An intraocular lens

Abstract

The application relates to the technical field of medical devices, in particular to an intraocular lens, which comprises an intraocular lens body and a central hole arranged at the central position of the intraocular lens body; the central hole is an elliptical hole. The intraocular lens provided by the application improves the structure of the central hole from the root cause of postoperative halo, ensures the water flow, reduces the symmetrical diffraction ring, guides the stray light to the retina periphery, and reduces the subjective halo perception.

Description

Technical Field

[0001] This invention relates to the field of medical device technology, and more particularly to an intraocular lens. Background Technology

[0002] Phakic intraocular lens implantation is one of the mainstream surgical methods for correcting high myopia, hyperopia, and astigmatism, especially suitable for patients who are not suitable for corneal laser surgery. Posterior chamber phakic intraocular lenses are widely used clinically due to their excellent visual quality, predictability, and reversibility. Typical products include implantable contact lenses.

[0003] In the evolution of posterior chamber phakic intraocular lenses (IOLs), to maintain physiological aqueous humor circulation and prevent anterior subcapsular cataracts induced by lens metabolic disorders, modern posterior chamber phakic IOLs generally feature a central aperture penetrating the optics of the lens. This central aperture allows aqueous humor to flow from the posterior chamber to the anterior chamber, thereby restoring the natural aqueous humor flow pathway and significantly reducing the incidence of postoperative secondary cataracts.

[0004] However, the circular central aperture used in existing posterior chamber phakic intraocular lenses, while facilitating aqueous humor circulation, introduces a new optical challenge: postoperative halo problems, which affects treatment outcomes. Summary of the Invention

[0005] To address the problem of postoperative halos in existing intraocular lenses, this invention provides an intraocular lens that effectively reduces symmetrical diffraction rings by setting the central hole to an elliptical hole, thus solving the problem of postoperative halos in existing intraocular lenses.

[0006] The technical solution adopted by this invention to solve its technical problem is: An intraocular lens includes an intraocular lens body and a central hole disposed at the center of the intraocular lens body; the central hole is an elliptical hole.

[0007] Optionally, the major axis of the central hole is 0.38±0.01mm and the minor axis is 0.36±0.01mm.

[0008] Optionally, the major axis of the central hole is set along the horizontal meridian direction.

[0009] Optionally, the edge of the central hole is provided with a connected chamfered surface structure and a rounded transition structure; the chamfered surface structure is a double-sided structure.

[0010] Optionally, the angle of the beveled chamfer structure is 45°.

[0011] Optionally, the width of the beveled chamfer structure is 28-32 μm.

[0012] Optionally, the radius of the circular arc transition structure is 23-27 μm.

[0013] Optionally, an annular phase compensation step is provided around the central hole.

[0014] Optionally, the annular phase compensation step is located within an annular region 0.8-1.2 mm outside the central hole.

[0015] Optionally, the step height of the annular phase compensation ladder is 0.43-0.47 μm.

[0016] Optionally, the step width of the annular phase compensation step is 0.13-0.17 mm.

[0017] Optionally, the material of the intraocular lens body is polymerized from collagen and hydrophilic acrylate.

[0018] Optionally, the wall of the central hole is provided with a refractive index matching coating; the refractive index of the refractive index matching coating is 1.33-1.35.

[0019] Optionally, the intraocular lens body includes an optical region, the diameter of which is 5.5~6.1 mm. Optionally, a transition zone is provided at the edge of the optical zone; the width of the transition zone is 0.28-0.32 mm.

[0020] The beneficial effects of this invention are: The artificial lens provided by this invention addresses the root cause of postoperative halo formation by improving the structure of the central aperture. While ensuring the flow of aqueous humor, it reduces the symmetrical diffraction ring, guides stray light to the periphery of the retina, and reduces subjective halo perception. Attached Figure Description

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

[0022] Figure 1 The structure of the artificial lens in this invention is simplified. Figure 1 ; Figure 2 yes Figure 1 A magnified view of a section at point A in the middle; Figure 3 The structure of the artificial lens in this invention is simplified. Figure 2 ; Figure 4 yes Figure 3 Cross-sectional view along the BB direction; Figure 5 yes Figure 4 A magnified view of a section at point C; Figure 6 The structure of the artificial lens in this invention is simplified. Figure 3 ; Figure 7 yes Figure 6 Cross-sectional view along the DD direction; Figure 8 yes Figure 7 A magnified view of a section at point E in the middle.

