Cornea Grafts

About Cornea Grafts

A corneal transplant is surgery to remove all or part of a damaged cornea and replace it with healthy corneal tissue from the eye of a donor who has passed away.

Symptoms

Needing a cornea graft (also known as a corneal transplant) usually means your cornea has become damaged or diseased to the point where it interferes with vision or causes pain. Here are the common symptoms that might indicate someone needs a corneal transplant:

Symptoms That May Indicate the Need for a Cornea Graft:

1. Severe Vision Problems

Blurred or cloudy vision that glasses or contacts can’t correct

Distorted vision (e.g., straight lines appearing wavy)

Halos or glare around lights, especially at night

Sensitivity to light (photophobia)

2. Chronic Eye Pain or Discomfort

Persistent eye pain or irritation that does not improve with treatment

Feeling like something is in the eye (foreign body sensation)

3. Visible Corneal Damage

Scarring or cloudiness visible on the surface of the eye

Bulging or misshapen cornea (as seen in conditions like keratoconus)

4. Repeated Eye Infections or Inflammation

Especially when the cornea is affected and leads to scarring

5. History of Corneal Disease or Injury

Advanced keratoconus

Fuchs’ endothelial dystrophy

Corneal ulcers or infections that have caused scarring

Trauma to the eye leading to corneal opacity

6. Failure of Previous Corneal Surgery

A previously transplanted cornea has failed (graft rejection or failure)

Diagnosis

Diagnosis is based on a combination of symptoms, clinical examination, imaging, and sometimes the failure of other treatments. The ophthalmologist will evaluate whether a corneal transplant is the best option to restore vision and eye health.

Treatment

If your cornea is scarred, damaged or distorted to a point where the vision can no longer be improved with glasses or contact lenses, you may need a corneal transplant to provide clear vision once more. A corneal transplant can also be used to relieve pain or discomfort caused by severe infection or injury that is no longer being managed effectively with treatment.

Types of corneal transplant

There are three different types of corneal transplant:

DALK – Deep Anterior Lamellar Keratoplasty, which removes and replaces part of the front layers of the cornea.

EK – Endothelial Keratoplasty, which removes and replaces the innermost layers of the cornea.

PK – Penetrating Keratoplasty, which removes and replaces all the layers of the cornea.

Endothelial Keratoplasty (EK)

Endothelial Keratoplasty (EK) is a type of corneal transplant used to treat diseases that affect the inner layer of the cornea, specifically the endothelium. This procedure is less invasive than traditional full-thickness corneal transplants and involves replacing only the damaged layers rather than the entire cornea.

There are two main types of EK:

1. Descemet’s Stripping Endothelial Keratoplasty (DSEK): In this procedure, the surgeon removes the diseased endothelium, Descemet’s membrane, and a portion of the stroma (the middle layer of the cornea) from the recipient eye. A graft from a donor cornea is then placed, which includes the donor’s endothelium, Descemet’s membrane, and some of the stroma. This procedure aims to restore normal endothelial function and improve vision.

2. Descemet’s Membrane Endothelial Keratoplasty (DMEK): This is a more refined version of EK where only the donor’s endothelium and Descemet’s membrane are transplanted into the recipient’s eye. DMEK involves removing the patient’s diseased endothelium and Descemet’s membrane, then replacing them with the thin, delicate layers from the donor cornea. DMEK typically offers faster visual recovery and better outcomes compared to DSEK.

Both DSEK and DMEK are designed to treat conditions such as Fuchs’ endothelial dystrophy, a disease where the endothelial cells fail to function properly, leading to fluid build-up and clouding of the cornea. These techniques help to restore the transparency and health of the cornea, improving vision and reducing the need for full-thickness corneal transplants.

Surgical Procedure: In both DSEK and DMEK, the surgeon makes a small incision in the cornea and removes the diseased endothelial layer and Descemet’s membrane. A donor corneal graft is then inserted into the recipient’s eye, where it is carefully positioned and held in place, often with air or gas to help the graft adhere to the recipient’s cornea. Following the surgery, you will need to “posture” (lie flat on your back) to help the air bubble push the new corneal layers against your cornea, allowing the graft to attach to the inside of your cornea.

