Corneal transplantation

What is Keratoconus?

Before discussing keratoconus, let’s understand what the cornea is.

The cornea is an extremely thin and highly transparent layer located at the front of the eye, allowing for the visualization of the iris and pupil. The cornea focuses the incoming light rays onto the retina, which is located at the back of the eye. The image is then transmitted as neural signals to the visual center of the brain, where the process of vision occurs. The entire process takes only fractions of a second.

However, in the case of keratoconus, the normal spherical shape of the eye is altered, and the cornea undergoes structural changes. The central area of the cornea becomes thin and bulges outward, causing the cornea to assume a conical shape. This is why it is called keratoconus.

Symptoms of Keratoconus

The symptoms of keratoconus vary depending on the severity of the condition and its progression. They may include:

• Blurred and distorted vision.
• Lack of clarity in near and distant objects.
• Difficulty with night driving.
• Light sensitivity and discomfort from glare.
• The need to constantly change prescription glasses due to changing measurements.
• Chronic headaches resulting from eye strain.
  

  Complications of Untreated Keratoconus

If the condition is neglected, and appropriate medical intervention is not sought in a timely manner, several undesirable complications may occur, including:

• Rapid corneal swelling, leading to a significant and sudden decrease in visual quality.
• Collapse of the inner lining of the cornea.
• Formation of opacities and cloudy patches that permanently affect vision.
• Corneal scarring, which is one of the most severe complications and may require urgent corneal transplantation.

Conditions that Require Corneal Transplantation

There are certain medical conditions and exceptional circumstances that necessitate performing a corneal transplant as soon as possible. Among these cases that require immediate therapeutic intervention, we can mention:

– Presence of scars or ulcers on the cornea resulting from severe injuries or eye infections.
– Corneal swelling, as seen in untreated cases of keratoconus.
– Complex eye surgeries.
– Inherited eye diseases, such as Fuchs’ dystrophy.

Treatment Options for Keratoconus

Dr. Ammar Nassar aims to halt the progression of keratoconus in patients, to prevent complications and achieve the best therapeutic solution for improving visual quality. This is accomplished through:

• Prescription glasses/medical contact lenses: These are used in cases of mild to moderate keratoconus to significantly improve visual acuity.
• Implantation of corneal rings or inserts: This is the preferred solution for moderate cases, as it corrects the corneal shape and reduces surface irregularities.
• Corneal cross-linking: One of the most effective therapeutic interventions when keratoconus is detected early. It involves using ultraviolet light and riboflavin on the cornea to strengthen and increase the number of collagen fibers. This directly stabilizes the cornea and slows down disease progression.
• Surface laser ablation for corneal correction: This procedure cannot be generalized to all cases of keratoconus. It is specifically designed for certain cases where the corneal thickness allows for the use of low-dose excimer laser to correct corneal irregularities resulting from corneal damage. The procedure is further stabilized with ultraviolet light. It is crucial that the performing physician is highly skilled and experienced.
• Corneal transplantation: This is a preferred treatment option for many ophthalmologists, especially when the condition of keratoconus deteriorates to a point where other treatment methods no longer provide sufficient vision correction. Partial or full corneal transplantation remains the most suitable approach.

Types of Corneal Transplantation Procedures

Each patient with keratoconus has a unique condition, and therefore, the treatment approach cannot be standardized for all patients. Among the procedures commonly used to treat this condition are:

1. Penetrating Keratoplasty (PKP) – Full Thickness Corneal Transplantation

This procedure is performed when a patient requires the replacement of all layers of the cornea due to extensive damage or severe scarring and ulcers caused by external injuries. In this procedure, the entire lens is replaced, and the new lens is sutured with precise surgical stitches. The healing process typically takes several months.

