Corneal Transplant Surgery
Corneal transplant surgery replaces only the diseased layers of the cornea where possible, or the full corneal thickness when necessary. Modern techniques include DALK for selected keratoconus and stromal disease, DMEK or DSAEK for endothelial failure, and penetrating keratoplasty for full-thickness disease.
What is a corneal transplant?
The cornea is the clear front surface of the eye. If it becomes scarred, swollen, irregular or structurally damaged, light may no longer pass through or focus normally.
A corneal transplant - also called corneal graft surgery or keratoplasty - uses healthy donor corneal tissue to replace the diseased part of the cornea. The type of transplant depends on which corneal layer is affected.
When is a corneal transplant considered?
Corneal transplantation is generally considered when corneal disease significantly affects vision or comfort and other treatments cannot provide adequate function.
Conditions that may require transplantation include:
- Advanced keratoconus with significant corneal irregularity or scarring
- Fuchs' endothelial dystrophy
- Corneal endothelial failure or decompensation after previous eye surgery
- Corneal scarring after infection, injury or inflammation
- Failure or rejection of a previous corneal graft
- Selected inherited or structural corneal disorders
The main types of corneal transplant
DALK - Deep Anterior Lamellar Keratoplasty
DALK replaces the front and middle layers of the cornea while preserving the patient's own Descemet membrane and endothelium.
It is commonly considered for keratoconus and other disorders affecting the corneal stroma when the endothelium remains healthy.
Preserving the patient's own endothelium removes the risk of endothelial graft rejection and can offer long-term structural advantages. However, DALK is technically demanding and the interface between donor and host tissue can influence the final visual result.
DMEK - Descemet Membrane Endothelial Keratoplasty
DMEK is a selective transplant of the very thin inner layers of the cornea - Descemet membrane and the endothelial cells.
It is commonly used for endothelial diseases such as Fuchs' dystrophy or other forms of endothelial failure when the front layers of the cornea are otherwise suitable.
Because only a very thin layer is transplanted, DMEK can provide rapid visual rehabilitation and low rejection rates in suitable eyes. A recognised trade-off is graft detachment, which may require an additional air or gas injection called rebubbling.
DSAEK / UT-DSAEK - Endothelial Keratoplasty
DSAEK replaces the diseased endothelium together with a thin layer of donor posterior corneal tissue. Ultrathin DSAEK uses an even thinner donor layer.
It can be used for Fuchs' dystrophy and other causes of endothelial failure and may be preferred over DMEK in selected complex eyes.
Research comparing DMEK with ultrathin DSAEK generally finds faster or better visual acuity after DMEK, while DSAEK tends to have a lower rate of graft detachment requiring rebubbling.
Penetrating Keratoplasty (PK) - Full-Thickness Corneal Transplant
Penetrating keratoplasty replaces the full thickness of the central cornea with donor tissue.
It may be required when disease or scarring involves multiple corneal layers, when the endothelium is not healthy enough to preserve, or when a partial-thickness procedure is not suitable.
The donor cornea is usually secured with fine sutures. Visual recovery is typically slower than with endothelial keratoplasty and the final prescription can continue to change while the graft heals and sutures are adjusted or removed.
Which transplant is used for keratoconus?
Most people with keratoconus never require a corneal transplant. Glasses, specialised contact lenses, cross-linking and selected corneal-shaping treatments can often maintain useful vision.
When keratoconus becomes advanced and useful vision cannot be achieved with contact lenses, or when significant scarring is present, DALK or penetrating keratoplasty may be considered.
DALK is often attractive when the patient's own endothelium is healthy because it preserves this layer. PK remains an important option when full-thickness disease, deep scarring or surgical factors make DALK unsuitable.
Which transplant is used for Fuchs' dystrophy or endothelial failure?
When the main problem is failure of the corneal endothelium, the healthy front layers of the cornea can often be preserved.
DMEK or DSAEK/UT-DSAEK may then be used to replace only the diseased posterior layer. This selective approach generally avoids the large full-thickness wound and prolonged suture management associated with penetrating keratoplasty.
Corneal transplant options at a glance
| Procedure | Layer replaced | Common use | Sutures? | Key consideration |
|---|---|---|---|---|
| DALK | Anterior/stromal cornea | Keratoconus, stromal disease | Usually yes | Preserves patient's endothelium |
| DMEK | Descemet membrane + endothelium | Fuchs / endothelial failure | Usually no full-thickness corneal sutures | Fast visual recovery; rebubbling may be needed |
| DSAEK / UT-DSAEK | Endothelium + thin posterior stroma | Fuchs / endothelial failure | Usually no full-thickness corneal sutures | Useful in selected complex eyes |
| PK | Full-thickness cornea | Full-thickness scarring/disease | Yes | Longer healing and higher rejection exposure |
Where does donor corneal tissue come from?
