A multi-focal intraocular lens capable of different energy distribution and a preparation method thereof

Abstract

This invention discloses a multifocal intraocular lens capable of achieving different energy distributions and its fabrication method. The lens includes an optical body and a support haptic. The center of the optical body is the optical zone, which is divided into five areas: sector one, sector two, sector three, sector four, and a central circular area. Sector one and the central circular area are the distance vision zone, sector two and sector four are the intermediate vision zone, and sector three is the near vision zone. The distance vision zone provides a refractive power of -10.0D to +35.0D, and the intermediate vision zone provides +0.5D. The intraocular lens provides an additional optical power of +3.0D in the intermediate zone and +2.5D to +6.0D in the near zone. The refractive power smoothly transitions from the distance zone to the near zone. The focal energy distribution in the distance, intermediate, and near zones can be customized according to different usage needs. After intraocular implantation, the intraocular lens of this invention can simultaneously correct distance, intermediate, and near vision, and can also customize different focal energy distributions according to daily life needs, achieving true free vision. It has broad application prospects and is conducive to its widespread application.

Description

Technical Field

[0001] This invention relates to the field of intraocular lens technology, and in particular to a multifocal intraocular lens capable of achieving different energy distributions and its preparation method. Background Technology

[0002] Currently, surgically implanting an artificial lens (IOL) to replace the cloudy natural lens is the only effective treatment for cataracts, restoring clear vision to patients. The IOL is the most widely used artificial organ and implantable medical device worldwide. With rising living standards, cataract patients are no longer satisfied with simply regaining sight after a monofocal IOL implantation; they demand postoperative vision that meets all their daily needs, allowing them to go without glasses and regain youthful vision. Therefore, the optical design of IOLs has gradually evolved from monofocal spherical (aspherical) designs to bifocal and trifocal designs.

[0003] Trifocal intraocular lenses (IOLs) offer an additional focal point compared to bifocal IOLs, providing better intermediate vision. Most commercially available trifocal IOLs employ a diffraction structure design. This design is prone to light interference and, due to limitations in diffraction order, the energy distribution between the far, intermediate, and near focal points is typically 2:1:1, which cannot be adjusted to meet specific needs. Multifocal IOLs with a refractive structure design achieve far, intermediate, and near vision through multiple rings with varying curvatures; however, the energy distribution for far, intermediate, and near vision in this design is easily affected by the pupil diameter. Therefore, there is an urgent need to develop a multifocal IOL capable of achieving different energy distributions and its fabrication method to address these technical challenges.

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

[0005] The purpose of this invention is to provide a multifocal intraocular lens that can achieve different energy distributions and its preparation method. After intraocular implantation, the intraocular lens can simultaneously correct distance, intermediate, and near vision, and can also customize different focal energy distributions according to daily needs, achieving true free vision. It has broad application prospects and is conducive to its widespread application.

[0006] To achieve the above objectives, the present invention provides a multifocal intraocular lens capable of different energy distributions, comprising an optical body and a support haptic. The center of the optical body is an optical zone, which is divided into five regions: sector one, sector two, sector three, sector four, and a central circular region. Sector one and the central circular region are the distance vision zone, sector two and sector four are the intermediate vision zone, and sector three is the near vision zone. The distance vision zone provides a refractive power of -10.0D to +35.0D, providing clear distance vision when the human eye is viewing distant objects. Visual acuity is defined as follows: the intermediate visual zone provides an additional optical power of +0.5D to +3.0D, offering clear intermediate visual acuity when the human eye is viewing centrally; the near visual zone provides an additional near optical power of +2.5D to +6.0D, offering clear near visual acuity when the human eye is viewing centrally; the refractive power smoothly transitions from the distance visual zone to the near visual zone; the focal energy distribution of the distance, intermediate, and near visual zones is customized according to different usage requirements; the optical zone includes an anterior surface and a posterior surface, the posterior surface being either spherical or aspherical; the aspherical surface shape characterization equation is: ; Where c is the reciprocal of the radius of curvature of the basic spherical surface of the aspherical surface, x is the vertical distance of any point on the curve from the horizontal coordinate axis Z, A2i is the coefficient of the higher-order term of the aspherical surface, m and n are both integers not less than 1 and n>m, and k is the conic coefficient; The front surface consists of a central circular region and multiple spherical or aspherical sector regions with different radii of curvature. The area of ​​each sector is adjusted according to different needs to achieve different energy distributions for the far, middle, and near focal points. The energy proportion of each focal point is determined by the area weight of the region and the refractive efficiency, and the formula is as follows: ; in, The energy percentage of the i-th focus. This represents the effective area (mm²) of the corresponding optical region. This refers to the regional refractive efficiency.

