CAPSULAR MEMBRANE IMPLANTS TO INCREASE ACCOMMODATIVE AMPLITUDE
20170000601 ยท 2017-01-05
Inventors
- Daniel G. Brady (San Juan Capistrano, CA)
- Zsolt Bor (San Clemente, CA)
- Edward P. Geraghty (Rancho Santa Margarita, CA, US)
- Brooke C. Basinger (Long Beach, CA, US)
- Carina R. Reisin (Tustin, CA, US)
- Douglas S. Cali (Mission Viejo, CA, US)
Cpc classification
A61F9/00736
HUMAN NECESSITIES
A61F2002/1681
HUMAN NECESSITIES
A61F2/14
HUMAN NECESSITIES
F04C2270/0421
MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
A61F2/1624
HUMAN NECESSITIES
International classification
Abstract
A support is coupled to the lens capsule to increase accommodation. The support may be adjustable, such that patient refraction and accommodation can be adjusted following surgery. The support may comprise rigidity sufficient to decrease radial movement of the intermediate portion of the lens capsule. The support can be placed on the intermediate portion to decrease radial movement of the intermediate portion of the lens capsule and increase radial stretching of an outer portion of the lens capsule extending between the zonules and the intermediate portion coupled to the support, such that the amount of accommodation of the eye is increased. The support may comprise a biocompatible material capable of stable coupling to the lens capsule following implantation, such that the far vision refraction and accommodation of the eye can be stable following surgery.
Claims
1. A method of treating an eye, the eye having a lens and a capsule, the method comprising: placing a support on an intermediate portion of the capsule to decrease radial movement of the intermediate portion and increase an amount of accommodation of the eye.
2. The method of claim 1, wherein a peripheral portion of the lens capsule is coupled to the intermediate portion of the lens capsule and wherein radial movement of the peripheral portion is increased when the support is coupled to the intermediate portion.
3. The method of claim 1, wherein a central portion of the lens capsule is coupled to the peripheral portion and wherein an anterior movement of the central portion is increased when the intermediate portion is coupled to the support.
4. The method of claim 1, wherein the decreased radial movement comprises one or more of a stretching, a bending, a flexing, a translation or a rotation of the intermediate portion.
5. The method of claim 1, wherein the eye has a first amount of accommodation prior to placement of the support on the eye and a second amount of accommodation when the support is placed on the intermediate portion of the capsule, the second amount greater than the first amount.
6. The method of claim 1, wherein the capsule comprises one or more of an anterior capsule or a posterior capsule.
7. The method of claim 1, wherein the portion comprises an intermediate portion of the lens capsule located between a peripheral portion of the lens capsule and a central portion of the lens capsule.
8. The method of claim 7, wherein the peripheral portion is connected to zonules of the eye and the central portion corresponds to a center of a pupil of the eye, and wherein the intermediate portion of the capsule is coupled to the peripheral portion.
9. The method of claim 8, wherein the lens comprises a natural lens of the eye and wherein the portion of the lens capsule comprises an anterior capsule having an anterior outer surface and wherein the support is adhered to the anterior outer surface of the intermediate portion to increase accommodation of the central portion.
10. The method of claim 9, wherein the support is placed at least partially between the anterior capsule and the iris, the support comprising a thickness dimensioned such that the iris slides over the support when the iris contracts and dilates and wherein the support comprises a light absorbing material such that the support appears dark and appears as the pupil when the iris slides over the support.
11. The method of claim 10, wherein the support comprise at least one curved surface corresponding to curvature of the lens and wherein the support comprises a thickness of no more than about 500 um.
12. The method of claim 10, wherein the support comprises at least one flat surface.
13. The method of claim 9, wherein the central portion of the lens capsule protrudes anteriorly from the support with an elevation of the central portion so as to increase a curvature of the anterior lens capsule when the eye accommodates.
14. The method of claim 13, wherein the central portion of the lens capsule protrudes from the support with the elevation an amount greater than without the support and wherein the curvature of the central portion comprises an amount greater than the eye without the support.
15. The method of claim 9, wherein the support comprises a substantially annular structure extending around the central portion so as to enclose the central portion and define an outer boundary of the central portion with the support and wherein the central portion comprises a protrusion extending anteriorly when the eye accommodates.
16. The method of claim 7, wherein the support comprises an annular oval shape profile and wherein the intermediate portion comprises an annular oval portion coupled to the annular oval support to correct an astigmatism of the eye.
