RU2346679C1 - Method of pseudophakia eye ametropia correction - Google Patents

Abstract

FIELD: medicine; ophthalmology.

SUBSTANCE: invention can be used for pseudophakia eye ametropia correction in adults and children, including cases when intraocular lens (IOL) is fixed out of capsular bag partially or completely. Excimer laser intervention is preceded with two or four diametrical through holes by iris periphery using YAG-laser of wave length 1084 nm. Number of holes is determined by IOL fixation type in the given patient. After that vacuum microkeratoma ring is applied on the eye with following pedicle cornea graft. Interfacial graft is turned aside. Cornea stroma is ablated with excimer laser beam of wave length 193 nm. Interfacial cornea graft is repositioned in cornea bed.

EFFECT: prevented IOL decentration and dispositions while using vacuum ring due to pressure equalising in anterior and posterior chambers, lower risk of intra- and postoperative complications, restored binocular sight and improved quality of patient's rehabilitation.

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Description

The invention relates to medicine, namely to ophthalmology, and can be used in adults and children, including cases with partial or complete fixation of an intraocular lens outside the capsular bag.

The most optimal correction of aphakia at present is the implantation of a posterior chamber intraocular lens (IOL). At the same time, despite the existence of many formulas for calculating the optical power of the IOL, refractive errors are one of the problems of replacing the natural lens with an intraocular lens. In addition, the improvement of surgical technique and intraocular lenses contribute to the expansion of indications for their implantation in young children. The difficulties in calculating the optical power of the IOL and predicting the desired refractive effect of the operation are associated with the upcoming growth of the child’s eye, leading to a change in refraction, which necessitates the correction of ametropia of the fake eye in the long term after the operation, including in children and adolescents.

A known method for correcting ametropia of an artifact eye using an additional IOL (RF Patent for the invention No. 2155560, class A61F 2/16, publ. 09/10/2000, "Artificial eye lens for surgical correction of artifact with residual ametropia and method of implantation"). The essence of the method consists in implanting an additional IOL into the eye and placing it on the front surface of the base IOL with fixing the supporting elements of the additional IOL to the periphery of the optical part of the base IOL.

The disadvantages of the method are the technical complexity of the operation and the invasiveness of its implementation for intraocular structures, especially in children due to the increased reactivity of the children's eye. Repeated intraocular intervention increases the risk of intra- and postoperative complications. Formed over the years of fusion of the optical part of the base IOL with the iris or lens capsule, which are often observed during implantation of the base IOL in childhood, they prevent the fixation of the additional IOL to the base and cause the operation to be technically unfeasible. In addition, the correction of ametropia in this way is not accurate enough.

The closest technical solution is a method of correcting ametropia of an artifact eye by excimer laser exposure to the cornea (Doga A.A., Semenov A.D., Kachalina G.F. - Excimer laser correction of induced ametropias. - Refractive surgery and ophthalmology. - 2002. Volume 2 . - No. 3. - S.50-51). The method consists in placing a vacuum ring on the eye, cutting off the surface corneal flap of a given thickness and diameter on the “leg” with a microkeratome, and the flap is turned to the side. Next, an excimer laser with a wavelength of 193 nm perform ablation of the corneal stroma with a depth and diameter calculated by a computer program. At the end of ablation, reposition of the superficial corneal flap in the corneal bed is performed.

The disadvantage of this method is the risk of decentralization and dislocation of the IOL during application of a vacuum ring of the microkeratome head on the eye, which is caused by a stepwise increase in intraocular pressure and the resulting difference in pressure between the posterior and anterior chambers of the eye. Since the most reliable fixation of the IOL is intracapsular, the risk of IOL displacement increases when one or both of the haptic elements is fixed not in the capsular bag, but in the iridociliary sulcus. The risk of IOL decentration is increased in patients who underwent IOL implantation in early childhood, due to the growth of the eyeball and a change in the ratio of eye size to IOL size.

Based on the disadvantages of the prototype, the task is to reduce the risk of decentralization and dislocation of the IOL during the application of the vacuum ring of the microkeratome head during surgical correction of ametropia.

The technical result when using the invention is to prevent the decentralization and dislocation of IOLs by equalizing intraocular pressure in the anterior and posterior chambers of the eye, reducing the risk of intra- and postoperative complications, providing satisfactory functional results and improving the quality of patient rehabilitation.

