WO2018037356A1

WO2018037356A1 - Ophthalmic lenses with aspheric optical surfaces and method for their manufacture

Info

Publication number: WO2018037356A1
Application number: PCT/IB2017/055086
Authority: WO
Inventors: Vladimir Stoy; Roman CHALOUPKA; Tomas Drunecky
Original assignee: Medicem Ophthalmic (Cy) Limited
Priority date: 2016-08-23
Filing date: 2017-08-23
Publication date: 2018-03-01

Abstract

Implantable lenses are disclosed, made from at least one transparent material and having at least anterior and posterior optical surface from the viewpoint of their intended 5 position in the eye, comprising at least one smooth, continuous refractive surface or interface between materials with different refractive indices, wherein at least one of those surfaces or interfaces is defined by a function Z(ρ,θ) in cylindrical coordinate system (z, ρ, θ) such that Z(ρ,θ) = (ρ²)/{R(ρ,θ)∗(1+ [1-K(ρ,θ)∗(ρ/ R(ρ,θ))²]^0.5 }.

Description

OPHTHALMIC LENSES WITH ASPHERIC OPTICAL SURFACES AND METHOD

FOR THEIR MANUFACTURE

CROSS-REFERENCE TO RELATED APPLICATIONS This application claims the benefit of the priority of U.S. Provisional Patent

Application No. 62/378,375, filed August 23, 2016, the disclosure of which is incorporated herein by reference.

FIELD OF THE INVENTION

The present invention relates to aspheric implantable lenses from at least one optically transparent material with a main optical axis and at least two opposite optical surfaces or interfaces, at least one of them being a smooth optical surface or optical interface between two transparent materials that can be described by an aconic function.

BACKGROUND OF THE INVENTION

There is a long-term quest in ophthalmic surgery to improve human vision by improving optical quality of the eye by replacing or supplementing natural optical elements of the eye (primarily the cornea and the lens) by artificial lenses. Optical properties of such lenses are defined by geometry of their optical surfaces and/or internal interfaces and/or a gradient of the refractive index. Some lenses consist of two or more optical materials with various values of refractive index (RI). Then the optical properties are defined not only by geometries of external surfaces forming the interface with a surrounding transparent optical medium (e.g., air or corneal tissue or intraocular liquid), but also by geometries of the boundaries between adjacent materials (e.g., two different polymers, or a polymer and a fluid, or two fluids separated by a thin membrane). The interface between two adjacent materials can be either a sharply defined discontinuity, or be formed by a gradual transition between materials with the refractive index gradient (GRIN). The GRIN may be either perpendicular to the optical axis of the lens (radial GRIN_r), or RI can change along its optical axis (axial GRINa).

One of the optical characteristics deemed important for visual quality is Spherical Aberration (SA).

Consequently, there are numerous patents and published patent applications covering methods and devices for controlling aberrations of the eye, such as the following: Norrby, Sverker et al: Methods Of Obtaining Ophthalmic Lenses Providing The Eye With Reduced Aberrations, U.S. Patent No. 6,609,793 ; Tabernero, Juan et al: Intraocular Lens For Correcting Corneal Coma, U.S. Patent No. 8,801,781 ; Norrby, Sverker et al: Methods Of Obtaining Ophthalmic Lenses Providing The Eye With Reduced Aberrations, U.S. Patent Application Publication Nos. 2004/0088050; 2007/0121064; 2007/0258044; 2009/0036980; 2011/0082542 and 2012/0059463; Lai; Shui T.: Intrastromal Surgery Correcting Low Order And High Order Aberrations Of The Eye, U.S. Patent Application Publication No.

2008/0039825 ; Weeber, Hendrik Albert, et al.: System, Ophthalmic Lens, And Method For Extending Depth Of Focus, U.S. Patent Application Publication Nos. 2009/0210054 and 2013/0060330; Portnoy, V. : Adjustable Multifocal Intraocular Lens System, U.S. Patent No. 8,287,593; and Marmo, J.C.: Corneal Onlays And Wavefront Aberration Correction To Enhance Vision, U.S. Patent No. 7,585,075, each of which is incorporated herein by reference.

Spherical aberration can be also changed by implantation of an aspheric lens with conic optical surfaces, such as those described in the following patents and patent applications: Stoy, V. et al.: Bioanalogic Intraocular Lens, International Patent Application Publication No. WO2014111769; Wichterle, O.: Method Of Molding An Intraocular Lens, U.S. Patent No. 4,846,832; Wichterle, O.: Soft And Elastic Intracameral Lens And Method For Manufacturing Thereof, U.S. Patent No. 4,846,832; Stoy, V. : Implantable Ophthalmic Lens, A Method Of Manufacturing Same And A Mold For Carrying Out Said Method, U.S. Patent No. 5,674,283; Sulc, J., et al: Soft Intracameral Lens, U.S. Patent No. 4,994,083 and U.S. Patent No. 4,955,903; Sulc, J. et al: Intraocular Optical System, U.S. Patent No.