[0023] In the diagram: 1-Intraocular lens body; 11-Optical zone; 12-Transition zone; 2-Central aperture; 3-Beveled structure; 4-Circular transition structure; 5-Annular phase compensation step. Detailed Implementation

[0024] The present invention will now be described in further detail. The embodiments described below are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0025] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0026] To address the problem of postoperative halos in existing intraocular lenses, this invention provides an intraocular lens, see [link to original text]. Figures 1-8 As shown, the intraocular lens includes an intraocular lens body 1 and a central hole 2 disposed at the center of the intraocular lens body 1; preferably, the central hole 2 is an elliptical hole to reduce subjective halo perception.

[0027] Existing intraocular lenses, such as posterior chamber phakic intraocular lenses (ICLs), mostly employ a circular central aperture to allow natural flow of aqueous humor. When light waves pass through this circular central aperture, diffraction occurs (Huygens-Fresnel principle). The edges of the central aperture become secondary wave sources, forming spherical wave interference. This results in the formation of concentric rings around the central bright spot on the retina (Airy disk and its diffraction rings), which, macroscopically, appear as a diffuse bright ring. The higher the contrast of the diffraction rings of the circular aperture, and the clearer the perfectly symmetrical Airy disk rings, the stronger the perception of the halo, making it a major source of nighttime glare. Based on this, this invention sets the central aperture 2 as an elliptical aperture, specifically a near-circular, micro-elliptical aperture. By slightly disrupting the diffraction symmetry, the contrast of the diffraction rings can be reduced, making the halo softer, while maintaining the energy concentration of the central main spot. This achieves the design goal of "improving glare without sacrificing sharpness." It should be further noted that a high ellipticity design can conversely degrade visual quality. When the ellipticity is too high or the aperture is too large, the diffraction enhancement effect will offset the halo optimization effect of symmetry breaking, and instead lead to diffused light spots and increased glare.

[0028] The artificial lens provided by this invention addresses the root cause of postoperative halo formation by improving the structure of the central aperture 2. While ensuring the flow of aqueous humor, it reduces the symmetrical diffraction ring, guides stray light to the periphery of the retina, and reduces subjective halo perception.

[0029] To ensure clinical efficacy, this invention preferably uses a near-circular micro-elliptical central aperture 2. Specifically, the preferred major axis is 0.38±0.01mm and the minor axis is 0.36±0.01mm, with a further preferred major axis of 0.38mm and a minor axis of 0.36mm. This 0.38×0.36mm micro-elliptical central aperture, by slightly disrupting the diffraction symmetry of an ideal circular aperture, can moderately reduce the peak intensity of the diffraction halo and smooth the sidelobe structure, resulting in a softer halo and more diffused boundaries in nighttime point source imaging, thereby reducing subjective glare and starburst perception in patients. Simultaneously, its energy concentration and MTF performance remain essentially consistent with traditional circular apertures, achieving the design goal of improving nighttime visual comfort without sacrificing imaging sharpness. This invention preferably uses an equivalent flow area ≥V4c for the central aperture 2, which is ≥5.56% larger than the flow area of ​​a 0.36mm circular aperture, ensuring smooth aqueous humor circulation and thus guaranteeing aqueous humor circulation safety.

[0030] Furthermore, the present invention preferably has the central hole 2 eccentric by 0 mm, that is, strictly centered, to avoid asymmetrical halo caused by eccentricity.

[0031] The present invention further preferably sets the long axis of the central hole 2 along the horizontal meridian (0°) to reduce subjective discomfort from the halo.

[0032] In existing intraocular lenses, refraction and total internal reflection occur at the interface between the inner wall of the central aperture and the aqueous humor at the edge of the aperture. Light is scattered to the surrounding area, resulting in a visually perceived disc-shaped or ring-shaped structure with relatively clear boundaries and regular shape. Based on this, the present invention preferably provides a connected beveled chamfer structure 3 and a rounded transition structure 4 at the edge of the central aperture 2 to eliminate sharp edge diffraction point sources and reduce Fresnel reflection and interface stray light. Furthermore, it is preferred that the beveled chamfer structure 3 is a double-sided structure, that is, both the front and rear surface edges of the central aperture 2 are provided with a 45° beveled chamfer.

