Tag: corneal transplantation

Why do you need a corneal transplant?

The cornea is a window of transparent tissue at the front of the eyeball. It allows light to pass into the eye and provides focus so that images can be seen. Various diseases or injury can make the cornea either cloudy or out of shape. This prevents the normal passage of light and affects vision.
A cloudy cornea can be replaced by a healthy one from a donor to restore vision.If the full thickness of the cornea is affected by disease, then a full thickness transplant is performed. This is known as a penetrating keratoplasty.

Benefits of penetrating keratoplasty

Improved vision

• Approximately 75% of transplant recipients have vision sufficient to drive legally but may need glasses or contact lenses or sometimes further surgery for best results.
• It may take up to 18 months until the full improvement in vision is appreciated.

Risks of penetrating keratoplasty

Rare but serious complications

• Sight-threatening infection (1 in 1,000)
• Severe haemorrhage causing loss of vision
• Retinal detachment
• Severe inflammation or other rare causes of loss of vision

Corneal transplant rejection
A corneal transplant can be identified and attacked by your immune system. This happens in one in six patients in the first two years after transplantation and can cause graft failure. It can often be reversed if anti-rejection medication is started promptly.
Rejection remains a possibility for your lifetime.
Graft failure
When a graft fails, your cornea becomes cloudy again and your vision becomes blurred. This happens in one in 10 transplants for keratoconus in the first 10 years.
Glaucoma
This can usually be controlled by eye drops, but occasionally requires surgery and can damage the sight.
Cataract
This can be removed surgically.

About the operation

The operation
The operation is performed under general or local anaesthetic. The operation takes about one hour. A central 8mm button of your cornea is removed and a similar-sized button of the donor cornea is stitched in with tiny stitches (see front cover). These cannot be felt or seen. The abnormal cornea, which is removed, is sent to our pathology laboratory for examination under a microscope.
After the operation
You will usually be examined by the surgical team after the surgery and can generally go home the same day. You will be seen again within one week in the outpatient clinic and regularly thereafter (approximately six visits in the first year). We generally recommend that you take two weeks off work – discuss your individual circumstances with your doctor. You will need to use anti-rejection eye drops for at least six months and in some cases indefinitely. Individual
stitches may be removed from three months after the operation, but complete stitch removal is not performed until at least one year after the procedure.
What if my transplant fails?
A failed transplant can be replaced in a procedure known as a regraft, but the risk of subsequent rejection and failure increases each time for regrafts.
The percentages of full-thickness corneal grafts that are still functioning well five years after the operation under various conditions are:

Condition	%
Keratoconus	95
Fuchs’ dystrophy	80-90
Stormal Scar	80-90
Stromal dystrophies	80-90
Bullous keratopathy	50-80
Bacterial infections	50-80
Herpetic keratitis	50-80
Fungal infection	0-50
3rd or higher number regraft	0-50
4 quadrants of blood vessels	0-50
Inflammation at time of surgery	0-50
Severe ocular surface disease	0-50
Grafts greater than 10mm	0-50

Consenting for information sharing
We are required to share your information with the Eye Bank who supply donor corneas, to ensure high quality transplant material.
Corneal transplant rejection
Rejection needs urgent treatment as this can lead to failure of the transplant and loss of vision.
Symptoms of rejection are:

• Red eye
• Sensitivity to light
• Visual loss
• Pain

If you experience any of these symptoms, you should immediately call our 24-hour emergency phone line 055 516 1586.

Why do you need a corneal transplant?

The cornea is a window of transparent tissue at the front of the eyeball. It allows light to pass into the eye and provides focus so that images can be seen. Various diseases or injury can make the cornea either cloudy or out of shape. This prevents the normal passage of light and affects vision.
The cornea has three layers (thin outer and inner layers and a thick middle layer). In some diseases, only the inside layer (endothelium) is affected, causing corneal oedema (swelling) and clouding (see below). Endothelial keratoplasty is a modern technique to replace the inside layer of your cornea with the inside layer from a donor cornea through a relatively small incision (opening).

Benefits of endothelial Keratoplasty

Improved vision
The majority of transplant recipients have sufficiently good vision to be able to drive legally although many need glasses. It can take up to six months until the full improvement is appreciated. Comfort is improved in some cases.

Risks of endothelial Keratoplasty

Rare but serious complications

• Sight-threatening infection (1 in 1,000)
• Severe haemorrhage causing loss of vision
• Retinal detachment
• Severe inflammation or other rare causes of loss of vision

Corneal transplant rejection
A corneal transplant can be identified and attacked by your immune system. This happens in between 6% and 10% of DSAEK recipients in the first two years after transplantation and can cause graft failure. It can often be reversed if anti-rejection medication is started promptly. Rejection remains a possibility for your lifetime. The rejection risk in DMEK appears to be lower than in DSAEK.
Graft failure
When a graft fails, the cornea becomes cloudy again and vision becomes blurred.
Glaucoma
This can usually be controlled by eye drops, but occasionally requires surgery and can damage your sight.
Graft dislocation
About 10% of endothelial grafts dislocate and need to be repositioned in theatre.
Cataract
This can be removed surgically.

