The most common major complication of the corneal transplantation is the development of Astigmatism, which usually is improved by adjusting and removing stitches, and wearing glasses or contact lenses. Another important complication is Cornea Graft Rejection which, if not treated promptly, causes the grafted cornea become opaque
rejection occurs when the patient's immune system identifies the transplanted cornea as a stranger's tissue and tries to destroy it. Rejection can start as soon as two weeks after a graft, but is commonest several months afterwards
If the rejection is diagnosed soon, it can be treated with steroid eye drops, and occasionally with steroid tablets or injecting drugs around the eye, but in advanced cases of rejection, the rejection may not be controlled by medications and a second corneal transplantation surgery is needed which its success rate is less than the first one. For this reason, it is advisable to contact your Ophthalmologyis within 24 hours, if you have any of the following symptoms in the eye that has transplanted cornea

 Severe redness of the eyes or around the cornea
Light sensitivity
Abnormal eye tearing
  Blurred vision

Feeling foreign body in the eye that can be due to loose or torn stitches
 Other major complications of the corneal transplantation are not very common, however, there are likely to be complications such as intraocular bleeding, infection, cataracts, glaucoma, recurrence of the previous disease in the transplanted cornea and retinal tear
 
Causes for Corneal Transplantation
Make better vision in cases where corneal opacity leads to blurred vision.
Repairing corneal perforations to protect the internal structure of the eye sphere
Treating severe pain which is caused by a disease or corneal edema (swelling of the cornea)
Suitable Patients for Corneal Transplantation
Patients who suffer from corneal edema (swelling of the cornea) that is caused after cataract surgery.
Patients with corneal opacity that is commonly caused by frequent ocular herpes or microbial infections.
patients with chemical burns of the cornea.
Patients with genetic diseases that cause corneal edema or opacity.
Procedure for the preparation of the transplanted cornea
The transplanted corneas after death are removed from the eyes of people who were willing to help others by cornea donation. Without the charity donation of these people no corneal transplantation surgery is possible. All corneas donated in Iran are kept at the Eye Bank of the Islamic Republic of Iran. In Eye Bank these corneas are carefully examined to ensure their health. All donated corneas are also controlled for diseases such as AIDS and hepatitis to prevent the transmission the Diseases to corneas recipients.
Note: Approved corneas are stored in Iran's Eye Bank for 2 to 8 days and are provided to people in need; a healthy cornea is used at least to treat 3 patients.
 
Corneal transplantation procedure
For corneal transplantation surgery the patient usually should be admitted to Noor Surgery Center of Kermanshah, in Iran  before surgery in order to carry out the necessary tests and examinations. Usually, before the patient is hospitalized in Noor Center of Kermanshah, in Iran , the hospital communicates with the Eye Bank for reserving the cornea, but anyway, on the day of surgery, the suitable cornea for the corneal transplantation may not be available in the Eye Bank, and as a result, surgery is postponed to another day.
The surgery is done under general anesthesia. Of course, if there is no possibility of general anesthesia due to other diseases, such as heart or pulmonary diseases, the surgery is done under local anesthesia so that the patient becomes sleepy by medications and the eye becomes insensitive to pain, then the patient does not feel pain.
During the surgery, the surgeon uses a special microscopic instrument to remove a round section of the defective cornea from the patient’s eye and replaces it with a similar round section of the healthy donated cornea. After placing the donated cornea in the patient’s eye, the surgeon stitches it into the place with an ultra-fine thread. It should be noted that surgery takes between one and two hours. Depending on the situations, sometimes, in addition to corneal transplantation, Cataract or Glaucoma is also carried out at the same time. After the end of the surgery, the eye is dressed.
 