[0033] The present invention preferably uses a 45° chamfer angle for the beveled structure 3 to avoid the formation of a vertical reflective surface at the edge of the aperture and reduce Fresnel reflection. Specifically, when the chamfer angle is 45°, after the vertically incident light is reflected by the chamfered surface, the reflected light deviates from the central imaging area of ​​the retina (the reflection angle is 45° to the incident angle, and stray light is guided to the periphery of the retina, reducing the subjective perception of halo). At the same time, 45° is the angle most easily achieved in microfabrication technology (no special tooling is required) and is compatible with the thin structure of ICL crystals, so that the edge strength of the crystal will not decrease due to an excessively large chamfer angle.

[0034] The present invention preferably has a beveled chamfer structure 3 with a width of 28-32 μm (i.e., extending 28-32 μm from the edge of the hole into the crystal), and more preferably has a width of 30 μm. The chamfered surface is smooth and burr-free. The width of the beveled chamfer structure 3 is calculated based on the chamfer angle and the crystal thickness. The chamfer width is set to 30 μm to ensure that the chamfer can completely cover the sharp edge of the hole (eliminating diffraction point sources) without excessively occupying the effective optical area of ​​the crystal. At the same time, it avoids the reduction of the equivalent flow area of ​​the central hole 2 due to the chamfer being too wide, thereby affecting the aqueous humor circulation.

[0035] The radius (R) of the arc transition structure 4 is preferably 23-27 μm, and more preferably 25 μm. That is, the connection between the chamfer and the hole wall and the crystal surface adopts an arc transition of R=25 μm to eliminate all sharp edges and avoid the generation of diffraction point sources. The arc transition structure 4 is set to eliminate the secondary sharp edges between the chamfer and the hole wall and the crystal surface, and further suppress diffraction. This R value can make the hole edge form a smooth transition, reduce the scattering of light at the edge, and match the chamfer width to avoid the problem that the rounded corner is too small to eliminate the sharp edge, or too large to cause the hole wall structure to be weak.

[0036] In this invention, as verified by Zemax simulation, the combination of 45° chamfer + 30 μm width + 25 μm rounded corner can reduce stray scattering and Fresnel reflection at the aperture edge by ≥50%, and is compatible with existing ICL micromachining technology (accuracy up to ±1 μm), taking into account both optical effect and mass production feasibility.

[0037] Besides diffraction, edge refraction, and reflection, phase difference is also a significant cause of postoperative halos in existing intraocular lenses (IOLs). In existing IOLs, light passing through the aqueous humor and the lens material itself experiences an optical path difference before reaching the retina, leading to phase discontinuities and further enhancing the contrast and visibility of the halo in visual perception. Therefore, this invention preferably features an annular phase compensation step 5 around the central aperture 2. This annular phase compensation step 5 serves as a phase compensation structure to resolve optical path difference interference.

[0038] In this invention, the annular phase compensation step 5 is preferably concentric with the central hole 2, and preferably located within an annular region 0.8-1.2 mm outside the central hole 2, and even more preferably located within an annular region 1.0 mm outside the central hole 2. Specifically, the annular phase compensation step 5 is preferably set on the front surface of the crystal, within an annular region outside the central hole 2. This annular region is concentric with the central hole 2, has an inner radius of 0.19 mm (half the length of the major axis of the central hole 2), an outer radius of 1.19 mm (inner radius + 1.0 mm), and an annular region width of 1.0 mm.

[0039] Specifically, the step parameters of the annular phase compensation step 5 selected in this invention are as follows: the step height of the annular phase compensation step 5 is 0.43-0.47 μm (along the crystal thickness direction, the upper surface of the step is parallel to the front surface of the crystal, the lower surface is perpendicular to the side of the step, the step surface is smooth, and it is seamlessly connected to the Collamer body to compensate for the optical path difference between the aqueous humor and the Collamer), and more preferably 0.45 μm (adapted to λ / 4-level phase compensation for a visible light center wavelength of 550 nm); preferably, the annular phase compensation step 5 is a single step, and the step width of the annular phase compensation step 5 is 0.13-0.17 mm (radial), and more preferably 0.15 mm; the annular phase compensation step 5 is used to compensate for the optical path difference between the aqueous humor (n≈1.336) and the Collamer (n≈1.46) and suppress interference halos; specifically, the core of phase compensation is: the optical path difference generated by the step height cancels out the optical path difference between the aqueous humor and the Collamer. The inherent optical path difference between the two beams causes them to superimpose in phase on the retina.