17. The method of claim 16, wherein central portion comprises a toric shape profile when the eye accommodates to correct the astigmatism of the eye.
18. The method of claim 7, wherein the intermediate portion comprises a toric shape profile.
19. The method of claim 9, wherein the support extends substantially around the central portion so as to enclose the central portion and define an oval outer boundary of the central portion and wherein the central portion protrudes anteriorly from the oval outer boundary with an elevation and comprises a toric shape profile to correct the astigmatism when the eye accommodates.
20. The method of claim 9, wherein the support extends substantially around the central portion so as to enclose the central portion and define an oval outer boundary of the central portion and wherein the central portion protrudes anteriorly from the oval outer boundary with an elevation and comprises a toric shape profile to correct the astigmatism when the eye accommodates.
21. The method of claim 7, wherein the support is adhered to an anterior surface of an anterior capsule comprising the intermediate portion and wherein the support is used to guide removal of the central portion with a capsulorhexis to remove the central portion.
22. The method of claim 1, wherein the lens comprises an accommodating IOL.
23. The method of claim 22, further comprising removing a central portion of the lens capsule with a capsulorhexis, the removed central portion comprising a dimension across of at least about 4 mm and wherein the support comprises an inner dimension across of at least about 4 mm and wherein the capsule moves the peripheral portion radially inward toward the lens with a force of at least about 3 g.
24. The method of claim 22, wherein the accommodating IOL has a haptic to move the IOL and wherein a structure of the support is aligned with the haptic to couple the structure to the haptic to increase the amount of accommodation.
25. The method of claim 1, wherein support comprises a plurality of elongate segments passed through an incision and adhered on the lens capsule such that the support is assembled in situ within the eye.
26. The method of claim 1, wherein the support comprises an annular structure having an inner diameter across and outer diameter across corresponding to a width of the annular structure and wherein the thickness comprises no more than about half of the width.
27. The method of claim 26, wherein the annular structure comprises a ring.
28. The method of claim 26, wherein the annular structure defines an aperture having a center and wherein the center is aligned with a pupil corresponding to a visual axis of the eye.
29. The method of claim 1, wherein the support is adhered to the intermediate portion of the capsule and comprises a modulus of at least about 600 kPa, such that the support moves the peripheral portion inward radially when the eye accommodates.
30. The method of claim 29, wherein the support comprises one or more of metal, nickel, titanium, nitinol, silicone, plastic, polypropeleyene, acryalte, ceramic or polycarbonate.
31. The method of claim 29, wherein the support is adhered with an adhesive, the adhesive comprising one or more of cyanoacrylate, temperature sensitive adhesive, thermoreversible adhesive, a curable adhesive, a patterned microstructure based adhesive, a glycoprotein based adhesive or a cross-linker such as a photosensitive crosslinker.
32. The method of claim 29, wherein the support is adhered to the intermediate portion with mechanical coupling comprising one or more of clamping, locking, threads, bayonet mounting or mechanical force.
33. The method of claim 29, wherein the support is adhered to the intermediate portion with tack welding.
34. The method of claim 1, wherein the support comprises an adjustable support.
35. The method of claim 34, wherein a dimension across the support is adjusted to adjust one or more of a refraction of the eye for far vision or an amount of accommodation of the eye.
36. The method of claim 35, wherein the dimension across the support is increased to decrease myopia of the eye or increased to decrease hyperopia of the eye.
37. The method of claim 35, wherein the support comprises a shape changing material and wherein the shape changing material is treated with energy to adjust a dimension across the support.
38. The method of claim 37, wherein the shape changing material comprises a heat sensitive material and wherein the support is heated with light energy to stiffen the support when the support is coupled to the intermediate portion.
39. The method of claim 37, wherein the shape changing material comprises one or more of a metal or a polymer.
40. The method of claim 37, wherein the adjustable support comprises layers of polymer and wherein the layers of polymer are arranged in a progressively stiffer membrane such that inner layers comprise more stiffness than outer layers and wherein at least one inner layer is severed so as to release an amount of contractual force increase the dimension across the support.
41. The method of claim 43, wherein the at least one layer is severed with one or more of laser energy, laser pulses, Nd:YAG laser pulses, femto second laser pulses or mechanical cutting.
42. The method of claim 34, wherein the support is treated with light energy to weaken the support when the support is coupled to the intermediate portion.
43. The method of claim 1, wherein the support comprises an oval support and wherein a long dimension of the oval is aligned with an axis of an astigmatism of the eye to correct the astigmatism of the eye.