[0007] Preferably, the multifocal intraocular lens is made of a soft, transparent, hydrophilic or hydrophobic acrylic material with a refractive index nL ranging from 1.35 to 1.65 and a dispersion coefficient of 35 to 60.

[0008] Preferably, the optical body and the support haptic are integrally formed from the same material.

[0009] Preferably, the diameter of the optical body is 5.5-6.5 mm, the diameter of the optical zone is 5.0-6.5 mm, and the total diameter of the multifocal intraocular lens is 12.5-13.5 mm.

[0010] Preferably, the optical body has a refractive function, providing a refractive power of -10.0D to +35.0D, and an additional optical power of +0.5D to +6.0D.

[0011] The present invention also provides a method for preparing the above-mentioned multifocal intraocular lens capable of achieving different energy distributions, comprising the following steps: S1: Determine the patient's individualized visual needs, determine the energy requirements of the intraocular lens for distance, intermediate, and near vision, and determine the distance refractive power and additional optical power parameters; S2: Determine the curvature radii of the far, mid, and near points based on the distance refractive power and additional optical power, and design the curvature radius values ​​for different regions of the intraocular lens based on the curvature radius parameters; S3: Determine the area of ​​the distance, intermediate, and near vision regions based on the patient's individualized energy usage needs for distance, intermediate, and near vision; S4: Use MATLAB to program and calculate the processing parameters of the anterior and posterior surfaces of the artificial lens; S5: Using an ultra-precision single-point diamond lathe, the surface structure derived from MATLAB is machined on the front and back surfaces of the preform; S6: Optical Inspection: Using an optical parameter measuring instrument, measure the distance refractive power and additional optical power of the intraocular lens in the ISO model eye, measure the focus response curves of the far, intermediate and near focal points, and determine whether the energy distribution of the far, intermediate and near focal points matches the design value based on the MTF value of each peak. If it matches, the processing is completed; otherwise, return to S5 and reprocess until the above requirements are met.

[0012] The present invention provides a multifocal intraocular lens capable of achieving different energy distributions and a method for its preparation, which has the following beneficial effects.

[0013] 1. Different sector areas of the present invention have different focal points, and the refractive power gradually increases. The eye can see objects at far, intermediate and near distances from different areas without being affected by the pupil diameter. Different energy distributions for far, intermediate and near focal points can be achieved by changing the size of different areas.

[0014] 2. The front surface of the optical body of the present invention consists of a central circular area and multiple spherical or aspherical fan-shaped areas with different radii of curvature. The area of ​​the fan-shaped areas can be adjusted according to different needs, thereby realizing the free distribution of energy at far, medium and near focal points and producing personalized imaging effects.

[0015] 3. This invention is an implantable multifocal intraocular lens that can reduce diffraction loss. After implantation, the intraocular lens can achieve clear vision for distant, intermediate, and near objects, and achieve true vision correction. Attached Figure Description

[0016] Figure 1 This invention provides a schematic diagram of the structure of a multifocal intraocular lens capable of achieving different energy distributions; Figure 2 A map showing the optical zone distribution of a multifocal intraocular lens with conventional energy distribution; Figure 3 MTF curve distribution of a multifocal intraocular lens with conventional energy distribution under a 3mm aperture apex; Figure 4 This is a regional distribution diagram of the optical zone of the multifocal intraocular lens in Example 1; Figure 5 This is a graph showing the MTF curve distribution of Example 1 under a 3mm aperture stop. Figure 6 This is a regional distribution diagram of the optical zone of the multifocal intraocular lens in Example 2; Figure 7 This is a graph showing the distribution of the MTF curve with the focal length under a 3mm aperture in Example 2.

