Corneal Transplantation and Corneal Surgery: Procedures, Process, and Postoperative Care for Corneal Transplantation

The cornea of the eye consists of several layers and protects the sensitive interior of the eye. It is clear and requires a regular supply of tears to stay moist. The curvature of the cornea refracts incoming light, thereby contributing to sharp vision.

The Cornea and Its Layered Structure

Diseases can cause the cornea to become cloudy, preventing the eye from absorbing enough light. This impairs vision and can even lead to blindness.

You can prevent this process through a corneal transplant or the implantation of an artificial cornea.

Corneal surgery is recommended when a condition is present that impairs vision or poses a risk of blindness.

These conditions include:

• Fuchs’ endothelial dystrophy (hereditary): As a person ages, tear fluid can no longer be pumped from the cornea into the anterior chamber of the eye, causing the cornea to swell
• Sjögren’s syndrome: An autoimmune disorder of the lacrimal glands that leads to dry eyes
• Corneal degeneration: wear and tear, atrophy, degeneration, and wasting
• Inflammation of the cornea caused by bacteria, viruses, or fungi
• Ulcers
• Scarring
• Corneal curvature, particularly keratoconus

Preliminary examinations determine whether corneal surgery is necessary

Below, we briefly introduce some common procedures used in corneal surgery.

• Corneal Transplant (Keratoplasty)

A corneal transplant involves the donation of tissue from a deceased person. The patient is placed on a waiting list. As soon as a suitable cornea becomes available, doctors harvest it and implant it into the recipient within 72 hours.

To do this, doctors precisely cut out the healthy and diseased corneas in a circular shape. This is done using a laser or a scalpel.

They then implant the donor cornea into the recipient’s eye and suture it in place. The more precise the incision, the better the healing process.

In 20% of corneal transplants, a rejection reaction occurs within five years. After 15–20 years, a repeat transplant is often necessary because the density of the donor cornea decreases more rapidly than that of the recipient’s own cornea.

Eye after a corneal transplant

Corneal diseases can lead to blindness. Unlike lens replacement, corneal replacement is associated with significant challenges.

The goal of corneal surgery is to prevent blindness or restore vision. Advances in ophthalmology now make it possible to avoid corneal replacement through cross-linking or corneal laser treatment.

However, corneal surgery also carries risks, such as:

• Impaired night vision, as the eye has difficulty processing light-dark contrasts
• Infections resulting from the procedure
• Deterioration of the cornea due to tissue removal during the procedure
• Increased intraocular pressure, which can lead to corneal astigmatism and negatively affect visual acuity
• A very low risk of vision deterioration, up to and including blindness

With corneal transplantation, there is also the risk of rejection and an immune response. 

Early signs include:

• Persistent tearing
• Redness 
• Persistent deterioration of vision

There is also a risk of losing certain cells from the donor tissue, which may require a timely repeat transplant. Furthermore, as with any medical procedure, corneal surgery carries risks. These range from the general anesthesia to complications associated with the surgery itself.

In conclusion, a corneal transplant is a complex but highly effective procedure when surgery becomes necessary. A corneal transplant may be necessary, particularly in cases of severe corneal diseases or other corneal conditions, when the patient’s own cornea is no longer functional.

The corneal transplant is performed at a specialized eye clinic, where a thin slice of the diseased cornea is removed and replaced with healthy donor tissue. Depending on the findings, either the entire cornea or only individual layers are replaced, for example through deep anterior lamellar keratoplasty or modern procedures such as membrane endothelial keratoplasty. In penetrating keratoplasty, the entire cornea is replaced, whereas lamellar methods specifically treat only the affected areas. During the procedure, the recipient’s cornea is precisely prepared, and the new cornea is carefully inserted and sutured in place.

Follow-up visits are important on the first day after surgery and the following day to monitor the healing process. In the weeks following surgery—and especially during the first few weeks—vision may gradually improve. However, it is important to note that the complete healing process can take several months. The operated eye must be well protected during this time, as the cornea is sensitive to external influences and may be at risk from chemical burns or infections, for example.

Modern techniques ensure that the cornea is replaced, often restoring its natural curvature and the proper refraction of light rays. In some cases, existing corneal curvature or astigmatism can also be corrected, reducing patients’ reliance on glasses or contact lenses. Nevertheless, as with any surgical procedure, there are certain risks and complications, such as a possible rejection reaction or a risk of infection. The goal of the treatment is to improve vision and prevent potential vision loss.

The cornea is obtained from a specialized cornea bank that provides suitable tissue. This ensures that the healthy donor cornea is replaced and optimally integrated into the corneal tissue. The procedure is typically performed under controlled conditions so that the cornea can be transplanted and securely fixed in place. Some modern techniques also use lasers to enable even more precise incisions.

In general, a corneal transplant is necessary when conservative methods are no longer sufficient to preserve, treat, or restore the eye’s function. Despite all the advances, the procedure remains technically demanding, as it is complex and requires experienced specialists.