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At a glance
- A corneal transplant replaces a damaged or diseased cornea with healthy donor tissue to restore clear vision or relieve pain.
- It is used for conditions such as keratoconus, scarring from infection or injury, and clouding after other eye surgery.
- Modern techniques often replace only the affected layer of the cornea rather than its full thickness.
- Recovery is gradual, and the eye needs long-term monitoring.
What a corneal transplant is
The cornea is the clear, dome-shaped front window of the eye. It focuses light onto the retina and must stay transparent and smoothly curved for sharp vision. A corneal transplant, also called keratoplasty, is surgery to replace damaged or diseased corneal tissue with healthy tissue from a donor eye. The aim is to restore clarity, improve the shape of the eye’s surface, or relieve pain from a scarred or swollen cornea. Rather than always replacing the whole cornea, modern surgery can often replace just the layer that is affected, leaving the healthy layers in place. Which approach is used depends on the underlying condition and which part of the cornea has been damaged.
Why and when it is done
The cornea must be clear and evenly shaped for good vision. When it becomes scarred, cloudy, misshapen or swollen, light can no longer focus properly and glasses or contact lenses may no longer help. A transplant is usually considered once other treatments have been tried and vision or comfort cannot be restored another way.
Common reasons include keratoconus, where the cornea thins and bulges into an irregular cone; scarring left behind by a severe corneal infection or ulcer; injury from trauma or chemical burns; clouding and swelling of the cornea, sometimes after previous eye surgery; and some inherited conditions that affect the corneal layers over time. A corneal specialist assesses whether the tissue can recover on its own, whether the vision can be corrected another way, and whether a transplant offers a realistic chance of improvement.
Types of corneal transplant
In plain terms, transplants are either full-thickness or partial (layer-specific). The right choice depends on which part of the cornea is diseased.
Full-thickness transplant (penetrating keratoplasty) replaces the entire depth of the central cornea with a matching disc of donor tissue, held in place with fine stitches. It is used when scarring or damage runs through all the layers.
Partial or layer-specific transplants (lamellar keratoplasty) replace only the affected layer. When the front layers are diseased but the innermost layer is healthy, the surgeon can replace the outer tissue while keeping the patient’s own inner layer. When only the innermost layer has failed — the layer that keeps the cornea clear by pumping out fluid — just that thin layer is replaced through a small incision, often without full-thickness stitches. Layer-specific techniques tend to preserve more of the eye’s own tissue, can heal more quickly, and may carry a lower risk of rejection because less donor tissue is transplanted. Your surgeon will explain which technique suits your condition.
How it is done
Surgery is usually a day procedure carried out under local or general anaesthesia, discussed with you beforehand. The donor cornea is supplied through an eye bank from a consented donor and is carefully screened and prepared before use. During the operation the surgeon removes the damaged tissue — the full thickness or a single layer, depending on the plan — and positions the donor tissue in its place. Full-thickness and front-layer grafts are secured with very fine stitches, while an inner-layer graft may be supported by a temporary air or gas bubble inside the eye that holds it against the back of the cornea while it settles. A protective shield or pad is usually placed over the eye afterwards.
Preparing for surgery
Before the operation you will have a detailed eye assessment so the surgeon can measure the cornea, choose the technique and plan the donor tissue. Tell the team about all your medicines, allergies, and any blood-thinning medication, and about other eye conditions such as glaucoma or dry eye, as these can affect planning and healing. You may be given instructions about eating and drinking before anaesthesia. Because your vision will be blurred and the eye protected afterwards, arrange for someone to take you home and help you in the first days. It is also worth planning time off work and preparing your home so that you can rest and avoid strain.
Recovery and aftercare
Recovery from a corneal transplant is a gradual process, and it helps to expect months rather than days. Vision usually improves slowly as the eye settles and the donor tissue clears, and it can continue to change for a long time, especially after a full-thickness graft. Glasses or a contact lens are often needed afterwards for the sharpest focus once healing is well advanced.
