CN1933791A - Posterior chamber phakic intraocular lens - Google Patents

Abstract

A lenticular intraocular lens comprising: a lens body having a flat anterior optic surface and a curved posterior optic surface which determines the optical power of the lens. The lens allows liquid to flow between the lens and the iris and between the lens and the eye lens. The enlarged outer rim helps to maintain the position of the lens. We present embodiments in which there is an opening, channel, or both at the peripheral edge of the flat front optical surface or lens body that helps prevent a seal from being formed between the flat surface of the lens and the iris.

Description

posterior chamber phakic intraocular lens

technical field

The present invention relates generally to intraocular lenses, and more particularly to phakic intraocular lenses. In particular, the invention relates to phakic intraocular lenses having a flat anterior surface and a curved posterior surface in the lens optic.

Background technique

Various posterior chamber phakic intraocular lenses are known in the art. These lenses are implanted directly behind the iris in front of the lens of the eye. A disadvantage of these lenses is the need to utilize an iridotomy, which allows fluid to flow from the posterior chamber of the eye to the anterior chamber of the eye. The prior art requires the use of implants without iridotomy. Another disadvantage of the known lenses is the limitation on the size of the optical part of the lens. The prior art requires large optical section lenses. The prior art also requires lenses that are constructed so that they do not interfere with the flow pattern of the fluid in the eye, while at the same time being constructed so that they remain in place within the eye. Typical known lenses utilize a sense of touch that spans the anterior chamber of the eye and engages opposing portions of the ciliary body to hold the lens in place. Other lenses use the iris to exert a central force on the lens. The prior art requires lenses that do not rely on much contact with the eye, but remain in place like known lenses.

Contents of the invention

The present invention provides a phakic intraocular lens having a flat anterior surface and a curved posterior optical surface to determine the power of the lens. The lens may be iridotomy or non-iridotomy. The lens has positioning arms that help keep the lens in place in the eye. We disclose various structures for positioning the arm. In one embodiment, the positioning arm is short so that it cannot wedge into the opposing part of the ciliary body. In one embodiment of the invention, the radius of curvature of the posterior surface of the positioning arm is substantially equal to the radius of curvature of the anterior surface of the lens of the eye. The present invention also provides a lens having an optic body and a pair of positioning arms, wherein the lens is constructed such that there is an additional space behind the lens for liquid which helps to keep the lens spaced from the lens of the eye.

The present invention also provides a phakic intraocular lens having a flat anterior surface and a curved posterior optical surface to determine the optical power of the lens. The lens has an enlarged rim disposed around the optic portion, which maintains the lens in place within the eye.

The present invention provides a lens having a joint between the positioning arm and the optic, the joint defining a channel that prevents the formation of a seal between the iris and the lens when the lens is engaged with the iris. In another embodiment of the invention, openings are formed in the optics and/or positioning arms.

Another feature of the invention is a method of designing a lens based on eye measurements.

Description of drawings

Figure 1 is a cross-sectional view of an eye with a phakic intraocular lens implanted near the lens of the eye.

Fig. 2 is a front view of the lens of the first embodiment of the present invention.

Fig. 3 is a cross-sectional view along line 3-3 in Fig. 2 .

Figure 4 is a front view of the lens of the first embodiment in which two opposing channels are provided between the flat front surface and the positioning arm.

Fig. 5 is a cross-sectional view along line 5-5 in Fig. 4 .

FIG. 5A is an enlarged view of a circular portion in FIG. 5 .

Figure 6 is a cross-sectional view of the first embodiment phakic lens and eye lens showing the relative radii of the posterior surface of the phakic lens, the posterior surface of the positioning arm, and the anterior surface of the eye lens.

Figure 7 is a cross-sectional view of a second embodiment phakic lens and eye lens showing the relative radii of the posterior surface of the phakic lens, the posterior surface of the positioning arm, and the anterior surface of the eye lens.

Figure 8 is a cross-sectional view of a third embodiment phakic lens and eye lens showing the relative radii of the posterior surface of the phakic lens, the posterior surface of the positioning arm, and the anterior surface of the eye lens.