[0017] In the picture: 101. Optical Main Body 102. Optical Area 103. Support Plug 201. Sector Area 1 202. Sector Area 2 203. Sector Area 3 204. Sector Area 4 205. Central Circular Area 301. Central Circular Area 302. Annular Area 1 303. Annular Area 2. Detailed Implementation

[0018] 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.

[0019] like Figure 1 and Figure 4The figures shown are a schematic diagram of the structure and an optical region distribution diagram of a multifocal intraocular lens capable of achieving different energy distributions provided by the present invention. This multifocal intraocular lens capable of achieving different energy distributions includes an optical body 101 and a support haptic 103, wherein the optical body 101 and the support haptic 103 are integrally formed from the same material. The optical body 101 has an optical region 102 at its center, which is divided into five areas: sector one 201, sector two 202, sector three 203, sector four 204, and a central circular region 205. Sector one 201 and the central circular region 205 are the distance vision zone, sector two 202 and sector four 204 are the intermediate vision zone, and sector three 203 is the near vision zone. The distance vision zone provides a refractive power of -10.0D to +35.0D, providing clear distance vision when the human eye is viewing distant objects. The intermediate vision zone provides a medium additional power of +0.5D to +3.0D, providing clear vision when the human eye is viewing intermediate objects. The near vision zone provides an additional power of +2.5D to +6.0D, offering clear near vision when the eye is focused. The refractive power smoothly transitions from the distance vision zone to the near vision zone. The focal energy distribution among the distance, intermediate, and near vision zones is customized according to different usage needs. The optical body 101 has refractive function, providing a refractive power of -10.0D to +35.0D, and an additional power of +0.5D to +6.0D. The multifocal intraocular lens is made of soft, transparent, hydrophilic or hydrophobic acrylic material with a refractive index nL ranging from 1.35 to 1.65 and a dispersion coefficient of 35 to 60. The diameter of the optical body 101 is 5.5-6.5 mm, the diameter of the optical zone 102 is 5.0-6.5 mm, and the total diameter of the multifocal intraocular lens is 12.5-13.5 mm. The optical region 102 includes a front surface and a rear surface, wherein the rear surface is either spherical or aspherical, and the equation characterizing the aspherical surface shape is: ; Where c is the reciprocal of the radius of curvature of the basic spherical surface of the aspherical surface, x is the vertical distance of any point on the curve from the horizontal coordinate axis Z, A2i is the coefficient of the higher-order term of the aspherical surface, m and n are both integers not less than 1 and n>m, and k is the conic coefficient; The front surface consists of a central circular region 205 and multiple spherical or aspherical sector regions with different radii of curvature. The area of ​​the sector regions is adjusted according to different needs, thereby achieving different energy distributions for far, middle, and near focal points. The energy proportion of each focal point is determined by the area weight of the region and the refractive efficiency, and the formula is as follows: ; in, The energy percentage of the i-th focus. This represents the effective area (mm²) of the corresponding optical region. This refers to the regional refractive efficiency.

[0020] The present invention also provides a method for preparing the above-mentioned multifocal intraocular lens capable of achieving different energy distributions, comprising the following steps: S1: Determine the patient's individualized visual needs, determine the energy requirements of the intraocular lens for distance, intermediate, and near vision, and determine the distance refractive power and additional optical power parameters; S2: Determine the curvature radii of the far, mid, and near points based on the distance refractive power and additional optical power, and design the curvature radius values ​​for different regions of the intraocular lens based on the curvature radius parameters; S3: Determine the area of ​​the distance, intermediate, and near vision regions based on the patient's individualized energy usage needs for distance, intermediate, and near vision; S4: Use MATLAB to program and calculate the processing parameters of the anterior and posterior surfaces of the artificial lens; S5: Using an ultra-precision single-point diamond lathe, the surface structure derived from MATLAB is machined on the front and back surfaces of the preform; S6: Optical Inspection: Using an optical parameter measuring instrument, measure the distance refractive power and additional optical power of the intraocular lens in the ISO model eye, measure the focus response curves of the far, intermediate and near focal points, and determine whether the energy distribution of the far, intermediate and near focal points matches the design value based on the MTF value of each peak. If it matches, the processing is completed; otherwise, return to S5 and reprocess until the above requirements are met. Example 1

[0021] A multifocal intraocular lens capable of different energy distributions, such as Figure 4 The image shown is a regional distribution diagram of the optical zone of the multifocal intraocular lens in Example 1.

