What is corneal transplantation?
Corneal transplantation, also known as keratoplasty, is the total or partial replacement of the cornea, which is the transparent outer lens at the front of the eye that provides vision.
It is one of the most common transplants and is performed with the cornea of a recently deceased donor, whose eyes have been previously analyzed to ensure their validity for this operation. Local anesthesia is used for the procedure.
The cornea is the transparent lens that covers the eyeball and is responsible for giving us vision.
Why is it performed?
Corneal transplantation is performed when there are severe vision problems due to various corneal dysfunctions:
- Opacities in the cornea, is the most common pathology to be treated, whether acquired or from birth. In many cases corneal opacity is caused by Fuchs’ dystrophy.
- Thinning of the cornea, usually caused by keratoconus and causes vision problems.
- Corneal scarring, due to severe injury or infection.
How is it performed?
Corneal transplantation is performed using keratoprosthesis, a prosthesis made from a transparent material to replace the patient’s natural cornea. The material is designed so that it can be hydrated, admitting up to 80% of water in the internal structure, just like biological tissues. In addition, it resists protein accumulation on the surface. There are several types of keratoprostheses:
- Boston or Boston KPro type keratoprostheses manufactured using a synthetic material. They are used in difficult cases in which another type of corneal transplant would not work.
- The osteo-odonto-keratoprosthesis for which a patient’s tooth is used as a support for the artificial cornea.
- AlphaCor artificial cornea consists of a small, flexible plastic disc that is designed to replace the cornea. The center of this artificial cornea is transparent and has the same function as a lens.
It is used to treat corneal diseases such as ocular trachoma, Stevens-Johnson Syndrome, Lyell’s Syndrome, Sjögren’s Syndrome.
What does it consist of?
The corneal transplant procedure is a minimally invasive operation, during which the patient remains awake and is administered local anesthesia.
The operation consists of removing the central part of the patient’s cornea and inserting a new donor cornea of the same size, which is stitched (it usually requires about 16 stitches). The procedure can be assisted by femtosecond laser, if the ophthalmologist specialist requires it.
There are three transplant modalities, depending on the amount of cornea to be transplanted: We have three transplant modalities: anterior keratoplasty, when the two anterior layers of the cornea are transplanted, endothelial keratoplasty when only the inner layer is transplanted, and penetrating keratoplasty when the entire cornea is transplanted.
Preparation for corneal transplantation
The main guidelines to be followed by the patient before surgery are:
- Always tell the specialist about the medications and medical treatments you are taking.
- You may need to reduce anticoagulant medications for 10 days prior to surgery.
- You should restrict food and drink from midnight before surgery. Depending on the case, you may drink certain liquids (water, black coffee, tea, etc.) up to 2 hours before surgery.
- You will not be able to drink any alcohol 24 hours before and after the surgery.
- On the day of surgery you will not be able to use creams, lotions or make-up on your face or around your eyes.
- You will need a companion to drive you home after surgery.
Care after surgery
The patient can go home the same day of the surgery, he/she will have to wear an eye patch for 4 days after the surgery. The ophthalmologist will prescribe eye drops for the eye to heal and to prevent rejection of the transplant and possible infections.
The corneal stitches will be removed by the ophthalmologist at a subsequent follow-up visit. The first healing phase will last about 3 weeks. During this time, it is essential not to touch the eye, to protect it when sleeping and showering and to wear sunglasses during the day. After this process, the patient should generally wear glasses and contact lenses.
Alternatives to this treatment
Corneal transplantation is a major surgery, which is performed when there is no other option to recover vision. The cornea is affected and affects vision severely, so that medical treatment will not improve vision.
Specifically within the surgery, there are cases in which the patient may not need a corneal transplant, but his own cornea is displaced to hide or minimize the lesion or opaque region that hinders vision.