RU2444342C1 - Method for refraction surgeries in children - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention refers to medicine, particularly to ophthalmology, and can be used in refraction surgeries requiring general anaesthesia. A low-vacuum ring is repeatedly fixed on a cornea after cutting of a corneal valve that accompanies laser keratomileusis in situ; an eyeball is fixed in a correct position that is followed by tracker adjustment and excimer-laser ablation according to an optical correction procedure specified for a given patient; thereafter the valve is reduced, and the low-vacuum ring is removed.

EFFECT: method provides higher precision of the performed ablation ensured by fast and table eyeball fixation eliminated tracker failures.

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Description

The invention relates to medicine, in particular to ophthalmology, and can be used during refractive surgery (LASIK, Epi-LASIK) in children, providing for general anesthesia.

Various methods are known for correcting anomalies of eye refraction by changing its external surface during selective tissue removal by laser pulsed radiation from the UV wavelength range. The main condition for successful vision correction is the accuracy of the operation, in which the removal of corneal tissue in predetermined areas and at a predetermined depth ensures the formation of curvature of the cornea with a profile that maximally corresponds to the calculated value.

Surgical methods for performing refractive surgeries in children have their own characteristics, since, as a rule, they provide for total inhalation or intravenous anesthesia. During anesthesia, as a result of relaxation of the eye muscles, slow circular movements appear, then the eyeball is thrown up, as in physiological sleep, which is an additional technical difficulty during the operation. The surgeon needs to bring the eye to the correct position and fix the eye with tweezers. It is difficult to achieve a good centering of the cornea in this way of fixation; interruptions in the work of the tracking system (tracker) occur due to the large amplitude of the eyeball movement. Thus, the development of techniques for fixing the eyeball in the correct position during refractive operations is an urgent task.

A known method of photorefractive keratectomy to correct myopia in children, including total intravenous anesthesia with sodium thiopental to eliminate involuntary eye movements during excimer laser keratectomy (Kanyukov V.P., Likhachev D.P., Lanovskaya Yu.I., Skoy-Bedo I.E. // Mizhnar.Ophthalmic sympos. XII: Abstracts, Odessa, 2001, p.192).

The disadvantage of this method is the incomplete fixation of the eyeball, insufficient centering and accuracy, difficulties in setting up the tracker.

The closest to the claimed method - the prototype, is a method of refractive surgery in children and adolescents with hyperopia and hyperopic astigmatism, including the preparation of the surgical field, total inhalation or intravenous anesthesia, applying a vacuum ring around the periphery of the cornea, creating a vacuum, applanation monitoring of intraocular pressure, cutting surface corneal flap, turning it to the side, exposure of the stroma of the cornea to an excimer laser beam, reposition of the flap and (patent RU №2317055 C1, 20.02.2008).

The disadvantage of this method is its duration and the complexity associated with the need to fix the eyeball (usually with tweezers) in the absence of fixation of the gaze due to total inhalation or intravenous anesthesia.

An object of the invention is to reduce the duration and complexity of the operation, improving the accuracy of ablation.

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

In the preoperative period, the child is given intravenous anesthesia or total inhalation anesthesia using a laryngeal mask in spontaneous respiration. As a result of relaxation of the eye muscles, slow circular movements appear, then the eyeball is thrown up. A vacuum ring is applied around the periphery of the cornea, centered according to the location of the pupil, a vacuum is created and the amount of intraocular pressure is monitored. After cutting off the corneal valve with a microkeratome, in order to fix the eyeball in the correct position and hold it in control of the position of the corneal reflex, another vacuum ring, “LSK One” (Moria), is reinstalled under low pressure. Make tracker settings. After raising the valve and confirming the operation of the servo system, excimer laser ablation is performed according to the optical correction algorithm of this patient. After the laser beam is completed, the corneal bed is washed with saline, the valve is put in place, the vacuum ring is removed.

The defining difference of the proposed method from the prototype is that after cutting off the corneal valve before laser ablation, a low pressure vacuum ring (Low vacuum) is reinstalled on the cornea, the eyeball is fixed in the correct position, then the tracker is set up and excimer laser ablation is performed. After the laser stops and the valve is repositioned, the vacuum ring is removed. This technique allows to reduce the duration and complexity of the method due to the fast and stable fixation of the eyeball and eliminate interruptions in the tracker.

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

Example 1

Patient T., 14 years old, East. illness No. 162158-07, was admitted to the Novosibirsk branch of the Federal State Institution Scientific and Technological Center "Eye Microsurgery" with a diagnosis of mixed astigmatism in both eyes.

Visual acuity: OD 0.5 s corr. Sph 0.00 Cyl - 2.5 ax 15 = 1.0

OS 0.3 corr. Sph 0.00 cyl - 2.5 ax 158 = 1.0

Refractometry: OD Sph 0.25 cyl - 2.25 ax 8

OS Sph 0.5 cyl - 2.25 ax 155

Keratometry: OD Ver. Mer. 45.12 ax 92 Mountains Mer. 43.37 ax 2

OS Ver. Mer. 45.12 ax 75 Mountains Mer. 43.12 ax 165

The patient underwent surgery LASIK on both eyes of the claimed method.

