Descemet’s stripping automated endothelial keratoplasty (DSAEK) and Descemet’s membrane endothelial keratoplasty (DMEK) are partial thickness corneal transplants which replace primarily the endothelium(innermost portion of the cornea) rather than the full thickness of the cornea (as in standard corneal transplants).
DSAEK and DMEK are indicated when there is corneal clouding due to a dysfunction of the endothelium but where the other layers of the cornea remain healthy. With Fuchs’ endothelial dystrophy or when there is swelling of the cornea after cataract surgery, it is the endothelium which is compromised.
What is endothelial failure?
The cells of the corneal endothelium are very fragile.Once an endothelial cell dies it will not grow back. If an eye loses too many endothelial cells, it is not able to maintain the proper corneal thickness and clarity.
Advantages of DSAEK and DMEK compared to standard corneal transplantation
What is the difference between DSAEK and DMEK?
After the treatment, patient will be able to resume work within 3 to 4 days.Care should be taken to avoid entry of water into the eyes during this period.The use of contact lenses may be resumed 6 weeks after treatment.
How often must the patient come for follow up ?
DMEK is very similar to DSAEK, except that the donor tissue implanted does not include any stromal tissue. It is a pure replacement of endothelium..
Preparing for DSAEK and DMEK Surgery
Do not eat or drink anything for at least 8 hours prior to the surgery. Needed medications can be taken with a small sip of water. It is important to continue taking the medical eye drops (e.g. for glaucoma) that you would normally use on the same day as the surgery.
The procedure is done through a small incision on the side of the cornea and usually takes about 30 minutes to complete. DSAEK and DMEK involve peeling the diseased endothelial layer from the back of the cornea and leaving the healthy remainder intact (approximately 95%). Then, healthy corneal tissue (called a donor disc) is placed inside the eye through a small incision and positioned with an air bubble in the place of the diseased layer.
After surgery, the eye is patched and minimal discomfort should be experienced. Standard over-the-counter pain medications can be taken, as needed. Your surgeon may also give other medications for the eye, if indicated. As much as possible, you should lie down on your back, facing the ceiling for the first 24 hours.
The patch will be removed and your eye will be examined on the next day. You will be placed on antibiotic and steroid drops to prevent infection and to help with healing. The first visit after surgery is primarily to check the pressure and to verify that the donor disc is in the proper position. After that, you will have a brief visit to the clinic one week after surgery, and then again at one and three months. For DMEK, you will have an additional visit 10-14 day’s following surgery.
Donor Disc Dislocation
On the first day after surgery, your surgeon will make sure that your donor disc is still in the intended position. If the donor disc is NOT in proper position, then the disc will have to re-positioned, and that means a visit to a minor operating room in the office for a 15 minute procedure.
A dislocated donor disc can be successfully re-positioned with good function and restoration of vision over 90% of the time. In the worst case scenario, if the disc cannot be successfully repositioned with an air bubble, then the donor transplant can be replaced with another surgery and the vision is restored.