RU2234903C1 - Method for applying surgical laser extraction of congenital cataract and implanting posterior chamber intraocular lens - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method involves carrying out continuous circular anterior YAG-laser capsulorrhexis of 5mm large diameter beginning from the inferior segment in milky cataract cases and from the superior segment in zonular cataract cases. Preliminary phacofragmentation with YAG-laser is carried out through closed anterior capsule followed with laser-mediated capsulorrhexix in atypic cases. Lenticular masses becoming opaque after being exposed to laser radiation and anterior capsule flap cut out with laser are removed by applying microsurgical suction-irrigation method without removing the posterior capsule. Posterior chamber intraocular lens is implanted in capsule sack.

EFFECT: enhanced optical and functional effectiveness of treatment; reduced risk of complications; excluded risk of involuntary rupture and left anterior chamber flaps; high quality of intraocular lens implantation.

Description

The invention relates to medicine, namely to pediatric ophthalmology, and is intended for laser microsurgical treatment of congenital cataracts with implantation of posterior chamber (ZKL) intraocular lenses (IOLs) taking into account the clinical and age-related features of the forms, leading to an increase in the effectiveness and reduction of the invasiveness of congenital cataract removal in children.

To date, microsurgical extracapsular extraction remains the generally accepted method for removing congenital cataracts in children (A. Khvatova, 1963). In recent years, the implantation of posterior chamber IOLs in children over 6 years of age has been considered an effective and safe procedure in pediatric cataract surgery (Malukiewicz - Wisniewska G, 1999, Bobrova NF, 1992, Zubareva LN, 1993). The number of surgeons promoting the implantation of IOLs for children is growing (Bobrova et al., 1987-2002; Zubareva L.N., 1986-93; Ben Ezra 1983-97; Dahan 1990; Gimbel, 1993; Hiles D.A., 1980; Sinskey R.M., 1993). However, fear for the fate of the operated eye of a child, an insufficient number of observations in the long term, a significant number of complications, and a number of unresolved problems of pediatric implant surgery do not yet allow the PKI method to be widely used in pediatric ophthalmology (Fedorov S.N. et al., 1997).

The main prerequisite for the possibility of intracapsular IOL implantation is a high-quality anterior capsulotomy, which creates a reliable capsule bag for intracapsular IOL fixation. However, pediatric ophthalmosurgeons know that anterior capsulotomy (or “capsulorexis”) in children is the most complex and difficult stage of phacoaspiration (Bobrova N.F. et al., 2002; Gimbel et al., 1993), often forcing them to refuse implantation in a child. In addition, the remnants of the anterior capsule not completely excised and not removed from the eye in children often (42.3%) lead to the formation of secondary cataract and the need for repeated intervention (6.7-76.9% - Khvatova A.V., Arestova N .N., 1980). This is due to the well-known features of congenital cataracts in children: thinness and unevenness of the thickness of the anterior capsule, lack of a nucleus, the presence of milky masses, calcifications (Khvatova A.V. 1982), elasticity of the posterior capsule, “softness” of the crystalline substance and increased pressure on the crystalline lens from the vitreous bodies (Bobrova N.F. et al., 2002; Gimbel et al., 1993). Therefore, accurate and complete dissection of the anterior capsule of the lens made by a microsurgical instrument during this operation is very difficult and not always feasible with some forms of congenital cataracts. But the guarantee of intracapsular fixation of the IOL is precisely a small (no more than 5 mm), but even hole in the front capsule with smooth edges, which prevents the capsule from tearing when removing the lens substance and implanting the IOL (Fedorov S.P., Egorova E.V. 1992 )

There are many ways to open the anterior capsule: multiple small perforations along the edge of the dilated pupil, combined by circular opening - the “canning” method - the Kelman method (Krasnov MM, 1977, Khvatova AV, 1982), an incision in the lower segment with removing the capsule flap with a micro hook (Khvatova A.V., 1982), a horizontal incision from 2 to 10 hours with microperforations in the lower segment and removing the capsule with a micro hook (Fedorov S.N., Egorova E.V., 1992) and others.

