RU2102048C1 - Method for extracting cataract - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves applying laser radiation on operating needle tip directly to lens nucleus. Solid-state laser is used operating in medium infrared region of the spectrum at wavelength of 1900-2200 nm, pulse energy of 10-800 mJ, pulse frequency of 10-100 Hz, pulse duration of 50-500 mcs and quasi-rectangular pulse shape with 500-600 pulses in the whole radiation pulse train. Duration of laser exposure applied to lens nucleus is 3-3.5 min. Small splinters obtained are aspirated through operating portion of needle end piece to enable complete destruction and aspiration of lens nucleus fragments in hard cataract cases with minimum risk of pathological changes arisen in tissues surrounding the eye lens. EFFECT: enhanced effectiveness of treatment. 1 dwg

Description

 The invention relates to medicine, namely to ophthalmology, and can be used in the surgical treatment of cataracts.

 A known method of cataract removal, including: a 3-mm incision of the sclera near the limb, circular capsulorexis, insertion into the cavity of the eye through the incision of the working needle, the needle including a light guide for supplying laser radiation, a cannula for irrigation, an aspiration tube, a titanium plate receiving laser radiation with a wavelength of 1064 nm, a pulse power of 4.0 mJ, a pulse frequency of 10 Hz, and oscillating under the influence of a laser hydrodynamic shock, the destruction of the lens nucleus due to hydrodynamic shock is caused by th vibrations titanium plates, aspirate the fragments of the lens nucleus and lens masses, weld overlay on the immersion zone section (Dodik J.M. Arch Ophalmol 1993, Vol 111, p 903-904).

 The disadvantages of the method are: the difficulty of removing "hard" cataracts, the duration of the operation, the spread of hydrodynamic shock to the surrounding tissues of the eye, causing dystrophic changes primarily in the endothelium, a large amount of irrigation fluid.

 The technical result of the invention is the achievement of complete destruction and aspiration of fragments of the lens nucleus with "hard cataracts" with a minimal risk of changes in the surrounding tissues of the lens of the eye.

 The technical result is achieved by the fact that in the cataract extraction method, which includes the action of laser radiation, irrigation and aspiration of fragments of the lens nucleus, according to the invention, laser radiation at the tip of the working needle directly affects the lens nucleus, using a mid-IR solid-state laser with a wavelength of 1900 2200 nm, pulse energy 10 800 mJ, pulse frequency 10 100 Hz, pulse duration 50 500 μs, quasi-rectangular pulse shape, 500 600 pulses in the entire emission series I, the duration of laser irradiation of the lens nucleus is 3.5 minutes, which breaks the intermolecular bonds in the irradiated tissue and fragmentation of the lens nucleus into small "fragments", which are then aspirated through the tip of the working part of the needle.

 Pulse frequency, radiation energy and pulse duration are parameters that determine the intensity of the destruction of the lens nucleus. With a pulse energy of less than 10 mJ, it is not possible to achieve visible fragmentation of the lens nucleus, with a pulse energy of more than 800 mJ, the fragmentation rate is very high, but in this case, along with fragmentation of the lens nucleus, a hydrodynamic shock appears, causing changes in the tissues of the eye surrounding the lens. If the pulse frequency is less than 10 Hz, then even with high radiation energy the lens fragmentation rate is 30–40 min. At a pulse frequency greater than 100 Hz, even at low energy values of radiation, the coagulation effect increases, which increases the risk of damage to the structures of the eyeball surrounding the lens. If the pulse duration is 50 μs, then to obtain the effect it is necessary to use threshold values of the energy and frequency of the pulses, with a pulse duration of 500 μs, the thermal effect and hydrodynamic shock appear even at the lowest radiation energies.

 The method allows to destroy both "dense" and "soft" cataracts. The hydrodynamic shock with the proposed laser is expressed to a much lesser extent than when working with the Nd-YAG laser, accordingly, the intensity of the hydrodynamic effect on the surrounding tissues of the eye is lower, which provides the method with greater safety. For the complete destruction of the lens nucleus, 3 3.5 min of laser operation is required, which significantly reduces the volume of irrigation fluid and thereby increases the safety of the technique with respect to the corneal endothelium.

 The invention is illustrated by the drawing, which shows the working needle 1, inserted into the cavity of the eye for the destruction of the lens and aspiration of the crystalline fragments, including the light guide 2, a cannula for irrigation nat. solution 3, a cavity for aspiration of lens fragments 4.

 The method is as follows. Under local anesthesia, the conjunctiva is incised 3 mm from the limbus. 0.5 mm from the limb produce a 3 mm incision of the sclera. A mesaton is introduced into the chamber, the Fedorov microcystome is used to open the anterior lens capsule in a circle at a distance of 5-6 mm from the equator of the lens, the capsule is removed with iris forceps. The tip of the needle 1 is inserted into the anterior chamber, including the light guide 2, a cannula for irrigation of saline solution 3, a cavity for aspiration of the lens fragments 4. Hydrodissection of the lens nucleus is performed. The front camera is filled with a visitor. The tip of the needle 1 is brought as close as possible to the equator of the lens, the generation of pulses supplied to the lens core through the optical fiber 2 is turned on, pulse frequency 10 100 Hz, pulse energy 10 800 mJ, pulse duration 50 500 μs, duration of each series of pulses 5 6 s. Aspiration of the lens fragments is performed in the intervals between a series of pulses. The surgeon includes the surgeon using the foot pedal. As the lens nucleus is fragmented and aspirated, the tip of the needle moves toward the center of the nucleus. At the final stages of the operation, the nucleus of the lens "breaks" into several fragments, which are then fragmented and aspirated in turn. The duration of the entire operation is 25-30 minutes, laser radiation acts on the lens for 3 3.5 minutes. The testimony operation may end with the implantation of an IOL, for which the incision expands to 5–6 mm. After implantation and leaching, the surgical wound visited is sutured with a continuous suture 10.0. Conjunctive joint 8.0.

