RU2440082C1 - Method of refractive error correction in nystagmus - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, namely ophthalmology, and concerns refractive error correction in nystagmus. That is ensured by preoperative transconjunctival injections of the preparation Disport 7-17 Units in muscular sacs of two or four horizontal rectus muscles of both eyes. If observing pendular and pendular jerk nystagmus, Disport is injected in the four horizontal muscles, while jerk nystagmus requires the injections only in the sacs of the two muscles enabling eye turn to a nystagmus relative rest area. In 7-14 days, a standard LASIK or Photorefractive Keratectomy operation follows.

EFFECT: method provides simplified treatment process with higher effectiveness, and decreased number of complications.

3 cl, 3 dwg, 2 ex

Description

The invention relates to medicine, namely to ophthalmology, and can be used during refractive surgery (LASIK, PRK) in patients with various refractive errors associated with nystagmus.

Nystagmus is such an imbalance of the oculomotor system in which the patient’s eyes are in a relatively constant pendulum-like or jerk-like movement, and the patient’s gaze deviates from the object of fixation. This leads to a decrease in visual acuity, oscillopsia (sensation of movement of the environment), compensatory tremor or compensatory head rotation. Nystagmus is often combined with various refractive errors. The spectacle correction of ametropia is ineffective, since the visual axis constantly deviates from the optical center of the spectacle lens. Contact correction is also unacceptable, because eye movements cause the contact lens to constantly move relative to the cornea, touching the edge of the eyelids. The optimal way to correct refractive errors with nystagmus is a refractive surgery. However, its technical execution requires a state of rest of the eyeballs.

Currently, due to the widespread use of surgical methods for correcting refractive errors, the development of methods for suppressing nystagmus in the preoperative period or during refractive operations is an urgent task.

A known method of suppressing nystagmus during photorefractive keratectomy (PRK) for correcting myopia by total intravenous anesthesia with thiopental sodium to eliminate the oscillating movements of the eyeballs during excimer laser keratectomy (Kanyukov V.P., Likhachev D.P., Lanovskaya Yu.I. ., Skoy-Bedo I.E. // Mizhnar.ophthalmol.sympos. XII-th: Abstracts - Odessa, 2001, p.192).

The disadvantage of this method is the need for general anesthesia, which lengthens the time of surgery and the patient’s rehabilitation time, and also increases the complexity of the method, since with full anesthesia the patient’s eyes are tilted up, as in physiological sleep, which is an additional technical difficulty during the operation.

There is a method of drug treatment of horizontal nystagmus by prescribing inside the drug Baclofen 10-20 mg 3 times a day (Yee RD, Baloh RW, Honrubia V .: Effect of baclofen on congenital nystagmus. In Lennerstrand G., Zee DS, Keller EL, eds : Functional Basis of Ocular Motility Disorders. Oxford, Pergamon Press: 1982, p. 151).

The method of drug treatment of nystagmus described above has several disadvantages:

1. Treatment is aimed at eliminating the symptom of the disease, and not at pathogenesis;

2. There are numerous side effects from the cardiovascular, digestive, urinary, central and peripheral nervous systems, including the induction of nystagmus;

3. There are a large number of contraindications for prescribing the drug.

Closest to the claimed method, the prototype is a method for refractive surgery for nystagmus (patent No. 2337657, publ. 10.11.08), which consists in the fact that with a large-scale horizontal or rotator component of nystagmus in the preoperative period, a medicinal mixture containing 20-40 mg of lidocaine, 0.4-0.5 mg of adrenaline and 4-6 units of lidase; after which the laser is tuned according to the glow of the macular reflex with subsequent ablation; and with small- or medium-spreading nystagmus after a cut of the corneal valve during laser keratomileusis in situ (LASIK) or without a cut of the corneal valve during photorefractive keratectomy (PRK), a vacuum ring is installed on the cornea; after which, with finely spreading nystagmus, the tracer is tuned, and with a medium-spread nystagmus, the laser is tuned according to the glow of the macular reflex; further carry out ablation. In this case, after setting up the tracer, the vacuum ring is removed and the operation is carried out in the normal mode under the control of the tracer.

However, the known method of refractive surgery for nystagmus has a number of significant disadvantages:

1. Suppression of nystagmic eye movements occurs with small- and medium-spread nystagmus already during the operation;

2. With large-scale nystagmus, retrobulbar anesthesia-akinesia is performed, which leads to dilated pupils, there is a risk of acute vascular insufficiency, vision is reduced, which is unfavorable for the operation, when a clear fixation of the gaze is required.

An object of the invention is to simplify the known method, increase its effectiveness and reduce side complications.

The technical task is achieved by the proposed method, which consists in the following.