After treating the skin of the eyelids with 65% Erisan disinfectant solution, inhaled anesthesia with Sevoran in combination with oxygen in MAK according to age and weight. Five minutes later, the eyelids were immobilized with an eyelid extender and a vacuum ring was applied along the periphery of the cornea, centered according to the location of the pupil. A vacuum was created and intraocular pressure was checked by palpation. The pre-assembled cutting part of the keratoma head “Zyoptix XP” (Bausch & Lomb) was mounted on the pin of the vacuum ring and after switching on the moving mechanism, a surface flap of a round cornea with a diameter of 9.5 mm was cut with a base at 12 o’clock. Without lifting the valve, the eyeball again in the same position, controlling the position of the corneal reflex, installed another “LSK” One vacuum ring (Moria) under low pressure (Low vacuum), fixing the eye, set up the tracker (tracking) system. Then, throwing the corneal flap to the side on the leg, after confirming the operation of the tracker, excimer laser ablation was performed using the Technolas 217Z100 laser device (Bausch & Lomb) using standard technology. The stroma of the cornea was exposed to laser radiation with a wavelength of 193 nm, a pulse energy density of 160 mJ at 2 Hz, a pulse repetition rate of 100 Hz, a pulse duration of 18 ns, and a pulse number of 1652. The focal spot diameter was 2 and 1 mm. The leg of the folded flap was protected with a tuper. After the laser beam was completed, the surface of the stroma of the corneal bed was washed with saline, the flap was repositioned to its previous position, and fixed with a saline stream. The vacuum ring was removed, the corneal groove was drained with a tuffer. After instillation of antibiotics into the conjunctival sac, an eyelid was removed. An hour after the operation, a control examination was performed using a slit lamp.

Examination after treatment:

Visual acuity: OD 1.0 without corr.

OS 1.0 without correspondent

Refractometry: OD Sph - 0.25 cyl 0.00 ax 0

OS Sph 0.25 cyl - 0.5 ax 20

Keratometry: OD Ver. Mer. 43.50 ax 68 Mountains Mer. 42.75 ax 158

OS Ver. Mer. 43.25 ax 111 Mountains Mer. 42.25 ax 21

Example 2

Patient T., 10 years old, East. Disease No. 219393-05, he was admitted to the Novosibirsk branch of the Federal State Institution Scientific and Technological Center "Eye Microsurgery" with a diagnosis of mild hyperopia, complex direct hyperopic astigmatism, mild refraction amblyopia of both eyes.

Visual acuity: OD 0.1 s corr. Sph 2.00 Cyl 4.00 ax 95 = 0.7

OS 0.1 corr. Sph 2.00 cyl 4.00 ax 95 = 0.85

Refractometry: OD Sph 2.00 cyl 4.5 ax 95

OS Sph 1.75 cyl 4.25 ax 94

Keratometry: OD Ver. Mer. 45.12 ax 94 Mountains Mer. 40.87 ax 4

OS Ver. Mer. 45.25 ax 91 Mountains Mer. 47.0 ax 1

The patient underwent surgery LASIK on both eyes of the claimed method.

After treating the skin of the eyelids with 65% Erisan disinfectant solution, inhaled anesthesia with Sevoran in combination with oxygen in MAK according to age and weight. Five minutes later, the eyelids were immobilized with an eyelid extender and a vacuum ring was applied along the periphery of the cornea, centered according to the location of the pupil. A vacuum was created and intraocular pressure was palpated. The pre-assembled cutting part of the keratoma head “Zyoptix XP” (Bausch & Lomb) was mounted on the pin of the vacuum ring and after switching on the moving mechanism, a surface flap of a round cornea with a diameter of 9.0 mm was cut with a base at 12 o’clock. Without lifting the valve, the eyeball again in the same position, controlling the position of the corneal reflex, installed another “LSK” One vacuum ring (Moria) under low pressure (Low vacuum), fixing the eye, set up the tracker (tracking) system. Then, throwing the corneal flap to the side on the leg, after confirming the operation of the tracker, excimer laser ablation was performed using the Technolas 217Z100 laser device (Bausch & Lomb) using standard technology. The stroma of the cornea was exposed to laser radiation with a wavelength of 193 nm, a pulse energy density of 160 mJ at 2 Hz, a pulse repetition rate of 100 Hz, a pulse duration of 18 ns, and a pulse number of 1652. The focal spot diameter was 2 and 1 mm. The leg of the folded flap was protected with a tuper. After the laser beam was completed, the surface of the stroma of the corneal bed was washed with saline, the flap was repositioned to its previous position, and fixed with a saline stream. The vacuum ring was removed, the corneal groove was drained with a tuffer. After instillation of antibiotics in the conjunctival sac, the vex expander was removed. An hour after the operation, a control examination was performed using a slit lamp.

Examination after treatment:

Visual acuity: OD 0.4

OS 0.3

Refractometry: OD Sph - 0.5 cyl - 0.75 ax 99

OS Sph 0.5 cyl - 1.5 ax 90

Keratometry: OD Ver. Mer. 48.12 ax 5 Mountains Mer. 46.87 ax 95

OS Ver. Mer. 47.62 ax 4 Mountains Mer. 46.50 ax 94

The use of the invention allows for stable fixation of the eyeball in the correct position, good centering of the cornea, correct and stable operation of the tracker during ablation in patients during general anesthesia. The creation of these conditions is especially important for the correction of a high degree of ametropia (decentration during deep ablation leads to a decrease in uncorrectable visual acuity, the appearance of high-order aberrations), correct and incorrect astigmatism (with post-traumatic cicatricial deformity of the cornea) in children with oculomotor lesion (various types of strabismus) and nervous systems.

Claims (1)

A method for performing refractive surgeries in children, including performing general anesthesia, applying a vacuum ring around the periphery of the cornea, creating a vacuum, applanating control of intraocular pressure, cutting a surface flap of the cornea, turning it to one side, exposing the corneal stroma to an excimer laser beam, repositioning the flap, characterized in that after a cut of the corneal valve, the vacuum ring under low pressure is re-installed on the cornea - Low vacuum - the eyeball is fixed in the correct position, after which the tracker is tuned and excimer laser ablation according to the optical correction algorithm of this patient with subsequent repositioning of the valve and removal of the vacuum ring.