Figure 9 is a cross-sectional view of a fourth embodiment phakic lens and eye lens showing the relative radii of the posterior surface of the phakic lens, the posterior surface of the positioning arm, and the anterior surface of the eye lens.

Figure 10 shows a comparison between a prior art lens having the same refractive power and a lens of the present invention.

Like numbers refer to like elements in this specification.

Detailed ways

A phakic intraocular lens made in accordance with the concept of the present invention is indicated by numeral 10 in these figures. Lens 10 is placed in the posterior chamber of the eye in FIG. 1 . Eye 12 includes: cornea 14 , iris 16 and eye lens 18 . The phakic intraocular lens 10 is placed behind the iris 16 and in front of the lens 18 of the eye so that it affects the light entering the lens 18 in the eye 12 .

At least one pair of positioning arms 20 extend from opposite sides of the lens 10 and help maintain the position of the lens 10 relative to the eye 12 . The edge of positioning arm 20 is a rounded surface that contacts the zonules. The positioning arm 20 is not designed to wedge into two opposing parts of the ciliary body, but it can contact the ciliary body or the zonules in different lens sizes and configurations. Various types and shapes of positioning arms 20 are known in the prior art, any of which is suitable for the lens of the present invention. In a front view from FIG. 2 , the positioning arm 20 may be rectangular. In other embodiments of the invention, three or four positioning arms 20 are equally spaced from the optical portion surrounding the lens 10 . In other embodiments, positioning arm 20 extends entirely around the optical portion of lens 10 .

In each of the lens embodiments described in this application, the lens body has a flat front optical face 30 and a curved rear optical face 32 . The large flat surface formed by the front optical face 30 is positioned directly behind the iris 16 so that the lens 10 slides smoothly behind the iris 16 when the lens 10 is moved into contact with the iris 16 . In most embodiments, the diameter 34 of the flat front optical face 30 is between 6mm and 9mm. In some embodiments, this diameter 34 may be reduced to 4mm. The radius of curvature 36 of the curved optical surface 32 is between 14 mm and 21 mm. By measuring the patient's refractive correction, and measuring the patient's eye, the exact size can be determined. This measurement can be done using ultrasound techniques. The design of the lens 10 is carried out after knowing the actual dimensions of the lens of the eye and the iris. For example, the overall size of the space between the lens of the eye and the iris can be measured, and the dimension 44 is designed to prevent wedging of the lens 10 itself. The curvature of the anterior surface of the eye lens 18 may also be measured for determining the appropriate curvature 42 across the lens 18 . In the context of this application, the term "flat surface" includes lens structures whose front surface is slightly curved to prevent unwanted reflections from entering the pupil. This curvature is insignificant to the optical properties of the lens, so it still falls within the definition of "flat surface" as used in this specification.

At the outer edge or part of the outer edge of the optical part, a positioning arm 20 is connected to the optical part of the lens 10 . The positioning arm 20 can have various shapes when viewed from the front view shown in FIG. 2 . FIG. 2 shows a rectangular embodiment, where the width of the rectangle is smaller than the diameter of the optical portion of lens 10. As shown in FIG. In another embodiment, the width of the rectangle is equal to the diameter of the optic of the lens. Even though the lens optics and the positioning arm 20 are integrally formed, the connection between the positioning arm 20 and the lens optics is referred to as the joint 40 of the lens 10 .

Another feature of lens 10 is that the outer diameter of the lens optic is the thickest region (cross-section) of lens 10 and forms a bulbous rim 41 around the outer edge of the optic. However, edge 41 does not protrude from the platform front surface of lens 10 . This area is called the outer edge 41 . The edge 41 corresponds to the joint 40 at the position of the positioning arm 20 . The thick rim 41 is placed in the gap 43 defined between the lens 18 of the eye, the iris 16, the ciliary body and the zonules that support the lens 18 of the eye. A thick bulbous rim 41 maintains the general position between the lens 10 and the posterior surface 30 of the pupil. Another function of the rim 41 is to prevent the lens 10 from slipping through the zonules and into the vitreous. The rim 41 can also cause the eye to exert a central force on the lens 10 when the eye is in contact with the rim 41 .

