Refractive EDOF intraocular lens for continuous vision

Abstract

To provide an extended depth of focus (EDOF) that provides a cataract patient with continuous vision from distance to near with minimal halo and glare, and an intraocular lens (IOL) that achieves continuous vision.SOLUTION: To obtain continuous vision from a long distance to a short distance near 40-35cm by providing the extension of a focal depth. The spherical aberration of each zone of the anterior surface of the intraocular lens is optimized to minimize halo and glare. The fourth zone 60 degree segment design of the present invention provides a balanced energy distribution at large pupil diameters and makes the lens pupil independent of power distribution. The lens power and its extended depth of focus are independent of pupil size and lighting conditions. Furthermore, the change of zone of the intraocular lens can be used as a controllable switch to change the depth of focus according to the demand from far vision to near vision or from far vision to intermediate vision.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to intraocular lenses. More specifically, the present invention relates to an intraocular lens (IOL) that provides continuous vision, extended depth of focus (EDOF), and more importantly, near to distance vision, helping cataract patients achieve adequate continuous vision from distance to near objects while minimizing halos and glare. Furthermore, the zonal modification of the IOL can be used as a controllable switch to change the depth of focus on demand, from distance to near vision or from distance to intermediate vision. [Background technology]

[0002] The natural lens has the ability to adjust its curvature, resulting in a focal length that can be adjusted according to the distance of an object imaged on the retina. However, after cataract surgery, an implanted intraocular lens functions like a natural lens but is limited in its range of vision. This is because its focal length and aperture are fixed and cannot be adjusted according to the distance of an object like a natural lens. As a result, people with implanted intraocular lenses cannot see beyond the visual acuity limit of the lens. Therefore, people with this type of intraocular lens must wear prescription glasses to see objects at other distances. For example, implanted monofocal intraocular lenses are generally suitable for viewing distant objects, but prescription glasses are required for intermediate and close-up viewing (for reading). This is due to the fixed focal length and aperture of the intraocular lens. The novel invention is an extended depth of focus (EDOF) intraocular lens that allows for continuous vision from near to far objects without the need for prescription eyeglasses. Prior art document US20030199976A1 relates to a narrow-profile, glare-reducing, posterior chamber intraocular lens comprising an optical system having an anterior surface, a posterior surface, and an optical axis. The posterior surface is formed with two adjacent axially stepped imaging zones, the two imaging zones having substantially the same optical power. The transition zone between the two imaging zones preferably has a surface of continuous curvature and is formed to reduce direct glare from light incident on the transition zone of the intraocular lens. In a variant, the transition zone is formed at the visual rim to minimize direct and indirect glare in the eye of an individual wearing the intraocular lens. Prior art documents describe progressive refractive lenses, with an optical power difference between distance and near vision of 2.5D, while other prior art documents describe refractive sector lenses, which do not have revolutionary profiles. One prior document describes aberration-corrected progressive lenses, which compensate for the aberrations caused by the cornea. Another prior patent describes the use of an opaque mask on an intraocular lens to induce a stenopic effect and improve depth of field. Various techniques, such as the bull's-eye principle with a higher-power central zone, have previously been used to extend depth of field. Furthermore, U.S. Patent No. US005864380A describes an intraocular lens design that provides clear vision up to a certain distance, but is particularly useful for near work. Another patent, U.S. Patent No. US9201250B2, describes a design used to reduce or treat refractive errors from far to near without significant ghosting. Other patents have described few opaque masks that induce a tunnel vision effect, but none have described multifocal planes or variable transmittance that is greatest in the center of the intraocular lens and least in the periphery. The patents claim that the varying transmittance can increase the lens's depth of field. Yet another prior art document describes the use of a phase-contrast mask to increase the depth of focus to 3.0D. All of these intraocular lenses offer limited solutions, as described above. Thus, all of the above prior art techniques fail to provide an intraocular lens for continuous vision with extended depth of focus, which is essential for viewing from distant to close objects with minimal glare and halation. Summary of the Invention

