Corneal transplantation (or keratoplasty) is a type of surgery to replace part of your cornea with corneal tissue from a donor. The cornea is the transparent, dome-shaped surface of the eye. It is the part through which light enters the eye and is the most important part of the ability to see objects clearly around us.
Corneal transplantation may reduce vision but also makes the person feel less pain, and improves the appearance of the damaged cornea. In most cases, corneal transplantation is a successful procedure, but sometimes it may also pose risks to both the donor and the recipient.
Corneal transplantation is often used to restore vision to a person whose cornea has been damaged in a variety of events. Corneal transplantation can also relieve pain or other signs and symptoms associated with corneal disease.
Which conditions may require corneal transplantation?
Corneal transplantation can be a good solution to some problems, such as:
- A protruding cornea. (Corneal hump)
- Fuchs’ dystrophy, which is a hereditary disease.
- Thinning or rupture of the cornea
- Corneal scarring caused by infection or damage to the cornea.
- Corneal swelling
- Corneal ulcers that are not healed with medical treatment.
- Complications of previous eye surgery
What is Fuchs’ Dystrophy?
In Fuchs’ dystrophy, fluid accumulates in the transparent layer of the cornea in front of your eyes, causing swelling and thickening of the cornea. It can lead to blurred vision and eye discomfort.
Fuchs’ dystrophy usually affects both eyes and can gradually worsen your vision. Typically, the disease starts in the 30s or 40s, but many people with Fuchs’ dystrophy have no symptoms until they reach the age of 50 or 60.
Some medications and special care may help reduce the signs and symptoms of Fuchs’ dystrophy. But as the disorder progresses sufficiently, it can have a significant effect on your vision. As mentioned, the best way to treat it, is corneal transplantation.
Symptoms of Fuchs’ dystrophic disease
As the disease progresses, symptoms of Fuchs’ dystrophy, which usually affects both eyes, may include the following:
- Blurred vision, sometimes described as a general lack of clarity of vision.
- Fluctuations in vision that appear with worse symptoms in the morning after waking up and gradually improve throughout the day. As the disease progresses, blurred vision either improves or not.
- Decreased vision in low light and brightness
- Seeing halos around the lights
- Pain or shedding of the skin due to tiny blisters on the surface of the cornea
Possible Complications of Corneal Transplantation
As stated earlier, corneal transplantation is relatively safe. However, like any other medical surgeries, it may cause complications. These side effects include:
- Eye infection
- Increased pressure in the eyeball (glaucoma)
- Problems caused by stitches used to immunize the cornea for the donor.
- Rejection of cornea donor eligibility
- Bleeding
- Retinal problems such as retinal detachment or swelling
- Signs and symptoms of corneal transplant rejection.
- The immune system mistakenly attacking the transplanted cornea, requiring a second surgery.
Signs of Corneal Transplant Rejection
The rejection of the new cornea by the recipient’s body has certain symptoms, including:
1- Vision loss
2- Eye Pain
3- Bloodshot eyes
4- Sensitivity to light
Rejection of the new cornea may happen in 10% of corneal transplantation surgeries.
Necessary Preparations before Corneal Transplantation
Before undergoing corneal transplant surgery, some essential assessments are necessary, including:
- A detailed eye examination
In this examination, the ophthalmologist identifies factors that may cause problems before, during, and after surgery.
- Measuring your eyes
This will determine the size of your cornea and which cornea you will need.
- The medications you are taking will be examined in a separate examination by specialists. You may need to stop taking certain medications for a while.
- Treatment of other medical problems
Unrelated eye problems, such as infection or inflammation, can reduce the success chances of a corneal transplant. The ophthalmologist treats these problems before surgery.
Finding a Corneal Donor
Corneas used in corneal transplantation are from donors who are not alive. If a person has died for unknown causes or the donor has certain conditions, for example contagious diseases, he or she may not be a good choice for corneal transplantation.