4,963,148; Blake, et al: Aspheric soft lens, U.S. Patent No. 7,192,444; Blake, et al: Method Of Making Aspheric Soft Lens, U.S. Patent No. 6,007,747; Hong, et al.: Intraocular Lens, U.S. Patent No. 7,350,916; Hong, et al.: Aspheric Toric Intraocular Lens, U.S. Patent No. 8,167,940; Hong, et al. : Optimal Intraocular Lens Shape Factor For Human Eyes, U.S. Patent Application Publication No. 2006/0227286; Portnoy, A.: Contra- Aspheric Toric Ophthalmic Lens, U.S. Patent No. 8,668,333; and Michalek, J. et al: Method Of

Manufacturing An Implantable Intraocular Planar/Convex, Biconvex, Planar/Concave Or Convex/Concave Lens And A Lens Made Using This Method, U.S. Patent No. 8,409,481 , each of which is incorporated herein by reference. Conic surfaces described in above references are spherical, elliptic, hyperbolic or parabolic surfaces symmetric along the optical axis.

Optical refractive surface is often formed by a combination of several surfaces with different optical parameters, with a sharp or gradual transition between them. The individual refractive surfaces (or interfaces) are often in the shape of concentric zones or segments, such as those described in HJ. Schlegel, One-piece Implantable Lens; U.S. Patent 4,673,406 and International Patent Application Publication No. W08606846 titled Compound Lens

Containing Discontinuous Refractive Surface. Other geometries are possible. For instance, optical surface can be composed from two or more segments with different refractive characteristics with one common point in the center, or can be arranged in some other pattern (e.g., L.W. Alvarez, U.S. Patent No. 3,739,445 and U.S. Patent No. 3,829,536). Refractive optical surfaces are often combined with diffractive zones or elements that are designed to provide several foci or extend the field of the focus. Note, for instance, S. Newman: Toric Lens with Axis Mislocation Latitude, U.S. Patent No 5,570,143; Roffman et al: Concentric Annular Ring Lens Designs for Astigmatism, U.S. Patent No. 5,652,638; and Aspheric Toric Lens Design, U.S. Patent No. 5,796,462, or Valdemar Portney: Contra- aspheric toric ophthalmic lens, U.S. Patent No. 8,668,333. Transitions between individual optical zones introduce certain optical discontinuities into the implantable lens than may cause visual problems, such as glares, halos or decrease in the contrast sensitivity. On the other hand, it is also sometimes difficult to design a lens with optical surfaces defined by a single "conic section" function, particularly for large lenses designed to at least partly fill the posterior capsule and maintain a contact with posterior capsule. In such cases, the posterior surface can be formed by a combination of coaxial conic surfaces to obtain a desirable overall geometry with desirable optical properties. Such "bioanalogic" intraocular lenses are described in Stoy, V. et al. : Bioanalogic Intraocular Lens, International Patent Application Publication No. WO2014111769, incorporated herein by reference.

Another class of implantable lenses with often complicated geometry are

accommodation lenses, such as those described in Sulc, J. et al, Intraocular Optical System, U.S. Patent No. 4,963,148, or in McCafferty, S., Accommodating Fluidic IOL with flexible interior membrane, U.S. Patent Application Publication No. 2014/0257478 Al , and

McCafferty, S., Refocusable IOL with aspheric surface, U.S. Patent Application Publication No. 2014/0257479. All of the above references are incorporated herein by reference. Such lenses can benefit from the present disclosure.

SUMMARY OF THE DISCLOSURE

This invention describes implantable lenses made from at least one transparent material and having at least anterior and posterior optical surface from the viewpoint of their intended position in the eye, comprising at least one smooth, continuous refractive surface or interface between materials with different refractive indices, wherein at least one of those surfaces or interfaces is defined by a function Ζ(ρ,θ) in cylindrical coordinate system (z, p, Θ) such that:

Ζ(ρ,θ) = (p²)/{R(p,6)*(l+ [1-Κ(ρ,θ)*(ρ/ R(p,6))^{2 5} } [1 ] where the longitudinal coordinate z coincides with the main optical axis of the lens, (ρ,θ) are radial and angular coordinates of any point M on the optical surface such that p is the radial distance of the point M from the longitudinal axis (or optical axis) and Θ is the angular coordinate of this point in the plane perpendicular to longitudinal axis, and where R(p,9) is the "radius function" and Κ(ρ,θ) is the "conic function", and those functions are selected for all aconic optical surfaces in such a way that the lens has negative spherical aberration on at least a major part of its optical surface. Such surfaces are called "aconic" since they cannot be described by rotation of a conic section along an axis ("conic surfaces") that can also affect the spherical aberration of the lens and are used frequently in the prior art. For clarity, the term "aconic curves" or "aconic surfaces" does involve not only the curves and surfaces exactly described by the Equation [1], but also curves and surfaces that approximate the Equation [1] within limits given by customary manufacturing and measurement tolerances. If the Ζ(ρ,θ) does not depend on Θ and both "radius function" and "conic function" are constants, then Equation [1] describes a conic surface (spherical, parabolic, elliptic or hyperbolic, depending on the value of conic constant). Such conic optical surfaces were used in earlier work.

