A corneal transplant, also known as keratoplasty, is just like any other organ transplant: a donor organ – in this case a cornea – is surgically implanted in place of a diseased organ. This is a complicated procedure with several risks and is often a last resort of treatment.
The cornea is the clear front part of the eye. In a healthy eye, the cornea is completely clear, without any blood vessels, and is smooth throughout the entire eye.
The cornea is responsible for bending light into the eye and focusing the light on the retina. This is extremely important when considering how clear vision is formed in the eyes.
The cornea also transmits all of the light through to the back of the eye, allowing things to be seen brightly and with contrast.
There are many diseases that affect the cornea. In general, these conditions will not lead to the need for a corneal transplant, however there are a few conditions which are frequently associated with the need for a transplant.
Conditions that result in a central opacity in the cornea, recurrent corneal swelling, uncorrectable astigmatism, or intense pain may need to be treated with a corneal transplant.
In a healthy eye, the cornea is completely clear throughout the entire eye – especially in the center of the visual axis.
When the cornea becomes cloudy or blocked, it may require a corneal transplant.
A central corneal scar or corneal ulcer are the two most common causes of central opacities in the cornea.
The scar is usually a result of severe trauma to the eye while an ulcer is an infection of the cornea.
If the cornea swells extensively, it can decrease vision and result in complications in the eye including increased eye pressure.
Conditions that cause the cornea to swell frequently may require a corneal transplant.
Fuch’s endothelial dystrophy or iridocorneal endothelium syndrome are the two most common diseases that lead to recurrent corneal edema and the need for a transplant.
Astigmatism is a refractive condition in which the eye focuses at two different locations instead of a single spot.
Some diseases can lead to an irregular type of astigmatism which is not correctable with glasses or contact lenses.
Keratoconus and pellucid marginal degeneration are two naturally occurring diseases which can cause this irregular astigmatism.
It is also possible for LASIK surgery to lead to a similar type of irregular astigmatism.
In these cases, a corneal transplant is required to attain better vision and stabilize the cornea.
The cornea has many nerve endings and can feel pain from even a small stimulus.
Thus, when there is a condition that causes a constant, painful sensation a corneal transplant may be needed.
Bullous keratopathy is the most common condition that leads to pain requiring a corneal transplant.