In recent years, the term “capsulorexis” has become more commonly used, combining the methods of different authors on the dosed cutting of the flap of the anterior capsule of a rounded shape and, if possible, with even edges with a diameter of up to 5 mm (Fedorov S.N., Egorova E.V., 1992). Most often, an injection needle is used to open the front capsule, bent at an angle of 90 °, connected to a syringe through which an irrigation solution is fed (Fedorov S.N., Egorova E.V., 1992, Bobrova I.F. et al., 2002 ) Variants of the “capsulorexis” methods differ in the place of the beginning of manipulations on the capsule - in the center, in the segment of 6 or 12 hours, by the course of successive perforations (Fedorov S.N., Egorova E.V., 1992, p. 115).

In recent years, the technique of anterior continuous circular capsulotomy or anterior capsulorexis (Gimbel, 1990) is considered the most adapted to the needs of implant surgery (Gimbel, 1990), but it is this technique that is most difficult for children to perform (Bobrova N.F. et al., 2002, Girnbel et al., 1993 )

The use of a YAG laser expanded the possibilities of dosed opening the front capsule; perforation of the capsule can be performed in any line, even in cases of pathological changes in the capsule and violation of its strength characteristics.

Analogs of the invention are the following:

1. Currently, for the extraction of congenital cataracts with IOL implantation, most pediatric ophthalmic surgeons prefer the method of instrumental surgical anterior circular capsulotomy in combination with aspiration-irrigation removal of the lens masses (Zubareva LN, 1993, Benezra D., 1993-1997: Dahan E ., Salmenol BD, 1990: Gimbel, 1993: Zetterstrem Ch., 1994-2002).

2. In adult patients, it is known to use the method of YAG laser anterior capsulotomy - with laser perforations in a horizontal line in the upper section and single perforations in the lower segment. An average of 35-40 laser perforations with a pulse energy of 2.2-2.4 mJ is required. After intracapsular implantation of the IOL, the capsule sheet in the area of lower perforation is fixed with a microcystotome and is removed from the eye without traumatic use of scissors (Fedorov S.N., Egorova E.V., 1992). However, in pediatric ophthalmology, in particular, taking into account the characteristics of the clinical forms of congenital cataracts in children, these methods are not used.

3. In recent years, our proposed new method of combined laser-surgical removal of congenital cataracts in children has begun to be introduced (Khvatova A.V., Arestova N.N., Egiyan N.S., RF patent for invention No. 2180546. Priority dated 22.02. 2000), combining YAG laser anterior capsulotomy with subsequent microsurgical removal of congenital cataract by irrigation-aspiration method. Laser dissection of the anterior capsule provides more complete removal of the anterior capsule without leaving flaps, increases efficiency and improves the conditions for microsurgical removal of various clinical forms of congenital cataracts, ensures complete elimination of the lens masses, which is an effective prevention of secondary cataracts. Increasing the ability to preserve the integrity of the posterior capsule, this method reduces the morbidity and frequency of complications of removal of congenital cataracts in children, prevents the risk of serious complications.

However, the above method, on the one hand, does not take into account the features of various clinical forms of congenital cataracts in children, which does not allow the use of a single universal technique of laser capsulorexis for different forms of cataracts.

On the other hand, this method is intended only for extraction of congenital cataracts without IOL implantation. Implantation of an IOL requires not a subtotal complete circular excision of the anterior capsule (D 6-7 mm), but a dosed partial dissection of its special shape, configuration, size and localization, designed specifically for the intracapsular posterior chamber model of the IOL T-26, taking into account the clinical features forms of congenital cataracts in children.

The difference of our invention from the analogues listed above lies in the choice of the method of anterior capsulorexis depending on the shape of the congenital cataract, the features of the method of YAG laser circular continuous anterior capsulorexis and fragmentation of the lens masses before aspiration-irrigation removal of them and the dissected anterior capsule, followed by intracapsular implantation.

The technical result of the invention is to prevent the development of an unintentional complete rupture of the anterior capsule, opening of the posterior capsule with prolapse of the vitreous body and other severe complications that make it impossible to implant the posterior chamber model of the IOL.

