RU2376001C1 - Method of improving visual functions after multi-focal intraocular lens implantation - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to ophthalmology. After implantation of multifocal intraocular lens (MIOL) in case if lens center and pupil center point coagulation of medial and peripheral parts of iris stroma is carried out by argon laser in 2-3 mm from pupil border, in sector, opposite to shift zone, on circumference arc, concentrically to pupil. Power of argon laser irradiation constitutes from 100 to 500 mW, time of exposure from 0.2 to 0.5 ms, spot with diametre 300-500 mcm. Center of MIOL is localised by position of ring-shaped cuts or ring-shaped aspherical zones on its optical part.

EFFECT: method ensures submergence of MIOL optics and pupil centres, increases visual acuity, reduces side effects.

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Description

The invention relates to medicine, and more particularly to ophthalmology, and can be used to increase visual function and improve the quality of vision in patients after cataract extraction by phacoemulsification with simultaneous implantation of a multifocal intraocular lens (MIOL) in cases of mismatch between the optical center of the MIOL and the pupil center . One of the most common causes of mismatch between the centers of the pupil and the optical center of the lens can be the anatomical and physiological features of the eye of a particular patient: mismatch of the optical and anatomical axes of the eye, asymmetry of the capsular bag, congenital ectopia of the pupil of a small degree. In addition, the displacement of the IOL from the center can be observed in cases of asymmetric contraction of the capsular bag during its fibrosis, or it may be associated with a number of design features of a particular MIOL model. The authors do not know how to improve visual functions after implantation of a multifocal IOL model in cases of mismatch of its optical center and the center of the pupil in the postoperative period. However, this is a very important and necessary task, because in the case of mismatch of the centers, a decrease in visual acuity occurs near, side optical phenomena appear in the form of double vision, light, and the patient's working capacity decreases.

The objective of the invention is to improve visual functions after implantation of the myolol implant by conducting pupil plastics by argon laser coagulation of the iris stroma in its middle and peripheral regions. The problem is solved in that according to the invention, when the center of the lens and the center of the pupil do not coincide with an argon laser, point coagulation of the mid-peripheral parts of the iris stroma is 2-3 mm from the edge of the pupil in the sector opposite to the displacement zone, along the arc of a circle, concentrically to the pupil, while the power radiation of an argon laser is from 100 to 500 mW, the exposure time is from 0.2 to 0.5 s, a spot with a diameter of 300-500 μm, and the center of the MIOL optics is localized by the location of annular notches or ring aspherical zones on the lens optics. In this case, the stroma of the iris under the influence of laser coagulates is reduced, and the pupil is displaced in this direction. The radiation power of an argon laser depends on the degree of pigmentation of the iris, and a power of less than 100 mW is not enough to coagulate the stroma of the iris, and this will not lead to a displacement of the pupil in the right direction, and a power of more than 500 mW can damage the deeper layers of the iris. The exposure time from 0.2 to 0.5 s and a spot with a diameter of 300-500 microns are sufficient for coagulation of the iris stroma with the claimed power range. The number and density of application of coagulates, as well as the length of the arc of the circle along which they are applied, depend on the degree of displacement of the pupil. Pupil displacement using local coagulation of the iris stroma with an argon laser is performed in patients who, after MIOL implantation, notice visual discomfort in the form of the need to use glasses when working at close range, double vision, light scattering circles when looking at the light source, light exposure, which is a result of the mismatch of the optical center MIOL and the center of the pupil.

When combining the MIOL optics centers and the pupil as a result of laser exposure, there is an increase in visual acuity both without additional spectacle correction and with correction, the patient's working capacity at close range increases, side optical phenomena in the form of light, double vision, light scattering circles and others decrease.

The method is as follows.

Using an argon laser, using a radiation power in the range from 100 to 500 mW (depending on the degree of pigmentation of the iris), exposure time from 0.2 to 0.5 s, a spot with a diameter of 300-500 μm, coagulation of the mid-peripheral sections of the iris stroma is performed. Coagulates are located 2-3 mm from the edge of the pupil in the sector opposite the displacement zone. The surgeon localizes the MIOL optics center by the location of the ring notches on the optics (typical for multifocal diffractive IOLs, for example Restor (manufacturer - Alcon company), or ring-shaped aspherical zones (typical for multifocal refractive IOLs, for example ReZoom (manufacturer - AMO company). as a result of exposure, the pupil shifts towards the applied coagulates and is centered in accordance with the MIOL optics.

Example 1

Patient K., 53 years old, was hospitalized with a diagnosis of nuclear cataract of the left eye.

