NOVEL REFRACTIVE EDOF INTRAOCULAR LENS FOR CONTINUOUS VISION

Abstract

The lens of invention has been proven most suitable for the cataract patients. The invention provides extended depth of focus to get continuous vision from far to near distance up to closer distances. The third zone 60 degree segment design of invention is to provide balanced energy distribution at larger pupil diameter and the controlled spherical aberration at each zone provides minimalistic glares and halos. Further the EDOF IOL balances the nominal power and provide pupil independence further optimizing energy distribution in each annular zone to maintain the good contrast irrespective of the pupil size and light condition. Further, zonal modification in the IOL can be used as a controllable switch to change the depth of focus according to the requirement, viz. from distant to near vision or distant to intermediate vision.

Claims

1. A refractive EDOF IOL comprising: a tangible circuit configured to and/or capable of providing extended depth of focus to get continuous vision from far to near distance up to closer distances.

2. The refractive EDOF-IOL according to claim 1, wherein said refractive EDOF-IOL or said circuit is a fourth zone 60-degree segment design to be configured to and/or capable of providing a balanced energy distribution without compromising a depth of focus at larger pupil diameter like scotopic condition.

3. The refractive EDOF-IOL according to claim 2, wherein zonal modification in the IOL is used as a controllable switch to change the depth of focus according to a requirement, viz. from distant to near vision or distant to intermediate vision.

4. The refractive EDOF-IOL according to claim 3, wherein said circuit is further configured to and/or capable of minimizing glares and halos by providing controlled spherical aberration at each zone.

5. The refractive EDOF-IOL according to claim 4, wherein said circuit is further configured to and/or capable of balancing nominal power or distance vision power and providing pupil independence.

6. The refractive EDOF IOL according to claim 5, wherein said circuit is further configured to and/or capable of maintaining optimized energy distribution in each annular zone to a predetermined contrast irrespective of pupil size and light conditions.

7. The refractive EDOF IOL according to claim 6, wherein said circuit is further configured to and/or capable of providing the vision at functional intermediate distance and functional near distance at any pupil size irrespective of the light condition, which are missing the traditional multifocal IOLs and monofocal IOLs.

8. The refractive EDOF IOL according to claim 7, further comprising: lens configured to and/or capable of providing balanced light distribution and maintaining the depth of focus along with the image quality and contrast due to the introduction of concentric 60 degree segmented circular zone design.

9. The refractive EDOF IOL according to claim 8, wherein EDOF-IOL anterior surface peripheral zone is given negative curvature by said circuit in order to reduce the central thickness whereby reduced central thickness is useful during unfold of the lens after passing through the small incision during implantation.

10. The refractive EDOF-IOL according to claim 1, wherein zonal modification in the IOL is used as a controllable switch to change the depth of focus according to a requirement, viz. from distant to near vision or distant to intermediate vision.

11. The refractive EDOF-IOL according to claim 1, wherein said circuit is further configured to and/or capable of minimizing glares and halos by providing controlled spherical aberration at each zone.

12. The refractive EDOF-IOL according to claim 1, wherein said circuit is further configured to and/or capable of balancing nominal power or distance vision power and providing pupil independence.

13. The refractive EDOF IOL according to claim 1, wherein said circuit is further configured to and/or capable of maintaining optimized energy distribution in each annular zone to a predetermined contrast irrespective of pupil size and light conditions.

14. The refractive EDOF IOL according to claim 1, wherein said circuit is further configured to and/or capable of providing the vision at functional intermediate distance and functional near distance at any pupil size irrespective of the light condition, which are missing the traditional multifocal IOLs and monofocal IOLs.

15. The refractive EDOF IOL according to claim 1, further comprising: lens configured to and/or capable of providing balanced light distribution and maintaining the depth of focus along with the image quality and contrast due to the introduction of concentric 60 degree segmented circular zone design.

16. The refractive EDOF IOL according to claim 1, wherein EDOF-IOL anterior surface peripheral zone is given negative curvature by said circuit in order to reduce the central thickness whereby reduced central thickness is useful during unfold of the lens after passing through the small incision during implantation.

Description

BRIEF DESCRIPTION OF DRAWINGS OF INVENTION

[0022] FIG. 1 represents the anterior surface of the invention.

[0023] FIG. 2 represents the posterior surface of the invention.

[0024] FIG. 3 represents the main parts of the intraocular lens

[0025] FIG. 4 describes the concentric annular zones in the invention.

[0026] FIG. 5 describes about the 60-degree arc segments in the fourth zone represented with the part number 7 in FIG. 4 of the invention.

[0027] FIG. 6 describes about the posterior surface square edge of EDOF IOL design.

[0028] FIG. 7 & FIG. 8 explains about the power distribution/optical output result (autofocus scan) of the invention with optimized circular zones.

DETAILED DESCRIPTION OF INVENTION

[0029] The following paragraphs describes about the design of EDOF IOL and its outcomes and advantages of the design. The subject matter is explained with the drawings at required places, where in like reference numerals are used.

[0030] The present invention of intraocular lens is called extended depth of focus Intraocular lens (EDOF IOL) to provide the continuous vision. This lens offers clear vision from far distance to near distance up to closer distances. This new additional feature is providing a near vision along with intermediate vision. Further, zonal modification in the IOL can be used as a controllable switch to change the depth of focus according to the requirement, viz. from distant to near vision or distant to intermediate vision.