The technical result is achieved using a differentiated approach to capsulorhexis, taking into account the condition of the anterior capsule of the lens, the consistency of the crystalline lens mass in various clinical forms of congenital cataracts in children, which allows the central round opening of the ideal shape, the right size, with smooth edges to be excised, which guarantees the implementation of intracapsular implantation of the IOL without complications.

The YAG laser technique, unlike the surgical one, allows a metered opening of the anterior capsule of any desired predetermined configuration, with any degree of transparency and density of the capsule.

The technique of laser anterior capsulorexis is determined by the features of various clinical forms of congenital cataracts in children:

1. With full milky forms of congenital cataracts with a thin anterior capsule: anterior continuous circular capsulorhexis - multiple small laser microperforations of the anterior capsule are applied in the form of a continuous line along the circumference D - 5 mm, starting from the lower segment (from 6 hours to 12 hours: and counterclockwise) - otherwise, liquid milk-like masses spilled into the anterior chamber will make the completion of capsulorexis impossible.

2. For zonal forms - the anterior capsulorhexis: multiple small laser microperforations of the anterior capsule are also applied along the circumference D - 5 mm, but starting from the upper segment (from 12 h to 6 h: clockwise and counterclockwise) - otherwise the “core” may fall into the anterior chamber, contact with the cornea.

3. In atypical forms (with uneven clouding of the lens, more in the back layers, with frequent calcifications): first, without opening the front capsule, YAG laser intracapsular phacofragmentation is performed - crushing of dense areas of the lens substance, calcifications, and then YAG laser linear anterior capsulotomy (horizontal linear incision from 10 to 2 hours in the upper 1/3 of the pupil, with microperforations in the lower part) or anterior continuous circular capsulorhexis (depending on the state of the capsule and the consistency of the lens masses).

The second stage of combined laser-surgical treatment: aspiration-irrigation removal of the lens masses is identical for all forms of congenital cataracts. The lens masses usually become turbid after exposure to the YAG laser, which greatly facilitates their removal and is an advantage of the proposed method. An anterior capsule flap excised by a YAG laser is easily aspirated in children - it does not require additional use of surgical methods.

The lack of contact of the removed lens masses with the corneal endothelium during intracapsular aspiration of the lens masses is a reliable prevention of corneal complications.

Accurate dosed dissection of the anterior capsule by the YAG laser anterior capsulorexis method in combination with aspiration-irrigation of the lens masses allows in most cases to preserve the integrity and intactness of the transparent posterior lens capsule. In children, maintaining the integrity and intactness of the posterior lens capsule is fundamentally important, because opening it on the immature eye of a child, often having a concomitant pathology of the vitreous body, etc., often leads to severe, irreversible complications (hernias of the vitreous body, vitreocorneal adhesions, Irwin-Gass syndrome, macular degeneration, secondary glaucoma, retinal detachment).

The absence of remnants of the anterior capsule of the lens, lens masses, and the intactness of the posterior capsule are a reliable prevention of secondary cataract formation in children.

The method is as follows:

1. Laser stage: YAG laser anterior partial circular continuous continuous capsulorexis.

They use, for example, a VISULAS laser system — YAG from Zeiss (Germany) or a laser capsule Kapsula (Russia) —nodymium-activated yttrium-aluminum garnet. The radiation wavelength is 1064 nm, the pulse duration is 2-3 ns, and the diameter of the focal spot is 30–50 μm. The number and energy of impulses are determined depending on the clinical form of congenital cataract, and most importantly on the transparency of the anterior capsule and adjacent cortical layers.

The minimum energy is required for laser perforation of an opaque anterior capsule or with a transparent capsule, but with turbid underlying cortical layers - enough pulse energy of 0.8-1.5 mJ. With a transparent capsule and transparent underlying cortical layers, an increase in pulse energy of up to 1.8-2.5 mJ is required. The number of pulses: 10-24.

In our experience, a relatively higher level of energy (up to 3.5 mJ) requires zonal forms, since with them, transparent front capsules with transparent underlying layers are more common than, for example, with half-absorbed or atypical forms. The YAG laser anterior capsulotomy is painless, therefore, children over 5 years old are performed under local anesthesia (two-time installation of 0.5% dicaine solution 2-3 minutes before the procedure). For children under 5 years of age and non-contact older children, laser surgery is performed under general anesthesia.