For instance, hyperbole is defined by the negative value of the conic constant and hyperbolic surfaces can be used to introduce negative spherical aberration into the lens, or to compensate for positive spherical aberration introduced by other optical surfaces of the same lens. Aconic surfaces provide much more flexibility to the overall design and may even generate, e.g., surfaces with inflexion line, i.e., surfaces that change the sign of the second derivative of the Ζ(ρ,θ) along the radial coordinate. Such "inflected surfaces" can provide to the lens desired overall geometry and certain desirable optical properties without introducing discontinuities on the optical surface. For instance, it is desirable to make spherical aberration dependent on the aperture in a certain fashion. Such optical properties of the surfaces cannot be generated by any of the previously disclosed conic surfaces.

In a preferred embodiment related to intraocular lenses implanted into the posterior chamber, the posterior surface will be convex and aconic. In the case of a lens replacing the natural lens, the posterior surface has to often serve also some non-optical purposes, such as maintenance of the contact with the posterior capsule and stabilization of the lens position. That implies certain optimal sagittal depth and certain lens diameter together with the convexity of the posterior surface. In addition, the posterior surface should be preferably smooth without any discontinuities. Such demands on general shape combined with the optical function can be best met by a single aconic surface.

In the case of lenses implantable to other locations of the eye, the posterior surface may be either concave or convex and aconic, depending on spatial and optical requirements on the implant.

The anterior surface or any internal interface may be either convex or concave and either conic or aconic or otherwise shaped depending on the target geometry and target optical properties of the lens.

Contrary to the conic surfaces, aconic surfaces described by Equation [1] could generate (or compensate for) not only spherical aberration, astigmatism or coma, but any other conceivable aberration defined by Zernike coefficients, as well.

In many cases, however, the aconic optical surface will be symmetric along the longitudinal (or optical) axis. In those cases, the radius function R(p,9) and/or conical function Κ(ρ,θ) are a function of p but not of Θ. Preferably, R(p,9) and/or Κ(ρ,θ) are monotone functions of p in the interval (0,3.2) mm, and even more preferably for p in the interval (0,2.1) mm.

Even more preferably, R(p,9) and/or Κ(ρ,θ) has decreasing second derivative with respect to p in that interval if the first derivative is positive, and vice versa. The radius and conic functions R(p,9) and Κ(ρ,θ) suitable for the present optical purpose can be expressed in various ways, for instance as a polynomial. For most purposes, either R(p,9) or Κ(ρ,θ) may be kept constant over some interval. In the most simple preferred embodiment, R(p,9) is kept constant (R(p,9)=Ro) while Κ(ρ,θ) is a 1 ^st degree polynomial, but polynomials up to 5^th degree can be conveniently used.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1A shows the profile of a first aconic mold design of the invention.

Figure IB shows the profile of a casting mold filled with monomer mixture according to Example 1.

Figure 2A displays the profile of a second aconic mold design of the invention (spin- casting mold). Figure 2B displays the profile of the mold of Example 2 filled with monomer mixture and forming a meniscus by spinning around its vertical axis.

Figure 3 shows the posterior optical surface geometry and optical parameter profile of the mold according to Example 3.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

All parameters (dimensions, constants, etc.) in this application refer to the final lens in its implanted state when the lens is in equilibrium with the intraocular environment. This invention relates to implantable lenses comprising a main optical axis and two or more smooth optical surfaces and/or interfaces between materials with different refractive indices, at least one of those surfaces or interfaces being defined by a function in cylindrical coordinate system:

Z(p,9) = (p²)/{R(p,9)*(l+ [l-K(p,9)*(p/ R(p,e))²]⁰-⁵ } [1 ] where the longitudinal coordinate z coincides with the main optical axis of the lens, (ρ,θ) are radial and angular coordinates of any point M on the optical surface such that p is the radial distance of the point M from the longitudinal axis (or optical axis) and Θ is the angular coordinate of this point in the plane perpendicular to longitudinal axis, and where R(p,9) is the "radius function" and Κ(ρ,θ) is the "conic function", and those functions are preferably selected for all aconic optical surfaces in such a way that the lens has negative spherical aberration on at least a major part of its optical surface.

