A cornea transplant is a surgical procedure to replace part of the cornea with corneal tissue from a deceased donor. The cornea is the transparent, dome-shaped surface of the eye that accounts for a large part of the eye's focusing power. A corneal transplant, called a keratoplasty can restore vision, reduce pain and improve the appearance of a damaged or diseased. The corneas used in corneal transplants come from deceased donors.

A corneal transplant is most often used to restore vision to a person who has a damaged cornea caused by a variety of diseases or injury. A corneal transplant may also relieve pain or other signs and symptoms associated with diseases of the cornea. A number of conditions result in the need for a corneal transplant such as:

• Thinning of the cornea

• Corneal scarring, caused by infection or injury

• Clouding of the The cornea

• Swelling of the cornea

• Corneal ulcers, including those caused by infection

• Complications caused by previous eye surgery

If the cornea becomes opaque, swollen, or scarred, vision is diminished. Medication to control the damage to the cornea is usually the first line of treatment, but once it is clear that medication will not halt or alter the damage, a corneal transplant is considered.

Before cornea transplant surgery, tests include

• A thorough eye exam that looks for conditions that may cause complications after surgery

• Measurements of the eye to determine what size donor cornea is needed.

• A review of all medications and supplements to identify those to stop before or after the corneal transplant.

During the most common type of corneal transplant (penetrating keratoplasty), a surgeon cuts through the entire thickness of the abnormal or diseased cornea to remove a small button-sized disc of corneal tissue. The donor cornea, cut to fit, is placed in the opening and stitched into place. The stitches may be removed at a later time.

With some types of corneal problems, a full-thickness corneal transplant isn't always the best treatment. Partial-thickness (lamellar) transplants may be used in certain situations. These types of procedures include:

• Replacing the inner layer of the cornea. Replaces only the innermost layer of the cornea's five layers.

• Replacing the surface layers of the cornea. The outer layers of the cornea that have been damaged by certain diseases and conditions can be replaced using a procedure called surface lamellar transplant.

Corneal transplant is often performed on an outpatient basis, although some patients need brief hospitalization after surgery. An eye shield or glasses must be worn to protect the eye until the surgical wound has healed. Eye drops will be prescribed to use for several weeks after surgery. Some patients require medication for at least a year. These drops include antibiotics to prevent infection as well as corticosteroids to reduce inflammation and prevent corneal rejection.

Unrelated eye problems, such as infection or inflammation, may reduce the chances of a successful cornea transplant, so treatment is given for those problems before surgery.

For the first few days after surgery, the eye may feel scratchy and irritated. Vision will be somewhat blurry for as long as several months. Sutures are often left in place for six months, and occasionally for as long as two years. Some surgeons may prescribe rigid contact lenses to reduce corneal astigmatism that follows corneal transplant. Vision may initially be worse than before surgery as the eye adjusts to the new cornea. It may take several months for vision to improve. Frequent eye exams are needed during the first year post surgery to check for complications such as corneal rejection and astigmatism. Prevention of future eye injury requires wearing safety glasses or eye protectors if there is any risk of damage to the post operative eye.

Once the outer layer of the cornea has healed — several weeks to several months after surgery — an eye doctor will work to make adjustments that can improve vision, such as:

• Correcting unevenness in the cornea (astigmatism). The stitches that hold the donor cornea in place on the eye may cause dips and bumps in the cornea, making vision blurry in spots. The surgeon may correct some of this by releasing some stitches and tightening others.

• Correcting vision problems. Refractive errors, such as nearsightedness and farsightedness, can be corrected with glasses, contact lenses or, in some cases, laser eye surgery.

Cornea transplant is a relatively safe procedure. Still, a cornea transplant does carry a small risk of serious complications, such as:

• Eye infection

• Increased risk of clouding of the eye's lens (cataracts)

• Pressure increase within the eyeball (glaucoma)

• Problems with the stitches used to secure the donor cornea

• Rejection of the donor cornea

• Swelling of the cornea

Most people who receive a corneal transplant will have their vision at least partially restored. Expectations after a corneal transplant depend on the reason for surgery and general health conditions. Risk of complications and cornea rejection continues for years after a cornea transplant. For this reason, an annual eye examination is recommended. Corneal rejection can often be managed with medications.

In some cases the body's immune system may mistakenly attack the donor cornea. This is called corneal rejection, and may require another corneal transplant. Rejection occurs in about 20 percent of corneal transplants. If an individual has any of the symptoms listed below, rejection may be the cause.

• Loss of vision

• Pain

• Redness

• Sensitivity to light

• May be entitled to special monthly compensation where the Veteran has a single service-connected disability rated as 100% with additional service-connected disability or disabilities independently ratable at 60% or more, which are separate and distinct from the 100% service-connected disability and involves different anatomical segments or bodily systems. See  38 CFR 3.350(i)(1) – Special Monthly Compensation (SMC).

• Consider entitlement to specially adapted housing under 38 U.S.C. 2101(a)(2)(A)(i) if there is visual impairment to the degree specified in 38 CFR 3.809(b)(2).

• The veteran, spouse, surviving spouse or parent will be considered in need of regular aid and attendance if he or she is blind or so nearly blind as to have corrected visual acuity of 5/200 or less, in both eyes, or concentric contraction of the visual field to 5 degrees or less (38 CFR 3.351(c)(1)).

• Consider entitlement to automobile allowance and/or automobile adaptive equipment if there is visual impairment to the degree specified in 38 CFR 3.808(b)(3).

• Review for entitlement to special monthly compensation under 38 CFR 3.350.

• For the purposes of evaluation under 38 CFR 4.79, an incapacitating episode is an eye condition severe enough to require a clinic visit to a provider specifically for treatment purposes.

• Examples of treatment may include but are not limited to: Systemic immunosuppressants or biologic agents; intravitreal or periocular injections; laser treatments; or other surgical interventions.

• For the purposes of evaluating visual impairment due to the particular condition, refer to 38 CFR 4.75, 38 CFR 4.76, 38 CFR 4.77, 38 CFR 4.78,  and  38 CFR 4.79, diagnostic codes 6061-6091.