20 minutes before laser intervention, 0.2 ml of mesatone solution is administered under the conjunctiva of the eyeball to achieve maximum drug mydriasis. Full laser surgery is possible only when reaching mydriasis of at least 6-7 mm.

Dissection of the front capsule by a YAG laser is performed in 1 session.

In the laser cabinet, a Abraham contact lens is put on the child’s eye for more accurate focusing, safety and additional immobilization of the child’s eye. The focus beam of the YAG laser is focused on the anterior lens capsule 1.0 mm from the edge of the pupil. Laser pulses are applied to the surface of the anterior capsule of the lens - perforations. Individually selecting the power and the number of pulses (see above modes), they achieve the formation of a section-defect in the surface of the anterior capsule:

- For complete milky forms of congenital cataracts with a thin anterior capsule: multiple small laser microperforations of the anterior capsule along the circumference D - 5 mm, starting from the lower segment (from 6 hours to 12 hours: clockwise and counterclockwise).

- In case of zonal forms - multiple small laser microperforations of the anterior capsule along the circumference D - 5 mm, starting from the upper segment (from 12 h to 6 h: clockwise and counterclockwise).

- In atypical forms (with uneven clouding of the lens, more in the back layers, with frequent calcifications): first, without opening the front capsule, YAG laser intracapsular phacofragmentation is performed - crushing of dense areas of the lens substance and calcifications. Then, a YAG laser linear anterior capsulotomy is performed: a horizontal linear incision from 10 to 2 hours in the upper 1/3 of the pupil, with microperforations in the lower part or anterior continuous circular capsulorhexis, depending on the state of the capsule and the consistency of the lens masses.

After the laser stage, the 2nd stage of treatment is carried out - microsurgical: intracapsular removal of the lens masses by aspiration-irrigation for all forms of congenital cataracts is performed according to the method of A.V. Khvatova (A. Khvatova. Removal of congenital cataracts in children. In the book: 3 eye lens diseases in children, Leningrad, 1982, p. 74-84).

In the operating room, under conditions of anesthesia, the eyelids and eyeball are immobilized. The palpebral fissure is dilated using an eyelid extender. Immobilization of the eyeball is provided by the application of the frenum suture on the superior rectus muscle. Two corneal incisions are made, 1.5 mm long, at a distance of 0.5-1 mm from the inner border of the limb in the upper segment. Through one surgical incision of the cornea and a laser linear incision of the anterior capsule, the lens masses are aspirated. At the same time, an irrigation fluid is introduced into the anterior chamber through a second incision, which ensures a constant depth of the anterior chamber and the level of intraocular pressure.

The flap of the laser-dissected anterior capsule is removed by aspiration (and not by a microsurgical instrument!), And it is finally aspirated after intracapsular aspiration of the lens masses.

Strive for the fundamental preservation of the integrity of the posterior capsule. Remove it with a microcystotome only in rare cases of intense congenital opacification.

3rd stage of treatment - the implantation of the posterior chamber IOL model into the capsule bag is carried out according to the traditional generally accepted technique (Zubareva L.N., 1993; Ben Ezra D., 1993-1997; Dahan E., Salmenol BD, 1990; Gimbel, 1993; Zetterstrem Ch, 1994-2002).

The operation is completed by narrowing the pupil with a 3-4-fold installation of a 2% solution of pilocarpine hydrochloride, restoring the anterior chamber by introducing sterile air, applying 2 nodal immersion sutures to both corneal incisions. Under the conjunctiva, 0.2 ml of dexamethasone, 0.2 ml of gentamicin solution, 0.3 ml of gordox are administered. Instill in the conjunctival sac 20% solution of sulfacyl sodium or 0.3% solution of chloramphenicol. A sterile binocular dressing is applied.

Example:

Patient St. A., 13 years old. The medical history No. 278/2001, a / c No. 26325/2000. Diagnosis at admission: OD-artifact, pupil dislocation (after removal of a congenital hereditary cataract with IOL implantation by the traditional method at 12 years old); OS - congenital hereditary atypical cataract, OI: high degree obscuration amblyopia. Eye condition upon admission to the DRL; Helmholtz: Right eye. OD: visual acuity at admission = 0.4 s cy1 + 1.5 D ax 90 ° = 0.7. The cornea is transparent, the area of corneal dystrophy at the limbus for 10 hours, iridocorneal fusion at 10-11 hours, the pupil is displaced by 10 hours, the position of the IOL is correct, the optical media and IOL are transparent, the fundus is without pathology.

