KERATOMILEZ

From Big Medical Encyclopedia

KERATOMILEZ (Greek keras, keratos a horn, horn substance + smileusis cutting) — the operation directed to change of curvature and the refracting force of a cornea at short-sightedness.

The refractivity of a cornea depends generally on the radius of curvature of its front surface in the central area.

The first attempts of impact on a refractivity of a cornea for the purpose of correction of a refraction were made in 19 century by Snellen (N. Snellen, 1869), Shyotts (H. Schiotz, 1885), etc.

Basic indication to operation K. unilateral high short-sightedness when correction by points and contact lenses is impossible is. Operation is justified and children for prevention have amblyopias and preservations of solid vision. Operation K. it can be shown also at a bilateral myopia in case of sharply expressed heterometropias (see) on an eye with higher degree of short-sightedness, and also at a bilateral high myopia at bad portability of contact lenses and low visual acuity after-point correction.

Two ways of change by a surgical method of the refracting force of a cornea are possible: impact on curvature of all layers of a cornea (without change of its thickness) and on curvature only of a front surface of a cornea (i.e. change of its thickness in the center).

For change of curvature of all layers of a cornea use methods of back and front corneal cuts.

the Scheme of some stages of operation of a keratomilez at short-sightedness: 1 — cutting of an autograft of a cornea (the autograft is specified by an arrow); 2 — the dotted line showed a zone of turning or thinning of the center of an autograft; 3 — fixing of an autograft on the former place.

Change of curvature of a cornea can be reached at the expense of a lamellar stromektomiya in the center for its flattening. The principle of operation consists in a resection of front layers of a stroma of a cornea, processing of an autograft to the necessary degree of curvature of its surface and reimplantation (fig.) by means of glue or a continuous suture thread of 8 — 10 zero thick. The electric microkeratomas allowing to make a smooth layer-by-layer cut of a cornea on the necessary depth, lathes of high precision with the freezing devices for processing of the resected autograft are used. Various designs allowing to simplify processing auto-and a gomotransplantata with use of the freezing microtome with the spherical modeling prefixes are offered.

More than at 75% of patients after operation the visual acuity equal or above that is reached, edges was before operation with the maximum correction.

Complications after operation are rare. Opacification in interlamellyarny layers of a cornea as a result of a drift is possible during operation of cells of an epithelium of a cornea, and also an astigmatism as a result of the wrong cutting of a corneal disk.


Bibliography: Belyaev V. S. To cornea operation and sclera, M., 1977; B of l and-vatsky E. D. Refraction keratoplasty, Yerevan, 1973, bibliogr.; Krasnov M. M. First experience of surgical correction of short-sightedness and aphakia by method of a refraction keratoplasty (operation of a keratomilez and kera-tofakiya), Vestn, oftalm., JW2, page 24, 1970, bibliogr.; Puchkovska/f N. A., about-lubenko E. A. and Golubenko Yu. E. Questions of hardware of operations of a keratomilez and keratofakiya, Oftalm, zhurn., No. 3, page 163, 1973; The Guide to eye surgery, under the editorship of M. L. Krasnov, M., 1976, bibliogr.

V. S. Belyaev.

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