WO2000000106A1

WO2000000106A1 - Antioxidant intraocular lens

Info

Publication number: WO2000000106A1
Application number: PCT/US1999/014811
Authority: WO
Inventors: George W. Rozakis; William G. Rozakis
Original assignee: Rozakis George W; Rozakis William G
Priority date: 1998-06-29
Filing date: 1999-06-29
Publication date: 2000-01-06
Also published as: AU4847999A

Abstract

An intraocular lens (10) includes a body (32) having an antioxidant substance (30) distributed throughout or coated thereon. The antioxidant substance detoxifies and neutralizes free radicals in the eye (12) when the lens is implanted in the eye. Free radicals can lead to cataracts and the antioxidant intraocular lens (50) will thus help combat cataract formation.

Description

ANTIOXIDANT INTRAOCULAR LENS

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority from United States Provisional

Application Serial No. 60/091 ,146 filed June 29, 1998, the disclosures of which are incorporated herein by reference.

BACKGROUND OF THE INVENTION

Technical Field

This invention generally relates to an intraocular lens and, more

particularly, to therapeutic intraocular lenses. Specifically, the present invention

is directed to an intraocular lens having antioxidant properties that assists the

eye in detoxifying and neutralizing free radicals.

Background Information

A cataract is an opaque area on the natural lens of the eye. The cataract

prevents light from cleanly passing through the lens and thus interferes with the

focus of the light on the retina. Cataracts naturally develop with age and it is

estimated that approximately half of the people between the ages of 75 and 85 have lost some vision as a result of a cataract.

Cataracts are normally formed by free radical oxidated damage to the

crystalline lens of the eye. Free radicals are present in the eye throughout a person's life but the eye avoids cataracts by detoxifying the free radicals with

antioxidants that are present in the eye. One such antioxidant is Vitamin C. As

a person grows older, the eyes lose their ability to successfully detoxify and neutralize these free radicals leaving the eyes more vulnerable to cataract

formation.

Numerous antioxidant molecules are known in the art. For instance,

vitamin E, (tocopherol), ascorbic Acid (vitamin C), beta-carotene, bilirubin, urate,

coenzyme Q10, glutathione, selenium, dithiocarbamates, and butylated hydroxyanisole are known antioxidants. In general, an antioxidant is a reducing

agent or an agent that inhibits outside oxidation. Oxidation is the combination

with oxygen or increasing the valence of an atom or ion by the loss from it of

hydrogen or of one or more electrons thus rendering it more electropostive

A free radical is an atom or atom group carrying an unpaired electron and

no charge; e.g. hydroxyl and methyl. Free radicals may be involved as short-lived, highly active intermediates in various reactions in living tissue,

notably in photosynthesis. The free radical nitric oxide, plays an important role

in vasodilation. It has been theorized that these also act in human tissues to

promote heart disease, cancer, Alzheimers disease, Parkinsons disease, and

rheumatoid arthritis. Free radicals may be introduced to the body (through

smoking, inhaling environmental pollutants, or exposure to UV radiation), and

also occur naturally within the body as a result of metabolic process. They interact readily with nearby molecules, and may thereby cause cellular damage

(including genetic material).

The only method for treating a cataract after it has severely reduced

vision is invasive surgery. Such surgery removes the natural lens of the eye

having the cataract and replaces the natural lens with an intraocular lens.

Although the surgery is commonly performed and is effective and successful, it

is always desirable to limit surgery where possible.

Although cataracts naturally form as the eye ages, cataract formation can be accelerated when a phakic intraocular lens is inserted adjacent the natural

lens of the eye to correct other vision defects. It is thought that the presence of

the intraocular lens increases agitation of the natural lens which may hasten the

formation of a cataract. It is thus desirable to provide an intraocular lens that

does not hasten cataract formation and even deters the formation of the cataract. It is especially desirable to provide such an intraocular lens because

the patient using the phakic intraocular lens has already undergone one surgical

procedure to insert the intraocular lens and it is desirable to prevent the second

surgical procedure if possible.

The natural lens of the eye fights the creation of cataracts by maintaining

a supply of antioxidants that neutralize the free radicals that are thought to help

cause cataracts. As discussed above, the natural lens gradually loses these

antioxidants as the lens ages and thus gradually loses its ability to fight

cataracts. It is thus desired in the art to provide an intraocular lens that assists the natural lens of the eye in battling the formation of cataracts by increasing the antioxidants in the eye. It is also desired to provide a replacement lens having

antioxidants.

SUMMARY OF THE INVENTION

In view of the foregoing, it is an objective of the present invention to

provide an intraocular lens having antioxidants in combination with the lens

material to provide a therapeutic lens for the eye.