44. The method of claim 1, wherein spherical aberration of the eye is decreased with the support placed on the intermediate portion.
45. The method of claim 1, wherein the support comprises a structure having protrusions separated by a distance dimensioned to receive the portion of the lens capsule.
46. The method of claim 45, wherein the structure comprises a channel and wherein the protrusions comprise rims extending circumferentially around the support, each rim having an inner surface to contact the portion of the capsule, the distance extending between the inner surfaces of the rims.
47. The method of claim 45, wherein the intermediate portion of the capsule is introduced between the protrusions to couple the intermediate portion to the support.
48. The method of claim 1, wherein an adhesive is positioned on the intermediate portion in an annular pattern and wherein the adhesive is hardened on the intermediate portion of the capsule such that the support comprises hardened adhesive and wherein the glue sticks to the intermediate portion when hardened to couple the support to the peripheral portion.
49. The method of claim 1, wherein the support comprises a first elongate narrow profile through an insertion in a cornea of the eye of no more than about 2 mm, and wherein the support is expanded to a wide profile configuration and coupled to the intermediate portion of the lens capsule when the support comprises the expanded wide profile configuration.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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[0088] FIG. 2M1 shows a narrow profile configuration for insertion into the eye through the incision with rotation of the support shown in 2L;
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[0090] FIG. 3A1 shows the support as in
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[0094] FIGS. 3E1 and 3E2 show a first plurality of the curved elongate segments aligned on the anterior lens capsule and a second plurality of the curved elongate segments aligned on the posterior lens capsule, respectively, so as to vault the lens capsule and increase accommodation, in accordance with embodiments of the present invention;
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DETAILED DESCRIPTION OF THE INVENTION
[0103] Embodiments of the present invention as described herein can be used in many ways to improve accommodation of the eye. The embodiments as described herein can be used to treat presbyopia with an otherwise healthy eye, in a non-invasive or minimally invasive manner, such that the accommodation of the natural lens of the eye is enhanced. The embodiments as described herein can also be used in conjunction with IOLs such that the amount of accommodation with the IOL can be increased. The accommodating IOL may comprise a deformable IOL that can provide increased curvature when the eye accommodates, or an IOL in which the support increases an amount of axial movement of the lens when the eye accommodates, or combinations thereof.
[0104] The treatment of the capsular tissue can increase radially inward force to an IOL from at least about 1 gram (hereinafter g) to at least about 3 g, for example at least about 4 g, in exemplary embodiments at least about 6 g, so as to provide corresponding improvement in accommodation, for example at least about a two fold increase, for example about a three fold increase, in the amount of accommodation when combined with a commercially available accommodating IOL.
[0105] The embodiments as described herein can be used in combination with other treatments such as a phakic IOLs, intracorneal inlays, laser softening of the lens, IOLs, for example accommodating IOLs so as to increase substantially the amount accommodation of the implanted accommodating IOLs.
[0106] Alternatively or in combination with increasing an amount of accommodation of the eye, the stiffening support as described herein can be used to treat astigmatism of the eye, and may decrease spherical aberration of the eye, for example with increased accommodation of the eye.
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[0109] Description of the eye 10 suitable for combination in accordance with the embodiments as described herein with reference to
[0116] During accommodation, the lens and ciliary components of the eye adjust to bring an object into focus. When the eye has a relaxed configuration for far vision, the ciliary muscle 32 of the eye is relaxed such that zonules 30 pull the lens capsule 22 outward. When the eye accommodates for near vision, the ciliary muscle 32 contracts such that zonules 30 allow the lens peripheral portion 22P of the lens capsule to move radially inward with a radially inward force 40. When the peripheral portion 22P moves radially inward, the front portion of the lens capsule moves forward with anterior movement 42 such that the anterior optical surface of the lens moves forward so as to bring the image of the near object into focus on the retina. In addition, the curvature of the anterior surface of the lens 20 can increase when the front portion of the lens capsule moves forward so as to increase the optical power of the lens 20 and bring the image of the object into focus on the retina. When the peripheral portion 22P moves radially outward, the front portion of the lens capsule moves with posterior movement 43 such that the anterior optical surface of the lens moves posteriorly and decreases curvature so as to bring the image of the far object into focus on the retina.
[0117] With presbyopia, the inner components of the lens such as the cortex 24 may stiffen, such that the amount of accommodation decreases. The amount of anterior movement 42 of lens 22 and the amount corresponding curvature change decrease such that the eye is no longer capable of bringing both near and far objects into focus with accommodation.
