Adjustable intraocular lens
Methods and devices for altering the power of a lens, such as an intraocular lens, are disclosed. In one method, the lens comprises a single polymer matrix containing crosslinkable pendant groups, wherein the polymer matrix increases in volume when crosslinked. The lens does not contain free monomer. Upon exposure to ultraviolet radiation, crosslinking causes the exposed portion of the lens to increase in volume, causing an increase in the refractive index. In another method, the lens comprises a polymer matrix containing photobleachable chromophores. Upon exposure to ultraviolet radiation, photobleaching causes a decrease in refractive index in the exposed portion without any change in lens thickness. These methods avoid the need to wait for diffusion to occur to change the lens shape and avoid the need for a second exposure to radiation to lock in the changes to the lens.
1. An intraocular lens comprising:
a single polymer matrix having crosslinkable pendant groups, wherein the polymer matrix increases in volume when crosslinked; and
wherein substantially no free monomers are present therein; and
further comprising a UV radiation absorbing layer on at least one surface of the polymer matrix.
2. The lens of claim 1 , wherein the pendant group is 3,9-divinyl-2,4,8,10-tetraoxy-spiro[5.5]undecane.
3. An intraocular lens comprising a polymer matrix including photobleachable chromophores; and
a UV radiation absorbing layer on at least one surface of the polymer matrix;
wherein the chromophores comprise a malononitrile moiety, or are of Formula (I), (II), (III), or (IV):
where R 1 -R 10 are independently selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, —COOH, and —NO 2 ;
where R 11 -R 20 are independently selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, —COOH, —NO 2 , halogen, amino, and substituted amino.
4. The lens of claim 3 , wherein the photobleachable chromophores are dispersed within the polymer matrix.
5. The lens of claim 3 , wherein the photobleachable chromophores are present as pendant groups on the polymer matrix.
6. The lens of claim 3 , wherein at least one chromophore comprises a reactive site which can crosslink with a reactive site on the polymer matrix.
7. The lens of claim 3 , wherein at least one chromophore must absorb more than one photon for photobleaching of the chromophore to occur.
8. A method of altering the optical power of a lens, comprising:
providing a lens comprising:
a single polymer matrix having crosslinkable pendant groups, wherein the polymer matrix increases in volume when crosslinked; and
wherein the lens is devoid of free monomers; and
further comprising a UV radiation absorbing layer on at least one surface of the polymer matrix; and
exposing a portion of the lens to radiation, causing crosslinking to occur in the exposed portion of the lens and increasing the refractive index of the exposed portion of the lens, thereby altering the optical power of the lens.
9. The method of claim 8 , wherein the exposed portion of the lens is in the center of the lens.
10. The method of claim 8 , wherein the radiation to which the lens is exposed has a wavelength of from about 200 nm to about 600 nm.
11. A method of altering the optical power of a lens, comprising:
providing a lens comprising (i) a polymer matrix having photobleachable chromophores and (ii) a UV radiation absorbing layer on at least one surface of the polymer matrix, wherein the chromophores comprise a malononitrile moiety, or are of Formula (I), (II), (III), or (IV):
where R 1 -R 10 are independently selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, —COOH, and —NO 2 ;
where R 11 -R 20 are independently selected from hydrogen, alkyl, substituted alkyl, aryl, substituted aryl, —COOH, —NO 2 , halogen, amino, and substituted amino; and
exposing a portion of the lens to radiation, causing photobleaching to occur in the exposed portion of the lens and decreasing the refractive index of the exposed portion of the lens, thereby altering the optical power of the lens.
12. The method of claim 11 , wherein the exposed portion of the lens is in the center of the lens.
13. The method of claim 11 , wherein the radiation to which the lens is exposed has a wavelength of from about 200 nm to about 600 nm.
14. The method of claim 11 , wherein the photobleachable chromophores are dispersed within the polymer matrix.
15. The method of claim 11 , wherein the photobleachable chromophores are present as pendant groups on the polymer matrix.
16. The method of claim 11 , wherein at least one chromophore comprises a reactive site which can crosslink with a reactive site on the polymer matrix.
17. The method of claim 11 , wherein at least one chromophore must absorb more than one photon for photobleaching of the chromophore to occur.