Upon receipt, visual acuity is 0.2, does not correct. Biomicroscopy: the cornea is transparent, the anterior chamber is of medium depth, the iris is unchanged, weakly pigmented, the pupil with a diameter of 3.0 mm is somewhat displaced to the nose.

Cataract phacoemulsification with implantation of a multifocal IOL of the Restor model (Alcon) was performed. The early postoperative period was uneventful. On the 1st day after the operation, visual acuity in the distance is 0.8. Near visual acuity with correction - 0.7, without correction - 0.6. On examination, MIOL is located in the capsule bag, occupies the correct position, there is a slight decentration of the pupil to the nose.

When viewed 3 weeks after the operation, the eye is calm, the cornea is transparent, MIOL is located correctly in the capsule bag. Visual acuity in the distance without correction is 1.0. Visual acuity near correction -1.0 without correction - 0.5. The patient complains about the impossibility of reading fine tex without glasses and long-term work at close range without the use of spectacle correction, pronounced circles of light scattering when looking at the light source. Given the nature of the patient's subjective complaints, they were regarded as related to the decentralized position of the MIOL optics in relation to the center of the pupil.

An operation was performed on the plastic surgery of the pupil with an argon laser. 5 coagulates were applied in the area of the middle periphery of the cornea in the meridians of 1, 2, 3, 4 and 5 hours. Parameters of laser exposure: radiation power of 100 mW, exposure time from 0.4 s, spot with a diameter of 400 μm, coagulates are located 2-3 mm from the edge of the pupil in the sector opposite the displacement zone. In the postoperative period, it was noted that the cornea was transparent, there was slight swelling of the iris stroma in the area of coagulation. Moisture in the front camera and other optical media were transparent. The center of the pupil is located at the center of the MIOL optics, which is determined by the concentric notches on the lens body. Immediately after the intervention, the visual acuity of the patient in the distance did not change, however, a significant increase in visual acuity near without correction to 0.9 was detected, side optical effects disappeared.

Example 2

Patient M., 50 years old, was hospitalized with a diagnosis of nuclear cataract of the right eye.

Upon receipt, visual acuity is 0.3-0.4, does not correct. Biomicroscopy: the cornea is transparent, the anterior chamber is of medium depth, the iris is unchanged, pronounced pigmentation is noted, the pupil with a diameter of 3.0 mm is slightly shifted upward to the area of 12 hours. Cataract phacoemulsification with implantation of a ReZoom multifocal IOL model (AMO) was performed. The early postoperative period was uneventful. On the 1st day after surgery, visual acuity in the distance is 0.9. Near visual acuity with correction - 0.9, without correction - 0.8. On examination, MIOL is located in the capsule bag, occupies the correct position, a slight decentration of the pupil upwards is noted.

When viewed 2 weeks after surgery, the eye is calm, the cornea is transparent, MIOL is located in the capsular bag. Visual acuity in the distance without correction is 1.0. Visual acuity near with a correction of -1.0, without correction - 0.4. The patient complains about the impossibility of reading small tex without glasses, double vision, light. This condition was regarded as the decentration of the position of the IOL optics with respect to the center of the pupil.

An operation was performed on the plastic surgery of the pupil with an argon laser. 6 coagulates were applied in the area of the middle periphery of the cornea in meridians of 4, 5, 6, 7, 8 and 9 hours. Laser exposure parameters: radiation power of 500 mW, exposure time from 0.2 s, spot with a diameter of 300 μm, coagulates are located 2-3 mm from the edge of the pupil in the sector opposite the displacement zone.

In the postoperative period, there was a slight swelling of the iris stroma in the area of coagulation. Moisture in the front camera and other optical media were transparent. The center of the pupil is located at the center of the MIOL optics, which is determined by the ring-shaped aspherical zones on the optical part of the lens.

Immediately after the intervention, visual acuity in the distance is 1.0; a significant increase in visual acuity near without correction to 0.9 was detected, the disappearance of side optical effects was noted.

Claims (1)

A method for improving visual functions after implantation of a multifocal intraocular lens (MIOL) with a mismatch between the center of the lens and the center of the pupil, which consists in the fact that to move the pupil, point coagulation of the mid-peripheral sections of the iris stroma with an argon laser is 2-3 mm from the edge of the pupil, in the sector opposite the displacement zone, along the arc of a circle, concentric to the pupil, while the radiation power of an argon laser is from 100 to 500 mW, the exposure time is from 0.2 to 0.5 ms, a spot with a diameter of 300-500 microns, and the center of the MIOL is localized t by the location of the annular notches or annular aspherical zones on its optical part.