RU2434613C1 - Method of implantation of drainage valve for normalisation of intraocular pressure - Google Patents

Abstract

FIELD: medicine. ^ SUBSTANCE: invention relates to medicine, namely, to ophthalmology and is intended for treatment of all types of refractory glaucoma. Installation of valve, in particular, of Ahmed valve, is performed behind the line of eye equator, behind the area of eyelid fit, on posterior side of eye ball. After that, threads for valve suturing are passed through sclera behind eye ball equator. Ends of threads are brought out of sclera limits. Ends of thread are passed through holes of valve base. Ends of thread are pulled, installing valve into preliminarily selected place. Ends of threads are fastened with rigid fixation of valve. Method ensures normal eye movements and fit of eyelid to eye, eliminates sense of discomfort and cosmetic defects. ^ EFFECT: method makes it possible to install valve into selected place, without its displacement in process of installation. ^ 2 cl, 14 dwg

Description

The invention relates to medicine, namely to microsurgery of the eye, and can be used to treat all types of refractory glaucoma when installing a valve drainage system to compensate for intraocular pressure.

Known methods for installing (implanting) the Ahmed drainage valve to compensate for intraocular pressure (see www.ahmedglaucoma.ru [1], A.Yu. Rascheskov, Ahmed Glaucoma Valve drainage system meets the requirements of modern surgery, Eye News, 2006, No. 3 (11), p.22-35 [2]), of which information from the site www.ahmedglaucoma.ru can be selected as the closest analogue. The specified method includes the following operations:

- preliminary selection of the future location of the drainage valve between adjacent rectus muscles of the eye and its front edge 8-10 mm from the limb of the eye;

- installation of the valve in a selected place directly on the sclera in a pocket. To install the valve in a pocket, the latter is formed in the upper tissues of the patient’s eyeball as follows:

- perform a conjunctival incision along the limb to the width of the valve;

- carry out the detachment of the conjunctiva along the incision line and along adjacent rectus muscles by a length equal to the sum of the valve length and the distance from the front edge of the valve to the limb of 8-10 mm, by bluntly separating the tenon capsule from the sclera with subsequent installation of the valve in the formed pocket and fixing it seam through the holes in the front of the valve base.

Then spend

- fixing the valve at the installation site by filing the valve through two front holes in the front of the valve base to the sclera with a nylon thread;

- preparation of a donor scleral flap or a flap from a patient’s sclera for installing the tube in the area of its entry into the anterior chamber of the eye. When using the sclera of the patient, a U-shaped incision is made of the scleral leaf with the location of its base at the limb 6 mm long, 4 mm wide;

- injection of a 23G needle into the anterior chamber of the eye parallel to the iris through the trabecula zone with the subsequent installation of the free end of the valve tube into the formed channel for a length of 2-3 mm, while the free end of the tube is performed with a bevel of 30 ° -45 ° relative to its axis;

- the imposition and straightening of the scleral flap of the patient or donor flap measuring 1 × 1 cm on the tube;

- Sewing the expanded scleral donor flap to the sclera of the eyeball at four points along the edges of the flap or flap of the patient along the parallel branches of the U-shaped incision. The scleral flap of the patient of the U-shaped form is used when donor sclera is inaccessible;

- after applying a donor flap or a patient’s flap to the valve tube, the detached part of the upper tissue of the pocket is completely pulled both on the valve and on its tube, covered with a flap, to the conjunctival incision site, followed by suturing along the pocket entry line in the area of the limb incision.

After installing a valve with a drainage tube, increased intraocular pressure opens the valve, and excess fluid from the anterior chamber of the eye enters the peri-valve space, reducing this pressure.

Despite the progressiveness of the described method of implanting a drainage valve, it has several disadvantages.

Firstly, a filtration “bubble” is formed in the peri-valvular space, filled with fluid expired from the anterior chamber of the eye. Close to the limb valve placement causes a close placement of the "bubble" to the limb - in front of the eyeball, which limits the mobility of the eye and can cause strabismus in the patient and diplopia (the appearance of a double image).

Secondly, the proximity of the bladder to the area of the eyelid to the eye violates its normal fit, and the surface of the eyeball is unevenly wetted by a tear; the process of cleansing the surface of the eyeball from the smallest foreign particles that have fallen on the eye is disrupted. The patient has a feeling of discomfort, a feeling of a foreign body. Possible erosion of the conjunctiva and cornea.

Thirdly, due to the location of the "bubble" in the front of the eyeball, cosmetic flaws are manifested in the fact that the patient has a filter bubble.

