Corneal Transplant

Introduction

A corneal transplant is the process of removing all, or part of, a cloudy or abnormally shaped cornea and replacing it with a healthy donor's cornea. Corneal transplants are mostly performed to improve vision, however if the cornea has perforated (or threatens to perforate) due to disease or trauma, then a transplant may be required to maintain the structural integrity of the eye.

The cornea is the clear window at the front of the eye, its main function is to focus and transmit light. Injury, disease, or hereditary conditions can cause clouding, distortion, or scarring of the cornea, which may all interfere with vision.

When is a corneal transplant needed?

A corneal transplant is required for a variety of eye conditions, the most common being;

Keratoconus: to learn about why a corneal transplant is required for keratoconus, Corneal clouding:  there are many conditions that may cause the cornea to become swollen and cloudy, such as Fuchs' endothelial dystrophy and pseudophakic bullous keratopathy. In severe cases the cornea may develop small blisters on the surface which can be very painful. Corneal infection: Infections of the cornea may be bacterial, fungal, or viral. Severe corneal infections may cause scarring, thinning, or perforation of the cornea. Herpes simplex is the most common viral infection that may lead to scarring.

Corneal dystrophy: some hereditary conditions called dystrophies cause the cornea to become opaque or irregular and may require corneal transplantation.

Corneal injury: injuries to the cornea, such as penetrating eye injuries, may cause corneal scarring that affects the vision and requires corneal transplantation.

Your ophthalmologist will assess your need for a corneal transplant by looking carefully into your condition.

Types of corneal transplants

We perform both the standard full-thickness corneal transplant called the penetrating keratoplasty, as well as more advanced and newer techniques called lamellar keratoplasty. Your ophthalmologist will assess which procedure is most suitable for you.

Penetrating Keratoplasty (PK): this is a full-thickness corneal transplant used to treat diseases that affect the full thickness of the cornea.

Endothelial Keratoplasty (DSAEK, DMEK): this is a partial-thickness corneal transplant used to treat diseases where only the endothelium (the back layer of the cornea) is affected, such as Fuchs Endothelial Dystrophy.

Anterior Lamellar Keratoplasty (ALK, DALK): this is a partial thickness corneal transplant used to treat diseases which affect the stroma (the front layers of the cornea), such as Keratoconus or certain dystrophies.

The Procedure

Corneal transplant surgery usually takes about an hour and is performed under a general or local anaesthetic. Fine instruments are used to remove the affected cornea and it is replaced with a clear donor cornea. Fine nylon stitches are used to suture the graft into place. In the case of endothelial keratoplasty, an air bubble is used to attach the graft into place. Most patients go home on the day of the surgery, though some may require an overnight stay.

Recovery

A pad or plastic shield will be placed over the eye after the operation and is left in place until the eye is examined the following day.  Eye drops will be prescribed for several months to years in order to reduce the chance of infection and rejection. Some sutures will be removed as early as four weeks, but suture removal can take up to one year for most people.

There is usually mild to moderate discomfort after the surgery, it is very unusual for there to be severe pain. Your ophthalmologist will explain your expected recovery time and vision quality in detail.

Donor Corneas

These have been generously donated by the families of recent deceased relatives.  Every cornea is thoroughly checked for transmissible diseases, including HIV and Hepatitis B and C.

Your ophthalmologist will advise you of the availability and waiting times for a donor cornea.