2. Deep Anterior Lamellar Keratoplasty (DALK) – Partial Thickness Corneal Transplantation

Unlike full thickness corneal transplantation, in DALK, only the deeper layers of the cornea are replaced. This procedure is suitable for patients with conditions such as Fuchs’ dystrophy. There are two main types of DALK:

• Descemet’s Membrane Endothelial Keratoplasty (DMEK): In this procedure, both the Descemet’s membrane and the corneal endothelium are transplanted without relying on the stroma. Patients undergoing this type of surgery have fragile and thin corneal tissue, making it necessary for an experienced surgeon to perform the operation. The recovery is typically rapid, and the postoperative improvement is very good.
• Deep Anterior Lamellar Keratoplasty (DALK): This procedure involves the excision of the inner lining of the cornea, along with the underlying Descemet’s membrane. The excised tissue is replaced with a new lamellar graft and Descemet’s membrane. The use of the stromal bed in the middle layer of the cornea facilitates the handling of the new tissues.

3. Anterior Lamellar Keratoplasty (ALK) – Superficial Corneal Transplantation

This procedure targets the outer and middle layers of the cornea. These layers are removed and replaced with new layers taken from a recently deceased donor, ensuring their safety. The layers are separated using controlled air currents to facilitate their manipulation. One disadvantage of this procedure is that it is susceptible to rejection, and the patient may require a subsequent full corneal transplantation.

4. Corneal Transplantation with Stem Cells

Many scientific studies and research have been conducted, particularly at high-level research centers in the United States, exploring the potential use of stem cells to create a healthy cornea for transplantation instead of a damaged cornea. However, the feasibility of using stem cells for corneal regeneration has not been established to date.

Preoperative Preparations for Corneal Transplantation

Patients should adhere to certain guidelines and instructions provided by their supervising physician to achieve the best possible results from corneal transplantation. Some of these recommendations include:

• Schedule the operation with Dr. Ammar and visit him before the procedure for a comprehensive and rapid eye examination.
• Undergo certain laboratory tests to ensure the patient’s health during and after the procedure, such as bleeding time and clotting speed tests.
• Discontinue certain types of chronic medications as advised by the doctor, such as anticoagulants and antiplatelet drugs like aspirin and clopidogrel.
• The doctor may prescribe certain eye drops, such as antibiotic-containing drops, to prevent bacterial infection during the procedure. In this case, the patient should strictly adhere to the prescribed schedule for applying these drops.

Important Postoperative Tips after Corneal Transplantation

The postoperative period following corneal transplantation is a delicate phase that requires extra attention from the patient and supervision from the medical center to prevent complications and side effects. Some important tips that patients should adhere to include:

• Regularly apply the prescribed eye drops as instructed by the doctor, as they significantly reduce the risk of immune rejection and protect against bacterial infection.
• Wear protective eye shields in the first few days after the procedure to safeguard the eyes from external factors.
• Avoid engaging in vigorous physical exercise and refrain from making sudden movements to keep the transplanted cornea in its proper position.
• Refrain from applying pressure to or rubbing the eyes.

Complications Following the Procedure

While corneal transplantation is one of the most successful and safest eye surgeries, it is worth noting that some patients may engage in improper habits or experience unforeseen accidents that can lead to unwanted complications. Some of these complications include:

• Bacterial infection due to inadequate care and attention to eye dressings.
• Eye hemorrhage, which can occur in some cases as a result of external mechanical trauma.
• Increased intraocular pressure (glaucoma).
• Cloudy opacity above the lens of the eye known as cataract.
• Swelling of the cornea.
• Retinal detachment, where the inner or posterior surface deviates from its normal position.
• Immune rejection of the transplanted cornea, which is the most severe complication.

Find the Best Corneal Doctor in Egypt

Determining the best eye doctor and the qualities that make them stand out can be challenging, especially with numerous options and dozens of doctors in one area. All these thoughts can cloud the patient’s mind, as they fear any harm or minor error that could result in vision loss.

In reality, every patient has the right to be concerned. However, when discussing the best eye doctor, it is not solely about surgical expertise or the correct application of therapeutic procedures. The focus extends to:

• Accurate diagnosis.
• Effective communication and interpersonal skills.
• Respecting the patient and addressing their concerns.
• Performing surgery with precision and high professionalism.
• Postoperative follow-up and patient care.
• Ensuring the patient’s well-being and achieving desired outcomes.

All these qualities are embodied in Dr. Ammar Nassar’s center, which has been recognized as one of the best eye doctors in the Arab Republic of Egypt. Let’s delve into some information about keratoconus before discussing Dr. Ammar Nassar’s academic qualifications and esteemed positions.