Akademik

Any surgical modification of the cornea; the removal of a portion of the cornea containing an opacity and the insertion in its place of a piece of cornea of the same size and shape removed from elsewhere. SYN: corneal graft, corneal transplantation, corneal trepanation, trepanation of cornea, transplantation of cornea. [kerato- + G. plasso, to form]

- allopathic k. corneal transplant with donor material of glass, plastic, or other inert material.

- autogenous k. corneal transplant with donor material from the same individual.

- epikeratophakic k. SYN: epikeratophakia.

- heterogenous k. corneal transplant with donor material from another species.

- homogenous k. corneal transplant with donor material from another individual of the same species.

- keratophakic k. SYN: keratophakia.

- lamellar k., layered k. SYN: nonpenetrating k..

- nonpenetrating k. k. in which only the anterior layer of the cornea is used (not a tectonic k.). SYN: lamellar k., layered k..

- optical k. transplantation of transparent corneal tissue to replace a leukoma or scar that impairs vision.

- penetrating k. corneal transplant with replacement of all layers of the cornea, but retaining the peripheral cornea. SYN: perforating k..

- perforating k. SYN: penetrating k..

- refractive k. any procedure in which the shape of the cornea is modified, with the intent of changing the refractive error of the eye; for example, if the cornea is flattened, the eye becomes less myopic. See photorefractive keratectomy, keratophakia, lamellar k., thermokeratoplasty, keratomileusis, radial keratotomy. SYN: keratorefractive surgery.

- tectonic k. grafting to replace lost corneal tissue.

- total k. corneal transplant in which the entire cornea is removed and replaced.

ker·a·to·plas·ty 'ker-ət-ō-.plas-tē n, pl -ties plastic surgery on the cornea esp corneal grafting

an eye operation in which any diseased parts of the cornea are replaced by clear corneal tissue from a donor. All layers of the cornea may need to be replaced (penetrating keratoplasty) or only the superficial layers, the deeper layer remaining (lamellar keratoplasty). In the latter case the thickness of the replacement cornea is correspondingly reduced. Lamellar keratoplasty has the advantage over penetrating keratoplasty of not requiring the eye to be opened, and therefore the risk of infection is greatly reduced.