Thus, one aspect of the invention relates to aspheric implantable lenses from at least one optically transparent material with a main optical axis and at least two opposite optical surfaces or interfaces, at least one of them being smooth optical surface or optical interface between two transparent materials that can be described by an aconic function as defined by Equation [1] above.

In a preferred embodiment, at least one of the transparent materials is a hydrophilic polymer or a hydrogel with refractive index between about 1.40 and 1.48, preferably containing negatively charged pendant groups and preferably containing UV absorbing pendant groups, and even more preferably containing both negatively charged pendant groups and UV-absorbing pendant groups. In another preferred embodiment, at least one of the said materials is a covalently crosslinked methacrylic polymer.

In one preferred embodiment, the functions R(p,9) and Κ(ρ,θ) are selected for at least one of the optical surfaces in such a way that Ζ(ρ,θ) has positive first partial derivative with respect to p and negative second partial derivative with respect to p for at least a major part

2 2

of the optical surface or vice versa. Specifically, δ [Ζ(ρ,θ)]/δρ and δ[Ζ(ρ,θ)]/δρ are of opposite sign for p ε [Α(θ) ; Β(θ)] (excluding extreme points of the interval), where Α(θ) has a positive value selected from 0 to B(9 _and Β(θ) has a positive value selected from Α(θ) to LOD/2, where "LOD" is the Lens Outer Diameter in mm. The LOD value is preferably between about 5 mm and about 10.5 mm, and more preferably between 6.5 and 9.5 mm. In one preferred embodiment, Α(θ) is > 1 mm. In another preferred embodiment, Β(θ) is < LOD/2. In still another embodiment, Α(θ) is < Β(θ). In still another embodiment, at least one of the optical surfaces R(p,9) and Κ(ρ,θ) is selected in such a way that the sign of the

2 2

second partial derivative δ [Ζ(ρ,θ)]/δρ = 0 at some distance C(9) from the optical axis. In a preferred embodiment, C(9) has a value between 1.0 and 4.5 mm. Even more preferably, C(9) value is between 1.5 mm and 3 mm.

The value of Ζ(ρ,θ) may be dependent on the angle Θ to achieve correction of higher aberrations or astigmatism. The function Ζ(ρ,θ) has preferably [Ζ(ρ,θ)]/δθ changing

2 2

periodically so that δ [Ζ(ρ,θ)]/δθ = 0 for 4 different values Θ that differ mutually by angle Π/2. Also preferably, the intersection of the Ζ(ρ,θ) with a plane Ζ(ρ,θ)= Z_a (that is perpendicular to the axis z) is a substantially elliptical or an ovaloid curve. Such optical surface will provide simultaneously toric refraction and spherical refraction with a spherical aberration that is preferably negative.

In some case, the aspheric implantable lens has all optical surfaces symmetrical with respect to the main optical axis for at least a major part of the optical surface so that δ[Ζ(ρ,θ)]/δθ = 0 for p £ [D ; E] where D has a positive value selected from 0 to E, and E has a positive value selected from D to LOD/2.

In one embodiment, the aspheric implantable lens has least one of said optical surfaces defined by the function [1] with either one or both functions R(p,9) and Κ(ρ,θ) being variable by either one or both p and Θ, and at least one of the additional optical surfaces or interfaces is described by the Equation [1] where both R(p,9) = R₀ and Κ(ρ,θ) = K are constants so that the said optical surface or interface is defined by rotation of a conic section along the main optical axis. In one embodiment, R(p,9) = R₀ is a constant in at least one of the aconic surfaces. In another embodiment, in at least one aconic surface Κ(ρ,θ) is a linear function of the distance from the main optical axis p such that Κ(ρ,θ) = Ko +Ki*p. The constant K₀ has a value between +1 and -25, and preferably between values 0 and -10 and even more preferably between -0.7 and -8.5. The constant Ki has a value between -0.1 and - 4.5, and preferably between values -0.2 and

-3.7, and even more preferably between -0.2 and -2.0.

In still another embodiment, for at least one aconic surface R(p,9) is a linear function of the distance from the main optical axis p such that R(p,9) = R₀ + Ri*p. The constant R₀ has a value between 2 mm and 5 mm, and preferably between values 2.2 mm and 4.8 mm, and even more preferably between 2.4 mm and 4.6 mm. The constant Ri has a value between -0.05 and -2, and preferably between values -0.1 and -1.5, and even more preferably between -0.2 and -1. While the linear change can provide many useful geometries, either Κ(ρ,θ) or R(p,9) (or both) can be conveniently described by polynomials up to 5^th degree that provide the desirable flexibility to the lens optical design and geometry.