The radius of curvature 42 of the positioning arm 20 is smaller than the radius 36 of the curved optical surface 32 . This arrangement isolates the posterior surface of lens 10 from the lens 18 of the eye, thereby allowing space between the lens 10 and the lens 18 of the eye for fluid to flow. This created additional space can be seen in the comparative example shown in Figure 10, where a lens of the same refractive power overlaps the eye lens. Used to illustrate that there is an additional liquid space behind the lens 10. In Figure 10 the additional space is shaded. The typical lens shown in Figure 10 is a type of lens disclosed in US6,015,435. The lens 10 creates a large space between the lens 18 of the eye and the rear surface of the lens 10 . This space allows the fluid of the eye to flow freely between the lens 10 and the lens 18 of the eye. In one embodiment of the invention, the radius 42 is equal to the radius of curvature 43 of the lens 18 of the eye. The length 44 between the ends of the positioning arm 20 is greater than the outer diameter of the eye lens 18 in the embodiment of FIGS. 6, 7, and 8 . In FIG. 9, the positioning arm 20 is relatively short with a length 44 between its ends that is less than the outer diameter of the lens 18 of the eye. In the embodiment of Fig. 9, the edge 41 may be larger, which may provide a larger central force. Furthermore, the embodiment of FIG. 9 does not constantly engage the zonules around the lens 18 of the eye.

Figures 2, 3 and 6 show an embodiment of the invention in which the positioning arm 20 is tapered to one end from a joint defining a sharp angle. In the embodiment of Figure 6, radius 36 is 20 mm, radius 42 is 10 mm, and radius 43 is 10 mm. The diameter 34 of the optic is 7mm. The length 44 between the two ends of the positioning arm is 12mm.

FIGS. 4 and 5 are similar embodiments to FIGS. 2 and 3 except that the connector of FIGS. 4 and 5 has a channel 46 which prevents a seal between the connector 40 of the lens 10 and the iris 16 . Channel 46 does not pass entirely through the lens body of lens 10, as shown in FIG. 5A. In other embodiments of the present invention, through holes may be formed in the joint 40 or the positioning arm 20 . In another embodiment, a small opening is formed in the center of the optic. The diameter of this central opening is 0.8 mm. These channels and openings allow the free flow of liquid.

FIG. 7 shows another embodiment in which joint 40 defines rounded corners. In the embodiment of Figure 7, radius 36 is 14.9mm, radius 42 is 10mm, and radius 43 is 10mm. The diameter 34 of the optic (inside the fillet) is 7.17mm and the diameter 48 of the optic (outside the fillet) is 8.03mm. The length 44 between the two ends of the positioning arm is 11.88mm.

Fig. 8 shows another embodiment of the fillet of the joint. In the embodiment of Figure 8, radius 36 is 18 mm, radius 42 is 10 mm, and radius 43 is 10 mm. The diameter 34 of the optic (inside the fillet) is 6.98mm and the diameter 48 of the optic (outside the fillet) is 7.18mm. The length 44 between the two ends of the positioning arm is 12mm. In Figure 8, the positioning arm has a substantially constant thickness at its outer end and adjacent the flat outer end.

Fig. 9 shows another embodiment of a joint defining rounded corners or smooth rounded corners. In the embodiment of Figure 9, radius 36 is 14.9 mm, radius 42 is 10 mm, and radius 43 is 10 mm. The diameter 34 of the optic (within the fillet) is 6.02mm. The length 44 between the two ends of the positioning arm is 8 mm.

Preferably, the lenses of the various embodiments of the present invention are made from acrylic. However, various lens materials are known to professionals. For example, it is well known that the optical portion of an intraocular lens can be made from the following materials: polymethyl methacrylate, poly-2-hydroxyethyl methacrylate, methyl methacrylate copolymer, siloxanylalkyl, fluoroalkyl, and Arylmethyl methacrylates, silicones, silicone elastomers, polysulfones, polyvinyl alcohols, polyethylene oxides, fluoroacrylic and methacrylic acid copolymers, and hydroxyalkyl methacrylic acid polymers and copolymers , for example, 2-hydroxyethyl methacrylate, and methacrylic acid, acrylic acid, acrylamide-methacrylamide, N,N-dimethacrylamide, and N-vinylpyrrolidone. In addition, compounds that absorb ultraviolet light or other short wavelengths (e.g., below 400 nm), e.g., compounds derived from benzotriazole-based, benzophenone-based, or mixtures thereof, can be added to the components that make up the implant. in monomers and/or polymers. Other compounds well known in the art may also be used to make the optics of lens 10 of the present invention.