Unlike organs such as the liver and kidney, people who need corneal transplants do not need tissue cloning. For example, there is no need for the blood type of the donor and the recipient to be the same. That’s why the waiting list for corneal transplantation isn’t too long.
Corneal Transplantation Methods
In corneal transplantation, the thickness of a patient’s cornea, fully or partially, is removed and replaced with a healthy one. The corneal surgeon will decide which method to use. Corneal transplant methods include:
1- Penetrating Keratoplasty (PK) (full-thickness corneal transplant)
The surgeon cuts the entire thickness of the patient’s abnormal cornea to remove a small piece of corneal tissue the size of a small button. Special tools are used to create this precise circular cut.
The new cornea is then placed in the opening of the previous cornea. Then the surgeon puts the new cornea in place using stitches. These stitches may be removed by an ophthalmologist at a later examination.
2- Endothelial Keratoplasty (EK)
In this procedure, the patient’s eye tissue protects the layers behind the cornea, including the endothelium, and a thin layer of tissue protects the eye from damage and infection. There are two types of Endothelial Keratoplasty.
The first type, called Descemet Stripping Endothelial Keratoplasty (DSEK), uses new corneal tissue to fill one-third of the cornea.
The second type is Descemet Membrane Endothelial Keratoplasty (DMEK), which uses a thinner layer of the new cornea. The second method is more common than the first method.
3- Anterior Lamellar Keratoplasty (ALK)
In two different ways, the patient’s corneal tissue is removed from the anterior layers of the cornea, such as the epithelium and stroma. The depth of corneal damage determines the type of procedure (ALK) for you. Anterior Layer Keratoplasty (SALK) replaces only the anterior layers of your cornea.
When corneal damage extends deeper than the stroma, the Deep Anterior Lamellar Keratoplasty (DALK) technique is used. Healthy tissue is then transplanted from a donor.
4- Artificial Corneal Transplantation (Keratoprosthesis)
In some cases, this method will be used if the person cannot find someone to donate their cornea. Your doctor will explain which corneal transplant method is best for you. He also explains the possible dangers and the process, therefore, there is no need to worry.
Post-Operative Care for Corneal Transplantation
After corneal transplantation, you will receive the medications you need to take. Eye drops and sometimes oral medications immediately after corneal transplantation and during recovery help control infection, swelling and pain.
Eye drops help prevent corneal rejection by the body. Wear blindfolds or glasses during the recovery period. Using them will help you recover faster.
You have to sleep on your back for a while to prevent any eye damage. Avoid risky activities that may cause damage to your eyes and take care of your daily activities slowly. Strictly avoid squeezing or rubbing your eyes.
For the rest of your life, you should be cautious to avoid damaging your eyes. Visit your ophthalmologist regularly to check the condition of your eyes.
The Result of Corneal Transplantation
Most people who have corneal transplant experience partial improvement in their vision. The outcome of the surgery depends on the type of surgery, your ophthalmologist and your physical health condition. The risk of complications or rejection of the new cornea by the body may continue for years.
Therefore, you should visit an ophthalmologist every year to control the risk of corneal rejection. Taking various medications can help reduce this risk. After the surgery, your vision may decrease, but after a few months, it will improve.
Treatments After Corneal Transplantation
After the outer layer of the cornea has healed, you will need to spend several weeks or even months undergoing various treatments under the supervision of your doctor. These courses include:
1- Correction of corneal roughness (astigmatism)
Stitches that hold the new cornea on the eye may cause corneal drooping and bulging, resulting in blurred vision by creating spots. Your doctor may correct these by removing some stitches and tightening some others.
2- Correction of vision
Eye diseases such as myopia and hyperopia can be resolved with glasses, contact lenses, or in some cases, lasers.
Proper Diet in Corneal Transplantation
After corneal transplant surgery, drink plenty of water to flush toxins out of your body and keep your body hydrated. Avoid consuming sugar, because sugar weakens the body’s white blood cells, causing the body to lose its ability to fight off a variety of infections.
