Asymmetric multifocal intraocular lens with four-loop structure and preparation method thereof

Abstract

This invention discloses an asymmetric astigmatic multifocal intraocular lens with a four-loop structure and its preparation method, comprising an optical region and supporting loops. The anterior surface of the optical region has a diffraction ring, and the posterior surface has an asymmetric toroidal surface structure. The supporting loops are symmetrically distributed with four loops, and each end has a laser-etched groove with a width of 30-60 μm and a depth of 10-20 μm. The surface of the loops is plasma-treated to form a nanoscale rough texture. This invention simultaneously corrects astigmatism, presbyopia, and higher-order aberrations through a composite optical design, and improves long-term stability through surface treatment. It is suitable for visual function reconstruction in patients with cataracts and corneal astigmatism, and has broad application prospects, which is conducive to its widespread application.

Description

Technical Field

[0001] This invention relates to the field of intraocular lens technology, and more particularly to an asymmetric astigmatic multifocal intraocular lens with a four-loop structure and its preparation method. Background Technology

[0002] Cataracts are the leading cause of blindness worldwide, and their incidence increases with age. The elderly are a high-risk group for cataracts, with an incidence rate exceeding 70% in those aged 60 and above, and reaching as high as 80% in those aged 80 and above. Currently, surgically implanting an artificial lens to replace the cloudy natural lens is the only effective treatment for cataracts, restoring clear vision. However, monofocal intraocular lenses (IOLs) only address the basic issue of restoring sight. Furthermore, statistics show that approximately 15% to 30% of cataract patients have corneal astigmatism ≥1.0 D before surgery, which cannot be corrected by monofocal IOLs, requiring postoperative glasses or a second surgery.

[0003] In existing technologies, astigmatic intraocular lenses correct astigmatism through a torus design, but cannot solve presbyopia; while multifocal lenses can provide multifocal vision, their optical performance is prone to degradation due to rotational shift when superimposed on astigmatism correction. Furthermore, the rotational stability of traditional double-loop structures is insufficient, resulting in a 5-10° shift post-operatively. Therefore, there is an urgent need to develop an asymmetric astigmatic multifocal intraocular lens with a four-loop structure and its fabrication method to solve the aforementioned technical problems.

[0004] In view of this, the present invention is hereby proposed. Summary of the Invention

[0005] The purpose of this invention is to provide an asymmetric astigmatic multifocal intraocular lens with a four-loop structure and its preparation method. Through composite optical design, it can simultaneously correct astigmatism, presbyopia and higher-order aberrations, and improve long-term stability through surface treatment. It is suitable for visual function reconstruction in patients with cataracts and corneal astigmatism, has broad application prospects and is conducive to promotion and application.

[0006] To achieve the above objectives, this invention provides an asymmetric astigmatic multifocal intraocular lens with a four-loop structure, comprising an optical region and supporting loops. The anterior surface of the optical region has a diffraction ring, and the posterior surface has an asymmetric toroidal surface structure. The supporting loops are symmetrically distributed with four loops, and each end has a laser-etched groove with a width of 30-60 μm and a depth of 10-20 μm. The surface of the loops is plasma-treated to form a nanoscale rough texture. The phase retardation function of the diffraction ring satisfies the optical path difference condition at the three focal points, and the phase function is expressed as: ; Where r is the radius of the diffraction ring, and the radius of the nth ring is r n ; For the design wavelength; The reference focal length for the far focal point; The phase jump amount for the nth additional focus, which includes the intermediate focus and the near focus; Step height of optical surface ; in, This is the phase delay. For the design wavelength, The refractive index of the lens material; The rear surface is an asymmetric torus structure, with a coma compensation term superimposed on the rear surface torus. The surface equation is: ; in, The curvature is the meridional / vertical direction. The aspherical coefficient, This is a higher-order aberration compensation factor.

[0007] Preferably, the additional optical power range of the optical region is +1.0 to +5.0D.

[0008] Preferably, the optical region and the support haptic are an integral structure.

[0009] Preferably, the optical region and the support haptic are integrally formed from the same material.

[0010] Preferably, the astigmatism correction range is 1.0-6.0D, and a wavefront aberration compensation function is integrated to counteract corneal coma.

[0011] Preferably, the surface roughness Ra of the nanoscale rough texture is 0.5-1.2 μm.

[0012] Preferably, the edge of the optical zone is provided with an axis marking system, which includes a main mark and a secondary mark.

[0013] Preferably, the diameter of the optical region is 5.5-6.5 mm, the center thickness is 0.35-1.35 mm, and the thickness of the support haptic is 0.15-0.45 mm.

