Cornea Transplantation

What is cornea transplantation?

The cornea is the clear, round surface of the eye that helps focus images in the eye. The cornea must be clear, smooth and healthy to be able to see. In certain conditions, the cornea can become cloudy, scarred, and swollen and the vision will decrease. If the cornea cannot be healed, the eye may require a cornea transplant. The cornea has layers and the outer, inner or whole cornea may be replaced with human donor tissue. The donor tissue is carefully checked to ensure that is safe and healthy for transplantation.

What causes cornea problems?

The cornea can become cloudy or scarred by:

• Infections (from bacteria, viruses, other organisms, contact lenses)
• Medications
• Inherited conditions (Fuch's dystrophy, other cornea dystrophies)
• Medical problems
• Injury (trauma or chemicals) or surgery (for example, glaucoma surgery, retina surgery, cataract surgery)

What are cornea transplant options?

The different layers of the cornea may be replaced. In DALK (deep anterior lamellar keratoplasty) the outer layers of the cornea are replaced. In EK (endothelial keratoplasty) the inner layers of the cornea are replaced. Most commonly DSEK (Descemet’s stripping endothelial keratoplasty) is performed where 20% of the inner cornea is replaced. In some cases, only the thinnest inner of the cornea is replaced in DMEK (Descemet’s membrane endothelial keratoplasty. When all layers of the cornea are replaced, a PK (penetrating keratoplasty) is performed. The goal is to replace the damaged cornea with healthy tissue and cells that can restore corneal clarity and improve vision.

What is DSEK (Descemet's stripping endothelial keratoplasty)?

DSEK is a form of endothelial keratoplasty in which the inner layer, Descemet’s membrane, is removed and the replaced with donor tissue from 20% of the inner cornea. Compared with a PK, the healing time is shorter, there is a smaller incision, less chance for astigmatism, and there is a lower chance that your body will reject the tissue.

What is DMEK (Descemet's membrane endothelial keratoplasty)?

In DMEK, another form of endothelial keratoplasty, the Descemet’s membrane, is removed and the replaced with donor tissue Descemet’s membrane. In DMEK, compared with DSEK, the tissue is thinner and can be more difficult to transplant, but in DMEK the recovery is faster and the vision may be better.

What are the reasons for needing endothelial keratoplasty?

EK is needed if the cells on the inner cornea, or endothelium, stop working. This can occur after previous eye surgery, previous failed graft or inherited conditions such as Fuch’s dystrophy and Iridocorneal Endothelial Syndrome.

What can be expected after an endothelial cornea transplant?

The eye may feel irritated with mild to moderate pain for the first few days. The patient may be instructed to lie on his or her back for the first few days to help the graft remain in position. The vision will improve gradually over the first few weeks. The initial visit will be the first day after surgery and then scheduled accordingly. The eye will be monitored closely for vision, pressure, signs of infection, graft healing, signs of graft detachment, and signs of graft rejection.

What is a full thickness transplant?

A full thickness transplant is also called a penetrating keratoplasty or PK, which all the layers of the cornea are replaced. The cornea is sewn into place. The healing time is longer for PK, often a year or longer. With a PK compared with an EK, there is a higher risk that your body can reject the transplant tissue. ‘