Corneal transplant surgery replaces damaged or diseased corneal tissue with healthy donor tissue to improve corneal clarity, vision, or comfort. Depending on which layers have been affected, a cornea specialist may recommend a partial-thickness transplant or a full-thickness transplant.
Barnet Dulaney Perkins Eye Center provides advanced cornea care for patients across Arizona. Our cornea team evaluates the location and severity of the damage, your overall eye health, and your visual needs before recommending a personalized treatment plan.
A transplant is generally considered when glasses, specialty contact lenses, medications, corneal cross-linking, or other treatments can no longer provide adequate vision or control the condition.
Partial-Thickness Corneal Transplant Surgery
A partial-thickness corneal transplant replaces only the diseased or damaged layers of the cornea. The surgeon preserves the patient’s healthy corneal tissue whenever possible.
Different procedures treat different parts of the cornea:
- DMEK replaces Descemet’s membrane and the endothelium.
- DSAEK replaces Descemet’s membrane, the endothelium, and a thin layer of posterior stroma.
- DALK replaces the anterior and middle corneal layers while preserving the endothelium.
Partial-thickness techniques may provide faster visual recovery, a smaller surgical incision, or a lower risk of certain complications than a full-thickness transplant. However, the appropriate procedure depends on which layers are damaged and whether the remaining tissue is healthy enough to preserve.
The Five Layers of the Cornea
The cornea is the clear, curved surface at the front of the eye. Its five layers work together to protect the eye, focus light, and maintain clear vision.
- Epithelium: The outermost layer protects the eye from dust, bacteria, and other foreign material. Its many nerve endings make the cornea highly sensitive to pain and injury.
- Bowman’s layer: This thin, strong layer lies directly beneath the epithelium and helps protect the cornea from injury.
- Stroma: The stroma makes up most of the cornea’s thickness. Its carefully arranged collagen fibers provide strength, flexibility, and transparency.
- Descemet’s membrane: This thin but resilient layer forms a protective barrier between the stroma and the endothelium.
- Endothelium: The innermost layer pumps excess fluid out of the cornea. When these cells stop working properly, the cornea can swell and become cloudy.
Knowing which layers have been affected helps the cornea specialist select the most appropriate transplant technique.
Types of Corneal Transplant Surgery
| Procedure | Tissue Replaced | May Be Considered For |
|---|---|---|
| DMEK | Descemet’s membrane and endothelium | Fuchs’ dystrophy and other forms of endothelial failure |
| DSAEK | Descemet’s membrane, endothelium, and a thin layer of posterior stroma | Fuchs’ dystrophy, corneal swelling, and endothelial damage |
| DALK | Epithelium, Bowman’s layer, and stroma | Keratoconus and corneal disease that has not damaged the endothelium |
| Full-thickness transplant (PK) | All five corneal layers | Deep scarring, extensive damage, advanced disease, or a failed previous graft |
No single procedure works best for every patient. Your surgeon will examine the cornea and recommend the technique that addresses the damaged tissue while preserving healthy layers whenever possible.
Full-Thickness Corneal Transplant
A full-thickness corneal transplant, also called penetrating keratoplasty or PK, replaces a circular section containing all five layers of the central cornea. It may be recommended when disease, injury, or scarring affects several corneal layers and a partial-thickness procedure cannot adequately address the damage.
During surgery, the surgeon removes the damaged central tissue and replaces it with carefully screened donor corneal tissue from an eye bank. Fine sutures secure the donor graft while the eye heals.
Because the entire thickness of the cornea must heal, vision often changes gradually after surgery. It may take a year or longer for vision to stabilize, and the surgeon may adjust or remove sutures at different stages of recovery. Glasses or specialty contact lenses may still be needed to provide the clearest possible vision.
Femtosecond Laser-Assisted Keratoplasty
For selected patients, a femtosecond laser may assist with a full-thickness corneal transplant. The laser creates precisely shaped incisions in the patient’s cornea and the donor tissue. These matching incision patterns can help the graft fit securely and may support wound stability and more even healing.
Femtosecond laser-assisted keratoplasty is not appropriate for every eye. The peripheral cornea must be clear enough for the laser to create the planned incision. Specialized corneal imaging helps the surgeon determine whether a laser-assisted or traditional surgical approach is more appropriate.
DSAEK Corneal Transplant
Descemet’s stripping automated endothelial keratoplasty, or DSAEK, replaces the unhealthy endothelium and Descemet’s membrane with donor tissue that also includes a thin layer of posterior stroma.
DSAEK may be considered when damaged endothelial cells allow fluid to accumulate in the cornea. Causes can include Fuchs’ corneal dystrophy, previous eye surgery, injury, infection, inflammation, or failure of an earlier corneal graft.
How DSAEK Is Performed
DSAEK is generally performed as an outpatient procedure. Anesthesia and sedation depend on the patient’s needs and the surgeon’s recommendation.
The surgeon creates a small incision near the edge of the cornea and removes the unhealthy Descemet’s membrane and endothelial cells. A thin donor graft containing healthy endothelial cells, Descemet’s membrane, and a small amount of stroma is then inserted and positioned against the back of the cornea.
An air or gas bubble supports the graft while it begins to attach. The graft itself does not require sutures, although the surgeon may use one or more small sutures to close the incision.
If part of the graft does not attach properly, the surgeon may recommend a re-bubbling procedure. During re-bubbling, another air or gas bubble is placed inside the eye to help the graft attach.