Eat lots of red or orange vegetables, such as carrots and dark green vegetables. These vegetables contain beta-carotene, which helps protect the immune system. Garlic is a good antibacterial food that boosts the immune system that you should consume to reduce recovery time.
Pros and Cons of Corneal Transplantation
Corneal transplantation, like all medical surgeries, has advantages and disadvantages.
- Advantages of Corneal Transplantation
Replacing damaged tissue from the patient’s eye with clear, healthy donor tissue can help improve vision. It also acts as reconstructive surgery in cases where it is used to maintain the anatomy and integrity of the patient’s cornea.
The natural anatomy of the cornea is in the form of a small dome, but sometimes, due to some genetic diseases or injuries, the shape of the cornea can be far from ideal, which impedes vision. One of the benefits of corneal transplantation or Keratoplasty is the replacement of the damaged cornea, which improves the appearance of the person. Because the eyes may look completely white or opaque.
- Disadvantages of Corneal Transplantation
There are disadvantages to this procedure. For example, as it was mentioned earlier, there is a risk of rejection in corneal transplantation, i.e. the host tissue in the eye does not accept the tissue of the transplanted cornea. This leads to rash, itching, inflammation, etc.
Recent studies have shown that this can be easily prevented by conducting tests to match blood groups (not tissue matching between host and donor). Since corneal blood is not supplied, the recovery period takes longer and thus increases the chance of infection.
The probability of this happening is greatly reduced by taking a proper antibiotic. Corneal transplantation increases the risk of cataracts. Cataract surgery has become relatively safe over several decades and is no longer a new treatment method. In some patients, stitches may be at risk, which is likely in all medical surgeries. Of course, this treatment can be overcome by treating by professional surgeons and many specialties.
Dangerous Corneal Transplants
Corneal transplantation treats several of diseases, such as:
1- Thinning of the cornea
2- Corneal hump
3- Corneal ulcers
However, corneal transplants are not suitable for people who have already had one damaged eye and may be at increased risk with further treatment. In addition, corneal transplantation is not an option for people who are prone to cataracts. One of the complications of this operation is cataract which may increase the chance of contracting the disease.
Suitable Surgeries for Corneal Treatment
In the following, different types of corneal surgeries are introduced.
- Epidemic Keratoprosthesis
Epidemic Keratoprosthesis is an effective surgical option for the treatment of corneal blindness. In this procedure, an artificial cornea made of a biocompatible polymer is designed to replace the damaged cornea. This tissue is usually selected if donor tissue is not available for corneal transplantation.
Phototherapy Keratectomy (PTK) is one of the latest advances in eye care used to treat corneal dystrophy and infection. In this method, thin layers of the patient’s corneal tissue are vaporized microscopically, and surface irregularities are evacuated with the help of an oximeter. The laser in this method involves great precision that minimizes damage to healthy tissues.
Corneal Transplantation in Iran
More than 40,000 Iranian and foreign patients undergo corneal transplants every month in Iran. Iran is one of the countries with the most successful corneal transplants, owing to the skills of Iranian specialists. Many patients travel to Iran for corneal transplants. Corneal transplantation in Iran has other benefits, including:
1- Low cost of corneal transplantation in Iran
2- Low cost of accommodation in Iran
3- Experienced specialists
4- High number of successful corneal transplantations in Iran
Diagnostic and surgical centers complying with modern European standards perform the highest quality surgery in Iran.
The Cost of Corneal Transplantation
Perhaps the most important part of any surgery is its cost. Due to the importance of this issue, in the continuation of this article, we will state the price of corneal transplantation in different countries.
1- United States: $17,000
2- European countries: $14,500
3- Thailand: $10,400
4- Turkey: $6,700
There is a significant difference between the cost of corneal transplantation in Iran and other countries.
The most important factors of the low cost of this procedure in Iran are:
1- A large number of corneal transplant clinics in Iran
2- A large number of corneal transplant applicants in Iran
The cost of corneal transplantation in Iran varies depending on the surgery and the hospital. On average, the cost of this operation is $2,000.