You will use several eye drops during healing, including anti-rejection steroid eye drops to calm the immune response, along with drops to prevent infection and keep the eye comfortable. Using these exactly as prescribed, for as long as directed, is one of the most important things you can do to protect the graft. The eye needs careful protection: wear the shield as advised, especially while sleeping, avoid rubbing or pressing the eye, keep water and irritants out during washing, and avoid swimming, dusty or dirty environments, and strenuous activity until you are cleared. Stitches may stay in place for a long time and are removed gradually, at the pace the eye allows, sometimes many months later. Follow-up appointments continue over a long period so the surgeon can watch the graft, adjust drops, manage stitches and check eye pressure.
Risks and complications
Most corneal transplants improve vision or comfort, but every operation carries risks that are worth understanding. The main one is rejection, where the immune system recognises the donor tissue as foreign and attacks it; this can often be reversed if caught and treated early, which is why knowing the warning signs matters so much. Other possible problems include infection, raised pressure inside the eye that can lead to glaucoma, and issues with the stitches, such as loosening, breakage or irritation, which may need attention. Astigmatism, an uneven curvature of the healed surface, is common and is usually managed with glasses or contact lenses. Less commonly, the graft can fail over time even without a clear rejection episode, and a repeat transplant may then be considered.
Preventing and spotting rejection
Rejection is the most important thing for a transplant recipient to understand, because prompt treatment can often save the graft. Reduce the risk by using your anti-rejection steroid eye drops exactly as prescribed, never stopping them on your own, attending every follow-up, and protecting the eye from injury and infection.
Learn the warning signs, remembered by the letters RSVP:
- R — Redness of the eye
- S — Sensitivity to light
- V — reduced Vision
- P — Pain
If you notice any of these, seek urgent eye care immediately rather than waiting — early treatment with intensive drops can often reverse a rejection episode and keep the graft clear. Do not assume a symptom will settle on its own.
Living with a transplant and long-term care
A corneal graft can stay clear and useful for many years with steady care. The key habits are simple but lifelong: keep using drops as directed, attend regular reviews even when the eye feels fine, protect the eye from knocks and infection, and report new symptoms early. Many people return to their usual activities as healing allows, though some contact sports and high-risk situations call for protective eyewear. Because rejection can occur even years later, the RSVP warning signs remain important for the life of the graft. If you have more than one eye condition, such as glaucoma or dry eye, these are managed alongside the transplant so the eye stays as healthy as possible.
When to seek help after surgery
Contact your eye surgeon or seek urgent eye care if you develop any RSVP warning sign — new redness, light sensitivity, reduced vision or pain — or if the eye discharges, the stitches feel loose or scratchy, or a protective bubble-related instruction has not settled as expected. Any sudden pain or sudden loss of vision needs emergency eye care without delay. When in doubt, it is always safer to have the eye checked promptly than to wait.
Where to get care in Singapore
In Singapore, corneal transplants are carried out by eye specialists and corneal surgeons, including centres such as the Singapore National Eye Centre, using donor tissue provided through an eye bank. General health information is also available through HealthHub. A corneal specialist can assess whether a transplant is appropriate, explain which technique suits your condition, and guide your long-term follow-up. Find an eye specialist experienced in corneal disease.
Common questions
How long does vision take to recover?
It is gradual — weeks to months — and depends on the technique; partial-thickness grafts often recover faster than full-thickness ones.
Can a corneal transplant be rejected?
Yes, rejection can occur but is often reversible if treated early, so prompt reporting of warning signs is important.
Where does the donor cornea come from?
Donor tissue is provided through eye banks from consented donors and screened for safety before use.
Related conditions & guides
Sources
- Singapore National Eye Centre — corneal transplantation.
- American Academy of Ophthalmology — corneal transplant.
- Singapore Eye Bank — donation information.
This article is for general information only and does not replace a consultation with a qualified eye-care professional. Please seek personalised advice for your own eyes.