KERATOPLASTY 

Types of Keratoplasty

1. Penetrating Keratoplasty (PKP): In penetrating keratoplasty, the entire thickness of the damaged cornea is removed and replaced with a donor cornea. This type of transplant is used when the entire cornea is damaged or diseased.

   • Indications:
     • Severe corneal scarring
     • Corneal infections
     • Keratoconus (thinning of the cornea)
     • Fuchs’ dystrophy (a condition causing corneal swelling)
   • Benefits:
     • Complete restoration of corneal clarity and function.
     • Can improve vision significantly, especially if the original cornea was severely scarred.

2. Lamellar Keratoplasty: Lamellar keratoplasty involves the replacement of only part of the cornea. This type is often preferred when only specific layers of the cornea are damaged. It can be either anterior lamellar keratoplasty (only the front layers of the cornea are replaced) or posterior lamellar keratoplasty (only the back layers of the cornea are replaced).

   • Indications:

     • Fuchs’ dystrophy (posterior lamellar keratoplasty)
     • Keratoconus (anterior lamellar keratoplasty)
     • Corneal scars that do not affect the entire cornea

   • Benefits:

     • Less risk of rejection because the transplant only involves partial layers of the cornea.
     • Faster recovery time compared to full-thickness transplants.

3. Descemet’s Membrane Endothelial Keratoplasty (DMEK): DMEK is a modern, highly advanced form of posterior lamellar keratoplasty in which only the inner layer of the cornea (Descemet’s membrane and endothelial cells) is transplanted. This technique is especially used for treating conditions like Fuchs’ dystrophy and other endothelial disorders.

   • Indications:

     • Fuchs’ dystrophy
     • Endothelial dystrophy
     • Corneal swelling that does not involve other corneal layers

   • Benefits:

     • Faster visual recovery.
     • Minimal risk of rejection compared to full-thickness transplants.
     • Less postoperative astigmatism.

Why Keratoplasty is Performed

Keratoplasty is performed for several reasons, including:

• Corneal scarring: Resulting from injury, infections, or previous surgeries.
• Keratoconus: A condition where the cornea becomes thin and cone-shaped, affecting vision.
• Fuchs’ dystrophy: A disease that causes the inner layer of the cornea to deteriorate, leading to corneal swelling and vision problems.
• Corneal ulcers: Resulting from infections, often due to trauma or diseases like herpes simplex.
• Corneal edema: Swelling of the cornea, leading to blurry vision, which may result from endothelial cell dysfunction.

Benefits of Keratoplasty

• Restoration of Vision: Keratoplasty is often performed to restore vision in patients with significant corneal damage or disease.
• Improvement in Quality of Life: Successful transplants can improve the patient’s quality of life by restoring their ability to perform daily activities, such as driving, reading, and recognizing faces.
• Long-Term Success: Many patients experience long-term improvements in vision following a corneal transplant, with the possibility of reduced dependency on corrective lenses.

Risks and Considerations

• Rejection: As with any transplant, there is a risk of the body rejecting the donor cornea. This can be managed with immunosuppressive eye drops.
• Infection: There is a risk of infection following surgery, although this can usually be controlled with antibiotics.
• Astigmatism: Some patients may experience astigmatism after the procedure, which can be corrected with glasses or further surgery.
• Graft Failure: The donor cornea may fail over time, requiring another transplant.
• Glaucoma: Increased eye pressure may occur after the transplant, leading to glaucoma in some cases.
• Delayed Recovery: Vision may not be fully restored immediately. Recovery can take several months, and full visual recovery may take up to a year or longer.

Postoperative Care

After keratoplasty, patients typically need to follow a strict postoperative regimen:

• Eye Drops: To prevent infection and reduce inflammation.
• Avoiding Trauma: Patients are advised to protect their eyes from physical trauma and avoid rubbing them.
• Follow-up Appointments: Regular follow-ups are essential to monitor healing and detect any potential complications, including rejection or infection.
• Avoiding Strain: Patients may need to avoid activities that can strain the eyes, such as reading or using digital screens, until the eye has healed sufficiently.

Ideal Candidates for Keratoplasty

• Severe Corneal Disease: Patients with conditions such as advanced keratoconus, Fuchs’ dystrophy, or corneal scarring from injury or infection.
• Unsuccessful Other Treatments: When other treatments like medication or contact lenses have failed to improve vision.
• Healthy Overall Health: Candidates should be in generally good health, as certain underlying health conditions can affect the healing process.

Conclusion

Keratoplasty (corneal transplant) is a life-changing procedure for individuals suffering from significant vision loss due to corneal diseases, trauma, or genetic conditions. Whether a full-thickness transplant (PKP) or a partial transplant (lamellar keratoplasty), this surgery can restore clarity and function to the cornea, greatly improving the patient’s quality of life. Consulting with an experienced ophthalmologist is crucial to determine the best type of keratoplasty based on the individual’s specific condition.