The present disclosure relates to an accommodative lens and in particular to an intraocular lens that accommodates in response to movement by a ciliary body of a patient's eye and is anchored to the capsular bag to prevent displacement of the intraocular lens during accommodation.
A cataract can occur when the natural lens of an eye or its surrounding transparent membrane becomes clouded, resulting in various degrees of blindness. One method of treating this condition is to perform cataract surgery, which involves removing the cataract and implanting an intraocular lens (“IOL”). Some conventional replacement IOLs are rigid and not intended to flex or provide accommodation and therefore requires the patient to use external vision correction such as eyeglasses or contact lenses for near vision. Other conventional IOLs may provide accommodation, but have drawbacks. For instance, movement or displacement of accommodating IOLs typically can create spaces in which material such as cells may accumulate, resulting in posterior capsular opacification, or clouding of the IOL.
It therefore can be seen that a need exists for an accommodating IOL that addresses the foregoing and other related and unrelated problems in the art.
According to various implementations of the invention, an accommodative intraocular lens (IOL) is formed having a lens body that is in a disaccommodative configuration (i.e., has a curvature that is in a disaccommodated shape). The lens body is attached, directly or indirectly, to an anatomical structure of an eye such as a ciliary body. In some implementations, the lens body is attached to the ciliary body via a haptic system that includes one or more haptics, which help support and transmit an accommodative force to the lens body. For example, the haptics may transmit an axial compressive force from the ciliary body to the lens body during accommodation of the patient's eye. The transmitted force causes the lens body to alter its shape from a disaccommodative shape to an accommodated shape, thereby changing the power of the IOL. In some implementations of the invention, in order to prevent movement of the lens body while the force is being transmitted, one or more wings may project from and help anchor the lens body, directly or indirectly, within the eye. For example, the wing(s) may anchor the lens body to the capsular bag such that the lens body is not displaced from its implanted location while the transmitted force deforms the lens body.
In some implementations of the invention, the accommodative lens assembly includes a first lens including a lens body, haptic system, and at least one wing projecting from the lens body. The accommodative lens assembly can be implanted in a patient's eye in a position to respond to forces transmitted by the ciliary body during accommodation. In order to stabilize the accommodative lens assembly so that the lens body is not displaced from its implantation site, the wing anchors the accommodative lens assembly in the capsular bag such that the transmitted forces that deform the lens body during accommodation do not also move the lens body from its implanted position. When implanted, the lens body of the accommodative lens assembly generally is anteriorly located with respect to the capsular bag.
In further implementations of the invention, a second intraocular lens can replace the natural lens within the capsular bag. In these implementations, an incision or capsulorhexis is made to remove the natural lens and implant the second intraocular lens. In some implementations, the wing of the first lens is configured to be attached to or otherwise tucked into the capsulorhexis. In some implementations, the second intraocular lens is configured to maintain or otherwise provide a base power during accommodation. In these implementations, the lens body of the first lens can change optical power during accommodation while the second intraocular lens generally does not change optical power. In this manner, the second intraocular lens may substantially maintain its shape while only the lens body of the first lens changes shape during accommodation.
Additionally, in some implementations of the invention, the lens body of the first lens is formed having an inner portion and an outer portion. During accommodation, when the transmitted force deforms the lens body, at least a portion of the inner portion bulges forwardly in a direction away from the capsular bag. In addition, the inner portion can be formed from a thinner, less dense or more flexible membrane material than the outer portion, thereby enabling bulging of the inner portion when force is transmitted to the lens body. In some implementations, the haptic system includes a plurality of haptics each configured to provide a deforming force to the inner portion of the lens body at radial angles during accommodation.
Various objects, features and advantages of the present invention will become apparent to those skilled in the art upon a review of the following Detailed Description of the Invention, when taken in conjunction with the accompanying drawings.
The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more examples of implementations of the invention and, together with the description, serve to explain various principles and aspects of the invention.
The accompanying drawings, which are incorporated into and constitute a part of this specification, illustrate one or more examples of implementations of the invention and, together with the description, serve to explain various principles and aspects of the invention.
According to various implementations of the invention, lens body 104 may be formed from soft, flexible optic lens materials such as hydrophyllic and/or hydrophobic acrylic, silicone, and/or hydrogel materials. For example, lens body 104 may be formed from Acrysof® acrylic material manufactured by Alcon Laboratories.
In some implementations of the invention, lens body 104 may include an outer portion 104A that radially surrounds an inner portion 104B. In some implementations of the invention, as illustrated, lens body 104 has a generally curved configuration, where inner portion 104B includes an apex of curvature 104C at an anterior side (i.e., side away from an eye when implanted into the eye) and generally coincident with optical axis A-A and thus can provide the lens body with a base optic power.
