KR20060092228A - Intraocular lens for inhibiting pco and aco - Google Patents

Abstract

An intraocular lens for inhibiting posterior and anterior capsular opacification, or secondary cataract, includes an optic having a periphery provided with sharp bevels extending along arc segments defined by the juncture of the haptic-optic points of attachment and adjacent both the anterior and posterior optic surfaces.

Description

 INTROOCULAR LENS FOR INHIBITING PCO AND ACO} Prevents Capsular Capsular Turbidity (PCO) and Capsular Capsular Turbidity (ACO)

The present invention relates to an intraocular lens (IOL) for implantation into an amorphous lens in which a natural lens has been removed, for example, by damage or disease (such as a cataract lens). A novel intraocular lens is designed to prevent unwanted growth of lens epithelial cells (LECs) between the capsular bag and on the intraocular lens optic surface.

When cell growth occurs along the posterior capsular wall, it is known to those skilled in the art as a posterior capsular clouding or "PCO". When cell growth occurs along the lens anterior capsular wall and anterior optic plane, it is known to those skilled in the art as lens anterior capsular clouding or "ACO".

A common and preferred method of treating cataracts is to remove the blurred natural lens with a surgical procedure known as cataract extraction and replace it with an intraocular lens.

In the extracapsular extraction method, the natural lens is removed from the capsular bag, leaving the posterior part of the capsular bag (and preferably at least part of the anterior part of the capsular bag) inside the eye. In this case, the capsular bag is fixed to the eye's ciliary body through the ciliary platoon (毛 樣 體 小 帶). In another process known as intracapsular extraction, the ciliary platoon is cut to remove both the lens and capsular bag as is, replacing the intraocular lens that must be fixed inside the eye without the capsular bag. The extracapsular extraction method is considered less attractive than the extracapsular extraction method because the capsular bag remains attached to the ciliary body of the eye and provides a focusing and positioning means to the inner eye lens inside the eye. The capsular bag also functions to provide a natural membrane between the waterproofing of the front of the eye and the vitreous body of the back of the eye.

One known problem with cataract capillary extraction is posterior capsular clouding or secondary cataract, in which proliferation and migration of lens epithelial cells occurs along the posterior capsular bag behind the intraocular lens posterior surface resulting in clouding of the lens along the optic axis. This requires follow-up surgery such as Er (Yag laser capsulotomy) to open the capsular bag and clean the optic axis. Undesired complications may follow after capsulotomy. For example, because the capsular bag provides a natural membrane between the posterior vitreous of the eye and the waterproofing of the entire eye, the removal of the capsular follicles causes the vitreous to move to the waterproofing, which can result in serious vision-threatening complications. . Therefore, it is highly desirable to first prevent posterior capsular clouding, thus eliminating the need for subsequent posterior capsulotomy.

Various methods have been proposed in the art to prevent or at least minimize the number of lens capsular turbidity and consequently the required number of Er (yak laser capsulotomy). This method of preventing posterior capsular clouding comprises two main categories: mechanical and medical means.

In the category of mechanical means of prevention of capsular bag turbidity, much effort has been made to create a sharp discontinuous band in the posterior capsular wall, which is well known to those skilled in the art as an effective means of minimizing capsular bag clouding. See, for example, January 1999, Vol. 25, Cataract and Refractive Surgery, Nishi's "Capsular Posterior Caps Turbidity". Such discontinuous bands in the posterior capsular wall may be formed using an intraocular lens having a posterior edge that produces a sharp edge into the peripheral wall of the intraocular lens.

To date, the most promising methods for preventing the formation of lens epithelial cells on the posterior surface of the intraocular lens include, for example, the intraocular lens having a sharp circumferential edge at the junction of the posterior surface and the circumferential edge to the posterior capsular wall. It is a mechanical means of designing to create discrete bands. This discontinuous band in the posterior capsular wall has been clinically proven to prevent the migration and growth of lens epithelial cells along the inner eye lens surface beyond this band. One of the earliest reports of these convex posterior capsule opacification effects of flat convex intraocular lenses was published in March 1996, after natural posterior dislocation of cataract and refractive surgery, Vol. 22, page 273, Nishi et al. Description of the endocapsule posterior chamber lens, wherein the authors tested an explanted flat convex PMMA eye lens in which the posterior surface of the eye lens was planar and formed a square edge with the peripheral edge of the eye lens.