In the preoperative period, the patient is administered transconjunctively with Dysport in a dose of 7-17 Units into muscle bags of two or four rectus muscles of horizontal action in both eyes, and then, after 7-14 days, they perform an operation according to the LASIK or PRK technique using standard technology.

The needle is injected through the conjunctiva 2 mm from the proposed anatomical place of muscle attachment to the sclera, the needle is advanced 5-7 mm in the distal direction, repeating the sphericity of the sclera (Fig. 1). In a similar way, manipulation is performed in the projection area of another muscle of the horizontal action of this eye and both horizontal muscles in the other eye.

When the pendulum-like type of nystagmus injection is performed in all four muscles of horizontal action in equal doses (figure 2). With the jerky type of nystagmus, the injections are performed only in the bags of two muscles, which ensure that the eyes rotate in the direction of the relative dormancy zone of the nystagmus in equal dosages (Fig. 3). With the pendulum-jerk-like type of nystagmus, injections are performed in all four horizontal rectus muscles, with the only difference being that the drug is injected 5 more units into a pair of muscles on the side of the relative rest zone.

Schematically in figure 2 and 3 presents the topography of the administration of the drug Dysport, where

- Экстраокулярная мышца, в мышечную сумку которой вводят препарат;

- Extraocular muscle, into the muscle bag of which the drug is administered;

- Направление зоны относительного покоя нистагма.

- The direction of the relative dormancy zone of nystagmus.

In a particular case, a syringe with a needle with a diameter of 27 G and a length of 25-27 mm is used for injection.

The specific dosage of the drug administered depends on the characteristics of the nystagmus. With finely spread nystagmus, the optimal dose of the drug is 7-10 Units, with a medium spread - 11-14 Units, with a large-scale nystagmus - 15-17 Units.

A significant difference of the proposed method from the prototype is that in the muscle bags of two or four rectus muscles of the horizontal action of both eyes, the drug Dysport is injected transconjunctively into an experimentally selected, optimal concentration of 7-17 Units, which allows to increase the stability of manipulation, reduce its invasiveness and reduce side effects.

The positive effect of the operation is achieved due to the following induced biomechanical changes that occur when transconjunctival injections of the drug Dysport are performed in muscle bags:

- relative blocking of pathological afferent hyperimpulsation by separation of synoptic transmission in the oculomotor muscles;

- performing refractive surgery under conditions of relative stabilization of nystagmus;

- a secondary decrease in the number of neuromuscular synapses in extraocular rectus muscles of horizontal action;

- a decrease in the potential dynamometric response of these muscles to unchanged central hyper-pulsation after cessation of chemo-denervation.

The combination of the above mechanisms causes a decrease in dynamometric and dynamostatic indicators of horizontal rectus muscles, which induces a reduced tone of these extraocular muscles. This, in turn, causes a decrease in the oscillation of nystagmus. As a result, favorable conditions are created for conducting refractive surgery, as well as increasing visual acuity and improving the quality of life.

The method provides suppression of any type of nystagmus, and also helps to reduce the degree of nystagmus.

A search by sources of scientific, technical and patent information did not reveal a method identical to the claimed one, in connection with which we can conclude that the claimed technical solution meets the criteria of “novelty” and “inventive step”.

The invention is illustrated by the following examples of specific performance.

Example 1

Patient P., 26 years old, was admitted to the Novosibirsk branch of the Federal State Institution IRTC “Eye Microsurgery” with a diagnosis of Mixed astigmatism in both eyes, medium-wide horizontal nystagmus.

On examination: visual acuity:

OD 0.2 with the correspondent. sph + 1.25D Su1-3.50D ah 27 ° = 1,0 OS 0.2 with the correspondent. sph + 1.25D Su1-3.50D ah 142 ° = 0.9

Refractometry:

OD sph + 1.25D Su1-3.50D ah 27 ° OS sph + 1.25D Su1-3.50D ah 142 °

Keratometry:

OD 41.25D ah 116 ° 38.50D ah 26 ° OS 41.75D ah 55 ° 39,00D ah 145 °

Medium-wide horizontal nystagmus up to 15 °.

The strabismus angle is 0 °, with a cover-anchor test without settings.

The range of motion is full.

Anterior segment of eyes without features. The environments are transparent. The fundus without pathological changes.

7 days before the planned refractive surgery (LASIK), the patient was given Dysport injections of the claimed method. The operating field was prepared accordingly. An enlarger was installed on the right eye, the palpebral fissure was maximized. At the request of the doctor, the patient looked to the right, following the object, moved so that the eye was in the abduction position at half the possible amplitude. The eyeball was fixed with serrated forceps in this position, by capturing the conjunctiva in a fold 10 mm distal from the proposed anatomical site of attachment of the internal rectus muscle to the sclera.