[0031] The refractive EDOF property is achieved based on the principle of refraction. Refraction is the bending of light ray when passing through one medium to another medium. The bending of light rays is proportional to the curvature of the medium, in which light rays are entering and exit from the medium. Based on this principle the present invention is developed.

[0032] The present invention refractive EDOF IOL is related to intraocular lenses, which are used in the cataract surgery. This refractive EDOF lens is developed with hydrophobic or hydrophilic acrylic material having the refractive index of 1.40-1.6. The EDOF intraocular lens design is having single piece structure as described in the FIG. 1. The front surface of the intraocular lens, called, anterior surface of the invention. This surface is the main objective of this invention, having the controllable refractive circular zones and 60 degree refractive segments in one of the concentric refractive circular zone to provide the continuous vision. The posterior surface of the invention is represented by FIG. 2, have the single radius of curvature for entire posterior surface.

[0033] The part number 1 in the FIG. 3 represents the optic portion of the intraocular lens, which is responsible for the light ray refraction and continuous vision inside the eye. The part number 2 & 3 represents the modified C type haptics of the intraocular lens. The modified C type haptics provides maximum contact angle with the capsular bag, which provides the better rotational stability in the eye.

[0034] FIG. 4 shows the center optic portion of the intraocular lens having the innovative design to provide extended depth of focus to see the objects from far distance to near distance with continuous vision. The center optic portion having five concentric annular refractive zones represented with the part numbers 4 to 9 as shown in FIG. 4 with in the 4.7 mm clear optic zone on the anterior surface of the optic portion. The peripheral zone as shown in part number 9 has been given negative curvature to the IOL anterior surface to control the thickness of the lens to fold and unfold easily during the implantation of the IOL by using micro incision process.

[0035] The part numbers 11 to 15 shown in FIG. 5 represents the 60 degree refractive segments in the fourth zone from the center of the invention to balance the energy distribution at larger pupil diameters as shown in the FIG. 4 part number 7. By, zonal modification in the IOL can be used as a controllable switch to change the depth of focus according to the requirement, viz. from distant to near vision or distant to intermediate vision.

[0036] Spherical aberration of the lens plays very important role in the optics. When light rays passing through the lens system, paraxial light rays and marginal light rays focus at different focal points on the optic axis, instead of focusing at a single point. In case of negative spherical aberration, marginal light rays refract less and focus far away from the lens surface and in the positive spherical aberration, marginal light rays refract more and focus near by the lens surface. By using this principle, the energy is distributed between the required powers uniformly and provides the extended depth of focus continuously with reduced glare and halos.

[0037] The part number 16 in FIG. 6 represents the posterior surface side view. The part number 17 represents the 360 degree posterior surface square edge of the intraocular lens. The design of the square edge will provide proper shrinkage of the capsular bag with the posterior surface of the intraocular lens and prevent the early stage PCO (Posterior Capsular Opacification).

[0038] In the design and development of invention, Hydrophobic or hydrophilic materials are used with variable range of refractive index 1.4-1.6. During the development of the invention, the size of the optic portion has been taken 6 mm with 13.0 mm overall diameter. The optic size and overall diameter of the proposed IOL can be varied as per requirement and it won't affect the optical performance of the depth of focus of the IOL. By using above mentioned methodology, around 3.5 D depth of focus has been achieved by optimizing the zone radius and power distribution on the concentric circular zones. The optimization of the zone diameters and power distribution on the concentric circular zones allow us to achieve desired depth of focus for intermediate distance to near distance visual activities along with far distance.

[0039] Optical Material: Hydrophobic or Hydrophilic material

[0040] Refractive Index: 1.40-1.6

[0041] Optic Surface: Aspheric

[0042] Optical Size of the IOL: 6 mm

[0043] Number of concentric refractive circular zones in the clear optic area: 5 (in the clear optic zone).

[0044] The invention of the Refractive EDOF IOL gives satisfactory results on the optical bench performance. Continuous and extended depth of focus observed in the output result from 1.0 D to 3.5 D. FIG. 7 represents the more than 2.0 D depth of field of the of the intraocular lens by using Modulation Transfer Function (MTF) curve and FIG. 8 represents the more than 3.0 D depth of field of the intraocular lens by using MTF curve. The Modulation Transfer Function (MTF) curve in the FIGS. 7 & 8 shows the energy distribution of the IOL at 3 mm aperture size. The achieved depth of field is useful to see the objects from far distance to intermediate distance as shown in the FIG. 7 and far distance to near distance as shown in the FIG. 8 for daily activities.

[0045] The present invention relates to intraocular lens (IOL) with extended depth of focus, which helps in providing adequate vision for far objects to near objects with minimized glares and halos. The main advantage of the present invention refractive EDOF intraocular lens is to provide extended depth of focus to get continuous vision from far distance to near distance. The optimized power distribution on each concentric circular zone and controlled zone width provides the continuous range of vision for daily activities. Controlled spherical aberration and 60 degree refractive segments in the fourth zone makes the nominal power independent from the pupil size (eye pupil) and minimize haloes and glares in the visual acuity of the patient after implanting the lens in the eye.