Another objective of the present invention to provide a phakic intraocular

lens that deters the formation of cataracts on the natural lens of the eye.

Another objective of the present invention is to provide a phakic

intraocular lens that is formed with an antioxidant distributed throughout the material of the intraocular lens.

Yet another objective of the present invention is to provide a phakic

intraocular lens that is formed from silicon having antioxidant dispersed

throughout the body of the lens such that the antioxidant may help assist the natural lens of the eye in battling cataract formation.

Still another objective of the present invention is to provide a phakic

intraocular lens that is coated with an antioxidant that assists the natural lens of

the eye in fighting cataract formation.

A further objective of the present invention is to provide a phakic

intraocular lens that includes a substance that detoxifies free radicals in the eye. Still a further objective of the present invention is to provide a phakic intraocular lens formed from a polymer material with cross-linked antioxidants.

Another objective of the present invention is to provide an intraocular lens

having antioxidant properties that may be implanted in the anterior or posterior

chamber of the eye.

Another objective of the present invention is to provide an antioxidant

intraocular lens that may be used to replace the natural lens of the eye after the

natural lens has been removed during cataract surgery.

Another objective of the present invention is to provide an antioxidant

intraocular lens wherein the antioxidants are not distributed into the eye from the intraocular lens after the lens is implanted.

An additional objective of the present invention is to provide a phakic

intraocular lens that is of simple construction, which achieves the stated

objectives of the invention in a simple, effective, and inexpensive manner, and

which solves the problems and which satisfies the needs existing in the art.

These and other objectives and advantages are obtained by the phakic

intraocular lens of the present invention, the general nature of which includes a

lens body having an antioxidant connected to the body.

BRIEF DESCRIPTION OF THE DRAWINGS

The preferred embodiments of the invention, illustrative of the best mode

in which applicant contemplated applying the principles of the invention, are set forth in the following description and are shown in the drawings and are distinctly

pointed out and set forth in the appended claims.

Fig. 1 is a sectional view of the eye having a phakic intraocular lens

implanted next to the natural lens; Fig. 2 is a top plan view of a phakic intraocular lens having antioxidants dispersed throughout the body of the intraocular lens;

Fig. 3 is a sectional view of a phakic intraocular lens having a polymer

body with an antioxidant coating;

Fig. 4 is a schematic diagram of a container having an antioxidant

solution into which a polymer intraocular lens is disposed to combine the antioxidants with the polymers;

Fig. 5 is a schematic view of an alternative method of adding the

antioxidants to the polymer that includes providing a closed environment having

a gaseous antioxidant into which the polymer lens is placed;

Fig. 6 is a schematic view of the cross-linked polymer phakic intraocular

lens material;

Fig. 7 is a view similarto Fig. 1 showing the intraocular lens in the anterior

chamber of the eye; and

Fig. 8 is a view similar to Fig. 1 showing a replacement antioxidant

intraocular lens.

Similar numbers refer to similar elements throughout the specification. DESCRIPTION OF THE PREFERRED EMBODIMENTS

A phakic intraocular lens made in accordance with the concepts of the

present invention is indicated generally by the numeral 10 in Figs. 1 and 2. Lens

10 is depicted as being positioned in the eye 12 in Fig. 1 . Eye 12 includes a

cornea 14, an iris 16 and a natural lens 18. Phakic intraocular lens 10 is

positioned behind iris 16 and in front of lens 18 so that it influences the light

entering natural lens 18 of eye 12. A pair of fixation arms 20 extend from

opposite sides of lens 10 to help fix the position of lens 10 with respect to eye

12. Numerous types of fixation arms 20 are known in the art and any of the

variety will function with the lens of the present invention. Lens 10 may also be

positioned in the anterior chamber of the eye in front of iris 16 as depicted in Fig.

7.

Both natural lens 18 and the vitreous humor 22 of eye 12 normally contain antioxidants that are capable of detoxifying free radicals. As discussed

in the Background of the Invention section of this specification, the antioxidants

are gradually reduced as eye 12 ages thus reducing the eye's ability to detoxify

free radicals. The free radicals help form cataracts on natural lens 18. In

addition to the cataract-forming influences of free radicals, the presence of a phakic intraocular lens closely adjacent natural lens 18 as depicted in Fig. 1 is

also thought to increase the likelihood that a cataract will form on natural lens

18. The combination of the phakic intraocular lens adjacent natural lens 18 and the natural reduction in antioxidant makes it even more likely that a cataract will

form on natural lens 18.