[0014] The present invention also provides a method for preparing the above-mentioned asymmetric astigmatic multifocal intraocular lens with a four-loop structure, comprising the following steps: S1: Material preparation: The optical area and the support haptic are manufactured as an integrated structure through precision injection molding, with a mold precision of ≤0.1um; S2: Optical front surface processing: Using an ultra-precision lathe, concentric stepped diffraction rings are machined on the front surface of the optical area, with a step height error ≤5nm; S3: Optical back surface machining: Using an ultra-precision lathe, a cylindrical mirror surface is machined on the back surface of the optical zone; S4: Axis Marking: Axis marking is made on the edge of the optical area using an ultra-precision lathe. The main mark is located on the short line between 90° and 270°, with a length of 0.2-0.4mm. The secondary mark is located on the dot between 0° and 180°, with a diameter of 0.1-0.2mm. S5: Plug treatment: Laser etching grooves are made at the ends of the support plugs using a laser system on an ultra-precision lathe; S6: Surface treatment of the support loop end: Plasma bombardment treatment is performed on the support loop end to form a nanoscale rough texture; S7: Optical Testing: Defocus response curves are measured in a simulated eye, and the image quality and cylinder power of the far, intermediate, and near focal points of the intraocular lens are tested with 546nm monochromatic light.

[0015] The present invention provides an asymmetric astigmatic multifocal intraocular lens with a four-loop structure and a method for its preparation, which has the following beneficial effects.

[0016] 1. This invention corrects astigmatism, presbyopia and higher-order aberrations simultaneously through composite optical design, and improves long-term stability through surface treatment, making it suitable for visual function reconstruction in patients with cataracts and corneal astigmatism.

[0017] 2. The support loop ends of the present invention are provided with nanoscale rough texture, combined with the symmetrical distribution design of the four loops, to achieve rotational stability within the bag.

[0018] 3. The present invention performs plasma bombardment treatment on the end of the support haptic. After plasma treatment, the surface roughness Ra increases, which can improve the friction between the end of the support haptic and the capsule, and maintain the stability of the lens. Attached Figure Description

[0019] Figure 1 A front view of an asymmetric astigmatic multifocal intraocular lens with a four-loop structure provided by the present invention; Figure 2 A side view of the support haptic end of an asymmetric astigmatic multifocal intraocular lens with a four-haptic structure provided by the present invention; Figure 3 This invention provides a measurement diagram of the defocus response curve of an asymmetric astigmatic multifocal intraocular lens with a four-loop structure.

[0020] In the picture: 101. Optical area 102. Support haptic 103. Main mark 104. Secondary mark 105. Diffraction ring 201. End of support haptic 202. Laser etched groove. Detailed Implementation

[0021] The present invention will be further described below with reference to specific embodiments and accompanying drawings to help understand the content of the present invention.

[0022] like Figures 1-2 The images show a front view and a side view of the end 201 of the support haptic of an asymmetric astigmatic multifocal intraocular lens with a four-loop structure provided by the present invention. This asymmetric astigmatic multifocal intraocular lens with a four-loop structure includes an optical region 101 and a support haptic 102, which are integrally formed. Preferably, the optical region 101 and the support haptic 102 are integrally molded from the same material. The diameter of the optical region 101 is 5.5-6.5 mm, the center thickness is 0.35-1.35 mm, and the additional optical power range of the optical region 101 is +1.0 to +5.0 D. An axis marking system is provided on the edge of the optical region 101, the axis marking system including a main mark 103 and a secondary mark 104. The thickness of the support haptic 102 is 0.15-0.45 mm. The optical region 101 has a diffraction ring 105 on its front surface and an asymmetric toroidal surface structure on its rear surface. The support loops 102 are symmetrically distributed with four loops, each end having a laser-etched groove 202 with a width of 30-60 μm and a depth of 10-20 μm. The loop surfaces are plasma-treated to form a nanoscale rough texture with a surface roughness Ra of 0.5-1.2 μm. The astigmatism correction range is 1.0-6.0D, and a wavefront aberration compensation function is integrated to compensate for corneal coma. The phase retardation function of the diffraction ring 105 satisfies the optical path difference condition at the three focal points, and the phase function is expressed as: ; Where r is the radius of diffraction ring 105, and the radius of the nth ring is r n ; For the design wavelength; The reference focal length for the far focal point; The phase jump amount for the nth additional focus, which includes the intermediate focus and the near focus; Step height of optical surface ; in, This is the phase delay. For the design wavelength, The refractive index of the lens material; The rear surface is an asymmetric torus structure, with a coma compensation term superimposed on the rear surface torus. The surface equation is: ; in, The curvature is the meridional / vertical direction. The aspherical coefficient, This is a higher-order aberration compensation factor.