[0022] The multifocal intraocular lens material in Example 1 is a hydrophobic acrylate with a refractive index of 1.52 and an Abbe number of 47; the aqueous humor refractive index is 1.336; the designed wavelength λ is 0.546 μm; the main body diameter is 6.0 mm; and the optical zone 102 has a diameter of 6.0 mm. The posterior surface is spherical, and the anterior surface consists of a central circular zone 205 and four aspherical sector zones. The patient desires greater distance vision, with equal energy distribution for intermediate and near vision. The preparation method includes the following steps: S1: Determine the patient's individual vision needs. Through testing, the patient's needs are: distance vision +20.0D, intermediate vision +2.0D, and near vision +3.5D. The energy requirements of the intraocular lens for distance, intermediate, and near vision are determined to be 3:1:1.

[0023] S2: Based on the distance refractive power of +20.0D and the additional optical power of +2.0D and +3.5D, the radius of curvature of the front surface is determined to be 13.940mm, and the radii of curvature of the distance, midpoint and near point regions of the rear surface are determined to be 26.869mm, 20.762mm and 17.739mm, respectively.

[0024] S3: Based on the patient's individualized energy usage needs for distance, intermediate, and near vision (3:1:1), the area ratio of the distance vision zone, intermediate vision zone, and near vision zone is determined to be 60%:20%:20%. Among them, sector 1 (201) and central circular area (205) are the distance vision zone, sector 2 (202) and sector 4 (204) are the intermediate vision zone, and sector 3 (203) is the near vision zone.

[0025] S4: Use MATLAB to program and calculate the lathe machining parameters for the anterior and posterior surfaces of the artificial lens.

[0026] S5: Using an ultra-precision single-point diamond lathe, the surface structure derived from MATLAB is machined on the front and back surfaces of the preform.

[0027] S6: Optical Inspection: Using an optical parameter measuring instrument, measure the distance refractive power and additional optical power of the intraocular lens in the ISO model eye, measure the focus response curves of the far, intermediate and near focal points, and determine whether the energy distribution of the far, intermediate and near focal points matches the design value based on the MTF value of each peak. If it matches, the processing is completed; otherwise, return to S5 and reprocess until the requirements in S6 are met.

[0028] Results analysis and discussion: like Figure 5 The figure shows the MTF curve distribution of Example 1 under a 3mm aperture stop. (Source: [Insert source here]) Figure 5 It can be seen that the refractive power of the intraocular lens in the distance vision zone is +20.01D, the refractive power in the intermediate vision zone is +22.07D (with an additional optical power of +2.06D), and the refractive power in the near vision zone is +23.48D (with an additional optical power of +3.47D). Therefore, the refractive power meets the design requirements of +20.0D +2.0D +3.5D. The MTF values ​​of the far, intermediate, and near focal points are 0.380, 0.128, and 0.131, respectively. Therefore, the peak MTF energy ratio of the far, intermediate, and near focal points meets the design requirement of 3:1:1.

[0029] like Figure 2 The diagram shows the optical zone distribution of a conventional energy-distribution multifocal intraocular lens. The optical zone is divided into three areas: a central circular area 301, annular area one 302, and annular area two 303. The central circular area 301 is the distance vision zone, annular area one 302 is the intermediate vision zone, and annular area two 303 is the near vision zone. Because each annular area has a different diameter, energy distribution is easily affected by the pupil diameter. Figure 3As shown, it is the distribution diagram of the defocus MTF curve of a multi-focal intraocular lens with conventional energy distribution under a 3mm aperture stop; Figure 3 It can be seen that the diopter of the distant vision area of the intraocular lens is +20.00D, the diopter of the middle vision area is +22.086D (additional optical power +2.09D), and the diopter of the near vision area is +23.57D (additional optical power +3.57D). It can be known that the diopter meets the design requirements of +20.0D +2.0D +3.5D. The MTF values of the far, middle, and near foci under a 3mm aperture stop are 0.376, 0.208, and 0.085 respectively. Due to the small aperture stop, affected by the light passing aperture, the light passing amount in the annular area 303 of the near vision area is small, resulting in a low MTF value for the near focus. Example 2

[0030] A multi-focal intraocular lens that can achieve different energy distributions, as Figure 6 shown, is the distribution diagram of the optical zone of the multi-focal intraocular lens of Example 2.