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[0119] The lens 20 stretches when the ciliary muscles relax such that the capsule is stretched radially outward. The relaxed lens configuration 20A for accommodation for near vision has a central portion 22C of the lens capsule 22, an intermediate portion 22IA, and a peripheral portion 22AP. The relaxed configuration 20A for accommodation comprises the central portion 22CA located along axis 11, the intermediate portion 22IA located a radial distance 22RIA from axis 11 and the peripheral portion 22PA located a radial distance 22PRA from axis 11. The relaxed configuration 20A comprises an outer portion 22OA extending from the intermediate portion 22IA to the peripheral portion 22PA with a distance 22ODA. The central portion 22CA has a curvature 22CAC when the lens comprises the relaxed configuration for accommodation.
[0120] The stretched lens configuration 20S for far vision has a central portion 22CS of the lens capsule 22, an intermediate portion 22IS, and a peripheral portion 22AS. The stretched lens configuration 20S for far vision comprises the central portion 22CS located along axis 11, the intermediate portion 22IS located a radial distance 22RIS from axis 11 and the peripheral portion 22PS located a radial distance 22PRS from axis 11. The stretched configuration 20S comprises an outer portion 22OS extending from the intermediate portion 22IS to the peripheral portion 22PS with a distance 22ODS. The central portion 22CS has a curvature 22CSC when the lens comprises the stretched configuration for far vision.
[0121] The stretching of lens capsule 22 with lens configuration 20S can store energy and provide an increased amount of radially inward force 40, so as move the anterior capsule forward with anterior movement 42. The stretching of lens capsule 42 extends from axis 11 to peripheral portion 22P. The radial distance 22PRS is greater than the radial distance 22PRA, corresponding to stretching of the central portion 22C, the intermediate portion 22I, the outer portion, and the peripheral portion 22P. The radial distance 22RIS is greater than the radial distance 22RIA corresponding to stretching of the intermediate portion 22I and central portion 22C. The radial distance 22ODA is less than the radial distance 22ODS corresponding to stretching of the outer portion 22O located between intermediate portion 22I and peripheral portion 22P. Although the stretched components of the lens capsule can move the peripheral portion 22P radially inward with the force 40, the presbyopic lens can be stiffer than the non-presbyopic lens such that the anterior movement 42 and the corresponding curvature change may not be enough to provide accommodation.
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[0123] The inner central optical portion 22C comprises an optically useful portion of the lens capsule 22, and corresponds to light transmitted through the pupil of the eye. The intermediate portion 22I can be located away from the central portion 22C such that the central portion remains optically clear and substantially free from aberrations and light scatter. The intermediate portion may correspond to a portion of the capsule covered by the pupil, for example in bright light. In many embodiments, the intermediate portion is covered by the pupil in dim illumination, for example, such that the patient can receive the benefit of increased accommodation when reading in dim light or viewing objects in dim light for example. The intermediate portion may comprise an intermediate portion of the anterior capsule, or an intermediate portion of the posterior capsule, or both, for example.
[0124] The stiffened intermediate portion of the capsule 22I can increase accommodation of the eye 10 in many ways. The accommodation can be increased with one or more of increased radially inward force 40 of the lens capsule, increase anterior movement 42 of the lens capsule, increased curvature 22AC of the lens capsule, or increased curvature 22CPC of the central portion comprising a protrusion 22CP (
[0125] The stiffening support as described herein can increase the modulus, for example the Young's modulus of the lens capsule of the intermediate portion 22I. The lens capsule may comprise a Young's modulus within a range from about 1.5 mN/mm2 to about 3 mN/mm2, for example. (See Weeber H A., Martin H. The Role of the Capsular Bag in Accommodation. In: Guthoff R, Ludwig K, eds. Current Aspects of Human Accommodation II. Heidelberg: Kaden Verlag; 2003). Although the material properties of the lens capsule can be at least somewhat non-linear and the Young's modulus of the lens capsule can vary with age, a person of ordinary skill in the art can determine empirically the thickness and corresponding modulus based on the teachings described herein, so as to provide stiffening treatment to the intermediate portion 22I and increased accommodation.