[0023] The present invention also provides a method for preparing the above-mentioned asymmetric astigmatic multifocal intraocular lens with a four-loop structure, comprising the following steps: S1: Material preparation: The optical area 101 and the support haptic 102 are manufactured as an integrated structure through precision injection molding process, with mold precision ≤0.1um; S2: Optical front surface processing: Using an ultra-precision lathe, concentric stepped diffraction rings 105 are machined on the front surface of the optical zone 101, with a step height error ≤5nm; S3: Optical back surface machining: Use an ultra-precision lathe to machine the cylindrical mirror surface on the back surface of optical zone 101; S4: Axis Marking: Axis marking is made on the edge of optical zone 101 using an ultra-precision lathe. The main mark 103 is located on the short line between 90° and 270°, with a length of 0.2-0.4mm. The secondary mark 104 is located on the dot between 0° and 180°, with a diameter of 0.1-0.2mm. S5: Plug treatment: Laser etching grooves are performed at the end 201 of the support plug using a laser system on an ultra-precision lathe; S6: Surface treatment of support loop end 201: Plasma bombardment treatment is performed on support loop end 201 to form nanoscale rough texture on support loop 102; S7: Optical Testing: Defocus response curves are measured in a simulated eye, and the image quality and cylinder power of the far, intermediate, and near focal points of the intraocular lens are tested with 546nm monochromatic light.

[0024] Example 1: A four-loop asymmetric astigmatic multifocal intraocular lens with a telephoto power of 20D, an additional power of +1.5D / +3.0D, and an astigmatism power of 2.0D was prepared.

[0025] S1: Material preparation: Hydrophobic acrylate prepolymer (refractive index 1.55) is injected into the mold at an injection temperature of 180°C and a holding time of 30s.

[0026] S2: Optical front surface machining: Using an ultra-precision lathe, concentric stepped diffraction rings 105 are machined on the front surface of the optical zone 101. The radius of the m-th order diffraction ring 105 is... satisfy: When the diffraction order is m=0, it corresponds to the far focal point; when the diffraction order is m=+1, it corresponds to the middle focal point; when the diffraction order is m=+2, it corresponds to the near focal point; and the step height error is ≤5nm.

[0027] S3: Optical back surface machining: Use an ultra-precision lathe to machine the cylindrical mirror surface on the back surface of optical zone 101.

[0028] S4: Axis Marking: Use an ultra-precision lathe to machine dots at the 0° and 180° axes, and short lines at the 90° and 270° axes.

[0029] S5: Plug treatment: Laser etching grooves are made at the end 201 of the support plug using a laser system on an ultra-precision lathe.

[0030] S6: Surface treatment of support loop end 201: Use a plasma treatment machine to bombard support loop end 201 with argon plasma for 30 seconds at a power of 100W to form a Ra=0.8um texture.

[0031] S7: Optical Testing: Defocus response curves were measured in a simulated eye. Image quality and cylinder power of the intraocular lens at far, intermediate, and near focal points were tested using 546nm monochromatic light. Test results are as follows: Figure 3 As shown: Within the full transverse axis test range, the peak interval between the meridional MTFtan curve and the sagittal MTFsag curve is 2.0D, confirming that the intraocular lens has 2.0D astigmatism. Both types of curves exhibit three characteristic peaks. For the meridional MTFtan curve, the first peak reference is at position 0D, and the defocusing amounts of the second and third peaks relative to the reference peak are 1.51D and 2.98D, respectively. For the sagittal MTFsag curve, the first peak reference is at position -2.0D, and the defocusing amounts of the second and third peaks relative to the reference peak are 1.53D and 3.07D, respectively. Therefore, the additional optical power of the intraocular lens is determined to be +1.5D / +3.0D. The three peak values ​​mentioned above correspond to the imaging quality values ​​of the far, intermediate, and near focal points of the intraocular lens in the meridional and sagittal directions, respectively. Among them, the imaging quality values ​​of the far, intermediate, and near focal points in the meridional direction are 0.343, 0.121, and 0.156, respectively, and the imaging quality values ​​of the far, intermediate, and near focal points in the sagittal direction are 0.327, 0.120, and 0.153, respectively.