Fourth, due to the narrowness of the valve location space when it is fixed on the sclera and when the “bubble” increases towards the limb, the risk of through perforation of the sclera increases, which can cause postoperative complications in the form of hemophthalmus, internal infection of the eye, rupture and detachment of the retina.

Fifthly, when sewing on a valve, it often displaces relative to the initial calculated place of its installation, which increases the time of the valve installation operation and causes additional injury to the patient’s eye tissues. Reducing the distance between the limb and the valve compared with the previously planned offset from the limb of 8-10 mm will further aggravate the above problems.

The objectives of the invention are the normalization of eye movement, ensuring a normal fit of the eyelid to the eye, eliminating feelings of discomfort and cosmetic defects, reducing the likelihood of postoperative complications in the form of strabismus, diplopia, erosion of the conjunctiva and cornea, hemophthalmus, internal infection of the eye, rupture and exfoliation of the retina, valve tube displacement .

Another task is the exact installation of the valve in the selected place, without displacement during installation.

Tasks are solved by the method of implanting a drainage valve to normalize the intraocular pressure, at which

- preliminary selection of the future location of the valve at a distance from the limb,

- the valve is installed in the selected place and

- fix it by sewing it through the holes in the base of the valve to the tissues of the eye.

The difference between the proposed method and the prototype is the choice of the location of the valve beyond the line of the equator of the eye, for the region of fit of the eyelids so that the front edge of the valve is at a distance from the limb no closer than 12 mm, on the back side of the eyeball, almost at a distance of 12-16 mm. Then, the valve is sewn to the sclera in a preselected location, i.e. beyond the equator of the eyeball, with the withdrawal of the ends of the filament beyond the sclera. After that, the ends of the thread are threaded into the holes of the valve base, and by pulling both ends of the thread, the valve is accurately set in a preselected location. The ends of the thread are tightened, gradually lowering the valve to the selected place, they are fixed, rigidly fixing the valve in the calculated place, at a distance of its front edge no closer than 12 mm from the edge of the limbus, behind the line of the equator of the eyeball. Such installation of the valve will exclude its displacement from the calculated place.

The Ahmed ™ valve manufactured by New World Medical, Incorporated, USA was used as a drain valve.

The proposed implantation method is sequentially illustrated by the attached photographs. The figure 1 shows how, after completing an incision of the conjunctiva for the pocket, a measurement is made to conduct an incision of the scleral flap to close the valve tube. The figure 2 shows the operation of performing a scleral incision to obtain a scleral flap to cover the drain valve tube. The figure 3 shows the operation of applying a U-shaped suture with a thread behind the equator line of the eyeball, on the back of it, with the ends of the thread outside the sclera. The figure 4 shows the activation of the valve by washing with saline. The figure 5 shows the operation of threading the withdrawn ends of the superimposed thread into the holes of the front of the base of the drainage valve, and tightening its ends with the gradual installation of the valve in the chosen place. Figure 6 shows an image of an installed and fixed valve. The figure 7 shows the operation of cutting the drainage tube two mm further than the limb. The figure 8 shows the operation of injecting the needle 23G into the anterior chamber of the eye through the Schlemm canal parallel to the iris. The figure 9 shows the operation of installing the tube in the front chamber through a pre-puncture needle 23G. The figure 10 shows a hermetically sutured scleral flap. The figure 11 shows two sutures superimposed on the conjunctiva after it is installed in its place. Figure 12 shows a view of the filtration "bubble" (cushion) A. Figure 13 shows how the shunt is installed in the form of a tube in the anterior chamber. The figure 14 shows a segment of the eye with an arrow indicating the direction of the rays to the eye and the location of the filtration "bubble" And beyond the equator line of the eyeball.

The implantation method in accordance with the invention and the above photographs with the application of a scleral flap of the patient on the valve tube is as follows.

First, the conjunctiva is cut along the limb to the width of the valve with the cut length being made with a certain tolerance for the free installation of the valve to avoid excessive tissue injury. Conjunctiva is detached along the incision line and along adjacent rectus muscles by a length equal to the sum of the distance from the front edge of the valve to the limb of at least 12 mm and the length of the valve. Peeling is carried out by bluntly separating the tenon capsule from the sclera. Next, measure the length of the future incision in the sclera (Fig. 1) from the limb for subsequent installation of the valve drainage tube and conduct this incision to form the scleral flap of the patient (Fig. 2). To install the valve, put a U-shaped seam outside the eyeball equator line in that place so that the valve with its front part is installed at a distance from the limb no closer than 12 mm, almost at a distance of 12-16 mm from the limb, with the conclusion at both ends of the thread outside the sclera, as shown in figure 3. Next, the Ahmed valve is activated by washing it with saline, for which 1 ml saline is injected into the drainage tube and valve through a 28G blunt cannula with filling of the valve tube (Fig. 4). An activated valve is installed in the formed pocket, orienting its front edge to the limb and the holes to the location of the free ends of the thread. The ends of the thread are threaded into the holes in the base of the valve and by tightening the ends of the thread, as shown in Fig. 5, the valve is precisely installed in the pocket with its front part at a distance from the limb of at least 12 mm. The valve is rigidly fixed with the ends of the thread at the sewing site (Fig.6).

