How cornea transplants are performed

Thetype of cornea transplant you'll be offered will depend on theparts of the cornea that need to be replaced.

Mostcornea transplant operations involve transplanting the full thickness of the cornea. However, recent advances in technology mean it's sometimes possibleto onlytransplant part ofthe cornea.

Full-thickness transplants

Afull-thickness transplant is called a penetrating keratoplasty (PK). During this procedure, a circular piece of damaged cornea from the centre of your eye is removed and replaced with the donated cornea. In most cases,a circularcutting instrument (similar to a cookie cutter) called a trephine is used to remove the damaged cornea.

The new cornea is held in place by tiny stitches, which sometimes form a star-like pattern around the edges.You may be able to see the stitches faintly after the operation.

The operation may bedone under Local anaesthetic or general anaesthetic , and usually takesabout 45 minutes.If local anaesthetic is used, you won't be able to see through the eye during the operation as the anaesthetic temporarily stops the eye working.

Most people have to stay in hospital for one night after a full-thickness cornea transplant.

Partial-thickness transplants

Recently, techniques have been developed that allow only parts of the cornea to be transplanted. These techniques aren't suitable for everyone in need of a cornea transplant and they can take longer to perform, but theyoften have a faster recovery time and a lower risk of complications.

There are several different techniques your surgeon mayuse, depending on which layers of thecorneaare transplanted. Generally, these techniques can be broken down into transplants involving the front portion of the cornea and those involving the back portion.

Most of these procedures arecarried out using cutting instruments, such asa trephine, although lasers are sometimes used. These procedures can be carried out using either local or general anaesthetic, and you may be able to go home on the same day of the procedure.

Transplanting the front portion of the cornea

The maintechniques for transplanting the front parts of the cornea include:

  • anterior lamellar keratoplasty (ALK) removingand replacing only theouter (front)layers of the cornea
  • deep anterior lamellar keratoplasty (DALK) removing and replacing the outer and middle layers of the cornea, leaving the inner (back)layers intact

As witha penetrating keratoplasty, stitches are used to fix the donated cornea in place during both of these procedures.

Transplanting the back portion of the cornea

The main techniques for transplanting the back parts of the cornea include:

  • Descemet's stripping endothelial keratoplasty (DSEK) replacing the inner lining of the cornea together with about 20% of the corneal supporting tissue (corneal stroma)
  • Descemet's membrane endothelial keratoplasty (DMEK) replacingonly the inner layer of cells of the cornea

These techniques allow faster visual recovery and have a lower risk of complications.

Stitches aren't used duringeither of these procedures. Instead, the donated tissue is held in place using a temporary air bubble.

and recovering from a cornea transplant .

Content supplied by the NHS Website

Medically Reviewed by a doctor on 5 Jan 2017