US 7815678 B2
An accommodating intraocular lens (AIOL) including a biasing mechanism for elastically deforming an elastically deformable shape memory disk-like optical element for affording the AIOL a natural positive diopter strength for near vision. The AIOL is intended to be implanted in a human eye such that relaxation of its ciliary body causes its capsular diaphragm to apply an accommodation force for overcoming the biasing mechanism to reduce the AIOL's natural positive diopter strength for distance vision.
1. An accommodating intraocular lens (AIOL) comprising:
(a) a cup shaped casing having a leading surface, a trailing surface with an aperture, and at least one elastically deformable shape memory optical element;
(b) a carriage having a base plate and an aperture lens, and being slidingly mounted on said casing with said base plate lateral to said trailing surface for reciprocation between a first extreme position with said base plate adjacent said trailing surface and a second extreme position with said base plate distanced from said trailing surface relative to said first extreme position; and
(c) a biasing mechanism for urging said carriage relative to said casing towards said second extreme position for deforming said at least one shape memory optical element to at least partially bulge through said aperture to afford the AIOL a natural positive diopter strength for near vision,
said carriage being driven to said first extreme position on application of an external force to said base plate in an opposite direction to said urging direction to allow said at least one shape memory optical element to revert to its natural shape to decrease the AIOL's natural positive diopter strength for distance vision.
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8. The AIOL according to
Domestic priority claim is made to U.S. Provisional Patent Application Ser. No. 60/617,738 filed on Oct. 13, 2004 and International priority claim is made to World Intellectual Property Organization (WIPO) PCT/IL2005/001069 filed on Oct. 9, 2005, assigned the International Publication Number WO 2006/040759 A1, published Apr. 20, 2006.
The invention pertains to accommodating intraocular lenses (AIOLs), and AIOL assemblies including same.
Commonly owned PCT International Application No. PCT/IL02/00693 entitled Accommodating Lens Assembly and published under PCT International Publication No. WO 03/015669 illustrates and describes accommodating intraocular lens (hereinafter AIOL) assemblies, the contents of which are incorporated herein by reference. The AIOL assemblies include a haptics system adapted to be securely fixed in a human eye's annular ciliary sulcus at at least two spaced apart stationary anchor points so that it may act as a reference plane for an AIOL of continuously variable diopter strength affected by a human eye's capsular diaphragm acting thereagainst from a posterior direction and under the control of its sphincter-like ciliary body. WO 03/015669's FIGS. 1 and 2 show an AIOL assembly 2 designed to replicate a human eye's natural crystalline lens. The AIOL assembly 2 has a lens 6 made of a rigid material and a natural spherical shaped silicone ball 10 both having a refractive index greater than that of water. A human eye's capsular diaphragm directly bears against the silicone ball 10 from a posterior direction for resiliently elastically deforming it to a compressed flattened shape on relaxation of a human eye's ciliary body for decreasing its natural positive diopter strength for distance vision in a similar fashion to a human eye's natural crystalline lens. However, a human eye, and particularly an aging human eye, may be too weak to apply sufficient force to overcome such a silicone ball's inherent tendency to retain its natural shape thereby precluding accommodation.
Exemplary AIOLs are illustrated and described in U.S. Pat. No. 4,254,509 to Tennant, U.S. Pat. No. 4,409,691 to Levy, U.S. Pat. No. 4,888,012 to Horn et al., U.S. Pat. No. 4,892,543 to Turley, U.S. Pat. No. 4,932,966 to Christie et al., U.S. Pat. No. 5,476,514 to Cumming, U.S. Pat. No. 5,489,302 to Skottun, U.S. Pat. No. 5,496,366 to Cumming, U.S. Pat. No. 5,522,891 to Klaas, U.S. Pat. No. 5,674,282 to Cumming, U.S. Pat. No. 6,117,171 to Skottun, U.S. Pat. No. 6,197,059 to Cumming, U.S. Pat. No. 6,299,641 to Woods, U.S. Pat. No. 6,342,073 to Cumming et al., U.S. Pat. No. 6,387,126 to Cumming, U.S. Pat. No. 6,406,494 to Laguette et al., U.S. Pat. No. 6,423,094 to Sarfarazi, U.S. Pat. No. 6,443,985 to Woods, U.S. Pat. No. 6,464,725 to Skotton, U.S. Pat. No. 6,494,911 to Cumming, U.S. Pat. No. 6,503,276 to Lang et al., U.S. Pat. No. 6,638,306 to Cumming, U.S. Pat. No. 6,645,245 to Preussner, and US Patent Application Publication No. US 2004/0169816 to Esch.
