The cornea, the eye’s clear and transparent outer layer, is crucial for transmitting light and enabling vision. However, any opacity in the cornea can lead to severe visual impairment or blindness. In India, corneal opacities are the second leading cause of blindness among people aged 50 and older, and the primary reason for younger patients. With approximately 1.2 million people affected by corneal blindness, the demand for corneal transplants has increased manifold. While an estimated 100,000 transplants are required annually, only 25,000 to 30,000 procedures are performed due to a significant shortage of donor corneas. However, there are many myths about corneal transplants. We got in touch with Dr Gulapalli Nageswara Rao, Founder- L.V Prasad Eye Institute, Hyderabad who debunks myths and states facts on corneal transplants.

Corneal Transplants ⁠Myths Vs Facts

Myth: The Whole Eye Is Transplanted

Fact: Only the cornea is transplanted. The cornea is the clear outer layer at the front of the eye that helps focus light. The sclera, or the white part of the eye, can also be donated. There is absolutely no disfigurement of the body when the cornea is donated as a lens is placed to cover the area of the cornea.

Fact: Cornea donation is to be made only after death and ideally retrieved. Within 6 - 8 hours after death is ideal however, this can be extended to 12 - 24 hours if the body is placed in an air-conditioned environment. The cornea can be retrieved/donated at home, funeral homes, hospices, or a hospital. The process of cornea retrieval hardly takes 15 minutes. The cornea is then preserved in a specialized medium and stored at a regular refrigerator temperature. These corneas are viable for up to 4 days, but the sooner it is used the better. There is also an alternative form of preservation that lasts for up to 10 days.

Fact: No. It is possible to donate corneas even if a person has poor eyesight. Corneal tissues are retrieved from deceased people of all ages. Corneas are not retrieved only when donors have a history of eye diseases that affect the cornea, or some infectious diseases, such as HIV, hepatitis B and C, and syphilis, to prevent the transmission of diseases from donor to recipient. Donors with certain medical conditions, such as autoimmune diseases, cancers that could metastasize to the eye, or systemic infections, will be excluded.

Fact: The cornea does not have any blood vessels. So, most cancer patients can also donate their corneas. Only in cases where cancers could metastasize to the eye, will the cornea not be used for transplantation. It would be used for research or training purposes.

Fact: There is absolutely no disfigurement of the body when the cornea is donated. The process of cornea retrieval hardly takes 15-20 minutes. They can be retrieved at the home of the deceased, the place of the funeral or the hospital, wherever the body is present.

When Is Corneal Transplant Needed?

Dr Rao shares that a corneal transplant is typically recommended when the cornea (the clear, dome-shaped surface at the front of the eye) becomes damaged or diseased in ways that severely impair vision and are not treatable by any other means. Some of the eye conditions that may require a corneal transplant include:

1. Keratoconus: A progressive condition where the cornea thins and bulges into a cone shape, distorting vision. In severe cases, a corneal transplant may be necessary to restore vision if other treatments, like rigid contact lenses or corneal cross-linking, are not effective.

2. Corneal Scarring or Clouding: Trauma, infections, or other injuries to the cornea can lead to scarring or cloudiness that obstructs vision. Common causes include injury, herpes simplex keratitis, a viral infection, or fungal infections.

3. Fuchs' Endothelial Dystrophy: This genetic condition affects the innermost layer of the cornea, leading to fluid buildup and swelling, which can blur or distort vision. A corneal transplant can help by replacing the damaged cells.

4. Corneal Edema (Swelling): Edema can occur from conditions like Fuchs' dystrophy or after cataract surgery, where the corneal endothelial cells fail to pump out fluid properly. Persistent swelling that leads to vision impairment may require a transplant.

5. Corneal Ulcers and Infections: Severe, recurrent corneal ulcers or infections, often from bacteria, fungi, or viruses, can lead to scarring and vision loss. If scarring is extensive, a transplant may be necessary to restore clarity.

6. Chemical Burns or Trauma: If the eye has been injured in a chemical burn, blunt trauma, or other injury, it can cause permanent damage to the cornea that may only be corrected with a transplant.

7. Previous Failed Corneal Transplants: In cases where a previous corneal transplant has failed due to rejection or other complications, a repeat transplant (re-grafting) may be needed.

The type of transplant procedure can vary, with options including full-thickness transplants (penetrating keratoplasty) and partial-thickness transplants (like DSAEK or DMEK) that replace only the damaged layers. The choice of procedure depends on the specific condition affecting the cornea.

What Are The Risks And Complications In A Corneal Transplant Surgery?

Dr Rao explains that corneal transplant surgery, while often successful, carries a few risks and complications much like any other transplant surgery.

- Graft rejection occurs when the body’s immune system attacks the transplanted cornea. This is one of the most common complications, with symptoms such as redness, sensitivity to light, vision changes, and eye pain.

- Signs of rejection often appear within the first year but can occur years later. Rejection risk varies with type of transplant, with full-thickness transplants having higher rejection rates than partial-thickness procedures like DMEK.

- Post-surgery infections can affect the eye's surface or deeper layers. Infections can cause inflammation, pain, and discharge and may harm the graft.

- Sterile handling and proper post-operative care can reduce this risk, but it remains a serious potential complication.

- Corneal transplant surgery can increase intraocular pressure (IOP), potentially leading to glaucoma, a condition that damages the optic nerve and can cause vision loss.

- Regular monitoring of IOP after surgery is essential, as glaucoma may require medication or even surgery if it is not controlled through medication.

- Corneal transplants can sometimes cause irregular astigmatism, where the cornea’s shape changes unevenly, leading to blurred or distorted vision.

- This may require corrective lenses, and in some cases, additional surgery to correct it.

- Sutures (stitches) used to hold the transplant in place can lead to problems like infection, irritation, or even loosening, which can affect the graft’s position or healing.

- Sometimes sutures may need to be removed or replaced earlier than planned if complications arise.

6. Swelling or Oedema: (Primary graft failure)

- Swelling of the cornea can occur if the endothelial cells (the innermost layer) do not function well. Persistent oedema can affect vision and, in severe cases, require additional treatment or even another transplant.

- Some patients may experience delayed healing due to factors like age, immune response, or pre-existing conditions. Delayed healing increases the risk of infection and other complications.

- Certain conditions, such as herpes simplex keratitis or dystrophies, can recur in the transplanted cornea, potentially leading to graft failure.

9. Postoperative infection

- This is a rare but serious infection of the eye’s interior, which can cause severe inflammation and damage, potentially leading to vision loss. This requires prompt medical attention and aggressive treatment.

“Anti-rejection and anti-inflammatory medications, and antibiotics usually in the form of eye drops, are prescribed post-surgery to reduce the risk of rejection and infection. Regular follow-ups with the eye surgeon are essential for early detection and prompt treatment of any problem,” he said.

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