Accommodating Intraocular Lens System Having Spherical Aberration Compensation and Method

Abstract

An accommodating intraocular lens includes an optic portion, a haptic portion. The optic portion of the lens includes an actuator that deflects a lens element to alter the optical power of the lens responsive to forces applied to the haptic portion of the lens by contraction of the ciliary muscles and a secondary deflection mechanism. Movement of the lens element by the actuator causes the lens element to deform and the secondary deflection mechanism causes the lens to further deform.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS [0001] This application is a continuation of pending U.S. application Ser. No. 11 / 646,913, filed Dec. 27, 2006; which application is a continuation-in-part of U.S. application Ser. No. 10 / 971,598, filed Oct. 22, 2004; which is a continuation-in-part of U.S. application Ser. No. 10 / 734,514, filed Dec. 12, 2003, and claims the benefit of priority from U.S. Provisional Application No. 60 / 433,046, filed Dec. 12, 2002, the disclosures of which are hereby incorporated by reference in their entirety.FIELD OF THE INVENTION [0002] The present invention relates to intraocular lenses (“IOLs”) having optical parameters that are changeable in-situ. More particularly, the invention has application in IOLs for in-capsule implantation for cataract patients or presbyopic patients, wherein movement of the lens capsule applies forces to a circumferentially supported haptic to more efficiently induce transfer of fluid media within the interior of the IOL to alter...

AI Technical Summary

Benefits of technology

[0022] It also is an object of the present invention to provide methods and apparatus for further enhancing conversion of lens capsule movements into hydraulic forces, so as to improve modulation of the lens actuator and dynamic surface.

[0023] It is another object of this invention to provide methods and apparatus to enhance the efficiency with which loads arising due to natural accommodating muscular action are converted to hydraulic forces.

[0027] Deflection of the dynamic surface causes the shaping fluid in the sealed fluid cavity to redistribute which, in turn, alters the shape of the dynamic surface so that it is aspherical. By making the dynamic surface aspherical the total amount of travel required by the actuator may be reduced from approximately 300 microns for non-aspheric lenses to 200 microns. As a result, a more efficient IOL may be produced that requires less influence from the lens capsule.

[0031] The actuator used in the optic portion of the IOL may be centrally located within the optic portion that, when filled with fluid, biases the dynamic surface of the IOL to the accommodated state. When the ciliary muscles are contracted, the zonules and capsular bag are less taut, and the haptics are unstressed. Relaxation of the ciliary muscle causes the zonules to transition the capsule to less convex shape, which applies compressive forces to the haptic, thereby withdrawing fluid from the actuator and causing the lens to transition to the unaccommodated state. Alternatively, the actuator may comprise structures disposed at the periphery of the optic portion, so as to further minimize refractive effects and optical aberrations in the optic portion.

Problems solved by technology

Since the lens can no longer accommodate, however, the patient typically needs glasses for reading.

After placement, accommodation is no longer possible, although this ability is typically already lost for persons receiving an IOL.

Although previously known workers in the field of accommodating IOLs have made some progress, the relative complexity of the methods and apparatus developed to date have prevented widespread commercialization of such devices.

Previously known devices have proved too complex to be practical to construct or have achieved only limited success, due to the inability to provide accommodation of more than 1-2 diopters.

According to Eyeonics, redistribution of the ciliary mass upon constriction causes increased vitreous pressure resulting in forward movement of the lens.

Another disadvantage of previously known devices is that they oftentimes create spherical aberrations.

As is well known in the art, lenses composed of elements having spherical surfaces are easy to manufacture but are not ideal for creating a sharp image because light passing through the elements does not focus on a single focal point.

As a result of spherical aberration in an intraocular lens, all of the light passing through the lens does not focus on the retina resulting in an image that may be blurred and may have softened contrast.

Such a device provides an obvious disadvantage that the amount of light allowed to pass through the lens is reduced.

However, such combined lenses and lenses having aspherical profiles are significantly more expensive to produce.

In addition, combining lenses requires additional space to house the multiple lenses.

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