Descemet Stripping Endothelial Keratoplasty (DSEK)

Descemet’s Stripping Endothelial Keratoplasty (DSEK) is a form of corneal transplant surgery in which only a thin, inner, layer of the cornea is replaced, leaving most of the patient’s cornea intact.

 

fuchs-diagram-2-001

When is DSEK performed?
DSEK surgery is indicated when the cornea has become hazy and vision impaired due to failure of the corneal endothelium, for example in Fuchs’ endothelial dystrophy.

What are the benefits of DSEK?
Compared to traditional penetrating keratoplasty (PK), in which the entire thickness of the cornea is replaced, DSEK only involves replacing one thin layer of tissue.  Since less foreign tissue is introduced into the eye, there is theoretically less chance of the body rejecting the new tissue. The eye remains intact and sealed through the procedure, reducing the risk of intra-operative complications such as expulsive haemorrhage. There are no sutures to be removed  – unlike PK surgery – which means a more rapid visual rehabilitation.

What does the surgery involve?
After the usual sterile preparation, keyhole incisions are created in the eye (very similar to cataract surgery), and the abnormal Descemets membrane is removed.

The donor tissue is prepared beforehand, and once the abnormal Descemets has been removed from the patient’s eye, the  donor material is inserted into the eye, and carefully positioned. Air is injected into the eye to float the transplanted tissue up against the back of the cornea, and then with extra air the pressure is raised for several minutes to ‘iron’ the new tissue in place and squeeze out any fluid trapped in the interface.

The pressure is then lowered to a normal, physiological, level, and the main entry wound is closed with a single stitch, and the operation is complete.

What are the potential complications?
As with all surgery, there is a small risk of complications: infection being the most significant. Specific to DSEK surgery is the risk of the transplant not sticking fully to the back of the cornea. This is referred to as ‘graft dehiscence’, and if it occurs then it may be necessary to repeat the last step of the operation to reposition the graft. The rate of graft dehiscence is 10-20%.

Accidental blows to the eye, or rubbing the eye, may increase the risk of graft dehiscence. For this reason it is recommended to wear the clear plastic shield at night for the first couple of weeks after surgery.

What drops do I need afterwards?
A combination of steroid (Dexamethasone) and antibiotic (Chloramphenicol) drops are needed to prevent infection, promote healing, and reduce the risk of graft rejection:

  • Dexamethasone 0.1% preservative-free
    – 2-hourly for one week
    – 6 times a day for one week
    – 4 times a day for one month
    and then slowly tapered off over a year
  • Chloramphenicol 0.5% preservative-free four times a day for two weeks.

Graft rejection
As with all transplant operations there is a risk of the body rejecting the donor tissue. This can usually be controlled with eye-drops, but if you experience redness, pain, or reduced vision in the operated eye at any time after surgery it is very important to seek ophthalmic attention.