CORECTOMY

From Big Medical Encyclopedia

CORECTOMY (iridectomia; Greek iris, irid[os] a rainbow + ektome excision, removal) — the operation consisting in excision of a part of an iris of the eye of an eye. And. it is considered full when it is excised tsiliarny and pupillary speak rapidly irises, and incomplete when its pupillary part or only a root of an iris is cut — basal And. The indication to And. are: the central opacifications of a cornea (creation of an artificial pupil — optical And.); glaucoma (for the purpose of decrease in intraocular pressure — protivoglaukomatozny And.); fusion of a pupil (And. for the purpose of the prevention for the second time the developing increase in intraocular pressure — at the same time protivoglaukomatozny and optical); tumors and cysts of an iris which are removed by And. or iridotsiklektomiya (see).

Optical corectomy

Fig. 1. The diagrammatic representation of operation of optical corectomy in the presence of the cataract closing a pupil: 1 — carrying out an iris tweezers for capture of an iris in an anterior chamber of an eye (a white spot — a cataract), the eyeglobe is fixed; 2 — removal of a part of an iris and cutting off its iris scissors for creation of an artificial pupil; 3 — operation is finished; the arrow specified an artificial pupil (a postoperative coloboma of an iris) in the field of a transparent part of a cornea.

The main indication to optical And. permanent central cicatricial opacifications of a cornea serve (most of ophthalmologists, however, even at a partial cataract of a cornea prefers optical And. a keratoplasty, edges has big advantages as in the optical, and cosmetic relation), fusion of a pupil, not progressing limited nomutneniye in the center of a crystalline lens. For optical And. especially carefully choose the place for an artificial pupil since it shall lie against a transparent cornea. The artificial pupil should be done but opportunities are closer to natural, it shall be the smallest size in order to avoid dazzle excessively large amount of light.

A section at optical And. make a lanceolated linear knife if the anterior chamber is not too small. The place in Coca shall lie at distance of 1 mm of a kzada from edge of a transparent cornea. After a section enter an iris tweezers into an anterior chamber, capture by him an iris at pupillary edge, extend outside from a wound and cut off an iris scissors (fig. 1).

Protivoglaukomatozny corectomy

corectomy is offered to Protivoglaukomatoznaya A. Gref in 1857 for decrease in high intraocular pressure.

The sense of operation consists in release on big space of a corner of an anterior chamber for improvement of outflow of liquid from an eye. Therefore the anterior chamber is opened in its corner for what the iris is excised at its root and it is possible more widely. And. do usually above in order that the upper eyelid covered postoperative coloboma (see) also reduced access of light to an eye; at the same time cosmetic defect becomes imperceptible.

Fig. 2. Diagrammatic representation of operation of protivoglaukomatozny corectomy: 1 — capture, removal of an iris an iris tweezers and excision of an upper part it from a pupil to a root; 2 — unwinding, stitching on a conjunctiva (the pupil got a form of «keyhole»).

At protivoglaukomatozny And. after a section and separating of a conjunctiva of an upper half of an eyeglobe the section of a sclera is done by mostly lanceolated linear knife or an edge of the razor is 2 mm higher than transparent edge of a cornea. At the same time the section remains parallel to a limb and does not exceed 5 — 7 mm. At a section a lanceolated knife he is brought slowly in order to avoid bystry emptying of the camera. For receiving a wide coloboma the iris tweezers is opened approximately on 5 mm and widely take an iris; it is extended perhaps more and cut off dvukhmomentno — at first one half, then another (fig. 2).

Outside corectomy according to Gayet (Page J. A. Gayet, 1884) gained big distribution at a small anterior chamber: the section of a sclera is made the sawing movements of a linear knife outside inside, otstupya is 2 mm higher than transparent edge of a cornea and parallel to it. As a result, except the gained antiglaukomatozny effect, there is filtering iod a conjunctiva of watery moisture in the field of the formed friable hem of a sclera that in turn promotes decrease in intraocular pressure.


Fig. 3. Diagrammatic representation of operation of basal corectomy: 1 — capture, removal and excision of a peripheral part of an iris; 2 — unwinding, stitching on a conjunctiva (above a small postoperative coloboma of an iris at its root, the pupil remained round).
Fig. 4. The diagrammatic representation of an iridotomy in afakichesky (deprived of a crystalline lens) an eye with a connective tissue film (a white spot), the iris closing pupillary area: 1 — a side section a lanceolated knife of a cornea and an iris; 2 — tweezers scissors are entered into an anterior chamber of an eye for a horizontal section of an iris: 3 — the iris is cut, the arrow specified the formed artificial pupil.

Basal corectomy it is offered instead of her full I. Sushchnost consists a peripheral part of an iris with its root at a distance that gives the chance to keep a round pupil (fig. 3) having advantage in the optical relation.

The filtering corectomy. At distance of 1 — 2 mm from a limb the layer-by-layer section of a sclera with thermocoagulation of its edges is made that, as well as at And. according to Gayet, leads to formation of a friable hem. After opening of an anterior chamber do basal And. At filtering And. perhaps sharp decrease in intraocular pressure (hypotonia of an eye). In certain cases instead of And. the iridotomy or an iridokapsulotomiya can be made.

An iridotomy

the Iridotomy (a section of an iris) and an iridokapsulotomiya (a section of an iris and the formed connective tissue capsule) are shown for creation of an artificial pupil in an afakichesky eye when the pupillary opening is closed by a film (fig. 4). At this operation the section of a cornea is often made a lanceolated knife that the middle of a section matched a horizontal meridian. Having entered a knife into an anterior chamber, puncture with it an iris of the eye. After that the knife is taken, and through a wound enter special scissors with the closed branches. At an opening of an iris of the eye they are a little moved apart, one branch is carried out behind, and another ahead of an iris. Smykany of scissors cut in the horizontal direction an iris and the capsule therefore in it the crack is formed sufficient size.

Complications

development is possible iridocyclitis (see) and hemorrhage in an anterior chamber of an eye (see. Hyphema ).

The microsurgical equipment made And. less traumatic and almost safe operation. Essentially new opportunities neurosurgical And. (without opening of a cavity of an eye) appeared with development laser And.



Bibliography: Belenky K. R. and And with-magayeva R. I. Results of the subsclerotic filtering corectomy at primary glaucoma, Vestn, oftalm., No. 1, page 21, 1975; Krasnov M. M. Microsurgery of glaucomas, M., 1974, bibliogr.; With and x and r at l and d z e I. A. Observations over the glaucoma operation Iridectomia ab externo, Vestn, oftalm., t. 28, No. 5, page 29, 1949; In e with k m and n H. and. lake of Laser iridectomies, Amer. J. Ophthal., v. 72. p. 393, 1971.

H. A. Pletneva.

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