Phakic intraocular lens 10 of the present invention includes a supply of antioxidant material 30 associated with the body 32 of lens 10. Antioxidant

material 30 is of the type that can detoxify the free radicals in eye 12 similar to

the antioxidants that are naturally present in natural lens 18 and vitreous humor

22. Numerous antioxidants are known in the art and any antioxidant known in

the art for use with implants or for use with living tissue may be used with the lens of the present invention. For purposes of example, antioxidant material 30

may be vitamin C, vitamin E, or other antioxidants known in the art. A

combination of antioxidant material 30 with body 32 of lens 10 allows antioxidant

material 30 to detoxify free radicals while maintaining the stability and optical

properties of body 32. By providing antioxidant material 30 with body 32 of lens 10, one objective of the present invention is achieved.

One method for adding antioxidant material 30 to body 32 of lens 10 is

to fabricate body 32 from a polymer material and combine antioxidant material

30 with the polymer of body 32 by cross-linking antioxidant material 30 with the

polymer of body 32. Such cross-linking can be achieved at relatively high

temperatures during formation of body 32. Various methods for cross-linking

antioxidant material 30 with the polymer of body 32 are known in the art and

any of the variety of known methods may be used to achieve lens 10. Various

lens materials and methods for fabricating intraocular lenses are known in the art. For instance, it is know that the optical portions of intraocular lenses may be fabricated from polymethyl methacrylate (PMMA), poly-2-hydroxyethyl

methacrylate, methyl methacrylate copolymers, siloxanylalkyl, fluoroalkyl and aryl methacrylate, silicone, acrylics, silicone elastomers, polysulfones, polyvinyl

alcohols, polyethylene oxides, copolymers of fluoroacrylates and methacrylate,

and polymers and copolymers of hydroxyalkyl methacrylate, such as 2-

hydroxyethyl methacrylate, as well as methacrylic acid, acrylic acid, acrylamide methacrylamide, N,N-dimethylacrylamide, and N-vinylpryrrolidone. Additionally,

compounds that absorb ultraviolet or other short wavelength (e.g. below about

400 nm) radiation, such compounds derived from benzotriazole groups, benzophenone groups, or mixtures thereof may be added to the monomers

and/or polymers that constitute the implant. Other compounds well known in the

art may also be used in fabricated optical portion of lens 10 of the present

invention. Lens 10 may be fabricated from any suitable medical grade polymer

known in the art that is inert and nontoxic to the fluids of the eye and which

impart sufficient strength and rigidity to the lens 10 to allow it to function in the eye. Suitable polymers may be derived from acrylate monomers including

methyl acrylate, ethyl acrylate, butyl acrylate and isodecyl acrylate, methacrylate

monomers such as methyl methacrylate, ethyl methacrylate, n-hexyl

methacrylate, butyl methacrylate and vinyl acetate monomers and appropriate

mixtures thereof as is well known in the art. In one such method, lens 10 having body 32 can be submerged in an antioxidant solution 34 as depicted in Fig. 4. When polymer body 32 is

submerged in solution 34 during the appropriate step during its formation,

antioxidant material 30 will cross-link with the polymer of body 32 to form a

cross-linked polymer and antioxidant material. This material is schematically depicted in Fig. 6 with the strings of "I" representing the polymer chains while the

"A" links represent the antioxidant cross-links. Lens body 32 is fabricated from

this cross-linked material to have the desired optical properties of lens 10. The

polymer forfabricating lens body 32 may also be formed by immersing lens body

32 in an atmosphere of antioxidant ions 36 as depicted in Fig. 5. Such immersion cross-links antioxidant material 30 with the polymer of body 32 to

form the desired material of lens 10 of the present invention.

Lens 10 may also be molded by creating a mixture of the polymer and the

antioxidant in a liquid state. The liquid mixture is then placed in a lens mold to

form lens 10. Lens 10 may be further treated after the molding process as is

known in the art. This method results in the antioxidant being distributed

throughout body 32 of lens 10. Methods for manufacturing lenses are disclosed

in US Patents 4,158,030, 4,786,657, 4,806,382, 5,108,776, 5,762,836, and

5,902,523; the disclosures of which are incorporated herein by reference.

An alternative embodiment of the phakic intraocular lens of the present

invention is depicted in Fig. 3 and is indicated generally by the numeral 50.

