1 – What is cornea transplant?
Cornea transplant (keratoplasty) is the replacement of all or part of the layers of the cornea, the outermost transparent optical layer of the eye, with tissue taken from deceased donors. In most cases, the entire tissue is replaced (penetrating keratoplasty), other times, if the damage is only to the covering layers, this covering tissue is replaced (lamellar keratoplasty), and sometimes the innermost endothelial layer is replaced (Descemet stripping endothelial keratoplasty/endothelial keratoplasty).
2 - Who is suitable for cornea transplant?
For normal vision, the cornea must be clear and smooth. This surgery becomes necessary when the cornea loses its transparency and its spherical shape is disrupted.
3 - Which conditions can be treated with cornea transplant?
Here are the cases that most often need a cornea transplant:
- Penetrating trauma damages the integrity of the cornea and leaves marks that will disrupt the transparency and sphericity of the cornea. In this case, the entire cornea must be replaced.
- Corneal inflammation (keratitis) can develop due to microbial or viral/fungal infections. When this infection is cured, it certainly results in corneal haze. According to the location of the haze in the corneal layers, superficial or total corneal replacement is planned.
- The layer called the endothelium, at the back of the cornea, maintains the balance of fluid in the cornea. If this layer is damaged due to traumatic/complex surgical interventions, the fluid ratio in the cornea rises, which means oedema develops. As a result, the cornea becomes cloudy, like that of opaque glass. In this case, either a complete cornea replacement or only the endothelial layer (Descemet stripping endothelial keratoplasty) is performed.
- Progressive thinning of the cornea and forward conical protrusion of the cornea is seen in the degenerative disease called keratoconus. If this disease is detected in the early phases, it can be stopped by radiotherapy called 'crosslinking'. If this period passes, there is no solution other than transplantation of the entire cornea.
Some inherited corneal diseases (dystrophy) cause corneal blurring that begins between 15-20 years of age. When vision is blurred, it can be improved with a whole cornea transplant.
4 - In which cases is the transfer rejected? Does it happen often?
Rejection of a tissue or organ is directly proportional to the vascularity of that tissue. Because the cornea is not a vascular tissue, the likelihood of rejection is very small if the postoperative period is well managed. Various studies have shown that rejection rates are around 10-15%, after 10 years of follow-up.
5 - What follow-up is needed after transplantation in children? Is there a likelihood of a second operation?
Cornea transplant in children is much more difficult as the eye is anatomically immature. Postoperative follow-up is particularly important in young children. In addition, it is particularly important to find a suitable donor for young patients. Cases should be followed up until 5-6 years of age, and the examination is performed under general anaesthesia. The doses of medications we use after surgery must be precisely determined to prevent complications related to medication intake.
Despite the preventive measures taken, more than one transplant may be necessary over time as the likelihood of rejection is greater in children.
6 - How many people in our country are waiting their turn for a cornea transplant?
The number of registered patients waiting their turn for a transplant is around 3000. In addition, I presume there are just as many patients who are not registered.
7 - Is it easy to find a cornea? Can you explain the process?
The supply of corneas in Turkey is carried out by the Tissue and Organ Transplantation and Dialysis Sector of the Ministry of Health. According to 2018 data, there are 41 eye banks in 23 counties. Every institution that can perform cornea transplant is linked to the eye bank. We request corneas for our patients through the common TDIS request platform that we all use and expect the bank to respond to the request. Although this period varies from city to city and depends on the location of the bank concerned and the intensity of the demand, the waiting period is usually between 3-6 months.
The way to increase the number of transplanted corneas in our country is to increase the number of donors. This can be achieved in collaboration with government institutions and the media, through proper communication methods.
There is also a serious demand for cornea transplants from abroad. It is easier for us to obtain corneas for foreign patients, as we are allowed to import corneas from abroad specifically for such patients. In this matter, we work with eye banks approved by the United States Food and Drug Administration.
8 - What type of surgery is a cornea transplant and how long does the recovery process take?
A corneal transplant is a difficult surgery with slow engraftment. We remove the cornea at the front of the eye, to the desired thickness, and replace it with new tissue, attaching this tissue in place using sutures.
The post-operative period requires very close observation during the first month. The patient must take medication for 4-6 months. Usually, the patient feels well after the 3rd month but needs to be followed up for life, at an interval of 6 months.
9 - How far has our country reached in the field of cornea transplants? Do you receive many patients from abroad for this surgery? What is the annual number for the services provided for foreign patients?
In Turkey, many successful operations are performed in the field of eye surgery, as well as in almost all fields of medicine. We have very successful doctors who have specialized in these fields, as well as well-equipped hospital facilities. Meanwhile, the demand for cornea transplantation is gradually increasing. About 2/3 of my patients are foreigners.
A country that has invested so much in people and equipment in the medical field should be in a better position. I think India is the best example of this in the world. They have developed very well in medical tourism. With the right strategy, there is no reason why we cannot reach a better position. If the relevant institutions, especially the Ministry of Health, take necessary measures, we may find an opportunity to serve a lot more foreign patients.
10 - Where and when can cornea transplant be performed in our country?
In our country, cornea transplant is performed by ophthalmologists and experienced specialists in this field, both in public and private hospitals.