Corneal donor tissue is donated after death and is screened and prepared through an eye bank before transplantation.
Because the cornea normally has no blood vessels, blood-group matching is generally not required in the same way as for many solid-organ transplants.
What happens during corneal transplant surgery?
Corneal transplant surgery may be performed under local or general anaesthetic depending on the procedure, patient and surgeon.
The exact operation differs significantly by transplant type. DALK and PK replace a central disc of corneal tissue and usually use sutures. DMEK and DSAEK insert a thin donor graft through a small incision and commonly use an air or gas bubble to support the graft against the back of the cornea.
Recovery after corneal transplant
Recovery varies considerably depending on the transplant.
After DMEK or DSAEK
- Vision may begin improving relatively early but can fluctuate while the cornea clears.
- You may be asked to spend periods lying on your back so an air or gas bubble supports the graft.
- A partially detached graft may require a further air or gas injection ('rebubbling').
- Regular eye drops and follow-up are required.
After DALK or penetrating keratoplasty
- Healing is slower and vision can continue changing for many months.
- Corneal sutures commonly remain in place for a prolonged period and may be selectively removed over time.
- Astigmatism can be significant and glasses or specialised contact lenses may still be required.
- Vision may take a year or longer to stabilise, particularly after full-thickness transplantation.
Corneal graft rejection: warning signs
URGENT: Contact your corneal specialist promptly if a transplanted eye develops new redness, soreness or pain, increased light sensitivity, or a sudden decrease/haze in vision. Graft rejection can occur even after a previously stable transplant and early treatment can be important.
A useful reminder is RSVP: Redness, Soreness, Vision change and Photophobia (light sensitivity).
Risks and possible complications
Corneal transplantation is established surgery, but it is not risk-free. Risks vary according to the transplant type and the health of the eye.
- Graft rejection
- Primary or later graft failure
- Infection
- Raised eye pressure or glaucoma
- Wound or suture problems
- Astigmatism and residual refractive error
- Graft detachment after endothelial keratoplasty and the need for rebubbling
- Cataract or progression of existing cataract
- Retinal or other intraocular complications
- The possible need for repeat transplantation
How successful is corneal transplant surgery?
Corneal transplantation can provide substantial visual benefit, but outcomes vary widely according to the diagnosis, transplant type, previous surgery, eye pressure, inflammation and other eye disease.
For keratoconus, both DALK and PK can provide good visual outcomes in appropriately selected patients. A large recent meta-analysis found similar one-year corrected visual acuity between DALK and PK, with a lower rejection risk after DALK.
For endothelial disease, DMEK tends to provide better or faster visual recovery than DSAEK in many uncomplicated eyes, while DSAEK generally has a lower graft-detachment/rebubbling rate.
Will I still need glasses or contact lenses?
Possibly. A transplant replaces diseased corneal tissue but does not guarantee a perfectly regular optical surface.
After DALK or PK, astigmatism can remain significant. Glasses, rigid or scleral contact lenses, suture adjustment or other refractive treatment may be required to achieve the best vision.
Can keratoconus return after a corneal transplant?
Recurrence of keratoconus in a donor graft is considered uncommon, but it has been reported. A transplant should therefore be described as a long-term treatment rather than a guaranteed permanent cure.
How is the right procedure chosen?
Your corneal ophthalmologist will assess which corneal layers are diseased and whether other treatments can provide adequate vision before recommending transplantation.
The assessment may include:
- Visual acuity and refraction
- Slit-lamp examination
- Corneal topography or tomography
- Corneal thickness measurements
- Endothelial cell assessment
- Anterior-segment OCT or other imaging when required
- Review of previous surgery, corneal scarring and contact-lens tolerance
- Assessment of the retina, optic nerve and other factors that could limit the final visual result
Questions to ask your corneal specialist
- Which corneal layer is diseased?
- Why are you recommending DALK, DMEK, DSAEK or PK?
- Are there non-transplant alternatives I should try first?
- How long is recovery likely to take for this particular procedure?
- Will I have stitches or need postoperative positioning?
- What is the risk of rejection or graft detachment?
- How long will I need steroid or other eye drops?
- What visual result is realistic given the rest of my eye health?
- Could I still need glasses or contact lenses?
Book a corneal specialist assessment
If corneal disease is affecting your vision or you have been advised that a transplant may be necessary, a corneal specialist assessment can determine which layers are affected and which treatment options should be considered.
Book an assessment with personalEYES or call 1300 68 3937.
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