"The visual observation of the exfoliated internal lens and the capsular film showed a diameter of 9.5 mm. An open circular ring was fitted along the capsular equator. The capsular equator, which did not contact the haptic, was well maintained (Fig. 3) An opaque lens scalpel (Hummering's ring cataract) was observed between the haptic and the optic, and the lens posterior capsule facing the internal lens optic was transparent.

Histopathological examination of the explanted lens revealed little epithelial cells (LECs) on the capsular bag. Between the rings and the optics, accumulated lens scalpel was observed at the edge of the optics (FIG. 4). There was a clear band in the capsular bag at this site. ”(Highlighted)

Thus, for many years after this report, there has been much research in the industry to create a sharp inner edge lens with a sharp rear edge to produce a sharp discontinuous band in the posterior capsular wall. The intraocular lens with a sharp posterior edge prevents capsular posterior capsule clouding compared to the intraocular lens with rounded edges at the posterior surface and peripheral edge junction, but especially if there is an unbalanced contact and force between the inner lens circumference and the capsular bag. There remains a possibility that lens epithelial cells migrate behind the inner eye lens surface along the posterior capsule. For example, this can happen if the intraocular lens moves inside the capsular bag after surgery.

In addition to these issues that are well known and reviewed for lens capsular turbidity that occurs along the capsular wall of the capsular bag, lens epithelial clouding may occur as the epithelial cells move along the isolated capsular bag and continue along the anterior surface of the intraocular lens optics. ACO) may also occur. This problem occurs particularly easily in eyeglass lenses made of hydrophilic materials. Thus, there remains a need for an improved intraocular lens structure that solves the problem of lens epithelial cell migration along both the capsular and anterior capsules, followed by the formation of lens posterior capsule turbidity, lens capsular turbidity, respectively.

The present invention solves the problem of both capsular capsular turbidity formation and lens capsular turbidity formation by providing a circumferential lens having a circumference comprising sharp edges along both the front and rear circumferential edges of the optic object. The sharp edge spans the entire circumference of the inner lens object, including the portion where the haptic is attached to the optic. The sharp edge may be formed in a bevel shape having pointed vertices around the outer circumference of the optic as well as the portion to which the haptic is attached. The outer structure of these intraocular lens optics is a significant improvement over conventional optics in that it provides an improved membrane for the movement of lens epithelial cells from the inner lens optics forward and backward. The optic circumferential structure is relatively easy to manufacture as compared to other more complex inner lens circumferential structures proposed in the prior art to prevent migration of lens epithelial cells. For example, referring to patents and patent application publications that disclose various inner lens optical outer periphery structures are as follows.

US Patent No. 5,171,320, issued to Nishi on December 15, 1992.

US Patent No. 5,693,093 to Woffinden et al. On December 2, 1997.

U.S. Patent No. 6,162,249 to Deacon, dated December 19, 2000.

1 is a cross-sectional view of the human eye showing a natural lens inside the capsular bag of the eye.

Fig. 2 is a cross sectional view of the human eye showing a state where a natural lens has been removed and replaced with a prior art internal lens.

3 is a perspective view of an inner lens according to an embodiment of the present invention.

4 is a side elevational view of an intraocular lens according to an embodiment of the present invention.

Fig. 5 is an enlarged partial cross-sectional view showing in detail the wall shape of the outer circumference of the inner lens of the present invention.

Referring to the drawings, a cross-sectional view of the human eye 10 with front chamber 12 and rear chamber 14 separated by iris 30 in FIG. 1 is shown. A ciliary 16 supporting the natural lens 17 of the eye is present in the posterior chamber 14. The light enters the eye by passing through the cornea 18 and into the lens. The cornea and the lens work together to direct and focus the light on the retina 20 located at the back of the eye. The retina is connected to the optic nerve 22 which delivers the image received by the retina to the brain to interpret the image.