The specified technical result is achieved by the fact that in the method of correcting ametropia of an artifact eye, including placing a vacuum ring on the eye, cutting off a surface corneal flap with a microkeratome, “turning off the flap to the side,” performing corneal stroma ablation with an excimer laser beam with a wavelength of 193 nm, reposition surface corneal flap in the bed of the cornea, according to the invention, before laying the vacuum ring perform two or four diametrically oppositely located through openings Holes around the periphery of the iris, respectively, when fixing one of the haptic elements of the posterior intraocular lens in the capsular bag or fixing the haptic elements in the iridociliary sulcus.

The advantage of this method in comparison with the prototype is to minimize the likelihood of decentralization and dislocation of the IOL due to equalization of intraocular pressure in the anterior and posterior chambers at the time of its jump-like increase when applying a vacuum ring to the eye, which is achieved due to the created additional outflow paths (holes in the iris) of the intraocular fluid from the back chamber to the front. The implementation of two or four holes in the iris, located diametrically opposite to each other, allows you to equalize the intraocular pressure between the posterior and anterior chambers evenly in the entire plane. The application of the proposed method allows for excimer laser correction of ametropia of the artifact eye with partial or complete fixation of the IOL outside the capsule bag, including in patients (including children and adolescents) who underwent IOL implantation in early childhood. Thanks to the proposed manipulations, the risk of intra- and postoperative complications and unsatisfactory functional results of the operation is reduced.

The proposed method is as follows. Previously, before excimer laser intervention, two or four diametrically oppositely located through holes are made along the periphery of the iris with a YAG laser with a wavelength of 1084 nm. When one of the haptic elements of the posterior chamber IOL is located in the capsular bag, two holes are made; when the haptic elements are located in the iridociliary sulcus, four holes are made. Then, a microkeratome vacuum ring is applied to the eye, and the surface corneal flap is cut off with a given thickness and diameter on the “leg”. The surface flap is turned to the side. Corneal stroma is ablated with an excimer laser beam with a wavelength of 193 nm in depth and diameter, calculated by a computer program. The surface corneal flap is repositioned in the corneal bed.

The method is illustrated by the following examples:

Example 1. Patient K., 14 years old. Received with a diagnosis of OD - moderate myopia, complex myopic astigmatism, artifactia, mild amblyopia. OS is healthy. Complaints upon receipt of low vision OD without correction. History: 9 years ago, at the age of 5 years, a congenital cataract was aspirated with implantation of an IOL from polymethyl methacrylate. Refraction OD in the early postoperative period was: sphere -0.75 D cylinder -2.00 D axis 180 °. Eye length 22.14 mm.

Currently refractory OD upon admission to the hospital: sphere-4.50 D cylinder -2.00 D axis 180 °. The average corneal refraction for the two main meridians is 42.62 D. Visual acuity OD: without correction 0.1, with complete correction 0.7. Eye length 23.40 mm. Biomicroscopy data: OD - calm, the cornea is transparent, the anterior chamber is of medium depth, the pupil is round, the posterior chamber IOL occupies a central position, the haptic elements of the IOL are fixed in the iridociliary sulcus. The fundus reflex is pink.

Correction of ametropia of artifact eye by the proposed method. A preliminary YAG laser (with a wavelength of 1084 nm) was performed on peripheral iridectomy at 3, 6, 9 and 12 hours. Applied local epibulbar anesthesia with 1% inocaine solution. A vacuum ring of a microkeratome is applied to the eye in the area of the cornea. The surface flap of the cornea was rounded off with a thickness of 130 μm, a diameter of 8.5 mm and a “leg” at 3 hours. The corneal flap is turned away. Corneal stroma was ablated in the optical zone with an excimer laser beam with a wavelength of 193 nm and a diameter of 7.5 mm to a depth of 73 μm. The reposition of the turned away superficial corneal flap in the corneal bed was performed. A solution of ophthalmoseptonex is instilled into the conjunctival cavity.

The day after excimer laser keratectomy, the clinical refraction of the artifact eye was: sphere -0.75 D cylinder -0.50 D axis 180 °, average of the two main meridians refraction of the cornea was 41.50 D, visual acuity without additional correction 0.6.

