While many people with Keratoconus manage to get excellent correction to their vision with contact lenses, a small percentage will require some additional medical treatment, and possibly even a Corneal Transplant. There are two basic types of corneal transplant, a full thickness or Penetrating Keratoplasty, and a partial thickness or DALK.
DALK stands for Deep Anterior Lamellar Keratoplasty. In people with Keratoconus the cornea thins and becomes progressively distorted into an irregular 'conical' shape. This distortion results in multiple focus points, blurred vision and 'ghosting', which is multiple overlapping images.
The vast majority of people with the disease cope well with corrective measures such as contact lenses, and a variety of different lens solutions are available. These include soft hydrogel lenses, Rigid Gas Permeable lenses, Scleral lenses, Hybrids and even Piggyback solutions.
In some people the cornea becomes scarred. This can happen for a variety of reasons such as through contact lenses rubbing and abrading the cornea, or through a condition known as Corneal Hydrops in which the outer layer of the Cornea splits.
This scarring can make it difficult to correct the vision as the scars can further distort the light entering the eye.
A Corneal Transplant of some kind may be the best option for people with Keratoconus that have significant scarring to the Cornea.
The DALK procedure involves the replacement of the top layer of the Cornea with donor tissue. Unlike the Penetrating Keratoplasty where the entire thickness of the cornea is replaced, in the DALK procedure only the outer layer is removed and replaced with donor tissue. This leaves the inner cell layer in place.
The advantages of this are primarily around the reduced risk of rejection of the transplanted tissue. As the inner layers are retained the chances of a rejection episode are significantly reduced.
Having said that it should be noted that, even with a full thickness transplant, the risk of rejection is low and in the vast majority of cases treatable with eye drops.
DALK may not be suitable for everyone with Keratoconus. If the thinning of the Cornea is too pronounced and extends too deeply then the inner layer may be too thin to act as a base for a partial thickness transplant. In these cases a full thickness transplant is likely to be the best way to go.
Both types of transplants have a high success rate in helping people with Keratoconus although it is normally the case that additional correction, such as contact lenses, will still be required after the operation.
As always your medical specialist will advise on the most appropriate treatment for you.
Find out more and get free downloadable information about Keratoconus and living with the condition at WHAT IS KERATOCONUS!
http://whatiskeratoconus.com/