[0040] The inherent optical path difference analysis is as follows: Let the thickness of the ICL through which the light rays pass perpendicularly be d, the optical path through the Collamer be n2×d, and the optical path through the aqueous humor be n1×d. The inherent optical path difference between the two is Δ = (n2- n1)×d. To simplify the calculation and adapt to mass production processes, "λ / 4 level compensation" (the most commonly used and most stable phase compensation method) is adopted, that is, the optical path difference generated by the step is λ / 4, which can completely cancel the influence of the inherent optical path difference.

[0041] The core calculation formula for the step height h is as follows: The step is made of Collamer material. When light passes through the step, the additional optical path difference is (n² - 1) × h (air refractive index ≈ 1, the step height is the additional Collamer thickness). Combining the λ / 4 compensation target, let: (n² - 1) × h = λ / 4. Substituting the parameters, we get: λ = 550nm = 0.55μm; n² = 1.46; Derivation: h =λ / [4×(n2-1)] = 0.55 / [4×(1.46 - 1)] = 0.55 / (4×0.45) ≈0.305μm; In the above formula, the actual calculation needs to correct the "optical path difference superposition". Taking into account the thickness of the ICL crystal and the aqueous humor filling scenario, the final value after correction is 0.45μm, which is consistent with simulation and clinical verification.

[0042] Specifically, the actual ICL central hole 2 is a through hole (filled with aqueous humor). When light passes through the central hole, there is no Collamer obstruction. However, the phase compensation step is located on the Collamer surface, and it is necessary to compensate for the optical path effect of the refractive index difference between the Collamer and the aqueous humor, plus the thickness of the step itself. In clinical and simulation verification, the step height is set to 0.45μm. According to Zemax / CodeV simulation verification, this height can reduce the contrast of the phase difference interference fringes by ≥60%, which fully meets the anti-halo requirements. In terms of process adaptation, 0.45μm is a micron-level precision, which can be achieved through existing ICL micromachining technology, matching the precision of the hole edge rounded corners and chamfers, taking into account both performance and mass production feasibility.

[0043] The present invention preferably uses a material for the intraocular lens body 1 made of collagen and hydrophilic acrylate polymer. Specifically, the intraocular lens body 1 is preferably made of Collamer material or Collamer-like material. The central thickness of the intraocular lens body is preferably 0.28-0.32 mm, the refractive index of the lens material is 1.44-1.46, and the Abbe number is 50-55.

[0044] The present invention preferably provides a refractive index matching coating on the wall of the central hole 2; the refractive index of the refractive index matching coating is 1.33-1.35, more preferably 1.34, and the thickness of the refractive index matching coating is preferably 80-100nm to match the refractive index of aqueous humor, and the interface reflectivity of the coating is ≤0.5%.

[0045] The refractive index matching coating adheres tightly to the hole wall, and the coating surface is in contact with the aqueous humor, achieving refractive index matching between the coating and the aqueous humor (coating n=1.34, aqueous humor n=1.336), thus reducing interface reflection.

[0046] The preferred material for the refractive index matching coating in this invention is a hydrophilic hydrogel / plasma-deposited SiO₂. x A modification layer was applied to reduce the interface reflectivity from 4% to <0.5%.

[0047] The present invention preferably includes an optical region 11 in the intraocular lens body 1, the diameter of which is 5.5-6.1 mm, more preferably 6.1 mm; preferably, a transition zone 12 is provided at the edge of the optical region 11, the transition zone 12 being a gradually changing aspherical transition zone; preferably, the width of the transition zone 12 is 0.28-0.32 mm, more preferably 0.3 mm, to ensure that the coverage of the pupil in dark light is ≤6.5 mm, and to avoid additional halo generation at the pupil cut-off edge.

[0048] Specifically, the present invention preferably uses an intraocular lens in the form of a thin lens; the main body material is Collamer with a refractive index of 1.45, the optical zone diameter is 6.1 mm, and a 0.3 mm gradually changing aspherical transition zone is set at the edge of the optical zone. The transition zone smoothly transitions from the edge of the optical zone to the non-optical zone of the lens without obvious steps; a near-circular micro-elliptical central hole is opened at the center of the lens. The longitudinal section of the hole is a symmetrical ellipse with a major axis (horizontal direction) length of 0.38 mm and a minor axis (vertical direction) length of 0.36 mm. The hole penetrates the front and rear surfaces of the lens and is filled with aqueous humor (refractive index 1.336).

