Corneal Transplant

The corneal transplant process begins with a comprehensive evaluation of the patient's eye condition to determine the most suitable type of transplant. Donated corneas are obtained from accredited eye banks, where they undergo rigorous testing to ensure their safety and absence of diseases. There are several types of corneal transplants depending on the affected part of the cornea: Penetrating Keratoplasty (PK), which involves replacing all layers of the cornea, and Lamellar Keratoplasty, which replaces only specific layers, such as Deep Anterior Lamellar Keratoplasty (DALK) for the front and middle layers, and Endothelial Keratoplasty (EK) like DSAEK and DMEK for the inner endothelial layer. The surgery is performed under local or general anesthesia, where the damaged portion of the patient's cornea is removed and replaced with the donor cornea. The donor cornea is secured with very fine stitches in full-thickness or anterior lamellar transplants, or with an air bubble to help position the tissue in endothelial transplants. The surgery typically takes between one to two hours. After the surgery, a shield is placed over the eye, and the patient is given eye drops and medications to aid healing and prevent rejection.

Symptoms that may indicate the need for a corneal transplant are often related to vision deterioration and pain due to corneal damage. These symptoms include:

• Severe blurring or clouding of vision: Even with the use of eyeglasses or contact lenses.
• Increased sensitivity to light (photophobia): With difficulty seeing in bright light.
• Eye pain: Can be acute or chronic, especially in cases of severe ulcers or swelling.
• Redness in the eye: May be accompanied by discharge in cases of infection.
• Change in the shape of the cornea: Such as severe bulging in advanced keratoconus.

The causes that lead to corneal damage and necessitate a transplant are varied and include:

• Keratoconus: A progressive disease where the cornea thins and bulges into an abnormal cone shape.
• Fuchs' Endothelial Dystrophy: A hereditary condition affecting the endothelial cells in the cornea, leading to fluid buildup, corneal swelling, and blurred vision.
• Corneal scarring: Resulting from severe inflammation (such as herpes simplex), infections (like bacterial or fungal corneal ulcers), traumatic injuries, or chemical burns.
• Corneal failure after other eye surgeries: Such as certain complications of cataract surgery.
• Hereditary corneal dystrophies: A group of genetic disorders affecting the transparency of the cornea.
• Rejection of a previous corneal transplant: In some cases, the body may reject a previously transplanted cornea, requiring a re-transplant.

Diagnosis to determine the need for a corneal transplant relies on a comprehensive clinical eye examination and a detailed medical history. Diagnostic methods include:

• Slit-lamp examination: Allows the doctor to examine the different layers of the cornea and determine the extent of damage or changes.
• Visual acuity test: To determine the degree of vision impairment.
• Keratometry: To measure the curvature of the cornea.
• Corneal Topography / Tomography: To create a detailed map of the cornea's shape and surface, especially useful in diagnosing and monitoring keratoconus.
• Pachymetry: To measure corneal thickness, which can be affected in conditions like Fuchs' dystrophy.
• Endothelial cell count: To assess the health and density of endothelial cells, which are essential for maintaining corneal transparency.

The primary treatment for severe corneal damage unresponsive to other therapies is corneal transplant. Treatment stages include:

• Evaluation and determination of the appropriate transplant type: Based on the cause and type of corneal damage and the affected part.
• Obtaining the donor cornea: The cornea is requested from an accredited eye bank after the donor's death and necessary tests are performed.
• Preparation for surgery: Includes performing general medical tests for the patient and discussing the details of the surgery and potential risks.
• Surgery: The surgery is performed in a sterile operating room under appropriate anesthesia. The surgeon removes the damaged part of the patient's cornea and replaces it with the donor cornea using fine surgical instruments.
• Post-operative care: Includes using anti-inflammatory and antibiotic eye drops and other medications as needed to prevent infection, reduce the risk of rejection, and aid healing. The patient must strictly follow the doctor's instructions and attend follow-up appointments regularly.
• Suture removal (if applicable): In cases of full-thickness or anterior transplants, sutures may remain for several months to a year or more before being gradually removed based on tissue healing.
• Vision correction: After the transplanted cornea stabilizes, the patient may need eyeglasses, rigid contact lenses, or laser procedures to improve vision and correct any astigmatism resulting from the surgery.