[0032] This invention simultaneously corrects astigmatism, presbyopia, and higher-order aberrations through a composite optical design, and enhances long-term stability through surface treatment, making it suitable for visual function reconstruction in patients with cataracts and corneal astigmatism. The supporting haptic of this invention features nanoscale rough texture at its tip, combined with a symmetrical four-haptic distribution design, achieving rotational stability within the capsular bag. Furthermore, the supporting haptic is subjected to plasma bombardment treatment, which increases the surface roughness Ra, enhancing the friction between the supporting haptic and the capsular bag and maintaining lens stability.

[0033] This article uses specific examples to illustrate the inventive concept in detail. The description of the above embodiments is only for the purpose of helping to understand the core idea of ​​the present invention. It should be noted that any obvious modifications, equivalent substitutions or other improvements made by those skilled in the art without departing from the inventive concept should be included within the protection scope of the present invention.

Claims

1. An asymmetric astigmatic multifocal intraocular lens with a four-loop structure, characterized in that, The optical region includes an optical area and a support haptic. The front surface of the optical area has a diffraction ring, and the rear surface has an asymmetric toroidal surface structure. The support haptic has four symmetrically distributed haptices, each with a laser-etched groove at its end, 30-60 μm wide and 10-20 μm deep. The haptic surface is plasma-treated to form a nanoscale rough texture. The phase delay function of the diffraction ring satisfies the optical path difference condition at the three focal points. The phase function is expressed as: ； Where r is the radius of the diffraction ring, and the radius of the nth ring is r n ; For the design wavelength; The reference focal length for the far focal point; The phase jump amount for the nth additional focus, which includes the intermediate focus and the near focus; Step height of optical surface ; in, This is the phase delay. For the design wavelength, The refractive index of the lens material; The rear surface is an asymmetric torus structure, with a coma compensation term superimposed on the rear surface torus. The surface equation is: ; in, The curvature is the meridian / vertical direction. The aspheric coefficient, This is a higher-order aberration compensation factor.

2. The asymmetric astigmatic multifocal intraocular lens with a four-loop structure according to claim 1, characterized in that, The additional optical power range of the optical region is +1.0 to +5.0D.

3. The asymmetric astigmatic multifocal intraocular lens with a four-loop structure according to claim 2, characterized in that, The optical zone and the support haptic are an integrated structure.

4. An asymmetric astigmatic multifocal intraocular lens with a four-loop structure according to claim 3, characterized in that, The optical zone and the support haptic are integrally formed from the same material.

5. An asymmetric astigmatic multifocal intraocular lens with a four-loop structure according to claim 4, characterized in that, The astigmatism correction range is 1.0-6.0D, and it integrates a wavefront aberration compensation function to counteract corneal coma.

6. An asymmetric astigmatic multifocal intraocular lens with a four-loop structure according to claim 5, characterized in that, The surface roughness Ra of the nanoscale rough texture is 0.5-1.2 μm.

7. An asymmetric astigmatic multifocal intraocular lens with a four-loop structure according to claim 6, characterized in that, The edge of the optical zone is provided with an axis marking system, which includes a main mark and a secondary mark.

8. An asymmetric astigmatic multifocal intraocular lens with a four-loop structure according to claim 7, characterized in that, The diameter of the optical area is 5.5-6.5 mm, the center thickness is 0.35-1.35 mm, and the thickness of the support haptic is 0.15-0.45 mm.

9. A method for preparing an asymmetric astigmatic multifocal intraocular lens with a four-loop structure as described in any one of claims 1-8, characterized in that, Includes the following steps: S1: Material preparation: The optical area and the support haptic are manufactured as an integrated structure through precision injection molding, with a mold precision of ≤0.1um; S2: Optical front surface processing: Using an ultra-precision lathe, concentric stepped diffraction rings are machined on the front surface of the optical area, with a step height error ≤5nm; S3: Optical back surface machining: Using an ultra-precision lathe, a cylindrical mirror surface is machined on the back surface of the optical zone; S4: Axis Marking: Axis marking is made on the edge of the optical area using an ultra-precision lathe. The main mark is located on the short line between 90° and 270°, with a length of 0.2-0.4mm. The secondary mark is located on the dot between 0° and 180°, with a diameter of 0.1-0.2mm. S5: Plug treatment: Laser etching grooves are made at the ends of the support plugs using a laser system on an ultra-precision lathe; S6: Surface treatment of the support loop end: Plasma bombardment treatment is performed on the support loop end to form a nanoscale rough texture; S7: Optical Testing: Defocus response curves are measured in a simulated eye, and the image quality and cylinder power of the far, intermediate, and near focal points of the intraocular lens are tested with 546nm monochromatic light.

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