Left eye: OS: visual acuity = 0.005 does not correct, the cornea is transparent, uneven clouding of the lens with a clearly defined disc of more dense opacification D - 6 mm and calcifications in the center, translucent masses on the periphery, but there is no reflex from the fundus. Ultrasound: PZO OI = 24.0, floating opacities of the vitreous, retinal detachment is not determined.

ERG: OD - total and rhythmic ERG - normal, OS - total ERG supernormal (increase in wave amplitude "a" and "b"), rhythmic ERG - normal.

VIZ on a flash: OI - amplitude and lability are normal. Perimetry of OI: norm.

IOP OI = 15-16 mm RT. Art.

On the left eye, congenital cataract was removed using the combined laser-surgical method described above with posterior chamber IOL implantation.

Without anesthesia, under local anesthesia (double instillation of a solution of dicain 0.5% 2-3 minutes before the laser procedure) through an unopened front capsule, YAG laser phacofragmentation (crushing) of densified portions of the lens masses and calcifications was performed, then YAG laser circular anterior capsulorexis: the central flap of the anterior capsule of an ideal round shape, 5 mm in diameter, with smooth smooth edges, has been dissected. The laser exposure consisted of 24 pulses with an energy of each from 1.9 to 2.2 mJ, the total energy of 48 mJ. No complications were observed during and after laser exposure. Then, in the operating room under anesthesia, an aspiration-irrigation removal of the lens masses that became cloudy after laser exposure was performed. The laser-cut thin transparent front capsule is removed by suction. A posterior chamber model IOL (T-26-22D) was implanted in the capsule bag.

The back capsule is transparent, intact, preserved. No operational complications were noted. The postoperative course is reactive, without complications.

Discharged from the hospital on the 10th day after the operation with visual acuity in the operated left eye of 0.5. The eye is calm, the cornea is transparent, the position of the IOL is correct, there are no remains of the anterior capsule and lens masses, there is a live pupil reaction to the light, there is no synechia. The pupil area is clean, the posterior capsule is perfectly transparent, the vitreous body and the fundus without pathology. Conducted 2 courses of laser pleoptic treatment. After 1 year of observation, visual acuity increased to 0.8 without correction, there is no synechia and secondary cataract - the posterior capsule retains transparency.

Thus, in spite of the later operation, which means a greater degree of obscuration amblyopia, the new method made it possible to achieve comparatively better results in the left eye compared to the second - the right eye operated according to the traditional method (without YAG laser phacofragmentation and anterior capsulorexis): higher visual acuity was obtained, there was no adhesion in the anterior chamber, there were no dystrophic changes in the cornea, there was no deformation of the pupil, as in the right eye.

Thus, the proposed method allows to increase optical and functional efficiency, reduce trauma, improve the conditions for microsurgical removal of any clinical forms of congenital cataracts, eliminate unintentional rupture or flaps of the anterior capsule, provide more complete removal of the lens masses and, most importantly, conditions for high-quality implantation of the posterior chamber IOL in a capsule bag, increases the chances of maintaining the integrity of the back capsule, i.e. prevents the risk of severe irreversible complications from the cornea and especially the posterior part of the eye in children.

Sources of information

1. Bobrova N.F., Romanova T.V., Khmaruk T.V., Enukidze D.Z., Zhekov A.K. Intracapsular implantation of flexible IOLs for congenital cataracts in children // Actual problems of pediatric ophthalmosurgery. - M., 2002, p. 12-17.

2. Bobrova N.F., Wenger G.E., Uvarova O.Yu. Intraocular correction in the rehabilitation treatment of unilateral traumatic cataracts in children // Ophthalmol. Zh., 1987, No. 6, p. 347-349.

1. Bobrova N.F. Reconstructive microsurgery for combined injuries of the anterior eye and their consequences in children: Abstract. diss .... doct. honey. Sciences, Odessa, 1992, 30 p.