Postoperative follow-up care
 After surgery, your eye is at first very vulnerable to blows on it, you must be careful not to touch or press your eye. Because even a small blow may damage it seriously. Therefore, it is necessary to wear a protective plastic eye shield during the first weeks after the surgery, so that it does not hit the eye. During this time avoid bending down, pushing, lifting heavy objects   or bending your head forward. If you have to pick things up from the floor, don't bend your waist, just bend your knees and keep your head up. When you wash your hair, make sure that the water and shampoo do not enter your eyes. Heavy exercise are prohibited. Don't take any more physical exercise than a brisk walk after the surgery. Above all, avoid rubbing and poking your eyes during this period.
Note: lf you do a desk job, you can usually go back to work after about two weeks, but if your job is more strenuous, you will be advised to stay off work for at least six weeks, or in some cases even longer.
Important recommendations after corneal transplantation surgery
Since after corneal transplantation surgery, the healing process of the cornea tissue is too late,  and an eye with a corneal graft is never as strong as a normal eye the following should be observed:

1. Always wear sunglasses or large prescription glasses with resistant glass to prevent accidental strokes.

2. Avoid major contact sports such as wrestling, judo, Success where there is a chance to hit.

3. Avoid activities that are likely to hit, and do not interfere with anyone.

4. When you are swimming or doing physical activities, be sure to wear swimming glasses.

 Note: Failure to observe these tips can result in blindness.
 
Clinical and pharmaceutical care
In the first days after transplantation, examinations are usually performed on a daily basis. After one to two weeks, the intervals between examinations are usually three to four days, and gradually the intervals of examinations are prolonged, so that the ophthalmic examination is repeated every few weeks after the cornea transplant. After 6 months, the intervals of examinations are prolonged and they occur every 3 to 6 months. The doctor examines the patient at any time in terms of visual acuity, stitches condition, the possibility of cornea graft rejection, and mediation complications such as Glaucoma and Cataracts.
Note that after cornea transplantation, even many years after the surgery, any abnormal symptoms such as vision loss, tearing, pain, foreign body sensation, photophobia (light sensitivity), or redness of the eye should be reported to your ophthalmologist within 24 hours at most.
Also after the corneal transplantation, it is usually necessary to use antibiotic drops for several weeks and steroid drops that control eye inflammation for several months. Other eye drops such as artificial tears or pressure-lowering topical eye drops may be prescribed by The ophthalmologist. After the surgery, be sure to take the drops carefully according to the ophthalmologist' s instructions and avoid the arbitrary discontinuation of the medication. The eye drops abuse leads to the destruction of the grafted cornea and blindness.
 
Outcomes of Corneal transplantation
 The result of the corneal transplantation depends to a large extent on the primary disease, which is due to corneal transplantation. In patients who have undergone surgery due to noninfectious corneal opacity, mild corneal edema (swelling of the cornea), the success rate is very good and about 90%. In cases where corneal transplantation is due to spots of ocular herpes or severe corneal edema, the success rate is above 80%. In emergency cases where corneal transplantation is performed to control corneal infection or repair the cornea hole, it is less likely that the cornea remains clear, but corneal transplantation is still required to maintain eye structures, and our colleagues at Noor Surgery Center of Kermanshah in Iran  carry out the surgery with great deal of accuracy and skill.
 
Corneal transplantation problems and complications
The most common major complication of the corneal transplantation is the development of Astigmatism, which usually is improved by adjusting and removing stitches, and wearing glasses or contact lenses. Another important complication is Cornea Graft Rejection which, if not treated promptly, causes the grafted cornea become opaque. The transplant rejection occurs when the patient's immune system identifies the transplanted cornea as a stranger's tissue and tries to destroy it. Rejection can start as soon as two weeks after a graft, but is commonest several months afterwards.
If the rejection is diagnosed soon, it can be treated with steroid eye drops, and occasionally with steroid tablets or injecting drugs around the eye, but in advanced cases of rejection, the rejection may not be controlled by medications and a second corneal transplantation surgery is needed which its success rate is less than the first one. For this reason, it is advisable to contact your Ophthalmic Surgeon within 24 hours, if you have any of the following symptoms in the eye that has transplanted cornea:

Severe redness of the eyes or around the cornea
Light sensitivity
Abnormal eye tearing
Blurred vision
Feeling foreign body in the eye that can be due to loose or torn stitches.

 Other major complications of the corneal transplantation are not very common, however, there are likely to be complications such as intraocular bleeding, infection, cataracts, glaucoma, recurrence of the previous disease in the transplanted cornea and retinal tear