"Cornea Transplant" is popularly referred to as "eye transplant". Thanks to the development of advanced techniques, this operation may be performed highly successfully in this day and age.

While it is possible to solve the cataract problem of the eye in the same session, tissue rejection may also be prevented to a great extent. Following a healing period of approximately one year, the patient is able to regain his/her eyesight.

The sun shining down on us bright and cheerful, green forests as far as the eye can take in. We can see all this beauty thanks to the cornea of our eye. The transparent layer covering the colourful parts of the eye is called the cornea. The beams which hit the eye are first refracted in the cornea and the transparency of this layer allows those beams to permeate to the posterior layers of the eye. However, when the cornea is afflicted with a problem, it becomes difficult, even impossible to see these beauties. In or day and age, a cornea which loses its transparency or gets deformed may be replaced with a healthy cornea obtained from an eye bank and eye sight may thus be restored. This procedure is called cornea transplant. Success rate varies depending on the reason for which cornea transplant is performed. Overall, success rate is generally over 90 per cent.

What kind of problem prompt people to apply for cornea transplant?

Cornea problems may afflict people of any age. If the cornea gets damaged by a problem such as an injury or infection, it may get blurred or suffer from loss of function. In the case of a damaged cornea, once light enters the eye, it causes deviations which impair the visual acuity of the person and may even feel painful. Consequently, the resulting eye surgery problem has a negative impact on the life of the person suffering from this condition. Associate Professor Banu Coşar, an ophthalmologist at Acıbadem Eye Health Centre lists the most common reasons for performing cornea transplant in our country as follows: Keratoconus (a deformation whereby the cornea sharpens towards the anterior), pseudophacic bullose keratopathy (permanent cornea oedema following cataract operation) and cornea injuries. Hereditary diseases called dystrophy and cases where the cornea has lost its transparency are also treatable by cornea transplant. Advanced cases of herpetic lesions called herpetic keratitis may also necessitate cornea transplant.

Eye banks may play a significant role

Established and operated solely within public organisations and universities, Eye Banks are charged with the task of obtaining corneas, assessing their suitability for transplant and the distribution of those corneas. Open for business 24 hours a day, these banks collect donated corneas for later use, assess and store them. Corneas used in transplant procedures are obtained from donors who have donated their

corneas prior to their death. Associate Professor Banu Coşar relates the process whereby donor corneas are subjected to various tests by the eye banks in order to ensure the protection of future cornea recipients: "First of all, we run blood tests in order to carefully examine the death cause and the medical condition of the donor. We exclude the donor cornea in cases of active septicaemia, rabies, viral hepatitis, certain intra-ocular diseases, previous history of eye surgery, leukaemia, lymphoma, hepatitis B/C and contagious diseases such as HIV (AIDS), deaths from unknown causes and in the presence of certain neurological diseases. Furthermore, eye banks also perform a cell count (specular microscope) and bio-microscope examination in order to determine whether or not the cornea in question will maintain its transparency in the long term. If the results of these tests reveal no obstacles for the purposes of transplant, the cornea is retained for future use. Care is taken to make sure that the age gap between the donor and the recipient is not too wide. As for the actual performance of the cornea transplant.

Not a challenging operation!

Associate Professor Banu Coşar says that in adults, cornea transplant is mostly performed by injecting the eye with an anaesthetic agent whereas in children, the same procedure is carried out under general anaesthesia. Just like local anaesthetics prevent the feeling of pain, medications administered intravenously also help relax the patient. All of the nerves in the eye are completely anaesthetised during the operation which helps prevent the eye from moving and thereby causing a negative picture to emerge. During the transplant of the cornea, the problematic cornea is removed in a round shape and replaced with the transparent piece of cornea obtained from the donor. The new cornea is fixated in its place with the help of very fine nylon sutures. Post-operatively, the patient may be discharged home on the very same day. Associate Professor Banu Coşar also draws attention to the fact that it would be possible to remove an eye cataract and implant an artificial contact lens inside the eye during the same operation. The entire procedure may be completed in approximately one hour.

Dalk Technique may help people prevent tissue rejection

Only until just a few years ago, cornea transplant necessitated the replacement of the entire full layer of the cornea. However, in recent years, it has become possible to perform this operation with the DALK (deep anterior lamellar keratoplasty) technique. The DALK technique protects the endothelium, the lowermost layer of the cornea. As such, the possibility of tissue rejection is greatly reduced. However, the DALK technique cannot be performed on each and every patient because this method requires the cornea of the recipient to have a healthy endothelium. Another innovation in cornea transplant is the replacement of trepan blades with lasers called phemtosecond. Laser incisions allow for finer contours compatible with one another. Refraction problems such as astigmatism and myopia which are frequently encountered conditions following cornea transplant may now be easily corrected with LASIK surgery. Because the edges of incisions performed by laser are particularly fine, it is possible to ensure a better recipient eye and donor cornea compatibility. Topography accompanied LASIK technology

provides customised treatment options for those patients who have previously undergone cornea transplant.

There is a 1 year waiting list

Explaining that visual rehabilitation starts after the removal of the sutures in the eye which takes place approximately one year after the transplant, Associate Professor Banu Coşar continues as follows,Provided that there are no problems in other parts of the eye, eye sight capacity increases to one hundred per cent following the transplant.So, can there develop any serious complications in a cornea transplant procedure? Associate Professor Banu Coşar responds as follows:Serious complications are exceedingly rare. Post-operative risks such as infection, increase in intra-ocular pressure and tissue rejection may easily be brought under control.She warns that particularly in corneas where vascularisation may be observed, there may develop complaints such as stinging- pain, blurred vision, sensitivity to light and pain which may be indicative of tissue rejection. In such cases, one should not lose any time and immediately contact a physician. Dense steroid containing drops, pomades, pills and injections may help suppress the rejection reaction in these situations. A very rare but most scary risk of cornea transplant is the emergence of what is called suprachoroid haemorrhage which may result in the loss of the eye.

Keep in mind!

* In our country, we cannot obtain adequate amounts of cornea tissue for transplant. The reason for this is the popular misperception that the entire eyeball gets removed, whereas it is only the transparent layer of the eye which gets removed for the purpose of cornea transplant.

* Your natural eye colour remains the same after the operation because the iris of the eye does not get impacted by the cornea transplant.

* There is no need to obtain an equivalent cornea with respect to tissue or blood type. The race, gender and eye colour of the donor are irrelevant.

* Cornea heals slowly. Full recovery and the improvement of visual acuity may take one year or even longer.

* It is a challenging task to give the new cornea a perfect shape. Therefore, the emergence of astigmatism (blurred or imperfect vision due to the irregular shape of the cornea) following cornea transplant is a rather commonly observed condition. However, this problem is easily corrigible in our day.

In cornea transplant, the problematic cornea is removed and replaced with the transparent cornea layer obtained from the donor.

Cornea problems may afflict people of any age. If the cornea gets damaged by a problem such as an injury or infection, it may get blurred or suffer from loss of function.