Having a DMEK or DSAEK corneal transplant

What is an endothelial keratoplasty?

The cornea is the normally clear window at the front of the eye. It has a thin inner layer called the endothelium, responsible for maintaining transparency. 

When the endothelium fails, the cornea becomes waterlogged and loses transparency. This can make your vision cloudy, cause glare, and can sometimes cause pain.

Endothelial keratoplasty is the replacement of the inner layer (endothelium) of the cornea in the eye when it is not functioning well. The two main variations of this surgery are:  

• Descemet's membrane endothelial keratoplasty (DMEK), where a thinner piece of tissue is transplanted
• Descemet's stripping automated endothelial keratoplasty (DSAEK), where a thicker piece of tissue is transplanted.  

How is an endothelial keratoplasty performed?

The operation usually takes about 60-90 minutes. It is usually performed under intravenous sedation or general anaesthesia. 

You should not experience any pain during the operation itself as you will be given an anaesthetic injection.  

During the operation, the inner layer of your cornea (endothelium) is removed. A small opening in the coloured part of your eye (iris) is created to stop the pressure of the eye from rising. 

In DMEK surgery, a thin layer of endothelium is then injected into the eye, unfolded, and attached with an air or gas bubble onto the back of your cornea. 

In DSAEK surgery, a thicker piece of tissue is injected and attached the same way. Stitches are needed with this operation, which are removed later in clinic. Usually, you will be asked to lie flat for one to two hours after the surgery. You are then reviewed by the surgeon before discharge.  

Benefits of an endothelial keratoplasty

The main benefit of surgery is that it will improve your vision. It usually takes up to one month until you will notice a full improvement in your vision, but this can take up to three months (and rarely longer). 

After receiving a corneal transplant, most patients will have eyesight adequate for driving unless you are affected by other eye diseases. You may need glasses to help achieve this.

Sometimes the surgery is done to ease discomfort or pain.  

Risks and side-effects

Rare but serious complications include: 

• infection inside the eye (endophthalmitis)  
• bleeding inside the eye  
• a detached retina (where the retina at the back of your eye becomes loose)
• severe inflammation  
• 1:1000 chance of losing vision,

Uncommon problems which can occur include:

Graft dislocation or detachment

About 10% of DSAEK procedures and 25% of DMEK procedures need to be repositioned (rebubbled) by an air or gas injection afterwards. This may be carried out in clinic or theatre.

Please follow any instructions from your surgeon regarding your positioning after surgery to minimise this risk. 

Corneal transplant rejection

This occurs when your immune system rejects the transplant. This happens in 5-10% of patients and can be reversed with eye drops if started promptly. The risk is highest in the first two years but remains a possibility in your lifetime.

To reduce the risk of rejection, you are prescribed a prolonged course of steroid eyedrops (if you have any vaccinations, this can be increased for a few days to protect the graft). Please do not stop your steroid drops unless advised to do so by the corneal team.  

Corneal transplant failure

This happens when the transplant stops working; your vision and the cornea becomes cloudy. The surgery can be repeated but the success rates of further surgeries are usually lower.  

Glaucoma (raised eye pressure)

You may not have any symptoms of raised eye pressure, but it can lead to sight loss. Most cases can be managed with eye drops; rarely, tablets or surgery may be needed.

Please attend your follow up appointments to monitor your eye pressure and your transplant as advised. 

Cataract (clouding of the lens)

If you have not had your cataract removed already, this may be removed at the time of your corneal transplant or occasionally later.  

Please discuss any specific concerns you may have with your surgeon prior to surgery. 

On the day of surgery

Before coming in for your surgery, you should:

• Please bring a list of any medications you take. 
• Have a bath or shower before coming into the hospital. 
• Wear comfortable, loose-fitting clothing. 
• Remove all make-up, body piercings and jewellery. You may wear a wedding ring. 
• You may wear hearing aids and glasses, but not contact lenses. Please bring equipment to store these. 
• Please bring something to help pass the time, such as a book. You will be in hospital for either the whole morning or afternoon.  