Possible advantages of EK over full-thickness graft

• Faster recovery
• Fewer stitches, which means that the shape of the cornea is more “normal” and you are less dependent on glasses/ contact lens
• Smaller wound so fewer wound complications such as leakage or wound rupture after accidental injury

About the operation

The operation
The operation is usually performed under local anaesthetic and takes about one hour. Through a small incision (opening), your endothelium is removed and an 8.5mm disc of donor endothelium is inserted and pressed in position against the back of your cornea by a bubble of air. You will need to lie flat for one hour after the operation. Usually, only two stitches are used to close the incision.
After the operation
You will usually be examined by the surgical team after your surgery and can generally go home the same day. You will be seen again the next day and within one week to make sure the graft stays in position. You will have about six visits to the outpatient clinic in the first year. We generally recommend that you take two weeks off work – discuss your individual circumstances with your doctor. You will need to use anti-rejection eyedrops for at least six months and in some cases indefinitely. The stitches are usually removed at about three months.

What if my transplant fails?

A failed transplant can be replaced in a procedure known as a regraft. However, the risk of subsequent rejection and failure increases each time for second and subsequent regrafts.
Consenting for information sharing
We are required to share your information with the Eye Bank who supply donor corneas, to ensure high quality transplant material.
Corneal transplant rejection
Rejection needs urgent treatment as this can lead to failure of the transplant and loss of vision.
Symptoms of rejection are:

• Red eye
• Sensitivity to light
• Visual loss
• Pain

If you experience any of these symptoms, you should immediately call our 24-hour emergency phone line 055 516 1586.

Why do you need a corneal transplant?

The cornea is a window of transparent tissue at the front of the eyeball. It allows light to pass into the eye and provides focus so that images can be seen. Various diseases or injury can make the cornea either cloudy or out of shape. This prevents the normal passage of light and affects vision. The cornea has 3 layers (thin outer and inner layers and a thick middle layer). In some diseases, only the middle layer or part of the middle layer is affected (see below).

DALK is a modern technique whereby the outer two layers of the cornea are removed and replaced with the outer 2 layers from a donor cornea to give a partial-thickness transplant.

Benefits of Deep Anterior Lamellar Keratoplasty

Improved vision

• 90% of transplant recipients reach driving standard if the eye is otherwise healthy but can need glasses or contact lenses or sometimes further surgery for best results.
• It may take up to 18 months until the full improvement in vision is appreciated.

Risks of Deep Anterior Lamellar Keratoplasty

Rare but serious complications

• Sight-threatening infection (1 in 1000)
• Severe haemorrhage causing loss of vision
• Retinal detachment

Corneal transplant rejection

A corneal transplant can be identified and attacked by your immune system. This happens in less than 10% of DALK recipients in the first two years after transplantation and can cause graft failure. It can often be reversed if  anti-rejection medication is started promptly. Rejection remains a possibility for your lifetime.

Graft Failure

When a graft fails the cornea becomes cloudy again and vision becomes blurred.

Glaucoma

This can usually be controlled by eyedrops but occasionally requires surgery.

Cataract

This can be removed surgically. Conversion to penetrating keratoplasty. Occasionally it is not possible to perform a partial thickness transplant and a full-thickness transplant must be performed instead. This happens in 10% of intended DALK procedures.

Possible advantages of DALK over full-thickness graft

• Lower risk of intraocular problems such as serious infection or bleeding.
• Lower risk of graft rejection.
• The corneal wound after DALK is stronger than that after a full-thickness graft (PK). This means that stitches can be removed sooner.

Possible disadvantages of DALK over full-thickness graft

DALK recipients have a slightly lower chance of achieving 6/6 vision (excellent vision) than recipients of full thickness grafts.

About the operation

The Operation

The operation is performed under general or local anaesthetic. The operation takes about one hour. A central partial thickness 8mm button of the patient’s cornea is removed and a similar-sized button of the donor cornea is stitched in with tiny stitches (see front cover). These cannot be felt nor seen. The abnormal cornea, which is removed is sent to our pathology laboratory for examination under a microscope.After the operation

After the operation you will usually be examined by the surgical team after the surgery and can usually go home the same day. You will be seen again within 1 week in the outpatient clinic and regularly thereafter (approximately 6 visits in the first year). We generally recommend that you take 2 weeks off work – discuss your case with your doctor. You will need to use anti-rejection eyedrops for at least 6 months and in some cases indefinitely. Individual stitches may be removed from 3 months after the operation but complete stitch removal is not performed until at least 1 year.

What if my transplant fails?

A failed transplant can be replaced in a procedure known as a regraft. However the risk of subsequent rejection and failure increases each time for second and subsequent regrafts.Corneal Transplant Rejection

If not treated urgently this can lead to failure of the transplant and loss of vision.

Symptoms of rejection are:

• Red eye
• Sensitivity to light
• Visual loss
• Pain

If you experience any of these symptoms, you should immediately call our 24-hour emergency phone line 055 516 1586.