[0049] A near-circular micro-elliptical central hole is formed at the center of the crystal. The longitudinal section of the hole is a symmetrical ellipse, with a major axis (horizontal direction) of 0.38 mm and a minor axis (vertical direction) of 0.36 mm. The hole penetrates the front and rear surfaces of the crystal and is filled with aqueous humor (refractive index 1.336). The parameters of the intraocular lens in this invention are determined based on the core objectives of "suppressing sharp-edge diffraction and reducing interface reflection," combined with the ICL processing precision, aqueous humor circulation safety, and optical performance requirements.

[0050] In summary, this invention reduces subjective halo perception by designing the central hole 2 as a micro-ellipse to lower the symmetrical diffraction ring and guide stray light to the periphery of the retina; by setting a beveled chamfered structure 3, the angle of which deflects reflected light away from the imaging area, and by using its width to match the thickness of the crystal edge, sharp edge diffraction is eliminated; by setting an arc transition structure 4, with its radius ≥ 80% of the chamfer width, secondary sharp edges are eliminated, further suppressing edge scattering; by setting a ring-shaped phase compensation step 5, based on the 550nm visible light λ / 4 compensation principle and combined with the calculation of the refractive index difference between aqueous humor and Collamer, the optical path difference is compensated, reducing the contrast of interference fringes by ≥ 60%; by setting a refractive index matching coating to match the refractive index of aqueous humor, the interface reflectivity is reduced to < 0.5%; and by limiting the diameter of the optical zone 11, the dark pupil is covered by ≤ 6.5mm, avoiding additional halo generated by the pupil cut edge.

[0051] Compared with the prior art, the artificial lens provided by this invention reduces the intensity of stray light diffraction at the central aperture by ≥50%, reduces edge stray light and Fresnel scattering by ≥65%, reduces the contrast of phase difference interference fringes by ≥60%, reduces the expansion of Airy disk at the aperture edge by ≥8%, and reduces the subjective halo score (VAS) by ≥45%.

[0052] Based on the above-described preferred embodiments of the present invention, and through the foregoing description, those skilled in the art can make various changes and modifications without departing from the inventive concept. The technical scope of this invention is not limited to the contents of the specification, but must be determined according to the scope of the claims.

Claims

1. An artificial lens, characterized in that, It includes an artificial lens body (1) and a central hole (2) located at the center of the artificial lens body (1); the central hole (2) is an elliptical hole.

2. The intraocular lens as described in claim 1, characterized in that, The major axis of the central hole (2) is 0.38±0.01mm and the minor axis is 0.36±0.01mm.

3. The intraocular lens as described in claim 2, characterized in that, The long axis of the central hole (2) is set along the horizontal meridian direction.

4. The intraocular lens as described in claim 1, characterized in that, The edge of the central hole (2) is provided with a connected chamfered structure (3) and a rounded transition structure (4); the chamfered structure (3) is a double-sided structure.

5. The intraocular lens as described in claim 4, characterized in that, The angle of the beveled structure (3) is 45°.

6. The intraocular lens as described in claim 4, characterized in that, The width of the beveled structure (3) is 28-32 μm.

7. The intraocular lens as described in claim 4, characterized in that, The radius of the circular arc transition structure (4) is 23-27 μm.

8. The intraocular lens as described in claim 1, characterized in that, An annular phase compensation step (5) is provided around the central hole (2).

9. The intraocular lens as described in claim 8, characterized in that, The annular phase compensation step (5) is located in an annular area 0.8-1.2 mm outside the central hole (2).

10. The intraocular lens as described in claim 8, characterized in that, The step height of the annular phase compensation ladder (5) is 0.43-0.47 μm.

11. The intraocular lens as described in claim 8, characterized in that, The step width of the annular phase compensation step (5) is 0.13-0.17 mm.

12. The intraocular lens according to any one of claims 1-11, characterized in that, The material of the artificial lens body (1) is polymerized from collagen and hydrophilic acrylate.

13. The intraocular lens as described in claim 12, characterized in that, The wall of the central hole (2) is provided with a refractive index matching coating; the refractive index of the refractive index matching coating is 1.33-1.

35.

14. The intraocular lens according to any one of claims 1-11, characterized in that, The artificial lens body (1) includes an optical region (11) with a diameter of 5.5-6.1 mm.

15. The intraocular lens as described in claim 14, characterized in that, The edge of the optical area (11) is provided with a transition zone (12); the width of the transition zone (12) is 0.28-0.32 mm.

Images