If you are having a general anaesthetic (sedation)

• You must not eat and drink for six hours before your operation. This reduces the risk of vomiting under anaesthesia. 
• You may only drink small sips of water up to two hours before your operation. 
• Please take all your eye drops and your medicines with small sips of water before you leave home in the morning. 

If you are having a local anaesthetic

If you are having your operation under local anaesthetic, please eat your breakfast or lunch before coming into hospital. You can take your medicines, including eye drops, as usual. 

After your surgery

Going home

You must arrange for an escort to take you home from the hospital and have a responsible adult stay with you for 24 hours after your operation.

We strongly recommend you go home by car or taxi. We discourage you from travelling by public transport as you will still be recovering from the effects of the operation and anaesthetic. 

Please arrange to take time off work for one to two weeks after your surgery, as advised by your treating surgeon. If you perform manual work or drive for work, you may need to take a longer time off. 

Post-operative care instructions

You may be advised to lie down as much as possible for four to seven days after the surgery, with your head flat, looking up towards the ceiling. This is to prevent transplant dislocation which may require further surgery. You may use a flat pillow, as long as the head remains flat and not raised.

You may get up to go to the bathroom or take your meals, but we advise that you remain in this position as much as possible, until your first follow-up.  

There will be an air or gas bubble inside the eye that will blur your vision significantly for one to two weeks. We may place a contact lens in your eye, which is removed at your follow-up appointment. If the contact lens falls off, do not re-insert it into the eye. 

An eye pad and shield will be placed over your eye after surgery. Please leave them in place overnight and remove them the next morning. The eye shield should be worn at night for one week after the operation to protect the eye during sleep.

Each morning after removing the eye shield, gently clean away any residue around your eyelids with a clean tissue and then put in your eye drops.

Wash your eye shield daily using warm water and soap; rinse and dry it carefully. 

You will be given eye drops to use at home and instructions on how to use them. If you are running out of eye drops, please contact your GP for a repeat prescription. Please continue with eye drops that you were using prior to surgery unless told to stop. 

Please avoid the following after surgery

• Rubbing your eye (if the eye waters, wipe it gently with a clean tissue). 
• Getting soap in the eye for two weeks, when showering or washing your face or hair. 
• Wearing eye makeup for two weeks. 
• Straining or heavy lifting (more than 7kg) for two weeks. 
• Strenuous exercise (eg running, cycling, yoga) for two weeks. 
• Swimming or gardening for four weeks. 
• High or low altitudes (flying, going up buildings taller than 2000 ft, diving) until the air or gas bubble has disappeared (this will take two to four weeks and you will be advised by your specialist at the post-operative visit).

What to expect after surgery

For the first few days after your surgery, please take care when stepping off pavements and going up and down stairs, as your depth perception may be affected. 

You may notice redness on the white of the eye – this is not harmful and usually resolves over two to three weeks. Your eye should not be painful, but you may feel slight discomfort. Please make sure you have some over the counter pain relief medication at home. 

You can use your old glasses after the operation, but your prescription may have changed. Your surgeon will advise you when you can visit your optician to obtain new glasses at your post-operative visit, and when you can return to driving. 

Follow-up appointments

You will be asked to return to the hospital for a follow-up appointment within a week after your surgery. This is to check the eye pressure and the position of the transplant.

When to seek help

Your vision will be blurred for one to two weeks after your surgery, and there will be some grittiness and light sensitivity after the operation. This should improve over time.  

You should contact us if you experience the following symptoms: 

• Pain or headache not relieved by over-the-counter pain medication. 
• Increased swelling of the eye. 
• Increased sticky discharge.  
• Worsening of vision. 
• Worsening redness, pain, or light sensitivity. 

During working hours, please contact the Royal Free Hospital switchboard and ask them to bleep the eye casualty nurse or the on-call ophthalmologist. Outside of hours or over the weekend, please contact the switchboard who will call the on-call ophthalmologist. 

If your operation was done at Edgware Community Hospital, you may contact this hospital as well (Monday to Thursday). 

If you are unable to contact us, you can attend the emergency department at the Royal Free Hospital.