Corneal Transplant and Eye Donation: Types, Recovery, Rejection

The cornea is the clear, dome-shaped window at the front of the eye. It does most of the focusing work and must stay perfectly transparent for sharp vision. When disease, injury or infection leaves it cloudy, swollen or badly misshapen, glasses and contact lenses may no longer help. In these cases a corneal transplant, also called keratoplasty or a corneal graft, can restore vision by replacing damaged tissue with healthy tissue from a deceased donor.

Corneal transplantation is one of the oldest and most frequently performed tissue transplants in the world. Over the past two decades it has changed dramatically: instead of always replacing the full thickness of the cornea, surgeons now often replace only the diseased layer, which means faster recovery and a lower risk of rejection. This guide explains the different techniques, who benefits, what recovery looks like, how to recognise rejection early and how eye donation makes it all possible.

Understanding the layers of the cornea

The cornea is only about half a millimetre thick but has several distinct layers. Knowing them makes it easier to understand modern transplant options:

• Epithelium – the thin, fast-healing outer skin.
• Bowman layer – a tough layer beneath the epithelium.
• Stroma – the thick middle layer, about 90 percent of corneal thickness, made of precisely arranged collagen fibres that keep it clear.
• Descemet membrane – a thin, strong membrane on the inner surface.
• Endothelium – a single layer of cells that pump fluid out of the cornea to keep it clear. These cells do not regenerate in adults, so when too many are lost, the cornea swells and becomes cloudy.

Our page on eye anatomy shows how the cornea fits with the rest of the eye.

Who needs a corneal transplant?

Common indications include:

• Fuchs endothelial corneal dystrophy – an inherited, gradually progressive loss of endothelial cells, usually in later adult life. It causes blurred vision, typically worst in the morning, glare and eventually painful blisters. It is now one of the leading reasons for transplantation in many high-income countries.
• Corneal swelling after cataract or other eye surgery (pseudophakic bullous keratopathy).
• Keratoconus – thinning and bulging of the cornea into a cone shape. Most people manage with glasses, special contact lenses and corneal cross-linking, but advanced cases may need a graft. See our keratoconus guide.
• Scarring after infection – such as herpes simplex keratitis, bacterial, fungal or Acanthamoeba ulcers. Read more in our guide to corneal ulcers and eye infections.
• Scarring after injury – including chemical burns, although these may require additional surface reconstruction.
• Other corneal dystrophies and degenerations.
• Failed previous grafts – a regraft is possible, though the risk of rejection is higher.
• Emergency (tectonic) grafts – to repair a perforated or severely thinned cornea.

Types of corneal transplant

Penetrating keratoplasty (PK)

In PK, the surgeon removes a central disc of the full thickness of the cornea, usually around 7 to 8 mm wide, and stitches in a matching disc of donor cornea with very fine sutures. PK remains essential when disease affects all layers. Its drawbacks are a long recovery, the need for stitches that may stay for a year or longer, frequent significant astigmatism, a wound that remains weaker than normal for life and vulnerable to injury, and a higher rejection risk.

Deep anterior lamellar keratoplasty (DALK)

DALK replaces the front layers of the cornea while leaving the patient's own Descemet membrane and endothelium in place. Because the endothelium is the main target of rejection, keeping it greatly reduces the risk of endothelial graft rejection. DALK is particularly useful for young people with keratoconus. It is technically demanding, and if the thin inner membrane tears during surgery, the surgeon may need to convert to PK.

Endothelial keratoplasty: DSAEK and DMEK

When only the endothelium has failed, it makes sense to replace only that layer. In both techniques, the surgeon removes the diseased inner layer through a small incision and inserts a thin donor graft, which is then pressed into place against the back of the cornea by a bubble of air or gas injected into the eye. Usually no or very few stitches are needed.

• DSAEK uses a slightly thicker graft that includes a thin layer of stroma, making it easier to handle.
• DMEK uses only the Descemet membrane and endothelium, a graft thinner than a human hair. It gives faster and often better visual recovery and the lowest rejection rate, but it is technically more demanding and more often requires an additional air injection (rebubbling) if the graft partly detaches.

