predating speed dating cleveland - Accomodating intraocular lenses
The capsular bag 18 is connected to the ciliary body 16 by means of a plurality of zonules 26 which are strands or fibers. 5,607,472 to Thompson describes a dual-lens design.
More particularly, this invention relates to intraocular lenses which are focusable and allow for accommodation for near vision. State of the Art Referring to , the human eye 10 generally comprises a cornea 12, an iris 14, a ciliary body (muscle) 16, a capsular bag 18 having an anterior wall 20 and a posterior wall 22, and a natural crystalline lens 24 contained with the walls of the capsular bag.
Accomodating intraocular lenses
One or more restraining elements are provided to maintain the stressed state configuration of the hinge portion during implantation and during a post-operative period during which the capsular bag of the eye heals about the lens. The opposite happens as accommodation occurs for near vision, where the stress is transferred from the elongated lens into the contracted ciliary body. Furthermore, fibrosis and stiffening of the capsular remnants following cataract surgery may make this approach problematic. Such shrinking can distort a lens glued to the bag in a pre-shrunk state, especially since the lens is permanently affixed to a structure which is not yet in equilibrium.
The restraining elements are thereafter removable, preferably via a non-surgically invasive manner, e.g., via dissolution or laser light. In this sense, referring to , there is conservation of potential energy (as measured by the stress or level of excitation) between the ciliary body and the crystalline lens from the point of complete ciliary body relaxation for distance vision through a continuum of states leading to full accommodation of the lens. 4,944,082 to Richards et al., also utilizes a lens having regions of different focus, or a pair of compound lenses, which are held in place by haptics attached to the ciliary body. Sixth, Thompson fails to provide a teaching as to how or when to release the gel from the expansion channel; i.e., remove the stress from the lens.
However, none are capable of providing an accommodating implant which does not, in one way or another, risk damage to the ciliary body or the capsular bag, present technical barriers, or present potential serious consequences upon failure of the device.
It is therefore an object of the invention to provide an intraocular lens that functions similarly to the natural crystalline lens.
When the ciliary body 16 relaxes, the diameter of the opening increases, and the zonules 26 are pulled taut and exert a tensile force on the anterior and posterior walls 20, 22 of the capsular bag 18, tending to flatten it. In each of these intraocular lenses, a shift in axial position and an increase in distance from the retina results in a relative increase in focusing power. At implantation, the surgeon must create a substantially perfectly round capsulorrhexis, and insert the lens therethrough.
5, 2002, now abandoned which is a continuation-in-part of U. The ciliary body 16 surrounds the capsular bag 18 and lens 24, defining an open space, the diameter of which depends upon the state (relaxed or contracted) of the ciliary body 16. 6,299,641 to Woods describes another intraocular lens that also increases effective focusing power as a result of a change in axial position during accommodation. Prior to implantation, the lens is stressed into a non-accommodative state with a gel forced into a circumferential expansion channel about the lens.It is an additional object of the invention to provide an intraocular lens that permits uncomplicated implantation of the lens in a manner compatible with modern-day cataract surgery techniques.In accord with these objects, which will be discussed in detail below, an intraocular lens (IOL) system that permits accommodation and a method of implanting such an intraocular lens system are provided.According to a preferred aspect of the invention, the ciliary body is maintained in the relaxed state for the duration of the time required for the capsule to naturally heal and shrink about the lens; i.e., possibly for several weeks.After healing has occurred, the restraining element automatically or under surgeon control releases the lens from the stressed state. Through a process termed accommodation, the human eye can increase its focusing power and bring into focus objects at near. In any arrangement that is connected to the ciliary body, by haptic connection or otherwise, extensive erosion, scarring, and distortion of the ciliary body usually results. The lens comprises front and rear flexible walls joined at their edges, which bear against the anterior and posterior inner surfaces of the capsular bag. 6,231,603 to Lang each disclose an intraocular lens design where the configuration of a hinged lens support ostensibly allows the intraocular lens to change axial position in response to accommodation and thus change effective optical power. This approach has numerous drawbacks, a few of which follow.Tags: Adult Dating, affair dating, sex dating