 Example 1. Patient B. 71 years. diagnosis: mature age-related cataract of the left eye, the right eye is healthy.

 Received complaints of decreased vision in the left eye.

Left eye:
Visual acuity of 0.01 n / a
Ophthalmetry 43.00 173, 42.50 83
Tonography
Po 12.2 C 0.20 F 0.45 V 3.12 Po / c 61. Fields of view narrowed by 10 degrees on the temporal side. Eye length 23.5, anterior chamber depth 2.58 mm. Threshold, lability within normal limits. ERG minor changes in the outer layers of the retina. PEC of the left eye 2500 per 1 mm square. Biomicroscopic: diffuse opacification of all layers of the lens, the nucleus has a dark brown hue, which indicates that it is a cataract with a dense nucleus.

 Cataract removal was performed on the left eye using the laser lens destruction method. The radiation parameters were: pulse energy 650 mJ, pulse frequency 15 Hz, pulse duration 230 μs, quasi-rectangular shape of pulses, 537 pulses in the entire series of radiation, duration of laser exposure to the lens nucleus 3 min. An IOL was implanted (T-26, 21 D).

 The patient was discharged for outpatient treatment 7 days after surgery. The data of instrumental studies of the operated eye at the time of discharge were as follows.

 In 7 days.

Left eye:
Visual acuity 0.7 sph + 1.0 0.75
Ophthalmometry 44.50 165, 43.00 82
Tonography
Po 15.8 C 0.32 F 1.88 Po / C 50.

 PEK 2000 per 1 mm2 Threshold, lability within normal limits. ERG - minor changes in the outer layers of the retina. Biomicroscopically, the cornea is transparent, the anterior chamber is deep, the position of the IOL is correct.

 30 days later.

Left eye:
Visual acuity 0.7 sph + 1.0 0.75
Ophthalmometry 44.00 165, 43.0 32
Po 14.2 C 0.25 F 0.400 Po / C 56
PEK 1950 per 1 mm sq. The threshold lability is within normal limits. ERG - minor changes in the outer layers of the retina. Biomicroscopically, the cornea is transparent, the anterior chamber is deep, the position of the IOL is correct.

 Example 2. Patient E., 68 years old, diagnosis: mature age-related cataract of the right eye, the left eye is healthy.

 Received complaints of decreased vision in the right eye.

Right eye:
Visual acuity of 0.1 n / a.

Ophthalmetry 42.25 176, 42.87 86
Po 15.0 C 0.20 F 0.91 Po / c 73. The field of view is normal. Eye length 23.1 depth of anterior chamber 3.0 mm. Threshold, lability within normal limits. ERG minor changes in the outer layers of the retina. PEK 2700 on 1 mm.kv. Biomicroscopic: diffuse opacification of all layers of the lens, the nucleus has a yellowish tint, which indicates that the soft core of the lens.

 Cataract was removed using the laser lens destruction method. The radiation parameters were; the pulse energy is 15 mJ, the pulse frequency is 86 Hz, the pulse duration is 230 μs, the quasi-rectangular shape of the pulses, 517 pulses in the entire series of radiation, the duration of laser exposure to the lens nucleus is 3.5 minutes. Implanted artificial lens T26, 23 D.

 The patient was discharged for outpatient treatment 7 days after surgery. The data of instrumental studies of the operated eye at the time of discharge were as follows.

 In 7 days.

 Right eye.

 Visual acuity of 0.8 n / a.

Ophthalmometry 44.50 165, 43.00 82
Tonography
Po 14.6 C 0.16 F 0.73 Po / c 91
PEK 2000 per 1 mm2 Threshold, lability within normal limits. ERG - minor changes in the outer layers of the retina. Biomicroscopically, the cornea is transparent, the anterior chamber is deep, the position of the IOL is correct.

 30 days later.

Right eye:
Visual acuity of 0.8 sph n / a.

Ophthalmometry 42.25 176, 42.87 87
Tonography
Po 12.3 C 0.29 F 0.65 Po / c 42.

 PEC 2700 per 1 mm2 Threshold, lability within normal limits. ERG - minor changes in the outer layers of the retina. Biomicroscopically, the cornea is transparent, the anterior chamber is deep, the position of the IOL is correct.

Claims (1)

 A method of cataract extraction, including laser irradiation, irrigation and aspiration of fragments of the lens nucleus, characterized in that laser radiation acts directly on the lens nucleus, using a laser with a wavelength of 1900-2200 nm, pulse energy 10 800 mJ, pulse frequency 10 100 Hz , with a pulse duration of 50,600 μs, a quasi-rectangular pulse shape, 500,600 pulses in the entire series of radiation, a duration of laser irradiation of the lens nucleus of 3.0–3.5 minutes.