[0003] The lenses of the present invention have proven ideal for cataract patients. Cataracts are an age-related eye disease that causes the lens to lose its transparency, resulting in clouded vision. During cataract surgery, doctors remove the inner lens, which causes clouded vision, and then implant an intraocular lens. The implanted intraocular lens provides visual acuity similar to that of the natural lens in the human eye. The present invention extends the depth of focus, providing continuous vision from far to near, as well as intermediate-distance objects, while minimizing glare and halation. Furthermore, the zonal modification of the intraocular lens can be used as a controllable switch to change the depth of focus on demand, from far to near vision or from far to intermediate vision. The primary purpose of the refractive-correcting EDOF intraocular lens of the present invention is to extend the depth of focus and provide continuous vision from far to near. Another main objective of the refractive EDOF intraocular lens of the present invention is the fourth zone 60-degree segment design to provide a balanced energy distribution without compromising depth of focus at large pupil diameters such as in scotopic conditions. Another object of the present invention is to use the zonal modification of the intraocular lens as a controllable switch to change the depth of focus depending on the need for distance to near vision or distance to intermediate vision. Another primary objective of the refractive EDOF-IOL of the present invention is to minimize glare and halo by providing controlled spherical aberration in each zone. Additionally, this EDOF-IOL balances nominal or distance vision and provides pupil independence. Another primary goal of EDOF intraocular lenses is to optimize the energy distribution in each annular zone to maintain good contrast regardless of pupil size or lighting conditions. Another primary purpose of EDOF IOLs is to provide functional intermediate and near vision at any pupil size, regardless of lighting conditions, something that is lacking in conventional multifocal and monofocal IOLs. Additionally, the lens introduces a concentric 60-degree divided circular zone design to provide balanced light distribution and maintain depth of field along with image quality and contrast. Additionally, the anterior peripheral portion of this EDOF-IOL has a negative curvature to reduce its central thickness, which aids in lens deployment after passing through a small incision during implantation. [Brief explanation of the drawings]

[0004] [Figure 1] FIG. 1 shows the front face of the present invention. [Figure 2] FIG. 2 shows the rear view of the present invention. [Figure 3] FIG. 3 shows the main parts of an intraocular lens. [Figure 4] FIG. 4 depicts the concentric annular zones of the present invention. [Figure 5] FIG. 5 is a diagram illustrating the 60-degree arc segment of the fourth zone represented by reference numeral 7 in FIG. 4 of the present invention. [Figure 6] FIG. 6 is a diagram illustrating the posterior square edge of the EDOF intraocular lens design. [Figure 7] FIG. 7 illustrates the power distribution / optical output results (autofocus scan) of the present invention with optimized circular zones. [Figure 8] FIG. 8 illustrates the power distribution / optical output results (autofocus scan) of the present invention with optimized circular zones. BEST MODE FOR CARRYING OUT THE INVENTION

[0005] The following paragraphs describe the design of the EDOF intraocular lens and its accomplishments and advantages. This subject matter is illustrated by the drawings where necessary, and like reference numerals are used. The intraocular lens of the present invention, called an extended depth of focus intraocular lens (EDOF IOL), provides continuous vision. This intraocular lens provides clear vision from far to near distances. This new added functionality provides near vision along with intermediate vision. Furthermore, the zonal modification of the intraocular lens can be used as a controllable switch to change the depth of focus on demand, from far to near vision or from far to intermediate vision. The refractive EDOF characteristics are achieved based on the principle of refraction. Refraction is when a ray of light passing through one medium is bent into another medium. The bending of the ray of light is proportional to the curvature of the medium into which the ray enters and the medium into which it exits. This invention was developed based on this principle. The EDOF intraocular lens of the present invention is an intraocular lens used in cataract surgery. This EDOF intraocular lens was developed using a hydrophobic or hydrophilic acrylic material with a refractive index of 1.40-1.6. The EDOF intraocular lens has a single-piece structure as shown in Figure 1. The anterior surface of the intraocular lens is referred to as the anterior surface of the present invention. This surface, which is the main focus of the present invention, has a controllable refractive circular zone and a 60-degree refractive segment in one of the concentric refractive circular zones to provide continuous vision. The posterior surface of the present invention is represented in Figure 2 and has a single radius of curvature for the entire posterior surface. In Figure 3, reference numeral 1 denotes the optical part of the intraocular lens, which is responsible for refracting light rays and providing continuous vision within the eye. Reference numerals 2 and 3 denote the improved C-type haptics of the intraocular lens. The improved C-type haptics maximize the contact angle with the capsular bag and improve rotational stability within the eye. Figure 4 shows the central target portion of an intraocular lens with an innovative design that extends depth of focus for continuous vision from distance to near. The central target portion has five concentric annular refractive zones, designated 4 through 9 as shown in Figure 4, within a 4.7 mm clear target zone on the front surface of the target portion. The peripheral zone, designated 9, imparts a negative curvature to the anterior surface of the intraocular lens, controlling the thickness of the lens so that it can be easily folded and unfolded during implantation using a microincision process. Reference numerals 11 to 15 in Figure 5 represent the 60 degree refractive segments in the fourth central zone of the present invention to balance the energy distribution at larger pupil diameters, as shown by reference numeral 7 in Figure 4. This allows the zonal change of the intraocular lens to be used as a controllable switch to change the depth of focus on demand, from distance to near vision or from distance to intermediate vision. Spherical aberration in lenses plays a very important role in optics. Light rays passing through a lens system do not converge to a single point, but rather to different focal points along the visual axis. In the case of negative spherical aberration, peripheral rays have a smaller refractive index and are focused farther from the lens surface, while in the case of positive spherical aberration, peripheral rays have a larger refractive index and are focused closer to the lens surface. By utilizing this principle, energy is uniformly distributed between the required powers, reducing glare and halos while continuously expanding the depth of focus. In Figure 6, reference numeral 16 denotes the posterior surface. Reference numeral 17 denotes the square edge of the 360-degree posterior surface of the intraocular lens. The square edge design allows for proper contraction of the posterior surface of the intraocular lens and the capsular bag, preventing early PCO (posterior capsular occlusion). In the design and development of this invention, hydrophobic or hydrophilic materials with refractive indices ranging from 1.4 to 1.6 were used. During the development of this invention, the optic size was set at 6 mm and the overall diameter at 13.0 mm. The size and overall diameter of the optic portion of the proposed intraocular lens can be varied as required without affecting the optical performance of the intraocular lens in terms of depth of focus. Using the above method, a depth of focus of approximately 3.5D was achieved by optimizing the concentric zone radius and power distribution. By optimizing the concentric zone radius and power distribution, the desired depth of focus can be achieved not only for distance vision but also for medium- to near-distance vision activities. Optical materials: Hydrophobic or hydrophilic materials Refractive index: 1.40-1.6 Optical surface Aspherical surface Intraocular lens size: 6mm Number of concentric refractive index circular zones: 5 (in the Clear Optic Zone)

