Corneal Transplant       

 

 

New windows on the world

 

Each year in the US, there are over 30,000 corneal transplants performed to restore vision and comfort to patients with diseases of the clear front tissue of the eye, the cornea.

 

Corneal transplants are by far the most commonly performed transplants, due to their success, the availability of tissue, and the unique “immunologically privileged” location of the cornea which makes tissue matching unnecessary. The success rate of transplants ranges up to 90% over 5 years, depending on the specific circumstances requiring the transplant.

 

 

Why would a transplant be necessary?

 

There are numerous reasons you might need a transplant. For example, one might have clouding of the cornea at birth, from congenital inherited diseases or from infections in childhood, due to scarring from trauma, from repeated surgery or from sustained inflammation within the eyeas a teen or adult, from the evolution of genetically determined, progressive warping of the cornea called keratoconus.

 

• At any time from corneal infections, whether bacterial (contact lens-associated), fungal (traumatic) or viral (herpes simplex)

• At any age, from rejection of a previous transplant
as an older adult, from attenuation of the single cell layer lining the inner cornea, the endothelium. The premature drop out of these endothelial cells is called Fuchs’ corneal dystrophy. This condition represents the most common indication for primary corneal transplant in the US.

• Fuchs’ Corneal Dystrophy

 

There might also be other ocular conditions that need to be addressed with surgery or medication at the same time as the transplant, such as glaucoma or cataract.

 

 

When is a transplant necessary?

 

Sometimes the answer to this question is obvious. For example, for a teen who had an injury to the eye and the vision is poor, the eye is stable, and function can be improved, surgery seems like a positive choice.

 

Sometimes the answer is not clear-cut at all. For example, when does a person who had cataract surgery, and who has fragility of the lining cell layer of the cornea (Fuchs’ dystrophy), decide to have surgery? Usually, the decline in their vision is very slow, they grow accustomed to their disability, and they assume they are “just getting old.”

 

It is important that the patient with corneal disease meet with a surgeon who understands and can communicate clearly the risks and benefits to corneal transplantation. The decision to operate is tempered by the patient’s visual potential, the presence of concomitant eye problems that determine the riskiness of the transplant, the success of nonsurgical interventions, and the patient’s willingness to follow through with long term use of eye drops and visits.

 

Corneal transplants require more effort on the part of both surgeon and patient for optimal outcome, and complications must be promptly managed in order to avoid failure of the transplant. However, this surgery can be one of the most rewarding in medicine.

 

 

Who does corneal transplants?

 

Corneal surgeons are M.D.s who are board certified in ophthalmology, who undergo one to two additional years of training in the subspecialty of corneal transplantation.

 

 

What can I expect from a visit to an ophthalmologist who specializes in cornea?

 

In addition to the standard measurements of the vision, the best spectacle-corrected vision, and screening for glaucoma, the corneal specialist may obtain surface maps of the cornea (topography), corneal thickness measurement (pachymetry) and sometimes corneal endothelial cell counts (specular micrography).

 

The most important test is the exam with a slit lamp, (or biomicroscope, the $2 word). The beauty of the corneal exam is the disease is often there for all to see. However, in some cases, the cornea is so cloudy that the structures inside the eye can’t be evaluated and ultrasound might be used to determine what other problems exist, the potential for vision, and the surgical plan.

 

Depending on the diagnosis and what has been tried before, medical intervention, with drops, might be suggested first. If there is a poor ocular surface, it needs to be improved before surgery to put less stress on the transplant. If glaucoma (elevated eye pressure) is present, it must be controlled. If cataract or retinal disease is present, the patient needs to be made aware of the options for dealing with them. If cataract surgery is to be done at the same time as the transplant, measurement for the IOL power is done.

 

A thorough discussion of the risks, benefits and alternatives to corneal transplant surgery is given to the patient and his family. This discussion takes into account all the factors that might impact visual outcome and survival of the transplant, and what can be done to alleviate risk as much as possible.

The transplant may be done alone, or combined with other surgery on the lens (a cataract), the iris, or the vitreous.

 

Return to top