Penetrating Keratoplasty (PK)

Penetrating Keratoplasty (PK) is a type of corneal transplant surgery in which the entire thickness of the cornea is replaced with a donor cornea. This is the most traditional form of corneal transplant and is typically performed when the entire cornea is damaged or diseased, affecting both the outer (epithelium) and inner (endothelium) layers, or when conditions cannot be treated with more modern techniques like endothelial keratoplasty (EK).

Key Features of Penetrating Keratoplasty:

Full-thickness transplant: Unlike endothelial keratoplasty, which only replaces the innermost layers of the cornea (the endothelium), PK involves replacing all layers of the cornea, from the outer epithelium to the inner endothelium.

PK is typically used for conditions that affect the entire cornea, such as:

Keratoconus (a condition where the cornea becomes thin and bulges out)

Corneal scarring (due to injury, infection, or disease)

Advanced Fuchs’ dystrophy (where both endothelial and stromal layers are affected)

Corneal dystrophies or degeneration that impacts the whole cornea.

Surgical procedure: During PK, the surgeon removes the damaged or diseased cornea and replaces it with a donor cornea, which is sutured in place. The donor cornea is typically round and fits the size of the recipient’s cornea.

Deep Anterior Lamellar Keratoplasty (DALK)

Deep Anterior Lamellar Keratoplasty (DALK) is a type of corneal transplant surgery that involves replacing only the front layers of the cornea, specifically the stroma (the middle layer), while leaving the innermost layer (the endothelium) intact. DALK is a partial-thickness corneal transplant, and it is typically used to treat diseases affecting the corneal stroma, such as keratoconus, corneal scars, and some forms of corneal dystrophies, where the endothelium remains healthy.

Key Features of DALK:

Partial-thickness transplant: In DALK, only the outer layers of the cornea (epithelium, Bowman’s layer, and stroma) are replaced with a donor cornea. The endothelium, which is the innermost layer responsible for maintaining corneal transparency and hydration, is not removed and is left intact in the recipient’s eye.

DALK is primarily used to treat conditions where the endothelium is healthy but the deeper layers (especially the stroma) are damaged or diseased. Common conditions treated with DALK include:

Keratoconus: A condition where the cornea becomes thin and bulges outward.

Corneal scarring: Due to trauma, infection, or previous surgeries.

Corneal dystrophies that primarily affect the stroma.

Surgical procedure: The surgeon carefully removes the diseased stroma and Bowman’s layer from the recipient cornea, leaving the healthy endothelium in place. The donor cornea, which is also partially dissected to include only the anterior layers, is then sutured into place.

Costs

A consultation including comprehensive assessment is at a cost of £350.  The cost of any surgical treatment required will be discussed at the consultation appointment.

The Process

1. Detailed Medical and Eye History

History of vision changes, pain, redness, or repeated infections

Previous eye surgeries or injuries

Known corneal diseases (e.g., keratoconus, Fuchs’ dystrophy)

2. Comprehensive Eye Examination

Visual acuity test: Measures how well you can see at various distances

Slit-lamp examination: Uses a microscope with a bright light to inspect the cornea’s surface and layers for scarring, swelling, or irregularities

Corneal thickness measurement (Pachymetry): Detects thinning or swelling

Corneal topography: Maps the shape and curvature of the cornea to detect abnormalities such as keratoconus

Specular microscopy: Assesses the health of corneal endothelial cells, which are critical for keeping the cornea clear

3. Assessing the Severity of Corneal Damage

If the cornea is significantly scarred, swollen, or deformed and vision cannot be corrected adequately with glasses, contacts, or other treatments, a graft may be recommended.

Persistent pain or risk of further complications also weigh into the decision.

4. Trial of Conservative Treatments

Sometimes, less invasive options like specialized contact lenses or medical treatments are attempted first.

If these do not improve vision or comfort, surgery is considered.

5. Patient’s Visual Needs and General Health

The impact on quality of life and daily functioning

Ability to undergo surgery and post-op care