An advantage of the present invention is that the flat front surface of the lens may have a larger diameter than the curved front surface lens. The large diameter and large radius of the posterior optical surface allow the formation of lenses with a wide range of optical powers, for example, for patients who are not candidates for corneal laser surgery. Large diameter optics also minimize haloing. The large flat face reduces pressure on the iris, so fluid can flow from the posterior to the anterior chamber of the eye. In addition, the channel of the present invention still allows fluid to flow even if the joint of the lens touches the iris. Therefore, the lens can be implanted without iridotomy. A thick rim placed around the lens optic keeps the lens in place.

The lens can be implanted by first folding the lens and then sliding the folded lens into the pupil of the eye.

In the above description, we have used certain terms for simplicity, clarity and understanding. There are no unnecessary limitations beyond what is required in the prior art, since these terms are used for descriptive purposes and have a broad meaning.

Furthermore, the invention has been described and illustrated as an example and, therefore, the invention is not limited to the exact details described.

Claims (17)

1. phakic intraocular lens comprises:

Smooth forward direction optical surface and the crooked back lenticular body to optical surface is arranged, and it determines the refractive power of these lens; And

This lenticular body has thick outer rim, is suitable for placing in eyes these lens.

2. according to the lens of claim 1, also comprise: the opticator of at least one registration arm and lenticular body; Being connected between registration arm and the opticator is joint; This joint has front surface.

3. according to the lens of claim 2, the front surface of its center tap is determined passage.

4. according to the lens of claim 2, its center tap is determined perforate.

5. according to the lens of claim 2, wherein the opticator of lenticular body is determined perforate.

6. according to the lens of claim 1, the diameter of wherein smooth forward direction optical surface is between 6mm and 9mm.

7. according to the lens of claim 1, the diameter of wherein smooth forward direction optical surface is between 4mm and 9mm.

8. according to the lens of claim 1, wherein crooked back is between 14mm and 21mm to the radius of curvature of optical surface.

9. according to the lens of claim 1, also comprise: at least one registration arm, it is connected to outer rim and stretches out from outer rim; Registration arm has crooked rear surface.

10. according to the lens of claim 9, wherein crooked back is between 14mm and 21mm to the radius of curvature of optical surface; The radius of curvature of the crooked rear surface of this at least one registration arm less than bending after to the radius of curvature of optical surface.

11. according to the lens of claim 9, wherein lens are to be used in combination with eye lens, its front surface has radius of curvature; The crooked back of lenticular body is to the radius of curvature of the optical surface radius of curvature greater than eye lens; The crooked back radius of curvature that equals the eye lens front surface to the radius of curvature on surface with this at least one registration arm.

12. according to the lens of claim 11, wherein the overall diameter of lenticular body and at least one registration arm is greater than the overall diameter of eye lens.

13. according to the lens of claim 11, wherein the overall diameter of lenticular body and at least one registration arm is less than the overall diameter of eye lens.

14., two registration arm of extending from outer rim are arranged wherein according to the lens of claim 13.

15. a phakic intraocular lens comprises:

Smooth forward direction optical surface and the crooked back lenticular body to optical surface is arranged, and it determines the refractive power of these lens;

Radius of curvature to optical surface after this bending is between 12mm and 21mm;

This lenticular body has thick outer rim, is suitable for placing in eyes these lens;

A pair of registration arm from the outer rim extension; Each registration arm has crooked rear surface; With

The crooked rear surface radius of curvature of this at least one registration arm less than bending after to the radius of curvature of optical surface.

16. according to the lens of claim 15, the diameter of wherein smooth forward direction optical surface is between 6mm and 9mm.

17. according to the lens of claim 16, wherein Zu He registration arm has overall diameter; This overall diameter is less than 11mm.

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