The desirable optical properties of the lens can be generally achieved even if one or more of the surfaces are other than aconic, and has geometry of, for instance, a "meniscoid". A "meniscoid" is to be understood as a shape of a solidified liquid meniscus. In this case, the lens can be fabricated by solidification of a polymer precursor in an open mold. The solidification can be achieved by, for instance, cooling of a polymer melt, cooling or heating of a thermoreversible gel, crosslinking of a polymer solution, crosslinking of a liquid polymer, or by polymerization of a liquid monomer mixture. Such polymers can be selected from the group of acrylate polymers, methacrylate polymers, vinyl polymers,

poly(dialkylsiloxanes), polyurethanes or other polymer types known to those skilled in the art. The liquid precursor surface can be also modified by spinning the lens around the vertical axis in the process known as the spin casting.

Solidification of the liquid precursor to the polymer is usually accompanied by a smaller or larger volume contraction. Some solidification processes are accompanied by a large volume contraction that can be as high as about 20%. Such large contractions are typical for crosslinking polymerization of acrylate or methacrylate of monomers.

Somewhat smaller contractions are typical for solidification of polymer melts or thermo-reversible gels by cooling. Even smaller volume contractions can be achieved with crosslinking of silicone rubber precursor. Whatever the contraction is, the volume contraction has to be taken into the account in considering the shape of meniscoid and its optical contributions to the lens properties. The solidification of the liquid precursors may form a hydrogel precursor, such as a solvent gel or a xerogel. Such hydrogel precursor is then hydrated, washed, and equilibrated in the appropriate isotonic aqueous liquid to reach the final volume and shape and optical properties corresponding to the implanted state. In the case of hydrophilic polymers or hydrogels, the hydration causes another volume change, usually positive. All these volume changes during the manufacturing process have to be taken into account when designing molds, forming tools or machining xerogel lenses. Of course, this applies to any lens, surface or manufacturing method. Meniscoid shape changes its properties through this process in a predictable way that is known to those skilled in the art. Meniscus casting of intraocular lenses is described in Wichterle, O. : Method Of Molding An Intraocular Lens, U.S. Patent No. 4,846,832; Wichterle, O.: Soft And Elastic Intracameral Lens And Method For

Manufacturing Thereof, U.S. Patent No. 4,846,832; Stoy, V. : Implantable Ophthalmic Lens, A Method Of Manufacturing Same And A Mold For Carrying Out Said Method, U.S. Patent No. 5,674,283. All of the above references are incorporated herein by reference. The open mold used in this procedure has geometry of aconic surface subject to this invention.

Liquid precursor can be also solidified in a two-part mold designed to compensate the solidification contractions. Such method is described in Stoy, V. et al.: Bioanalogic

Intraocular Lens, International Patent Application Publication No. WO2014111769;

incorporated herein by reference. The mold has to be designed to obtain the final lens geometry, taking into account all volume and dimensional changes during the manufacturing process.

If one of the outer surfaces may be a "meniscoid", then the resulting lens is formed by at least two surfaces, one being an "imprint" of the solid mold with the aconic surface and the other being the meniscoid. If the mold axis of symmetry is vertical and the mold is static, the meniscoid is approximating an ellipsoid that approaches spherical surface as the mold diameter is diminishing and the surface tension of the liquid precursor increases. This manufacturing method is usually called "meniscus-casting", as described e.g. in the US Patents by Wichterle, O.: Method Of Molding An Intraocular Lens, U.S. Patent No.

4,846,832; Wichterle, O.: Soft And Elastic Intracameral Lens And Method For

Manufacturing Thereof, U.S. Patent No. 4,846,832; and Stoy, V.: Implantable Ophthalmic Lens, A Method Of Manufacturing Same And A Mold For Carrying Out Said Method, U.S. Patent No. 5,674,283.

If the mold rotates around its vertical axis, the meniscus surface is modified in a subtle way as described, e.g., in Michalek, J. et al.: Method Of Manufacturing An Implantable Intraocular Planar/Convex, Biconvex, Planar/Concave Or Convex/Concave Lens And A Lens Made Using This Method, U.S. Patent Nos. 8,409,481 and 8,444,408.

Aconic surfaces can be also combined with conic surfaces. At least one of the optical surfaces can be optionally conic, i.e. having R(p,9) = R₀ (a constant) and/or Κ(ρ,θ) = K₀ (a constant) for the whole optical surface. Namely, for constant values of R(p,9) = R₀ and

Κ(ρ,θ) = Ko, the Equation [1] would became a conic surface equation (for spheroid, ellipsoid, paraboloid or hyperboloid surfaces, depending on the value of K).

Geometry of the mold in the above cases determines the shape of the posterior optical side of the intraocular lens. In previous work this shape is determined by rotation of a conic section around the mold axis forming a spherical cap, paraboloid or ellipsoid, the most useful shape being hyperboloid. The problem of surfaces described by a single conic curve is that it is difficult to balance all the curve lens parameters required by its optical properties (e.g., spherical aberration) and geometry (diameter, sagittal depth, central thickness, etc.) required for filling the space vacated by NCL using a single conic curve. Several conic curves can be combined into a one surface to accommodate size and shape requirements, but this may lead to optical discontinuities. Therefore, it is preferred to replace such a combination of conic surfaces with a single smooth aconic surface according to this invention.

