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Corneal transplantation, also referred to as corneal grafting, may be a surgery where a damaged or diseased cornea is replaced by donated corneal tissue (the graft). When the whole cornea is replaced it's referred to as penetrating keratoplasty and when only a part of the cornea is replaced it's referred to as lamellar keratoplasty. Keratoplasty simply means surgery to the cornea. The graft is taken from a recently deceased individual with no known diseases or other factors which will affect the prospect of survival of the donated tissue or the health of the recipient.

The cornea is that the transparent front a part of the attention that covers the iris, pupil and anterior chamber. The surgery is performed by ophthalmologists, physicians who concentrate on eyes, and is usually done on an outpatient basis. Donors are often of any age, as is shown within the case of Janis Babson, who donated her eyes after dying at the age 10. The corneal transplantation is performed when medicines, keratoconus conservative surgery and cross-linking can not heal the cornea.

Uses

Optical

To enhance acuity by replacing the opaque or distorted host tissue by clear healthy donor tissue. the foremost common indication during this category is pseudophakic bullous keratopathy, followed by keratoconus, corneal degeneration, keratoglobus and dystrophy, also as scarring thanks to keratitis and trauma.

Tectonic/reconstructive

To preserve corneal anatomy and integrity in patients with stromal thinning and descemetoceles, or to reconstruct the anatomy of the attention, e.g. after corneal perforation.

Therapeutic: to get rid of inflamed corneal tissue unresponsive to treatment by antibiotics or anti-virals.

Cosmetic: to enhance the looks of patients with corneal scars that have given a whitish or opaque hue to the cornea.

Synthetic corneas

Boston keratoprosthesis

The Boston keratoprosthesis is that the most generally used synthetic cornea so far with over 900 procedures performed worldwide in 2008. The Boston KPro was developed at the Massachusetts Eye and Ear Infirmary under the leadership of Claes Dohlman.

AlphaCor

In cases where there are several graft failures or the danger for keratoplasty is high, synthetic corneas can substitute successfully for donor corneas. Such a tool contains a peripheral skirt and a transparent central region. These two parts are connected on a molecular level by an interpenetrating polymer network, made up of poly-2-hydroxyethyl methacrylate (pHEMA). AlphaCor may be a U.S. FDA-approved sort of synthetic cornea measuring 7.0 mm in diameter and 0.5 mm in thickness. the most advantages of synthetic corneas are that they're biocompatible, and therefore the refore the network between the parts and the device prevents complications that would arise at their interface. The probability of retention in one large study was estimated at 62% at 2 years follow-up.

Osteo-Odonto-Keratoprosthesis

In a very rare and sophisticated multi-step surgery , employed to assist the foremost disabled patients, a lamina of the person's tooth is grafted into the attention , with a man-made lens installed within the transplanted piece.

Prognosis

The prognosis for visual restoration and maintenance of ocular health with corneal transplants is usually excellent. Risks for failure or guarded prognoses are multifactorial. The sort of transplant, the disease state requiring the procedure, the health of the opposite parts of the recipient eye and even the health of the donor tissue may all confer a more or less favorable prognosis.

The majority of corneal transplants end in significant improvement in visual function for several years or a lifetime. In cases of rejection or transplant failure, the surgery can generally be repeated.

Epidimology

Corneal transplant is one among the foremost common transplant procedures. Although approximately 100,000 procedures are performed worldwide annually, some estimates report that 10,000,000 people are suffering from various disorders that might enjoy corneal transplantation.

In Australia, approximately 2,000 grafts are performed annually. Consistent with the NHS Blood and Transplant, over 2,300 keratoplasty procedures are performed annually within the UK. Within the oneyear period ending March 31, 2006, 2,503 people received corneal transplants within the UK.

RISKS

There is also a risk of infection. Since the cornea has no blood vessels (it takes its nutrients from the aqueous humor) it heals far more slowly than a cut on the skin. While the wound is healing, it's possible that it'd become infected by various microorganisms. This risk is minimized by antibiotic prophylaxis (using antibiotic eyedrops, even when no infection exists).

There is a risk of cornea rejection, which occurs in about 10% of cases. Graft failure can occur at any time after the cornea has been transplanted, even years or decades later. The causes can vary, though it's usually thanks to new injury or illness. Treatment is often either medical or surgical, counting on the individual case. An early, technical explanation for failure could also be an excessively tight stitch cheesewiring through the sclera.