Keratoplasty Health Dictionary

Also known as keratoplasty. If the cornea (see EYE) becomes damaged or diseased and vision is impaired, it can be removed and replaced by a corneal graft. The graft is taken from the cornea of a human donor. Some of the indications for corneal grafting include keratoconus (conicalshaped cornea), corneal dystrophies, severe corneal scarring following HERPES SIMPLEX, and alkali burns or other injury. Because the graft is a foreign protein, there is a danger that the recipient’s immune system may set up a reaction causing rejection of the graft. Rejection results in OEDEMA of the graft with subsequent poor vision. Once a corneal graft has been taken from a donor, it should be used as quickly as possible. Corneas can be stored for days in tissue-culture medium at low temperature. A small number of grafts are autografts in which a patient’s cornea is repositioned.

The Department of Health has drawn up a list of suitable eye-banks to which people can apply to bequeath their eyes, and an o?cial form is now available for the bequest of eyes. (See also DONORS; TRANSPLANTATION.)... corneal graft

Descemet’s stripping endothelial *keratoplasty.... dsek

a hereditary condition in which the corneal endothelium loses its functional ability, usually with age. It may result in thickening and swelling of the cornea (*bullous keratopathy) and thus affect vision. Cornea guttata, small whitish deposits of hyalin, are seen on the inner surface of the cornea and signify a reduced number of endothelial cells. A corneal transplantation (see keratoplasty) may become necessary in certain cases. [E. Fuchs (1851–1913), German ophthalmologist]... fuchs’ endothelial dystrophy

1. n. any organ, tissue, or object used for *transplantation to replace a faulty part of the body. A *skin graft is used to heal a damaged area of skin. A *bone graft can be performed using natural bone or a synthetic material. A kidney removed from a live or dead person and transplanted to another individual is described as a kidney (or renal) graft. Corneal grafts are taken from a recently dead individual to repair corneal opacity (see keratoplasty). Diseased coronary arteries may be replaced by a *coronary artery bypass graft. Artificial grafts are used to replace diseased peripheral arteries and heart valves. 2. vb. to transplant an organ or tissue. See also allograft; xenograft.... graft

n. an optically clear prosthesis that is implanted into the cornea to replace an area that has become opaque. Due to its poor success rate, it is used only as a last resort in an attempt to restore some sight to patients with severe disease where corneal transplantation (see keratoplasty) is unlikely to succeed.... keratoprosthesis

n. the implantation of an organ or tissue (see graft) from one part of the body to another or from one person (the donor) to another (the recipient). Success for transplantation depends on the degree of compatibility between donor and graft: it is greatest for *autografts (self-grafts), less for *allografts (between individuals of the same species), and least for *xenografts (between different species; see xenotransplantation). Skin and bone grafting are examples of transplantation techniques in the same individual. A kidney transplant involves the grafting of a healthy kidney from a donor to replace the diseased kidney of the recipient: renal transplantation is the second commonest example of human transplant surgery using allografts (after corneal grafts – see keratoplasty). Bone-marrow, blood-stem-cell, heart, heart–lung, pancreatic, and liver transplants are also very successful. Patients have undergone laryngeal transplantation following *laryngectomy. Transplanting organs or tissues between individuals is a difficult procedure because the recipient’s immune system perceives the transplant as a foreign object and rejects it. Special treatment (e.g. with *immunosuppressant drugs) is needed to prevent transplant rejection, and the less common but equally devastating effects of an attack by the graft’s immune cells on the host.

Ethical questions arise over donated organs. If the donor is living, is the organ properly a *gift? If the donor has recently died, how has the death been judged and has *consent been given explicitly by the patient or surviving relatives (opting in) or is it assumed if the donor has not forbidden it (opting out)?... transplantation

n. a surgical instrument used to remove a circular area of tissue, usually from the cornea of the eye (in the operation of penetrating *keratoplasty) or from bone (for microscopical examination). It consists of a hollow tube with a serrated cutting edge. It is used during the preliminary stages of craniotomy.... trephine