In one preferred embodiment, the posterior lens surface (with respect to the eye) is a continuous convex optical surface with negative value of Κ(ρ,θ) for any point M. Preferably, such posterior optical surface has diameter equal to the Lens Outer Diameter (LOD) that is preferably larger than 8 mm including the peripheral parts or haptics (LOD > 8 mm) More preferably, LOD > 9 mm. Sagittal depth of the posterior surface is preferably the same as the sagittal depth of the lens and larger than S_P > 0.5 mm, preferably > 1 and even more preferably

> 1.25 mm. Conic function Κ(ρ,θ) of the posterior surface is preferably > -25 and < 1 in the whole interval p ε [0; LOD/2], and even more preferably > -15 in and < 0.5 in the same interval.

Also preferably, such posterior optical surface has radius function R(p,9) > 2.4 mm in the whole interval p £ [0; LOD/2].

In another preferred embodiment, at least the posterior surface has "inflexion line"

(i.e., any polar line of the surface has an inflexion point and the second derivative of Ζ(ρ,θ) with respect to p equals zero for a p value from the interval [l ;LOD/2]mm, and preferably for a p value from the interval [1.5;LOD/2] mm. The lens according to the present invention can be made from any transparent biocompatible and sufficiently stable material. Preferred materials are hydrogels and crosslinked hydrophilic polymers, particularly those based on various derivatives of methacrylic acid. One of the particularly suitable derivatives is 2-HydroxyEthylMethacrylate (2-HEMA) that can be copolymerized with methacrylic acid and its salts to achieve high biocompatibility, a resistance against deposits, and posterior capsular opacification.

Methacrylic acid content is advantageously between 0.5 %-mol and 5 % mol, preferably between 1 %-mol and 3.5 % mol. Another copolymer advantageously used in the composition is a methacryloyl derivative of an UV-absorbing compound, such as oxybenzophenone, benztriazole, or coumarine, that can be present in concentration between about 0.1 %-mol and 3 %-mol, preferably between 0.25 %-molar and 1.5 %-molar. Still another component is a copolymerizable crosslinking agent, preferably a dimethacrylate of ethylene glycol or di- or tri- or polyethylene glycol or a mixture thereof. Still another possible component is an ester of methacrylic acid including CI to C8 aliphatic alcohols or an aromatic alcohol. Examples of such co-monomers are methylmethacrylate, ethylmethacrylate, n-butylmethacrylate or benzylmethacrylate. Such copolymers combine the desired optical and mechanical properties with biocompatibility that provides long-term stability of the implant.

These and other advantages of the present invention will be apparent to those skilled in the art from the foregoing specification. Accordingly, it will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as defined in the claims. The invention can be illustrated by the following non-limiting examples.

EXAMPLES

Example 1

Haptic-less hydrogel lens is made by polymerization in an open plastic mold by static meniscus casting following the Wichterle, O.: Method Of Molding An Intraocular Lens, U.S. Patent No. 4,846,832. The profile of the mold is depicted in the Figure 1A showing various aspects of the mold design. In the upper part of the Figure 1 A, there are polynomial parameters K₀ to K_v and Ro to R_v for the functions Κ(ρ,θ) and R(p,9), respectively, the first being described as a linear function of the distance from the z-axis p, while the other is a constant. The graph on the right side of Figure 1A shows both these functions. The second graph in Figure 1A shows the 1^st and 2^nd derivative of the aconic surface function Ζ(ρ,θ) by p. It is noted that the 2^nd derivative reaches the zero value at some distance from the z-axis (here approx. 2 mm) indicating an inflection line on the surface. The last graph in Figure 1 A shows the physical profile of the casting mold defining the mold cavity that is limited by a sharp edge on its top.

The mold is filled with a monomer mixture containing 2-HEMA, ethylene glycol dimethacrylate crosslinker, methacrylic acid and methacryloylbenztriazol as monomers and isopropylpercarbonate as the initiator. The monomer mixture forms a meniscus that can be approximated by an ellipsoidal cap, as shown in the Figure IB. The monomer mixture is then polymerized by heating to 60 deg. C under nitrogen, swelled in 1% sodium carbonate solution, extracted multiple times in buffered isotonic solution and sterilized by autoclaving. The resulting product can serve as implantable hydrogel lens.