[0031] The material of the multi-focal intraocular lens in Example 2 is hydrophobic acrylate, the refractive index of the material is 1.52, and the Abbe number is 47; the refractive index of the aqueous humor is 1.336; the design wavelength λ is 0.546um; the main body diameter is 6.0mm; the diameter of the optical zone 102 is 6.0mm. The rear surface is spherical, and the front surface is composed of a central circular area 205 and 4 aspherical fan-shaped areas. The patient hopes to obtain a 1:1:1 ratio of distant vision, middle vision, and near vision. The preparation method includes the following steps: S1: Determine the patient's personalized eye use needs. Through detection, the patient's required distant vision degree is +15.0D, the additional optical power for middle vision is +1.5D, and the additional optical power for near vision is +3.0D. Determine the energy requirements for distant, middle, and near vision of the intraocular lens to be 1:1:1.

[0032] S2: According to the distant vision diopter of +15.0D and the additional optical powers of +1.5D and +3.0D, determine that the front surface curvature radius is 24.100mm, and determine that the curvature radii of the distant vision point, middle vision point, and near vision point areas on the rear surface are 24.882mm, 20.672mm, and 17.68mm respectively.

[0033] S3: According to the patient's personalized energy eye use needs of 1:1:1 for distant, middle, and near vision, determine that the area ratio of the distant vision area, middle vision area, and near vision area is 33%:33%:33%. Among them, the fan-shaped area 201 and the central circular area 205 are the distant vision areas, the fan-shaped area 202 and the fan-shaped area 204 are the middle vision areas, and the fan-shaped area 203 is the near vision area.

[0034] S4: Program through MATLAB to calculate and obtain the lathe processing parameters of the front and rear surfaces of the intraocular lens.

[0035] S5: Using an ultra-precision single-point diamond lathe, the surface structure derived from MATLAB is machined on the front and back surfaces of the preform.

[0036] S6: Optical Inspection: Using an optical parameter measuring instrument, measure the distance refractive power and additional optical power of the intraocular lens in the ISO model eye, measure the focus response curves of the far, intermediate and near focal points, and determine whether the energy distribution of the far, intermediate and near focal points matches the design value based on the MTF value of each peak. If it matches, the processing is completed; otherwise, return to S5 and reprocess until the requirements in S6 are met.

[0037] Results analysis and discussion: like Figure 7 The image shows the MTF curve distribution of Example 2 under a 3mm aperture stop. Figure 7 It can be seen that the refractive power of the intraocular lens in the distance vision zone is +14.97D, the refractive power in the intermediate vision zone is +16.45D (additional optical power +1.48D), and the refractive power in the near vision zone is +17.89D (additional optical power +2.92D). Therefore, the refractive power meets the design requirements of +15.0D +1.5D +3.0D. The MTF values ​​of the far, intermediate, and near focal points at the 3mm aperture are 0.237, 0.225, and 0.235, respectively. This indicates that the peak MTF energy of the far, intermediate, and near focal points meets the design requirement of 1:1:1.

[0038] The different sector regions of this invention have different focal points, with refractive power gradually increasing. The eye can view objects at distant, intermediate, and near distances from different regions, unaffected by pupil diameter. Different energy distributions for far, intermediate, and near focal points can be achieved by changing the size of different regions. The front surface of the optical body 101 of this invention consists of a central circular region 205 and multiple spherical or aspherical sector regions with different radii of curvature. The sector area can be adjusted according to different needs, thereby achieving free distribution of energy for far, intermediate, and near focal points and producing personalized imaging effects. This invention is an implantable multifocal intraocular lens that reduces diffraction loss. After implantation, the intraocular lens can achieve clear vision at far, intermediate, and near distances while achieving true glasses-free vision.