For people with Fuchs dystrophy and cataract, endothelial keratoplasty is often combined with cataract surgery in one operation.

Before and during surgery

The operation is usually done under local anaesthetic with sedation, or under general anaesthetic, and often as a day case. Your surgeon will discuss the type of graft, expected recovery and risks, which can include rejection, infection, raised eye pressure (glaucoma), graft failure, cataract, astigmatism and, for endothelial grafts, graft detachment. Our overview of eye surgery options explains general preparation.

Recovery and aftercare

• Eye drops – steroid drops to prevent rejection are used for many months, often tapered slowly, and sometimes long term at low frequency. Antibiotic drops are used initially. Use them exactly as prescribed and do not stop without advice.
• Follow-up visits – frequent at first (the next day, then weekly or monthly), then less often, but lifelong review is recommended.
• Protecting the eye – wear a shield at night for the first weeks and avoid rubbing the eye. After PK, the eye remains more vulnerable to rupture from a blow for life, so protective eyewear for sports and risky activities is strongly advised.
• Activities – light activities can usually resume within days; avoid swimming, heavy lifting and contact sports until your surgeon agrees.
• Vision correction – after PK or DALK, glasses or, often, rigid contact lenses may be needed for the best vision once stitches are adjusted or removed. After DMEK, many people need only a change of glasses.
• Eye pressure checks – steroid drops can raise eye pressure in some people, so it is monitored regularly.

Rejection: know the signs

Rejection happens when the immune system recognises the donor tissue as foreign and attacks it. The cornea has no blood vessels and is relatively protected, so rejection is less common than with organ transplants, and tissue matching is usually not required. Still, it can occur at any time, even many years later, and it is the main cause of graft failure.

The key message is that rejection caught early can often be reversed with intensive steroid treatment. Many eye units teach the mnemonic RSVP:

• Redness of the eye
• Sensitivity to light
• Vision getting worse or cloudier
• Pain or discomfort

Risk factors for rejection include previous rejection or failed grafts, blood vessels growing into the cornea, inflammation, large grafts, young age and stopping steroid drops too early. Loose or broken stitches can also trigger rejection and infection, so they need prompt attention.

Outcomes

Most corneal grafts succeed, with clear grafts and improved vision in the large majority of people having surgery for conditions like keratoconus and Fuchs dystrophy. Long-term survival is generally highest for keratoconus and Fuchs dystrophy and lower for regrafts, inflamed or vascularised eyes and grafts after chemical burns. Grafts do not last forever; endothelial cells gradually decline, and some people eventually need a further transplant.

How eye donation works

Every corneal transplant depends on the generosity of a donor and their family. In many countries there is a shortage of donor corneas, and globally many millions of people live with corneal blindness that could potentially be treated.

Who can donate?

• Most people can donate their corneas after death, including those who wore glasses or contact lenses, had cataract surgery or had poor eyesight.
• There is often no strict upper age limit for cornea donation, although eye banks set their own criteria.
• Certain conditions usually exclude donation for transplantation, such as some infections (for example HIV, hepatitis B or C), certain blood cancers, some neurological diseases and prior refractive surgery for some graft types. Tissue that cannot be transplanted may still be used for research or training if the donor agreed.

The donation process

1. Consent – depending on the country, through registration on an organ donor register, an opt-out system, and always discussion with the family. Tell your family your wishes; they are usually asked to confirm.
2. Retrieval – corneas or whole eyes are removed by trained staff, usually within 24 hours of death. The procedure is respectful and does not prevent an open-casket viewing; the eyelids are closed naturally.
3. Eye bank processing – the tissue is tested for infections, examined for quality and endothelial cell count, and stored in special culture media for days to weeks.
4. Allocation – the eye bank supplies corneas to surgeons according to clinical need. Donor identities are kept confidential, though recipients may send anonymous thank-you letters through the eye bank in many countries.

One donor can help more than one person, because the cornea can sometimes be split for different procedures, such as DMEK for one patient and DALK for another, and the white of the eye (sclera) can be used in reconstructive surgery.

When to see a doctor: warning signs

A corneal transplant can transform someone's sight and quality of life. With modern techniques, careful aftercare and the generosity of donors, the outlook for people with corneal blindness has never been better.