Example 2

Haptic-less hydrogel lens is made by polymerization in an open plastic mold by spin - casting following the Michalek, J. et al.: Method Of Manufacturing an Implantable

Intraocular Planar/Convex, Biconvex, Planar/Concave Or Convex/Concave Lens and a Lens Made Using This Method, U.S. Patent Nos. 8,409,481 and 8,444,408. The profile of the mold is depicted in the Figure 2A showing various aspects of the mold design. In the upper part of the Figure 2A, there are polynomial parameters K₀ to K_v and Ro to R_v for the functions Κ(ρ,θ) and R(p,9), respectively, the first being described as a 5^th degree polynomial of the distance from the z-axis p, while the other being a constant. The graph on the right side of Figure 2 A shows both these functions. The second graph shows the 1 ^st and 2^nd derivative of the aconic surface function Ζ(ρ,θ) by p. It is noted that the 2^nd derivative reaches the zero value at some distance from the z-axis (here approx. 1.3 mm) indicating an inflection line on the surface. The inflexion is also obvious on the mold cavity profile. The last graph of Figure 2A shows the physical profile of the casting mold defining the mold cavity that is limited by a sharp edge on its top.

The mold is filled with a monomer mixture containing 2-HEMA, benzylmethacrylate, triethyleneglycol dimethacrylate, methacrylic acid and methacryloyloxybenzophenone as monomers, and a photoinitiator. The mold filled with the monomer mixture is spun around it vertical axis at 235 rpms so that the monomer mixture forms a meniscus approximated in the Figure 2B. The monomer mixture is then polymerized by illumination by blue light under nitrogen, swelled in 1 % sodium carbonate solution, extracted multiple times in buffered isotonic solution and sterilized by autoclaving. The resulting product can serve as implantable hydrogel lens.

Example 3

Hydrogel implantable lens is made by polymerization-casting in a two-part mold by a method of polymerization casting described in Stoy, V. et al.: Bioanalogic Intraocular Lens, International Patent Application Publication No. WO2014111769. The profile of the posterior optical surface is shown in Figure 3. At the top part there are given polynomial parameters K₀ to Kv and Ro to R_v for the functions Κ(ρ,θ) and R(p,9), respectively, both being described as a 5^th degree polynomial of the distance from the z-axis p. In addition, other essential parameters, such as mold dimensions, central radius and central value of the conic constant are given. Underneath, the graph on the left side of Figure 3 shows both these functions and the graph on the right side shows the 1 ^st and 2^nd derivative of the aconic surface function Ζ(ρ,θ) by p. It can be noted that the 2^nd derivative reaches the zero value at some distance from the z-axis (here approx. 1.4 mm) indicating an inflection line on the surface. The inflexion is also obvious on the mold cavity profile. The bottom left graph shows half of the physical profile of the posterior optical surface while the bottom right graph shows optical profile of a hypothetical lens with planar anterior surface. The anterior part of the mold has either aconic or conic surface, preferably formed by a hyperboloid.

The mold is filled with a monomer mixture containing n-butyl methacrylate, benzylmethacrylate, butylene glycol glycol dimethacrylate, methacrylic acid and

methacryloylixybenzophenone as monomers and a benzoyl peroxide as the initiator. The monomer mixture is then polymerized by heating to 70 deg. C under nitrogen, extracted multiple times in acetone-ethanol mixtures, dried under vacuum, and sterilized by autoclaving. The resulting product can serve as an implantable ophthalmic lens.

These and other advantages of the present invention will be apparent to those skilled in the art from the foregoing specification. Accordingly, it will be recognized by those skilled in the art that changes or modifications may be made to the above-described embodiments without departing from the broad inventive concepts of the invention. It should therefore be understood that this invention is not limited to the particular embodiments described herein, but is intended to include all changes and modifications that are within the scope and spirit of the invention as defined in the claims.

Claims

claimed is:

An aspheric implantable ophthalmic lens with a diameter LOD and one main optical axis having two or more smooth optical surfaces and/or interfaces between media with different refractive indices that is made of at least one optically transparent material of refractive index m, wherein at least one of the optical surfaces or interfaces is defined by a function Z(p, Θ) in cylindrical coordinate system such that:

Ζ(ρ,θ) = (p²)/{R(p,9)*(l+ [1 -Κ(ρ,θ)*(ρ/ R(p,9))²]⁰-⁵ } [1 ]

where the longitudinal coordinate z coincides with the main optical axis of the lens, (ρ,θ) are radial and angular coordinates of any point M on the optical surface such that p is the radial distance of the point M from the longitudinal axis (or optical axis) and Θ is the angular coordinate of this point in the plane perpendicular to longitudinal axis, and where R(p,9) is the radius function and Κ(ρ,θ) is the conic function, and those functions are selected for all optical surfaces in such a way that the lens has negative spherical aberration on at least a major part of its surface.

The aspheric implantable lens according to the Claim 1 , wherein the said spherical aberration is negative for any aperture larger than 1 mm.