[0006] The invention of the refractive EDOF intraocular lens has yielded satisfactory results in optical bench performance. A continuous and extended depth of field was observed from 1.0D to 3.5D output results. Figure 7 shows the modulation transfer function (MTF) curve for the IOL's depth of field of 2.0D or greater, and Figure 8 shows the MTF curve for the IOL's depth of field of 3.0D or greater. The modulation transfer function (MTF) curves in Figures 7 and 8 represent the energy distribution of the IOL at a 3mm aperture size. The achieved depth of field is useful for viewing objects in daily life, from far to intermediate distances as shown in Figure 7, and from far to near distances as shown in Figure 8. The present invention relates to an intraocular lens (IOL) with extended depth of focus, which helps provide sufficient vision from distant to near objects while minimizing glare and halos. The primary benefit of the present EDOF intraocular lens is the extended depth of focus for continuous vision from far to near. The power distribution of each concentric zone is optimized and the zone widths are controlled, providing continuous vision in everyday life. By controlling spherical aberration and providing a 60° refractive segment in the fourth zone, the nominal power is independent of pupil size (pupil), minimizing halos and glare in the patient's vision after the lens is inserted into the eye.

Claims

1. A novel refractive power EDOF intraocular lens for continuous vision, comprising: a posterior segment having a single radius of curvature throughout the posterior surface (16) and a 360-degree square edge (17) to prevent early PCO (secondary cataract); an anterior segment with a refractive circular zone (1) and a peripheral zone (9) with negative curvature to control the thickness of the lens and allow it to be easily folded and unfolded; Optional sections for light diffraction and intraocular continuous vision; Improved C-type haptics (2, 3) maximize the contact angle with the capsular bag to improve rotational stability of the eyeball. a central optic nerve portion comprising five concentric annual refractive zones (4, 5, 6, 7, 8), characterized in that the fourth zone (7) from the center of the intraocular lens comprises a 60-degree refractive segment (10, 11, 12, 13, 14, 15) to balance the energy distribution at large pupil diameters; The intraocular lens zone change is a controllable switch for changing the depth of focus.

2. A novel refractive power EDOF intraocular lens for continuous vision according to claim 1, wherein the size of the optical zone is 6 mm and the diameter of the entire intraocular lens is 13.0 mm.

3. A novel refractive power EDOF intraocular lens for continuous vision according to claim 1, wherein said intraocular lens is selected from hydrophobic or hydrophilic acrylic materials with a refractive index of 1.40-1.

6.

4. 10. A novel refractive power EDOF intraocular lens for continuous vision according to claim 1, wherein said intraocular lens minimizes glare and halos by providing controlled spherical aberration in each refractive zone (4, 5, 6, 7, 8).

5. A novel refractive power EDOF intraocular lens for continuous vision according to claim 1, wherein the negative spherical aberration and the positive spherical aberration distribute the energy evenly between the required powers and continuously extend the depth of focus.

6. 10. A novel refractive power EDOF intraocular lens for continuous vision according to claim 1, wherein the intraocular lens balances nominal or distance vision and provides pupil independence along with continuous vision.

7. A novel refractive power EDOF intraocular lens for continuous vision according to claim 1, wherein the annual refractive zones (4, 5, 6, 7, 8) are configured with an optimized energy distribution to maintain good contrast regardless of pupil size or lighting conditions, providing continuous vision.

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