RU2197927C2 - Combined microsurgical laser method for treating solid congenital lens subluxation in children - Google Patents

Abstract

FIELD: medicine. SUBSTANCE: method involves carrying out partial intracapsulary strictly dosed YAG-laser phacofragmentation followed by intracapsulary suction of crushed lens mass using suction- irrigation techniques. EFFECT: reduced risk of complications; high accuracy surgical intervention; complete removal of lens fragments.

Description

 The invention relates to medicine, namely to ophthalmology, and is intended to reduce the morbidity and increase the efficiency of lens removal with its congenital subluxation in children.

 Currently, the generally accepted methods for removing the dislocated lens in children are ultrasonic phacoemulsification, phacofragmentation, lensectomy (Avetisov E.S. et al. Guide to Pediatric Ophthalmology, M .: Medicine, 1987, p. 305-325).

 The closest analogue of the invention is intracapsular aspiration of the lens through a puncture in its anterior capsule (A. Khvatova, “Actual Issues of Ophthalmology.” Thesis. 7th Republic Conference of the Lithuanian SSR, Kaunas, 1980, pp. 109-110), advantage which is the simplicity of technology, slight trauma, the ability to remove the subluxated lens through a small surgical incision (1.5 mm). However, surgeons are aware of the technical difficulty of piercing the anterior capsule of a subluxated lens with a surgical instrument, since an attempt to puncture an unfixed lens capsule with a needle or a Sato knife often leads to the displacement of the lens into the vitreous body, often the inability to further remove it at all. The clinical features of the lens during its congenital subluxation and the polymorphism 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, etc.) prompted the search for a more effective and safe removal of the lens during congenital subluxation of it in children.

 The difference of the present invention from the closest analogue (Khvatova A.V., 1980) is the replacement of the surgical technique of injecting into the anterior capsule with a needle or surgical instrument for YAG laser partial front capsulectomy with the aim of forming a channel for the introduction of an aspiration cannula and YAG laser phacofragmentation followed by surgical intracapsular aspiration fragmented lens masses with aspiration-irrigation technique for congenital subluxation of the lens in children.

 The technical result of the invention is the prevention of complete dislocation of the lens into the vitreous body during surgical intracapsular aspiration and the provision of conditions for the complete removal of the dislocated lens by aspiration-irrigation technique.

 The technical result is achieved by excising the anterior capsule and crushing the lens masses using YAG laser exposure before subsequent surgical removal of the dislocated lens using simple aspiration-irrigation techniques.

 The use of YAG laser technology of partial anterior capsulotomy allows mechanical excision of the accurately planned area of the anterior capsule, which is necessary for further introduction through it into the center of the lens of the aspiration cannula, without mechanical pressure on the unfixed movable dislocated lens. This allows a guaranteed complete removal of the entire lens without displacement into the vitreous body, without prolapse of the vitreous body and other complications.

 Intracapsular fragmentation of the lens masses using YAG laser exposure allows you to get a homogenized consistency of the lens substance, which facilitates the aspiration of the lens masses of any density, even calcifications, often found in congenital lens pathology. This allows in most cases not to use expensive vitreotomes for additional mechanical crushing of the masses with a vitreotome, but to remove them with a simple aspiracine-irrigation technique. The absence of a dense nucleus, transparent soft crystalline lens masses with congenital subluxation of the transparent crystalline lens, or “soft” crystalline lens masses with congenital opacities of the subluxated crystalline lens in children determine the advisability of using a simple aspiration-irrigation technique for microsurgical removal of the crystalline masses in children. The lens masses usually become turbid after exposure to the YAG laser, which greatly facilitates their removal and is an additional advantage of the proposed method.

 Accurate dosed excision of the anterior capsule with phacofragmentation by YAG laser capsulotomy combined with aspiration-irrigation of the lens masses allows in most cases to preserve the integrity of the anterior border membrane of the vitreous body, to avoid its loss, and therefore reduce the risk of the most serious complications: secondary glaucoma, retinal detachment and etc.

 The method is as follows.

Laser stages:
1) YAG laser partial anterior capsulotomy.

 2) YAG laser phacofragmentation.

 For example, a VISULAS-YAG laser system (yttrium-aluminum garnet activated by neodymium) is used. The wavelength of 1064 nm, the pulse duration of 2-3 ns, the diameter of the focal spot 30-50 microns. With capsulotomy, pulse energy: 1.2-3.5 mJ (depending on the thickness of the anterior capsule), the number of pulses 5-30, with phacofragmentation pulse energy: 1.2-2.5 mJ (depending on the transparency and density of the lens substance ), the number of pulses: 20-40.

 20 minutes before the laser intervention to achieve maximum drug mydriasis, a solution of mesatone 1% - 0.2) is administered under the conjunctiva of the eyeball.

