Keratoconus Treatments - DALK Transplant

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!

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Keratoconus and Hydrogel Contact Lenses

For people with Keratoconus contact lenses are often the best way to achieve vision correction. There are many different types of lenses and this article looks at the limitations of Hydrogel lenses for Keratoconus.

Keratoconus is a disease of the eye. The cornea, which is the front part of the eye, thins and becomes misshapen leading to the front of the eye developing an irregular 'cone' shape.

This bulging effect results in distortion of the light entering the eye causing blurring and ghosting of images.

While spectacles may produce some correction for early, or very mild, cases of Keratoconus, once the condition progresses beyond a certain point it becomes impossible to get reasonable correction with spectacles.

Contact lenses are often the next form of correction used, however there are many different types of contact lenses and some of them are more effective than others.

Hydrogel lenses are what are sometimes called 'soft' contact lenses.

Traditional Hydrogel lenses are very soft and flimsy and as such they fit very closely to the cornea of the eye.

This has the advantage of making them very comfortable to wear and this is, of course, one of the reasons they have become the most popular kind of lenses for normal vision correction.

However, this close fit makes them of very limited use in the treatment of Keratoconus.

Because they fit very closely, they form the same shape as the cornea. As it is this very shape of the cornea that is the basic cause of vision problems in someone with Keratoconus, the correction offered by these very soft and thin lenses is minimal.

If you imagine that a normal eye is rounded like a soccer ball and an eye with Keratoconus is shaped more like the end of a rugby ball. In order to correct vision the shape at the front of the eye needs to be made as close to the normal shape as possible.

A traditional Hydrogel lens is like laying a cloth over the end of the rugby ball. It moulds to the contours and the light coming into the eye is still distorted.

In the last few years there have been some advances in contact lens material technology. New materials have allowed the creation of contact lenses that are slightly thicker than traditional hydrogel lenses.

Although they retain much of the comfort of soft lenses they have more of a tendency to hold their own shape rather than just draping over the surface of the eye.

This means that they can be more effective for some cases of Keratoconus than has previously been possible with hydrogels. Having said that they are still of limited effect if the condition becomes more severe.

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Find out more about Keratoconus, treatments and living with the condition at WHAT IS KERATOCONUS!

http://whatiskeratoconus.com/

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How to Fit Contact Lenses With Keratoconus

 A rigid gas permeable contact lens Keratoconus is a degenerative eye disorder which is characterized by corneal thinning and protrusion resulting in decreased vision such as shortsightedness and corneal distortion.
Rigid gas permeable contact lenses (also known as hard lenses) are the first option for keratoconus when good vision is not achievable with the use of spectacles.

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