The present invention is for a novel AIOL including a biasing mechanism for elastically deforming an elastically deformable shape memory optical element for affording the AIOL with a natural positive diopter strength for near vision. The biasing mechanism is designed to apply a deforming force FBM bounded on its lower side to be marginally greater than a minimum deformation force FOE required to deform the optical element and on its upper side by the sum of the deformation force FOE and an accommodation force FCD effected by a human eye's capsular diaphragm in an anterior direction on relaxation of the human eye's ciliary body for enabling the optical element to revert to its natural shape to decrease the AIOL's natural positive diopter strength for distance vision. The forces acting on the optical element of the AIOL of the present invention can be mathematically expressed as FOE+FCD>FBM>FOE. By virtue of this arrangement, the AIOL of the present invention facilitates accommodation even in the case of an aging eye capable of applying an accommodation force FCD which may be considerably less than that of a healthy eye.
The AIOL forms part of an AIOL assembly intended for self-anchoring implantation in a human eye's ciliary sulcus at least two spaced apart stationary anchoring points. The AIOL can be mounted in a discrete haptics system enabling in situ displacement of the AIOL along a human eye's visual axis for enabling accurate eyesight correction in general, and for compensating for capsular contraction in particular. Alternatively, the AIOL can be integrally formed with a haptics system including plastically deformable haptics also enabling in situ AIOL displacement. Commonly owned PCT International Application No. PCT/IL2005/000456 entitled Accommodating Intraocular Lens Assemblies and Accommodation Measurement Implant illustrates and describes such a discrete haptics system, and a unitary construction including a haptics system with plastically deformable haptics and integrally formed with an AIOL both enabling in situ AIOL displacement, the contents of which are incorporated herein by reference.
The foregoing has outlined rather broadly the features and technical advantages of the present invention in order that the detailed description of the invention that follows may be better understood. Additional features and advantages of the invention will be described hereinafter which form the subject of the claims of the invention. It should be appreciated by those skilled in the art that the conception and specific embodiment disclosed may be readily utilized as a basis for modifying or designing other structures for carrying out the same purposes of the present invention. It should also be realized by those skilled in the art that such equivalent constructions do not depart from the spirit and scope of the invention as set forth in the appended claims. The novel features which are believed to be characteristic of the invention, both as to its organization and method of operation, together with further objects and advantages will be better understood from the following description when considered in connection with the accompanying figures. It is to be expressly understood, however, that each of the figures is provided for the purpose of illustration and description only and is not intended as a definition of the limits of the present invention.
In order to understand the invention and to see how it can be carried out in practice, preferred embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings in which similar parts are likewise numbered, and in which:
A rigid carriage 67 is slidingly mounted on the casing 51 from the exterior and includes an annular base plate 68 formed with an aperture 69 and three longitudinally directed struts 71 having free ends 72 each formed with an aperture 73, and an aperture lens 74 having a leading portion 76 and a trailing portion 77 formed with three equispaced radially directed protrusions 78 for snap fitting into the apertures 73. The base plate 68 is preferably formed from a suitable rigid bio-compatible material such as PMMA, and the like. The aperture lens 74 is preferably formed from a suitable rigid bio-compatible material such as PMMA, and the like. The aperture lens 74 preferably has sufficient positive diopter strength, say, in the range of between about +10 to about +30, for basic eyesight correction. The struts 71 are slidingly received in the grooves 63 such that the aperture lens 74 is lateral to the leading surface 53 and the base plate 68 is lateral to the trailing surface 59. The carriage 67 reciprocates through a stroke S between a first extreme position in which the base plate 68 is adjacent the trailing surface 59 and a second extreme position in which the base plate 68 is distanced from the trailing surface 59 relative to the first extreme position. A biasing mechanism 79 constituted by a compression spring is disposed between the trailing portion 57 and the struts 71 for urging the carriage 67 to its second extreme position. The biasing mechanism 79 applies a deforming force FBM where FBM=FOE+Δ for deforming the optical element 66 to bulge through the aperture 62 to afford the AIOL 33 with a positive diopter strength for near vision (see
Although the present invention and its advantages have been described in detail, it should be understood that various changes, substitutions and alterations can be made herein without departing from the spirit and scope of the invention as defined by the appended claims. For example, the biasing mechanism 79 can be implemented by longitudinally compressible flex elements 81 (see
Moreover, the scope of the present application is not intended to be limited to the particular embodiments of the process, machine, manufacture, composition of matter, means, methods and steps described in the specification. As one of ordinary skill in the art will readily appreciate from the disclosure of the present invention, processes, machines, manufacture, compositions of matter, means, methods, or steps, presently existing or later to be developed that perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein may be utilized according to the present invention. Accordingly, the appended claims are intended to include within their scope such processes, machines, manufacture, compositions of matter, means, methods, or steps.