[0039] 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. A multifocal intraocular lens capable of achieving different energy distributions, characterized in that, The system includes an optical body and a supporting haptic. The center of the optical body is the optical zone, which is divided into five areas: sector one, sector two, sector three, sector four, and a central circular area. Sector one and the central circular area are the distance vision zone; sector two and sector four are the intermediate vision zone; and sector three is the near vision zone. The distance vision zone provides a refractive power of -10.0D to +35.0D, offering clear distance vision. The intermediate vision zone provides a refractive power of +0.5D to +35.0D. The optical zone provides an additional optical power of 0.0D, offering clear intermediate vision when the human eye is viewing centrally. The near vision zone provides an additional near optical power of +2.5D to +6.0D, offering clear near vision when the human eye is viewing centrally. The refractive power smoothly transitions from the distance vision zone to the near vision zone. The focal energy distribution of the distance, intermediate, and near vision zones is customized according to different usage requirements. The optical zone includes a front surface and a rear surface. The rear surface can be spherical or aspherical, and the aspherical surface shape characterization equation is: ； Where c is the reciprocal of the radius of curvature of the basic spherical surface of the aspherical surface, x is the vertical distance of any point on the curve from the horizontal coordinate axis Z, A2i is the coefficient of the higher-order term of the aspherical surface, m and n are both integers not less than 1 and n>m, and k is the conic coefficient; The front surface consists of a central circular region and multiple spherical or aspherical sector regions with different radii of curvature. The area of ​​each sector is adjusted according to different needs to achieve different energy distributions for the far, middle, and near focal points. The energy proportion of each focal point is determined by the area weight of the region and the refractive efficiency, and the formula is as follows: ； in, The energy percentage of the i-th focus. This represents the effective area of ​​the corresponding optical region. This refers to the regional refractive efficiency.

2. A multifocal intraocular lens capable of achieving different energy distributions according to claim 1, characterized in that, The multifocal intraocular lens is made of soft, transparent, hydrophilic or hydrophobic acrylic material, with a refractive index nL ranging from 1.35 to 1.65 and a dispersion coefficient of 35 to 60.

3. A multifocal intraocular lens capable of achieving different energy distributions according to claim 2, characterized in that, The optical body and the support haptic are integrally formed from the same material.

4. A multifocal intraocular lens capable of achieving different energy distributions according to claim 3, characterized in that, The diameter of the optical body is 5.5-6.5 mm, the diameter of the optical zone is 5.0-6.5 mm, and the total diameter of the multifocal intraocular lens is 12.5-13.5 mm.

5. A multifocal intraocular lens capable of achieving different energy distributions according to claim 4, characterized in that, The optical body has a refractive function, providing a refractive power of -10.0D to +35.0D, and an additional optical power of +0.5D to +6.0D.

6. A method for preparing a multifocal intraocular lens capable of achieving different energy distributions as described in any one of claims 1-5, characterized in that, Includes the following steps: S1: Determine the patient's individualized visual needs, determine the energy requirements of the intraocular lens for distance, intermediate, and near vision, and determine the distance refractive power and additional optical power parameters; S2: Determine the curvature radii of the far, mid, and near points based on the distance refractive power and additional optical power, and design the curvature radius values ​​for different regions of the intraocular lens based on the curvature radius parameters; S3: Determine the area of ​​the distance, intermediate, and near vision regions based on the patient's individualized energy usage needs for distance, intermediate, and near vision; S4: Use MATLAB to program and calculate the processing parameters of the anterior and posterior surfaces of the artificial lens; S5: Using an ultra-precision single-point diamond lathe, the surface structure derived from MATLAB is machined on the front and back surfaces of the preform; S6: Optical Inspection: Using an optical parameter measuring instrument, measure the distance refractive power and additional optical power of the intraocular lens in the ISO model eye, measure the focus response curves of the far, intermediate and near focal points, and determine whether the energy distribution of the far, intermediate and near focal points matches the design value based on the MTF value of each peak. If it matches, the processing is completed; otherwise, return to S5 and reprocess until the above requirements are met.

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