6 months after the excimer laser intervention, clinical refraction: sphere -0.50 D cylinder -0.50 D axis 180 °, average of the two main meridians the refraction of the cornea was 37.50 D, visual acuity without additional correction 0.7.

Biomicroscopy data at various times after surgery:

the cornea is transparent, the anterior chamber is of medium depth, the pupil is round, the posterior chamber IOL occupies a central position. The fundus reflex is pink.

Example 2. Patient B., 15 years. Received with a diagnosis of OD - mild myopia, artifactia, moderate amblyopia. OS is healthy. Complaints upon receipt of a decrease in vision OD without additional correction. History: 5 years ago, at the age of 10 years, a refractive lansectomy was performed with the implantation of a developing IOL in order to correct a high degree of myopic anisometropia. The initial refraction OD was: sphere -14.00 D cylinder -0.25 D axis 20 °, uncorrected visual acuity 0.02, with a maximum correction of 0.1. The replacement of the clear crystalline lens with an intraocular lens and the postoperative period were uneventful. OD refraction in the early postoperative period was: sphere -0.5 cylinder -0.25 D axis 20 °, visual acuity without correction 0.1. Eye length 27.70 mm.

Refraction OD at admission to the hospital at present: sphere -2.00 D cylinder -0.25 D axis 20 °. The average corneal refraction for the two main meridians is 45.25 D. Visual acuity OD: without correction 0.07, with full correction 0.3. Eye length 28.24 mm. Biomicroscopy data: OD - calm, the cornea is transparent, the anterior chamber is of medium depth, the pupil is round, the posterior chamber IOL occupies a central position; one haptic element of the IOL is located in the capsular bag, the second in the iridociliary sulcus. The fundus reflex is pink.

Correction of ametropia of artifact eye by the proposed method. A preliminary YAG laser (with a wavelength of 1084 nm) was performed on peripheral iridectomy at 1 and 7 hours. Under epibulbar anesthesia with a 1% inocaine solution, a microkeratome vacuum ring is applied to the eye. The surface flap of the cornea was cut with a thickness of 130 μm, a diameter of 8.5 mm and a “leg” for 3 hours. The corneal flap is turned away. Corneal stroma was ablated in the optical zone with an excimer laser beam with a wavelength of 193 nm and a diameter of 7.5 mm to a depth of 59 μm. The reposition of the turned away superficial corneal flap in the corneal bed was performed. A solution of ophthalmoseptonex is instilled into the conjunctival cavity.

The day after excimer laser keratectomy, the clinical refraction of the artifact eye was: sphere -0.50 D cylinder -0.25 D axis 20 °, the average for the two main meridians refraction of the cornea was 44.00 D, visual acuity without additional correction of 0.3. After 3 and 6 months after excimer laser intervention, the data of refraction and visual acuity remained stable.

Biomicroscopy data at various times after surgery: the cornea is transparent, the anterior chamber is of medium depth, the pupil is round, the posterior chamber IOL occupies a central position. The fundus reflex is pink.

Thus, clinical results show that the proposed method for correcting ametropia of the artifact eye can eliminate ametropia and increase uncorrected visual acuity, helping to restore binocular vision, while maintaining the correct stable position of the IOL. The method is possible with partial or complete fixation of the IOL outside the capsule bag. The use of the invention is especially relevant in children and adolescents in connection with the inevitably occurring ametropia due to eye growth, continuing after IOL implantation performed in early childhood. The proposed method is non-penetrating, less traumatic, short-term, highly predictable and makes it possible to increase the efficiency of rehabilitation of patients with a minimal risk of intra- and postoperative complications.

Claims (1)

A method for correcting ametropia of an artifact eye, including placing a vacuum ring on an eye, cutting off a superficial corneal flap with a microkeratome, turning the flap to the side, performing ablation of the corneal stroma with an excimer laser with a wavelength of 193 nm, reposition of the superficial corneal flap in the corneal bed, characterized the fact that before laying the vacuum ring perform two or four diametrically oppositely located through holes on the periphery of the iris, respectively, when fixing one of the haptic elements of the posterior intraocular lens in the capsular bag or the fixation of the haptic elements in the iridociliary sulcus.