The drainage tube is cut at an angle of 30-45 ° to a length of 2-3 mm, sufficient to enter it into the anterior chamber of the eye to the required depth (Fig. 7). In the anterior chamber of the eye in the area of the scleral flap, under its flap, an injection with a 23G needle is carried out (Fig. 8), parallel to the iris through the trabecula zone, followed by installation of the free end of the valve tube into the resulting channel for a length of 2-3 mm (Fig. 9 ) Then the tube is covered with a scleral flap, straightening it, and the edges of the scleral flap are connected with several sutures (Fig. 10), while fixing the tube under the scleral flap. After applying a scleral flap to the valve tube and securing it, the peeled upper part of the pocket is completely pulled both over the valve and its tube (Fig. 10), fixed with a scleral flap with sutures, to the incision site, covering both the valve and the tube fixed stitches. Next, two sutures are applied at the extreme points of the conjunctival incision (Fig. 11). Figure 13 shows a shunt in the anterior chamber of the eye made of a tube.

After installing the valve with the drainage tube with excessive intraocular pressure through the drainage tube and the valve membrane, excess fluid from the anterior chamber of the eye enters the periclungar space. In the near-valve space, the patient’s body forms a flat, spilled filtration cushion “A” (“bubble”) in the form of a reservoir in the sub-tone space (Fig. 12). In the filter cushion, subconjunctival channels for the outflow of intraocular fluid will be formed, providing a decrease in intraocular pressure and its normalization. The pillow will provide a gradual resorption and evacuation of fluid through the sutenon-generated streams. By installing the valve behind the line of the equator of the eyeball, the filter pad will also be located behind the line of the equator (Fig. 14), beyond the line of fit of the eyelid, without interfering with the normal mobility of the eye, ensuring that the eyelid performs its functions of uniformly wetting the surface of the eye, cleansing it without causing discomfort and cosmetic problems in the patient, as well as postoperative complications.

After installation of the valve, a constant outflow of fluid is ensured at a constant rate of 12 μl / min while maintaining intraocular pressure of not higher than 18 mmHg. Installing the valve further from the limb of the eye compared with the prototype, at a distance of at least 12-16 mm, outside the equator of the eye does not interfere with the work of the rectus muscles and eye movement. The normal mode of muscle work will not cause complications in the form of strabismus, eliminate the unpleasant sensations of the presence of a foreign body in the patient, and also will not lead to cosmetic defects. Installing the valve by the proposed method by pre-executing a U-shaped seam with the end of the thread outside the sclera, threading the ends of the thread into the holes provided for them in the base of the valve, fixing the valve by tightening the free ends of the thread of the U-shaped seam, then securing them will ensure accurate installation of the valve in the selected place without moving the valve from the intended place in the process of fixing it.

The method passed clinical trials, as a result of which more than a hundred patients with diagnoses were operated on: secondary neovascular post-thrombotic glaucoma, absolutely painful glaucoma, primary open-angle glaucoma from the first to fourth stages. The observation period was up to three months. In all patients, intraocular pressure returned to normal, patients did not feel discomfort. No cosmetic defects were observed in the patients operated on in accordance with the invention and postoperative complications. The resulting filtration "bubble" behind the line of the equator of the eye did not interfere with the movement of the eye and eyelid.

Claims (2)

1. A method of implanting a drainage valve to normalize intraocular pressure, in which a preliminary selection of the future location of the valve at a distance from the limbus is carried out, the valve is installed in the selected place and fixed by sewing it through the holes in the base of the valve to the tissues of the eyes, characterized in that the place the location of the valve is chosen behind the line of the equator of the eye, for the region of fit of the eyelids, on the back side of the eyeball, then the thread of the valve is sutured to the sclera behind the equator of the eye block, with the ends of the thread outside the sclera, the ends of the thread are threaded into the holes of the valve base and the pulling of both ends of the thread, the valve is accurately installed in a pre-selected place, the ends of the thread are tightened, gradually lowering the valve to the selected location, fix them, fixing the valve firmly in place . 2. The method according to claim 1, characterized in that the front edge of the valve is located at a distance from the limb no closer than 12 mm.

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