 YAG laser operations on the lens are painless, therefore, children over 5 years old are performed under local anesthesia (two-time installation of 0.5% dicain solution 2-3 minutes before the procedure). Children under 5 years of age and non-contact older children undergo laser surgery under anesthesia, lying on their sides.

 In the laser cabinet, a Abraham contact lens is put on the child’s eye for accurate focusing and additional immobilization of the eye. The focus beam of the YAG laser is focused on the front lens capsule 1.0 mm from the edge of the subluxated lens, in the place of the planned introduction of the vitreotome - i.e. at 11 o’clock. Individually selecting the power and the number of pulses (see above modes), they achieve the formation of a round defect in the surface of the front capsule with a diameter of 3 mm. Then, the target beam of the YAG laser is focused on all compacted, calcified areas of the lens substance and they are crushed (achieving homogenization of the lens substance) without expanding the opening in the anterior capsule and without opening the posterior lens capsule.

 The 3rd stage - microsurgical - is carried out immediately after the laser.

 Under anesthesia, the dislocated lens is removed using the usual aspiration-irrigation technique (A. Khvatova. Removal of congenital cataracts in children. In the book: “Diseases of the eye lens in children”, Leningrad, 1982, pp. 74-84).

 In the operating room, under conditions of anesthesia, the palpebral fissure is dilated with an eyelid dilator, and the eyeball is immobilized by applying a frenulum suture to the superior rectus muscle. Two corneal incisions are made at a distance of 0.5-1 mm from the inner border of the limb at 1 and 11 hours. An irrigation cannula is introduced through the corneal incision for 1 hour, through which irrigation fluid is continuously supplied to the anterior chamber, which ensures the preservation of a constant depth of the anterior chamber and the level of intraocular pressure during the operation. A suction cannula is inserted through the corneal incision at 11 o’clock, which is then easily introduced into the center of the lens through a defect in the anterior lens capsule, made by a laser, without mechanical effort or displacement of the lens. Laser-cut, homogenized crystalline lens masses are easily removed in the aspiration-irrigation mode. Aspiration removes the remnants of the front and back capsules: in children they are distinguished by their subtlety and do not require special crushing. Only in extremely rare cases, with viscous lens masses or calcified posterior capsule, it is necessary to perform additional mechanical crushing of the lens masses with a vitreotome before aspiration.

 The final stages of the operation are: narrowing the pupil with 3-4 times instillation of a 2% solution of pilocarpine hydrochloride, restoring the anterior chamber by introducing sterile air, imposing nodal immersion sutures on both corneal incisions. Under the conjunctiva, 0.2 ml of dexamethasone and an antibiotic solution (gentamicin 0.2), gordox 0.3 ml are administered. A 20% solution of sodium sulfacyl-sodium or 0.3% solution of chloramphenicol is introduced into the conjunctival sac. A sterile binocular dressing is applied.

 Example. Patient D., 5 years old, visually impaired since childhood. Diagnosis: congenital subluxation of the lens of both eyes. Visual acuity at admission 0.01 does not correct.

 Both eyes of the child were operated on using the combined laser-microsurgical method described above (the interval between operations on both eyes is 3 months).

 Under anesthesia, a metered dissection of the anterior capsule was performed by a YAG laser. The laser action on the anterior lens capsule consisted of 33 pulses with an energy of each from 2.5 to 3.5 mJ, the total power being 122 mJ. A round defect was formed in the anterior capsule with a diameter of 3 mm at 11 hours 1 mm from the edge of the pupil, expanded by mesatone injection. Then the YAG laser fragmented the substance of the crystalline lens, crushed its dense areas without additional expansion of the opening in the anterior and without opening the posterior capsule. Complications during and after laser exposure were not observed. Then, in the operating room, the subluxated lens was removed by the irrigation-aspiration method. The lens masses that are cloudy after laser exposure are aspirated, and at the end, the remains of both capsules. There was no displacement of the removed lens into the vitreous and prolapse of the vitreous. The postoperative course is reactive, without complications.

 Discharged from the hospital on the 10th day after the operation with visual acuity in the operated eye 0.1 with a correction of + 10.0 D. The pupil area is clear, there is a live pupil reaction to light, there is no synechia. Vitreous body and fundus without pathology. Conducted 2 courses of laser pleoptic treatment. After 1 year of observation, visual acuity with correction increased to 0.5, there is no synechia and secondary cataract, the vitreous is intact, the fundus without pathology.

 T. about. The method allows to reduce the invasiveness of the removal of the subluxated lens in children, to prevent the complete dislocation of the lens into the vitreous body, to avoid the prolapse of the vitreous body, to improve the conditions for microsurgical removal of the subluxated lens, even without the use of vitreotomes, which increases the effectiveness of treatment.

Claims (1)

 A method for treating congenital lens subluxation in children, including removal of the lens using aspiration-irrigation, characterized in that a hole is formed in the anterior capsule of the lens using an YAG laser for introducing an aspiration cannula and intracapsular fragmentation of the lens masses is performed by a YAG laser.