Lens 50 also includes a pair of fixation arms 52 configured to hold lens 50 in its desired location in eye 12. Lens 50 further includes a lens body 54 that may be

preferably formed from a polymer material. Lens body 54 has the desired

optical properties to correct the patient's vision. Lens body 54 is coated with an

antioxidant coating 56 that is adapted to detoxify free radicals in eye 12 that encourage cataract formation. Antioxidant coating 56 may be applied to lens

body 54 by any of the variety of methods known in the art. One such method

involves dissolving the antioxidant in a carrier that will attach to the intraocular

lens. The carrier either bonds itself to the lens or evaporates leaving the

antioxidant coating on the lens. Methods for coating intraocular lenses are

disclosed in US Patents 5,618,316, 5,026,395, 5,007,928, 4,955,901 , 4,774,036,

4,731 ,080, 4,312,575, and 4,240,163; the disclosures of which are incorporated

herein by reference. Antioxidant coating 56 does not significantly interfere with

the optical properties of lens body 54 and functions to detoxify free radicals in

eye 12 once intraocular lens 50 is positioned behind iris 16 and in front of

natural lens 18. In either embodiment of the invention, it is desirable that the

antioxidants in lens 10 are exposed to the eye elements but not distributed into

the eye.

Fig. 8 depicts another embodiment of the present invention where a

replacement lens 100 is implanted in eye 12. Lens 100 is different from lens 10

described above because it replaces natural lens 18 when lens 18 is removed.

Although lens 100 may have a different shape than lens 10 and interact with

light differently, lens 100 of the present invention includes antioxidants 102 thus providing an antioxidant presence in eye 12 after lens 18 is removed.

Antioxidant 102 may be dispersed through the body of lens 100 or may be

disposed about the surface of lens 100 depending on the manufacturing process

used to fabricate lens 100.

Accordingly, the improved antioxidant intraocular lens is simplified,

provides an effective, safe, inexpensive, and efficient device which achieves all

the enumerated objectives of the invention, provides for eliminating difficulties

encountered with prior devices, and solves problems and obtains new results in

the art.

In the foregoing description, certain terms have been used for brevity,

clearness, and understanding; but no unnecessary limitations are to be implied therefrom beyond the requirement of the prior art, because such terms are used

for descriptive purposes and are intended to be broadly construed.

Moreover, the description and illustration of the invention is by way of

example, and the scope of the invention is not limited to the exact details shown

or described.

Having now described the features, discoveries, and principles of the invention, the manner in which the antioxidant intraocular lens is constructed

and used, the characteristics of the construction, and the advantageous new

and useful results obtained; the new and useful structures, devices, elements,

arrangements, parts, and combinations are set forth in the appended claims.

Claims

1. An intraocular lens for implanting in the eye, the lens comprising a body having an antioxidant connected to the body.

2. The lens of claim 1 , wherein the body is fabricated from a polymer.

3. The lens of claim 2, wherein the body is fabricated from a silicone.

4. The lens of claim 2, wherein the antioxidant is cross linked with the polymer.

5. The lens of claim 4, wherein the polymer is one of polymethyl methacrylate, poly-2-hydroxyethyl methacrylate, methyl methacrylate copolymers, siloxanylalkyl, fluoroalkyl and aryl methacrylate, silicone elastomers, polysulfones, polyvinyl alcohols, polyethylene oxides, copolymers of fluoroacrylates and methacrylate, and polymers and copolymers of hydroxyalkyl methacrylate, such as 2-hydroxyethyl methacrylate, as well as methacrylic acid, acrylic acid, acrylamide methacrylamide, N,N-dimethylacryiamide, and N- vinylpryrrolidone.

6. The lens of claim 1 , wherein the lens further includes haptics.

7. The lens of claim 1 , in combination with an eye having a natural lens, the lens positioned in the anterior chamber of the eye.

8. The lens of claim 1 , in combination with an eye having a natural lens, the lens positioned in the posterior chamber of the eye.

9. The lens of claim 1 , in combination with an eye having the natural lens removed, the lens being a replacement lens and positioned in the posterior chamber of the eye.

10. The lens of claim 1 , wherein the antioxidant is one of vitamin E, vitamin C, beta-carotene, bilirubin, urate, coenzyme Q10, glutathione, selenium, dithiocarbamates, and butylated hydroxyanisole.

11. The lens of claim 1 , wherein the antioxidant is distributed throughout the body.

12. The lens of claim 1 , wherein the body of the lens is coated with the antioxidant.

13. The lens of claim 12, wherein the antioxidant is also distributed throughout the body.

14. A method of introducing antioxidants to an eye, the method comprising the

steps of: adding an antioxidant to an intraocular lens; and implanting the intraocular lens having the antioxidant in the eye.

15. The method of claim 14, further comprising the step of adding the antioxidant to the lens while the optical portion of the lens is being fabricated.

16. The method of claim 14, further comprising the step of adding the antioxidant to the lens after the optical portion of the lens is being fabricated.

17. The method of claim 14, wherein the step of adding an antioxidant to an intraocular lens includes the step of coating the lens with the antioxidant.

18. The method of claim 14, wherein the step of adding an antioxidant to an intraocular lens includes the step of distributing the antioxidant through the body

of the lens.