2. Zubareva L.N., Khvatov V.N. Intraocular correction of traumatic and congenital cataracts in children // Conference of Ophthalmologists of Belarus, 5th Abstract, Gorki, 1986, p.144-146.

3. Zubareva L.I. Intraocular correction in cataract surgery in children Diss .... Dr. honey. sciences (in the form of a scientific report). - M., 1993, 50 p.

4. Fedorov S. N., Zubareva L. N., Ovchinnikova A. V., Korobkova G. V., Marchenkova T. E., Zubareva S. A., Gavrilyuk A. S., Khvatov V. N. Long-term results of post-traumatic artifact in children // Ophthalmosurgery, 1997, No. 2, pp. 7-15.

5. Fedorov S. N., Egorova E. V. Errors and complications during implantation of an artificial lens // M., 1992, 247 p.

6. Khvatova A.V. Congenital cataracts // Diseases of the lens of the eye in children. - L .: Medicine, 1982, p. 47-90.

7. Khvatova A.V. The results of cataract extraction surgery in schoolchildren for blind and visually impaired children // Cataracts: Scientific notes of the State Research Institute of Chap. Helmholtz diseases. - M., 1963, issue. 8, p. 128-135.

8. Khvatova A.V., Arestova N.N. Features of the clinic and microsurgical tactics for secondary cataracts in children // Ophthalmological Journal, 1980, No. 5, p. 35-38.

9. Ben Ezra D., Paez J.H. Cogenital cataract and intraocular lenses // Amer. J., Ophthalmol, 1983, v. 96, p. 311-314.

10. Ben Ezra D., Cohen E. Posterior capsulectomy in pediatric cataract surgery // Ophthalmology, 1997, v. 104, p. 2168-2174.

11. Dahan E., Salmenol B.D. // Pseudophakia in children: precautions, technique, and feasibility // J. Cataract Refract. Surg, 1990, vol. 16, p. 75-82.

12. Gimbel H.V., Neuhann T. Development, advantages and methods of the continuous circular capsulorhexis technique // J. Cataract Refract. Surg., 1990, v. 16, p.31-37.

13. Gimbel H.V., Ferensowicz M., Raanan M., DeLuca M. Implantation in children // J. Pediatr. Ophthalmol. Strabismus, 1993, v. 30, p. 69-79.

14. Hiles D.A. Indications, Techniques and Complications Associated with Intraocular lens implants in Children // Intraocular lens implants in Children - London, Grune a Stratton, 1980, p. 282-290.

15. Malukiewicz - Wisniewska G., Kaluzny J., Lesiewska-Junk H., Eliks I. Intraocular lens implantation in children and youth // J. Pediatr. Ophthalmol. Strabismus, 1999, v. 36, No. 3, p. 129-133.

16. Metge P., Cohen H., Chemila J.F. Intercapsular implantation in children // Eur. J. Implant. Refract. Surg., 1990, v. 2, p. 319-323.

17. Michalos P., Avila E.N. “Capsulorecopsis”, a new surgical instalment and method for capsulotomies // Optalmic Surg. Lasers, 1996, vol. 27, No. 6, p. 476-478.

18. Sinskey R.M., Stoppel J.G., Amin P. Long - term results of intraocular lens implantation in pediatric patients // J. Cataract. Refract. Surg., 1993, v. 19, p. 405-408.

19. Zetterstrem Ch., Kugelberg U., Oscarson Ch. Cataract surgery in children with capsulorhexis of anterior and posterior capsules and heparin-surface-modified intraocular lenses // J. Cataract. Refract. Surg., 1994, v. 20, p. 599.

Claims (1)

The method of choosing the method of anterior capsulorexis in the extraction of congenital cataract with IOL implantation in children, including a continuous circular anterior YAG laser capsulorexis with a diameter of 5 mm, starting from the lower segment in milky forms; starting from the upper segment — in zonal forms, preliminary YAG laser phacofragmentation through an unopened anterior capsule, followed by laser capsulorexis — in atypical forms; in this case, the lens masses and the anterior capsule are removed by aspiration - irrigation and the posterior chamber model of the IOL is implanted into the capsular bag, preserving the whole posterior capsule.