutures in some cases and shorter operating and recovery times. Femtosecond lasers can now be used instead of a surgical blade during the transplant procedure to create a zigzag incision, allowing donor tissue to fit more closely and securely.
The latest area of research in graft techniques involves growing corneal cells outside the body and then injecting then into the eye where they miraculously make their way to the back surface of the cornea. This is good news for sufferers of some corneal diseases such as Fuchs disease but not applicable to keratoconus sufferers where the whole cornea is affected. It’s an exciting space and one we are watching carefully for any further developments in keratoconus treatment.