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. A 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 malonoitrile moiety, or are of the Formula (I), (II), (III), (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.
2. The lens of claim 1 , wherein the lens is a contact lens.
3. The lens of claim 1 , wherein the photobleachable chromophores are dispersed within the polymer matrix.
4. The lens of claim 1 , wherein the photobleachable chromophores are present as pendant groups on the polymer matrix.
5. The lens of claim 1 , wherein at least one chromophore comprises a reactive site which can crosslink with a reactive site on the polymer matrix.
6. The lens of claim 1 , wherein at least one chromophore must absorb more than one photon for photobleaching of the chromophore to occur.
7. The lens of claim 1 , wherein the chromophores are of Formula (III), and wherein R 1 , R 5 , or R 10 is a crosslinkable group.