Our Summary

This research paper discusses the potential solutions for the global shortage of human corneas needed for transplant surgeries. The only cure for corneal opacity (cloudiness in the eye) is through corneal transplant, but there’s a shortage of human corneas available for this procedure.

To address this, researchers have been looking at using pig corneas as substitutes. These can be from wild-type pigs, genetically modified pigs, corneas from pigs that have had all cells removed (decellularized), or pig corneas that have had all cells removed and then had human cells added back in. This last option could even use the patient’s own cells. All options except for using corneas from wild-type pigs could potentially lower the risk of the recipient’s immune system rejecting the transplant.

However, there’s no standardized method yet for completely removing all cells from a pig cornea. This paper reviews nine different ways of doing this, each with different efficiency, safety, and effects on the cornea’s structure. Some of these methods include using chemicals like sodium dodecyl sulfate or triton x-100, using high hydrostatic pressure, or freeze-thawing. The researchers suggest that combining different methods might be more effective for completely removing all cells from a pig cornea.

FAQs

  1. What is the current solution for corneal opacity and what is the challenge with it?
  2. How could pig corneas potentially be used in corneal transplants and what benefits could they have?
  3. What are some of the methods researchers are considering for removing cells from pig corneas?

Doctor’s Tip

A doctor might tell a patient undergoing a corneal transplant that there is promising research being done on using pig corneas as substitutes due to the global shortage of human corneas. They would explain that using pig corneas could potentially lower the risk of rejection by the recipient’s immune system. The doctor might also mention that there is ongoing research to find the most effective method for completely removing all cells from a pig cornea to ensure safety and success of the transplant.

Suitable For

Typically, patients who are recommended for corneal transplant surgery are those suffering from corneal diseases or conditions that cannot be treated through other means such as medication or corrective lenses. These conditions may include:

  1. Corneal scarring: Scarring of the cornea can occur due to injuries, infections, or certain diseases, leading to vision impairment that cannot be corrected with glasses or contact lenses.

  2. Keratoconus: This is a progressive thinning of the cornea that causes it to bulge outwards, resulting in distorted vision. In severe cases, a corneal transplant may be necessary to improve vision.

  3. Fuchs’ dystrophy: This is a hereditary condition where cells in the inner layer of the cornea deteriorate over time, leading to swelling and cloudiness in the cornea. A corneal transplant may be recommended to restore clear vision.

  4. Corneal ulcers: Severe infections or injuries to the cornea can result in the formation of ulcers that do not heal properly, leading to vision loss. In such cases, a corneal transplant may be necessary to replace the damaged tissue.

  5. Corneal ectasia: This is a condition in which the cornea progressively thins and bulges outwards, leading to distorted vision. In advanced cases, a corneal transplant may be recommended to improve vision.

Overall, patients who are experiencing significant vision impairment due to corneal diseases or conditions that cannot be treated through other methods may be recommended for corneal transplant surgery.

Timeline

Before a corneal transplant, a patient typically experiences a gradual worsening of vision, often due to conditions such as corneal scarring, keratoconus, or Fuchs’ dystrophy. They may undergo various treatments such as glasses, contact lenses, or medications to manage their symptoms. However, if these treatments are no longer effective, a corneal transplant may be recommended by their ophthalmologist.

After the decision is made to proceed with a corneal transplant, the patient will undergo a series of pre-operative evaluations to assess their overall health and determine the best course of action for the surgery. This may include obtaining consent, conducting various eye tests, and discussing the details of the procedure with their surgeon.

During the corneal transplant surgery, the patient will be given local or general anesthesia, depending on the type of transplant being performed. The surgeon will remove the damaged or diseased cornea and replace it with a healthy donor cornea. The surgery typically takes about an hour to complete.

After the surgery, the patient will be monitored closely for any signs of infection or rejection of the transplanted cornea. They will be prescribed medications to prevent infection and reduce inflammation, as well as eye drops to promote healing. The patient will need to attend follow-up appointments with their surgeon to ensure the success of the transplant and monitor their progress.

Overall, the timeline for a patient before and after a corneal transplant can vary depending on their specific condition and the type of transplant being performed. However, with proper care and monitoring, most patients can expect to experience improved vision and quality of life following a successful corneal transplant.

What to Ask Your Doctor

  1. What are the risks and benefits of using pig corneas for a corneal transplant compared to using human corneas?
  2. How likely is it that my immune system will reject a pig cornea transplant compared to a human cornea transplant?
  3. What is the success rate of corneal transplants using pig corneas compared to human corneas?
  4. Are there any long-term complications or side effects associated with using pig corneas for a corneal transplant?
  5. How do you determine which type of pig cornea transplant would be best for me - wild-type, genetically modified, decellularized, or with human cells added back in?
  6. What is the process for removing all cells from a pig cornea, and how is this different from traditional human cornea transplants?
  7. What is the recovery time and post-operative care like for a pig cornea transplant compared to a human cornea transplant?
  8. Are there any limitations or restrictions on activities or lifestyle changes I should be aware of after receiving a pig cornea transplant?
  9. How often will I need follow-up appointments and monitoring after a pig cornea transplant?
  10. Are there any ongoing research or advancements in pig cornea transplants that I should be aware of?

Reference

Authors: Isidan A, Liu S, Li P, Lashmet M, Smith LJ, Hara H, Cooper DKC, Ekser B. Journal: Xenotransplantation. 2019 Nov;26(6):e12564. doi: 10.1111/xen.12564. Epub 2019 Oct 28. PMID: 31659811