What Is a Cornea Transplant?

Corneal transplantation is a treatment method that replaces the cornea of the patient's existing lesion with the normal cornea of the eye, rejuvenates the affected eye, or controls the corneal lesion, so as to improve vision or treat certain corneal disorders. Some corneal diseases that cause patients with severe visual impairment or even blindness can be treated by corneal transplantation, helping these unfortunate patients to avoid suffering. Because the cornea itself does not contain blood vessels, it is in an "immunity pardon" status, making the success rate of corneal transplantation the highest among other allogeneic organ transplants.

Basic Information

English name

cornealtransplantation

Visiting department

Ophthalmology

Common locations

Eye

Contagious

no

The structure of the human eye is like an optical camera. The functions of the retina, optic nerve, and visual center of the brain are like film, the iris is like an aperture, and the cornea is like a camera lens. If the cornea becomes cloudy, it is like the lens of the camera is worn out, which will affect the quality of the camera image. If it is replaced with a good transparent lens, it can take a clear picture. This is what we usually call corneal transplantation. Therefore, the prerequisite for corneal transplantation is to confirm that the functions of the retina, optic nerve, and visual center of the brain are normal. If there is no good film, simply changing the lens is useless. The normal cornea is as clear as crystal, also known as "black eyeballs". It is equivalent to a transparent window in the structure of the human eye. Although it is only half a millimeter thick, it not only forms the outer wall of the eye, but also has a powerful focusing function to light. Focus on the retina. When the cornea becomes cloudy due to various reasons and affects vision, a clean and clear cornea can be replaced by corneal transplantation to restore vision.

In China, corneal transplantation is suitable for corneal turbidity or edema caused by various reasons, which seriously affects vision: such as corneal turbidity caused by recurrent viral keratitis, and patients who have not completely relapsed within six months after being completely cured. Corneal transplantation may be considered; corneal opacity patients who have been burned with acid and alkali chemicals can perform corneal transplantation after one year of healing; corneal ulcers have a large scope, deep invasion, and long-term cure, and there is a danger of perforation or failure of drug treatment Corrupted corneal ulcers should immediately undergo corneal transplantation; patients with congenital corneal degeneration, keratoconus, corneal stroma degeneration, and decompensation of corneal endothelial cells should also undergo corneal transplantation immediately; corneal tumors, corneal fistula, cornea Corneal transplantation can be considered in patients with osteoma; corneal transplantation can also be considered in patients with blind leukoplakia to improve appearance.

Corneal transplant material source

The donor cornea used for corneal transplantation is donated by others. Generally, healthy people aged 6 to 60 are suitable corneal donors. It is not suitable if the donated cornea has a history of surgery, or has glaucoma or eye tumors.

At present, some big cities in China have established their own eye banks, and are making more corneal blind patients get the opportunity of corneal transplantation. The central task of the eye bank is to collect, preserve, and study corneal materials and other eye tissues, to provide corneal materials in a timely and reasonable manner for corneal transplantation operations, etc., to meet the needs of the majority of blind people.

Corneal transplant classification

Corneal penetration

Penetrating corneal transplantation is a method in which full-thickness transparent cornea replaces full-thickness opaque and diseased cornea. According to the purpose of surgery, indications can be divided into optical, therapeutic, forming, and cosmetic aspects. The common indications of optical corneal transplantation are keratoconus, corneal scars caused by various reasons, corneal dystrophy of various kinds, and corneal endothelial cell failure caused by various reasons. The main indications of therapeutic corneal transplantation are infectious corneal disease and ocular chemical injury. Penetrating keratoplasty carries the risk of immune rejection.

2. Lamellar corneal transplantation

Lamellar corneal transplantation is a partial thickness corneal transplantation. During the operation, only the diseased tissue in front of the cornea was removed, and then a transparent corneal donor with a partial thickness was transplanted to repair the resected area. The chance of immune rejection after surgery is low. It is commonly used in the treatment of middle and superficial corneal opacities, corneal dystrophic opacities, corneal keratoconus, superficial corneal infections, and corneal tumors.

3. Artificial corneal transplantation

Artificial corneal transplantation is a special optical device made of transparent medical polymer materials. It is surgically implanted into the corneal tissue to replace part of the corneal scar tissue and restore vision. Because the corneal tissue rejection of synthetic materials and other issues have not been finally resolved, the long-term effect is not good, and often causes the leakage of aqueous humor at the transplant site and the exfoliation of the graft, so it is currently not widely used. At this stage, artificial cornea is only suitable for binocular blindness after suffering from various serious corneal diseases, especially all corneal leukoplakia caused by severe chemical burns and multiple corneal transplantation failures, and no other surgery can be performed.

Corneal transplantation indication

Corneal diseases make the cornea transparent and cloudy, affecting people with vision, such as leukoplakia, corneal creases, keratoconus, glaucoma, or corneal bullous keratopathy after corneal surgery, corneal dystrophy, and some types of cornea Ulcers and so on.

Corneal transplant complications

1. Rejection: All organizations that transplant others may have rejection;

2. Various infections of the eyes;

3. Glaucoma

4. Loosening of corneal sutures;

5. Postoperative refractive error.

Corneal transplantation precautions

Surgery is only a part of corneal transplantation. Postoperative management and self-care are also important aspects of corneal transplantation.

1. Periodic review.

2. Corneal suture removal time is determined by the doctor

If the patient's vision is good when the suture is present and the corneal topographic map is regular, consider retaining the suture for a long period of time, because the removal of the suture may change the curvature of the cornea, resulting in significant astigmatism, leading to a significant decrease in vision after suture removal .

3. Pay attention to rejection

Rejection often occurs within 6 months after surgery, but it also occurs in some patients several years after surgery. Therefore, if the patient feels red eyes, pain, sudden vision loss, and corneal grafts become cloudy, they should go to the hospital immediately. Those with the best conditions can return to the surgery hospital for follow-up.

4. Safe and effective eye drops

Be careful not to touch the corneal graft with the dropper tip; use two or more eye drops alternately, every few minutes to ensure the concentration of the drug in the eye.

5. Reasonable diet

Properly supplement nutrition to enhance the body's resistance; eat more fruits and vegetables to maintain smooth stool; eat less spicy and greasy food.

6. Pay attention to activities and rest

Pay attention to eye hygiene, do not rub your eyes; wear protective glasses when going out to avoid touching the eye. Nerve consciousness has not been established within one year of transplantation, so it has no sensation and is easy to be injured, so care should be taken to avoid friction. For patients with herpes simplex virus, care should be taken to prevent colds, upper respiratory tract inflammation, and overwork after surgery. Do not smoke to prevent recurrence of keratitis.