Advantages of DSAEK vs. Full-Thickness Corneal Transplant
Corneal transplant recovery is faster after DSAEK than after a full-thickness transplant, provided the eye has no other problems that would limit the best potential vision. Although vision is typically quite cloudy immediately after DSAEK, it typically begins improving within 1 to 2 months after surgery. Patients can usually be fitted for glasses within 4 to 6 months (compared to 12 to 18 months after a full-thickness transplant). In addition, because only the thin innermost layers of the patient’s cornea are replaced, corneal integrity is less affected than it is with a full-thickness transplant.
DSAEK Recovery and Potential Benefits
DSAEK preserves the front and middle layers of the patient’s cornea. This generally provides better structural stability and a faster recovery than a full-thickness transplant.
Vision will usually appear cloudy immediately after surgery and improve gradually as the graft attaches and the corneal swelling clears. Recovery may take several weeks or months. Other eye conditions, including cataracts, retinal disease, glaucoma, or optic nerve damage, can affect the final visual result.
Patients must use prescribed eye drops and attend every follow-up visit. The surgeon may also provide temporary restrictions on positioning, activity, altitude, or air travel while the bubble remains in the eye.
DMEK
DMEK Corneal Transplant
Descemet’s membrane endothelial keratoplasty, or DMEK, is a partial-thickness transplant that replaces only Descemet’s membrane and the endothelium. It does not include donor stroma.
DMEK may be considered when disease or damage primarily affects the endothelial cells, including many cases of Fuchs’ dystrophy and corneal swelling caused by endothelial failure. Because the graft contains only the layers that need replacement, DMEK preserves more of the patient’s natural cornea.
How DMEK Is Performed
DMEK is generally performed as an outpatient procedure. The donor tissue comes from an eye bank and undergoes careful screening before transplantation.
The surgeon creates a small incision and removes the unhealthy Descemet’s membrane and endothelial cells. The very thin donor graft is inserted into the eye, unfolded, and positioned against the back of the cornea.
An air or gas bubble holds the graft in place as it begins to attach. The graft itself does not require sutures, although the incision may need one or more small sutures. If the graft does not attach completely, a re-bubbling procedure may be necessary.
DMEK Recovery and Potential Benefits
DMEK can provide faster visual recovery than DSAEK or a full-thickness transplant when the rest of the eye is healthy. Because DMEK uses a very thin graft and does not create a stromal interface, it may also provide excellent visual clarity and a lower risk of graft rejection than procedures that transplant more tissue.
Vision is normally blurry immediately after surgery. Many patients begin to notice improvement in the following weeks, but healing and visual stabilization vary. Swelling, graft attachment, preexisting eye conditions, and the need for additional treatment can all affect recovery.
DMEK is technically complex and may not be the best option for every eye. Your corneal surgeon will compare the potential benefits and risks of DSAEK with those of other available treatments.
Risks of Corneal Transplant Surgery
All corneal transplant procedures carry potential risks. These can include infection, bleeding, inflammation, elevated eye pressure, glaucoma, graft detachment, irregular astigmatism, graft failure, retinal detachment, and rejection of donor tissue. The risks differ by procedure and by the health of the individual eye.
Graft rejection does not always mean the transplant will fail. Prompt treatment may help protect the donor tissue. The National Eye Institute advises patients to contact their eye doctor immediately if they develop possible rejection symptoms, including:
- New or increasing eye redness
- Eye pain
- Increased sensitivity to light
- Cloudy, hazy, or worsening vision
Do not wait for these symptoms to improve on their own. Contact your eye doctor immediately if you develop after a corneal transplant.
If a graft fails and the eye still has the potential for improved vision, another transplant may be considered. The surgeon will determine whether a repeat partial-thickness procedure, a different transplant technique, or a full-thickness transplant is appropriate.
DALK Corneal Transplant
Deep anterior lamellar keratoplasty, or DALK, replaces the front and middle layers of the cornea while preserving a healthy Descemet’s membrane and endothelium.
DALK may be considered for advanced keratoconus, corneal scarring, or other conditions that affect the stroma without damaging the innermost corneal layers. Preserving the patient’s endothelium eliminates the risk of endothelial graft rejection, although other complications and forms of rejection can still occur.
The surgeon removes the damaged anterior tissue and secures the donor graft with fine sutures. Healing is gradual, and vision can continue changing while the sutures remain in place. Glasses or specialty contact lenses may be needed after recovery.
Corneal Transplant Recovery
Recovery depends on the transplant technique, the condition being treated, and the health of the rest of the eye. Endothelial procedures such as DMEK and DSAEK generally provide faster visual recovery than DALK or a full-thickness transplant, but every eye heals differently.
After corneal transplant surgery, your care plan may include:
- Prescription antibiotic and anti-inflammatory eye drops
- An eye shield, particularly while sleeping
- Temporary lifting, exercise, bending, or positioning restrictions
- Restrictions on rubbing the eye, swimming, and wearing eye makeup
- Frequent follow-up examinations
- Long-term medication to reduce the risk of graft rejection
- Glasses or specialty contact lenses after vision stabilizes
Follow all instructions concerning air travel, elevation changes, and nitrous oxide anesthesia if an air or gas bubble was placed in the eye. Read our guide to preparing for a corneal transplant for additional surgery and recovery planning.
Schedule a Corneal Transplant Evaluation in Arizona
Cloudy, distorted, or declining vision from corneal disease can interfere with reading, driving, working, and enjoying time with the people who matter most. A cornea evaluation can determine what is affecting your vision and whether a transplant or another treatment may help.
Barnet Dulaney Perkins Eye Center provides specialized cornea care for patients across Arizona. Schedule an appointment online to discuss your symptoms, diagnosis, and corneal transplant surgery options.