Disease:

The cornea is the clear layer in front of the iris and pupil. It protects the iris and lens and helps focus light on the retina. It is composed of cells, protein, and fluid. The cornea looks fragile but is almost as stiff as a fingernail. However, it is very sensitive to touch.

Corneal disorders include the following:

Bullous keratopathy
Cogan syndrome
Corneal ulcer
Herpes simplex keratitis
Herpes zoster ophthalmicus
Interstitial keratitis
Keratoconjunctivitis sicca
Keratoconus
Keratomalacia
Peripheral ulcerative keratitis
Phlyctenular keratoconjunctivitis
Superficial punctate keratitis

Corneal disease or damage can cause pain, tearing, and decreased sharpness of vision (visual acuity).

Causes:

Infections
Trauma
Dystrophies and degenerative corneal disorders
Autoimmune disorders
Nutritional deficiencies
Vernal and atopic keratoconjunctivitis
Growths
Ectasia (thinning)

Diagnosis:

A slit lamp, which is an instrument that enables a doctor to examine the eye under high magnification, is usually used to examine the cornea. During the examination, the doctor may apply eye drops that contain a yellow-green dye called fluorescein. The fluorescein temporarily stains damaged areas of the cornea, making it possible to see damaged areas that are not otherwise visible

Treatment: 

A Corneal Transplant or Keratoplasty is a surgical procedure that is performed to replace part of the cornea with a corneal tissue of a donor. This surgery helps restore vision, improves the appearance of a damaged or diseased cornea and reduces pain.

For the most part, cornea transplant procedures are successful. But having said complications like rejection of the donor cornea come with it.

Donor Cornea

More often than not, corneas are quickly available when it is needed for a cornea transplant. This is because a lot of donors request to get their corneas donated soon after they pass away.

Thus, individuals who have to get their cornea transplant surgery done will not have to wait for too long to get their donor cornea. 

A thorough examination is done before using the cornea of a donor. Donor corneas will not be accepted for transplantation if the donor has suffered from infections or central nervous system conditions, previously undergone an eye surgery or died of an unknown cause.

Pre-Surgical  preparation:

You will be required to undergo the following in preparation of your cornea transplant surgery.

1. Eye Examination This will allow the doctor to determine if you have another condition that may cause complications after the surgical procedure is complete.
2. Reviewing Medications The doctor will look into all the medications that you�ve been consuming and may ask you to put a pause on certain ones before or after your cornea transplant is done.
3. Treating Other Eye Problems Before your surgery, the doctor will first treat problems like an infection or inflammation because these could prevent the transplant from being a success.
4. Measuring the Eye  Doing so will help the doctor decide the size of donor cornea you will need.

Post-Surgery Procedure

After you're done with the cornea transplant surgery, you need to keep certain things in mind.

1. Medications aid in controlling any kind of pain, swelling or infection. Therefore, you will be required to take medications post the surgery. 
2. Eye Patch will protect the eye during its healing stage.
3. Eye Protection. After your surgery, give yourself time to get back to your normal activities. Take it slow and do not rush into anything. And for the rest of your life, you will have to be extra cautious with your eye.
4. Follow-Ups will help the doctor gauge if there are any complications. So do not miss out on these.

Takeaway

Going regularly for your check-up is a must because after you are done with this surgical procedure, risk of complications and cornea rejection may arise.