Lens body 104 generally can be manufactured having a shape in a disaccommodated configuration. Therefore, when a deforming force is applied to lens body 104 during accommodation of the patient's eye in which the IOL is implanted., inner portion 104B may bulge or otherwise be urged in a direction generally along optical axis A-A such that when deformed, lens body 104 changes its shape (i.e., its curvature) to an accommodative configuration. In some implementations of the invention, in response to the applied deforming force when implanted into the patient's eye, inner portion 104B bulges “forward” toward the anterior chamber of the eye (i.e., away from the capsular bag).
In some implementations of the invention, the inner portion 104B of the lens body 104 may be deformed in response to the accommodative force due at least in part to a difference in rigidity between inner portion 104B and outer portion 104A. In some implementations of the invention, the difference in rigidity may be achieved by using a thinner and/or more flexible material for inner portion 104B than for outer portion 104A. In these implementations, outer portion 104A generally is less rigid than inner portion 104B because outer portion 104A is thicker than inner portion 104B.
In still further implementations of the invention, the difference in rigidity also may be achieved by using different compositions of materials for inner portion 104B and outer portion 104A. For example, inner portion 104B may be formed from a material that is more flexible than a material used to form outer portion 104A. In particular, lens body 104 may be formed using one or more curing/cross-linking processes such that outer portion 104A forms into a relatively rigid structure while inner portion 104B can comprise a flexible membrane or bag that receives and contains an aqueous optic fluid material such as a liquid, gel, or soft, pliable solid materials therein. In one example, outer peripheral portion 104A may form a shell that encompasses at least a portion of the inner lens portion 104B. As an additional alternative, the difference in rigidity between the inner and outer lens portions may be achieved by forming outer and inner portions 104A, 104B using a combination of different thicknesses of material and different compositions of materials for outer and inner portions 104A, 104B. As illustrated in
The haptic 106 typically can be integrally formed with the lens body 104 and will project radially therefrom for a length/distance adapted to extend to a position adjacent and/or in contact with the ciliary body of the patient's eye upon implantation of the lens assembly. Thus, as the ciliary body moves inwardly and forwardly during accommodation, the haptic will be engaged so as to transfer an axial compressive force to the lens body. Alternatively, the haptics can be separately formed from a similar acrylic, silicone or hydrogel optic material as the lens body, having a similar or greater rigidity to that of the outer portion 104A of the lens body to apply a consistent compressive force thereto without collapsing or otherwise inadvertently deforming, and can be attached to a peripheral side edge of the outer portion 104A by adhesive or chemical bonding, welding or other methods as known in the art.
As further illustrated in
As indicated in
In operation, various processes of ciliary body C may cause haptic system 102 to transmit a deforming force to lens body 104. In some implementations of the invention, ciliary body C causes haptic system 102 to transfer the deforming force in a direction that is generally inward toward and perpendicular to optical axis A-A, causing lens body 104 to bulge forward along optical axis A-A toward the anterior side and away from capsular bag B, causing lens body 104 to enter an accommodative configuration. When the accommodative deforming force is released, such as when the patient's eye returns to a disaccommodated state, lens body 104 relaxes back to its original, disaccommodative shape.
In operation, lens body 104 has an optic power when in a disaccommodative shape/curvature. During accommodative movement of the ciliary body of the patient's eye, a haptic element of haptic system 102 is engaged and causes lens body 104 to deform, altering the curvature of the lens body to adjust the optic power. In this manner, the anterior lens changes power during accommodation. Engagement of the wing(s) 108 with the capsular bag helps locate and secure the lens body in a desired position within the patient's eye and can further provide support to help the lens body resist buckling and maintains the anterior lens in its implanted position in the patient's eye. In some implementations, the posterior lens maintains its optic power during accommodation. In these implementations, the posterior lens may provide a base power that does not change during accommodation while the anterior lens can change optic power during accommodation.
Implementations of the invention may be described as including a particular feature, structure, or characteristic, but every aspect or implementation may not necessarily include the particular feature, structure, or characteristic. Further, when a particular feature, structure, or characteristic is described in connection with an aspect or implementation, it will be understood that such feature, structure, or characteristic may be included in connection with other implementations, whether or not explicitly described. Thus, various changes and modifications may be made to the provided description without as would be appreciated. As such, the specification and drawings should be regarded as illustrative only, and the scope of the invention to be determined solely by the appended claims.
This application claims the priority of U.S. Provisional Patent Application No. 61/720,688 filed on Oct. 31, 2012.
| Number | Date | Country | |
|---|---|---|---|
| 61720688 | Oct 2012 | US |