The aspheric implantable lens according to the Claim 1 , wherein said functions

R(p,9) and Κ(ρ,θ) are selected for at least the posterior optical surface in such a way that Ζ(ρ,θ) has positive first partial derivative with respect to p and negative second partial derivative with respect to p for at least a part of the optical surface, and further wherein δ²[Ζ(ρ,θ)]/δρ² and δ[Ζ(ρ,θ)]/δρ are of opposite sign for p ε [Α(θ) ; Β(θ)], excluding extreme points of the interval, and wherein Α(θ) has a positive value selected from 0 to B(9),_and Β(θ) has a positive value selected from Α(θ) to LOD/2.

The aspheric implantable lens according to the Claim 3, wherein Α(θ) is > 1 mm.

The aspheric implantable lens according to the Claim 3, wherein Β(θ) is < LOD/2. The aspheric implantable lens according to the Claim 3, wherein Α(θ) < Β(θ). The aspheric implantable lens according to Claim 1, wherein said R(p,9) and Κ(ρ,θ) are selected in such a way that the sign of the second partial derivative of Ζ(ρ,θ) with respect to p changes at some distance C(9) from the optical axis.

The aspheric implantable lens according to the Claim 7, wherein C(9) has a positive value between 1.0 and 4.5 mm.

The aspheric implantable lens according to the Claim 8, wherein all optical surfaces are symmetrical according to the main optical axis for at least a major part of the optical surface such that δ[Ζ(ρ,θ)]/δθ = 0 for p ε [_D_; E] where D has a positive value selected from 0 to E, and E has a positive value selected from D to LOD/2.

The aspheric implantable lens according to the Claim 1 , wherein at least one of said optical surfaces is defined by the Equation [1 ], wherein either one or both functions R(p,9) and Κ(ρ,θ) are variable with respect to either one or both p and Θ, and at least one additional optical surface is described by the Equation [1 ], wherein both R(p,9) = R₀ and K(p,9) = Ko are constants so that the said optical surface or interface is defined by rotation of a conic section along the main optical axis.

The aspheric implantable lens according to the Claim 1 , wherein said R(p,9)

constant.

12. The aspheric implantable lens according to the Claim 1 , wherein said K(p,9) is a linear function of the distance from the main optical axis such that K(p,9) = K₀ + Ki*p.

13. The aspheric implantable lens according to the Claim 12, wherein said K₀ has a value between 0 and -10, and preferably values between -0.7 and -8.5.

14. The aspheric implantable lens according to the Claim 12, wherein said Ki has a value between -0.1 and -4.5, and preferably values between -0.2 and -2.0.

15. The aspheric implantable lens according to the Claim 1 , wherein at least one of said

materials is a hydrogel.

16. The aspheric implantable lens according to the Claim 15, wherein at least one of said hydrogels comprises a copolymer of derivatives of methacrylic acid. 17. The aspheric implantable lens according to the Claim 16, wherein the said copolymer comprises both methacrylic acid salt and an UV absorbing derivative of methacrylic acid.

18. The aspheric implantable lens according to the Claim 16, wherein at least one of said derivatives is methacryloyloxybenzophenone or methacryloylbenztriazole.

19. The aspheric implantable lens according to the Claim 16, wherein at least one of said derivatives is a salt of methacrylic acid.

20. The aspheric implantable lens according to the Claim 19 wherein at least one of said esters is a polyol ester of methacrylic acid.

21. The aspheric implantable lens according to the Claim 16, wherein at least one of said derivatives is an ester of methacrylic acid. 22. The aspheric implantable lens according to the Claim 1 , wherein at least one of the

external optical surfaces is a hydrophilic surface containing fixed negative charge.

23. The aspheric implantable lens according to the Claim 22, wherein the said hydrophilic surface comprises a gradient of fixed negative charge.

24. The aspheric implantable lens according to Claim 23, wherein the fixed negative charge is caused by neutralized groups selected from a group comprising carboxylate groups, sulfate groups, sulfonic acid groups and phosphate groups. 25. The aspheric implantable lens according to the Claim 1 , wherein at least one of the

optical surfaces has geometry of a meniscus of a solidified liquid precursor of a polymer contained in a mold with a sharp edge rotationally symmetric along its axis.

26. The aspheric implantable lens according to the Claim 25, wherein the solidification of the liquid meniscus takes place while the mold is rotating along the horizontal axis of symmetry.

27. The aspheric implantable lens according to the Claim 1 , wherein said refractive index of at least one optically transparent material is between 1.40 and 1.48.

28. The aspheric implantable lens according to the Claim 1 , wherein the lens comprises at least two optical transparent materials of different deformability.

29. The aspheric implantable lens according to the Claim 28, wherein the lens comprises at least two optical transparent materials of different refractive index.

30. The aspheric implantable lens according to the Claim 29, wherein the at least one of the optical transparent materials comprises a methacrylate copolymer and at least one of the transparent materials comprises a polysiloxane.