In eyes in which the natural lens is damaged (eg, as blurred as a cataract), the natural lens can no longer guide and focus properly the incoming light into the retina and the image is blurred. Well known surgical techniques for treating this situation can remove the damaged lens and replace it with an artificial lens known as an intraocular lens (IOL), such as the prior art intraocular lens 24 shown in FIG. While the precise placement of the intraocular lens within the eye and the design of the intraocular lens may vary, the present invention is directed only to the intraocular lens itself for implantation into the substantially oval lens capsule 16 of the eye 10. Related.

Such implantation techniques are generally referred to in the art as "in-the-bag" techniques. In this surgical technique, the posterior capsular bag 16a is left untouched and still fixed to the ciliary body, and a portion of the anterior part of the capsular bag is cut out (called "capsulorhexis").

Thus, in the "in-the-bag" technique of intraocular lens surgery, the intraocular lens is placed inside the capsular coating 16 located behind the iris 30 in the posterior chamber 14 of the eye. The intraocular lens includes a central optic 24a that mimics the extracted natural lens by directing and focusing light onto the retina and further includes means for securing the optic at a suitable location inside the capsular bag. A common inner lens structure for fixing an optic is called a haptic, an elastic structure that extends radially outward from the perimeter of the optic. In particular, in a typical intraocular lens design, the two haptics 24b and 24c extend and bend from opposite sides of the optic, providing a bias against the interior of the lens capsule to fix the optic at a suitable location inside the lens capsule ( 2).

As mentioned in the Background section of this specification, an undesired postoperative condition, known as lens posterior capsular opacity (PCO), may occur, resulting in the implanted intraocular lens becoming blurred and thus no longer suitably lighted. It can't be guided and focused. The main cause of this condition is that lens epithelial cells (LECs) mitosis and migrate across the posterior surface of the lens capsule behind the optics of the intraocular lens. As shown in Fig. 2, the rear surface 16a of the capsular coating 16 contacts the rear surface of the optics 24a of the intraocular lens. When damaged natural lenses are surgically removed, a large number of lens epithelial cells may remain inside the capsular 16 coating, particularly at the equator, which is the major source of embryonic lens epithelial cells. Surgeons may attempt to remove all lens epithelial cells from the capsular bag during intraocular lens implantation, but removing all lens epithelial cells is nearly impossible. Residual lens epithelial cells can multiply and migrate along the posterior capsular wall 16a. This is particularly true for intraocular lenses with rounded edges, and three years after surgery, clinically significant posterior capsular clouding (PCO) was found in about 20-50% of patients. A currently popular and effective way to prevent capsular bag clouding is to create a discontinuous sharp bend in the capsular bag wall 16a, as described in the background herein.

In addition to the problem of posterior capsular clouding, other postoperative conditions, known as capsular capsular clouding (ACO), may have the effect of obstructing clear vision. In this state, the lens epithelial cells migrate along the remaining portion of the anterior capsular lens capsule and then along the anterior surface of the inner lens optic. This phenomenon occurs in hydrophilic materials, in particular eyeglass lenses made of hydrophilic materials containing moisture in the range of about 18 to 26%. If this happens, the inner eye lens may unnecessarily need to eat out and implant a new inner eye lens in the eye.

3, 4 and 5, an embodiment of the inner lens 32 of the present invention is shown. The inner lens 32 is shown to include a central optic 34 having opposing front and rear surfaces 34a and 34b, respectively. When implanted inside the eye, the front optic surface 34a faces the cornea 18 and the back optic surface 34b faces the retina 20. In this particular type of inner lens, two haptic pairs 34a, 34b and 36c, 36d are attached and extended on opposite sides around the optic 34 to provide a bias against the interior of the capsule 16. It is configured to suitably position the inner lens 32 therein. More specifically, the haptics 36a-36d are configured to engage the haptic with the inner surface of the capsular bag when implanting an intraocular lens in the capsular bag. Coupling between the haptic and the capsular film leaps back toward the retina when the posterior surface 34b of the intraocular lens optic is pressed strongly against the posterior capsular wall 16a of the capsular film 16. Creates a biasing force that causes The present invention is not limited to the type of eyeglass lens shown herein, but is more useful in eyeglass lenses having various numbers and types of haptic elements. Moreover, although particularly useful in intraocular lenses formed of the cell-friendly materials described above, the intraocular lens 32 is a suitable intraocular lens material such as, for example, polymethyl methacrylate (PMMA), silicone, hydrogels and composites thereof. It can be formed as. The inner lens 32 may be a single piece (formed from a single block of the same or dissimilar material) or a multi-piece structure (such as when the haptic is attached to the optic after the optic is formed).