The place of the transconjunctival injection of the needle of an insulin syringe with a diameter of 27G was carried out 2 mm proximal to the localization of the forceps on the conjunctiva, followed by the advancement of the needle by 5 mm in the distal direction. Thus, the end of the needle was localized in the muscle bag. After which, by pressing the piston of the syringe, Dysport was introduced in a dose of 15 Units.

In a similar way, the manipulation was performed on the external rectus muscle of this eye and the internal and external rectus muscles of the other eye, with the only difference being that the needle was injected into the external rectus muscles 2 mm proximal to the point of capture with tweezers for the conjunctiva of the outside of the eye, 14 mm distal from the alleged anatomical site of attachment of the external rectus muscle to the sclera.

7 days after the injection, an operation was performed according to the LASIK method according to standard technology.

14 days after the operation, a control examination was performed:

Visual acuity without correction:

OD 0.9

OS 0.8

The amplitude of nystagmus decreased to 5 ° and was inconstant.

Example 2

Patient K., 20 years old, was admitted to the Novosibirsk branch of the Federal State Institution IRTC "Eye Microsurgery" with a diagnosis of Complex myopic astigmatism of a high degree of both eyes, amblyopia of an average degree of both eyes, mixed genesis, medium-wide horizontal nystagmus.

Visual acuity:

OD 0.04 with the correspondent. sph-4,00D su1-2,00D ah 20 ° = 0.4 OS 0.04 with the correspondent. sph-4,50D Su1-2.75D ah 165 ° = 0.4

Refractometry:

OD sph-4,50D su1-2,50D ah 20 ° OS sph-4.75D Su1-3.25D ah 164 °

Keratometry:

OD 45.75D ah 106 ° 44,00D ah 16 ° OS 46,00D ah 76 ° 44,00D ah 166 °

Medium-spreading mixed (pendulum-jerky) horizontal nystagmus with an amplitude of up to 10 °. The zone of relative peace when looking to the right, compensatory head rotation to the left by 10 °.

The strabismus angle is 0 °, with a cover-ankaver test without settings.

The range of motion is full.

Anterior segment of eyes without features. The environments are transparent. The fundus without pathological changes.

In the preoperative period, the patient was suppressed by nystagmus by subconjunctival injection of the drug Dysport by the claimed method as in Example 1, except that the dose of the drug injected into a pair of extraocular muscles on the side of the slow phase of nystagmus (the external rectus muscle of the right eye and the internal rectus of the left eye) , amounted to 17 Units, and the dose of the drug for a pair of extraocular muscles on the side of the fast phase (internal rectus muscle of the right eye and external rectus muscle of the left eye) - 7 Units .

10 days after the injection, an operation was performed according to the LASIK method according to standard technology.

14 days after the operation, a control examination was performed:

Visual acuity without correction:

OD 0.4 n / a OS 0.4 n / a

The amplitude of the finely mixed (pendulum-jerky) horizontal nystagmus decreased to 5 °. The zone of relative peace was kept when looking to the right; the compensatory rotation of the head to the left decreased to 3-5 °.

The strabismus angle is 0 °, with a cover-ankaver test without settings.

The volume of eye movements is limited to 10-15% compared with the preoperative.

The proposed method has several advantages compared with known methods.

1. Subconjunctival injection is safe and effective and is performed on an outpatient basis.

2. Stabilization of pathological eye mobility optimizes the work of the refractive surgeon, increases the guaranteed visual effect, eliminating the risk of complications that may occur when performing other methods of anesthesia.

3. The emmetropia achieved as a result of the refractive surgery has a positive effect on a more stable position of the eyes in combination with post-chemo-denervation changes in the extraocular muscle after the termination of botulinum toxin-A.

The proposed method allows not only effectively and simply to suppress nystagmus before refractive surgery, but also to ensure the disappearance or reduction of the amplitude of the rolling movements of the eyes.

Claims (3)

1. A method for the correction of refractive errors in nystagmus, including preliminary suppression of nystagmus followed by refractive surgery according to a standard method, characterized in that the patient in the preoperative period is administered transconjunctively with Dysport in a dose of 7-17 Units in muscle bags of two or four rectus muscles of horizontal action both eyes, while with the pendulum-like and pendulum-jerky type of nystagmus, Dysport injections are performed in all four muscles of horizontal action, and like manner type nystagmus injection is performed only in the two bags muscles providing eye rotation towards the zone of relative quiescence nystagmus. 2. The method according to claim 1, characterized in that with finely spread nystagmus, Dysport is administered in a dose of 7-10 Units, with a medium-spread nystagmus -11-14 Units, and with a large-scale nystagmus - 15-17 Units. 3. The method according to claim 1, characterized in that for the injection of the drug Dysport use a syringe with a needle with a diameter of 27 G and a length of 25-27 mm

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