3, 4, and 5, the inner lens optic 34 has an optical outer circumference O _P. For the purposes of the description herein, the arc portions of the optical periphery O _P are each identified. In particular, this arc portion spanned between the haptics referenced by reference numerals 38a to 38d is adjusted by the portions spanned adjacent to the haptic referenced by reference numerals 40a to 40d.

The arc portions spanning between the haptics 38a-38d each include a sharp edge E _ant defined adjacent to the front optic surface 34a and a sharp edge E _post defined adjacent to the rear optic surface 34b. . The edges E _ant, E _post are, for example, simply formed at substantially right angles, or for example edge arrangements, or hollow, shown herein with respect to the junction with the optics of the haptic described below. As shown in US Pat. No. 6,558,419, assigned to, other suitable arrangements can be taken to prevent migration of lens epithelial cells. The sharp edges E _ant, E _post are effective for forming bands in the anterior capsular and posterior capsular walls along the coalesced arc portions 38a-38d when the intraocular lens is implanted into the capsular bag as described above. Since the edges are provided adjacent to both the anterior and posterior optical surfaces, movement of the lens epithelial cells is likewise prevented along both the anterior capsular and posterior capsular walls along the coalesced arcs 38a-38d.

Sharp edges H _a to prevent movement of the lens epithelial cells along the remaining arc spanning adjacent to the point at which the haptic is attached to the optic periphery To H _d ) are adjacent to the front optic surface 34a, respectively, and arc portions 40 _a to. 40 _d ), the sharp edges He _e -H _h are each adjacent to the rear optic surface 34b, with arcs 40 _a to 40 _d ). Sharp edge (H _a To H _h ) may each be formed with a sharp bevel with the bevel vertex B _apex facing away from the haptic element that is generally integrated with the bevel. However, the sharp edge (H _a To The exact shape of H _h ) can vary and there is only a condition that the edges act to form bands in the coalesced portion of the capsular capsular wall to prevent lens epithelial cells from moving beyond this point.

Presently, a preferred method of forming a number of sharp edge shapes within the eye lens optic 34 includes a milling operation in which the eye lens optic is mounted to a fixture and a mill is used to cut around the rear optic surface. Other methods that can be used to form circumferential edge placement include, for example, lathe machining and molding. Medial lens 32 is preferred to ensure a tumble polishing processes (tumble polishing) prior to the formation of an edge disposed in an edge (E _ant, E _post, H _ah) to preserve the sharpness.

Claims (6)

Inner lens for implantation into the human eye, A lens optic having opposing front and rear surfaces defined by the outer periphery of the optic, One or more haptics attached to an outer periphery of the optic and extending from the optic, The junction of the outer circumference of each said haptic and optic forms an arc, Adjacent lenses each comprising first and second bevels adjacent to the front surface and the back surface, each having a sharp vertex formed along each arc portion The eye lens of claim 1, wherein the eye lens optic is formed of a hydrophilic material. The eye lens of claim 2, wherein the eye lens is formed of a hydrophilic material containing water in the range of about 18 to about 26%. The inner lens of claim 1, wherein the outer periphery of the optic extending between the haptic-optic junctions includes sharp edges (E _ant , E _post ) adjacent the front and rear surfaces, respectively. The eye lens of claim 1, wherein the lens optics and the one or more haptics are integrally formed together. The eye lens of claim 1, wherein the lens optics and the one or more haptics are formed separately and subsequently attached together.

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