[0126] The support can be coupled to the lens capsule in many ways. For example the support can be adhered to the lens capsule with an adhesive comprising one or more of a curable adhesive, cyanoacrylate, temperature sensitive adhesive such as Poly(N-isopropylacrylamide) (hereinafter p-Nipam), a patterned microstructure based adhesive such as a setae based adhesive, thermoreversible adhesive, a glycoprotein based adhesive such as a glycosylated hudroxytryptophan, or a cross-linker such as a photosensitive crosslinker. The setae may comprise setae similar to gecko footpads having the attractive forces that hold the setae to surfaces with van der Waals interactions between the finely divided setae and the surface of the lens capsule. The support can be coupled to the capsule mechanically, for example with sutures, tabs or channels, and can be tack welded to the capsule.
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[0129] The increased elevation and curvature of the central portion relative to the peripheral portion can increase the optical power of the central portion substantially. The lens has an index of refraction of about 1.45 and the aqueous humor has an index of refraction of about 1.33, such that the curvature of the central portion 22C provides optical power. The optical power of the protrusion can be determined based on the curvature corresponding to the height and diameter of the protrusion 22CP.
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TABLE-US-00001 TABLE I Diameters and corresponding elevations to provide curvature changes corresponding 1 D, 2 D, 3 D and 4 D of increased accommodation. Diameter Elevation Elevation Elevation Elevation mm @1 D @2 D @3 D @4 D 0 0 0 0 0 0.5 0.347 0.694 1.04 1.39 1 1.39 2.78 4.17 5.56 1.5 3.13 6.25 9.38 12.5 2 5.56 11.1 16.7 22.2 2.5 8.68 17.4 26.0 34.7 3 12.5 25 37.5 50 3.5 17.0 34.0 51.0 68.1 4 22.2 44.4 66.7 88.9 4.5 28.1 56.3 84.4 112.5 5 34.7 69.4 104.1 138.9 5.5 42.0 84.0 126.0 168.1 6 50 100 150 200 6.5 58.6 117.4 176.0 234.7 7 68.1 136.1 204.1 272.2
[0131] The additional optical power provided by protrusion 22CP can be combined with anterior movement of the central portion 22C and the intermediate portion 22I, so as to further increase the amount of accommodative optical power when protrusion 22CP increases curvature of the central portion 22C. For example, increased stretching of the peripheral and outer portions of the lens capsule can be combined with the protrusion 22CP and the anterior movement of the intermediate portion 22I and central portion 22C, so as to provide greater than about 2 D of accommodative optical power when the protrusion 22P provides about 2 D of accommodative optical power.
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[0134] While the support 100 may comprise one or more of many shapes to inhibit radial movement, in many embodiments support 100 comprises an annular structure such as an annular ring or annular oval. The annular structure can extend substantially around the central portion 22C, so as to enclose and define the central portion 22C with the support 100. The support 100 may resist radial movement and corresponding circumferential expansion and compression of the intermediate portion 22I, so as to encourage formation of protrusion 22CP when the eye accommodates.
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[0136] The increased stretching of lens capsule 22 with lens configuration 20S coupled to support 100 can store energy and provide an increased radially inward force as indicated by arrows 40, so as move the anterior capsule forward as indicated with arrow 42. The increased stretching of lens capsule 42 corresponds to increased stretching of outer portion 22O of the capsule between the intermediate portion 22I coupled to the support and the peripheral portion 22P coupled to the zonules. The radial distance 22RIS is similar to radial distance 22RIA corresponding to no substantial increased stretching of the intermediate portion 22I and central portion 22C. The radial distance 22ODA is less than the radial distance 22ODS corresponding to stretching of the outer portion 22O located between intermediate portion 22I and peripheral portion 22P. As the peripheral portion 22P of the lens may be pulled that radial distance 22PRS corresponds substantially to the eye without the support as shown above, the radial stretching distance 22ODS can be substantially greater for the eye with the support.
[0137] The lens capsule can be coupled to the intermediate support with amounts of strain corresponding to the relaxed lens capsule during accommodation, or amounts of strain corresponding to stretching of the lens capsule when the ciliary muscle of the eye relaxes for far vision, and amounts in between. For example, with capsulorhexis, it can be helpful to couple the support to capsule to provide support around the edge of the incision. With the natural crystalline lens of the eye, the amount of strain of the intermediate portion 22I and the central portion 22C can be related to the elevation of protrusion 22CP. The decreased radial movement and decreased circumferential stretching of intermediate portion 22I can define an outer boundary of protrusion 22CP and encourage formation of protrusion 22CP.
[0138] The curvature profile elevation data and figures as described herein show that presbyopia can be treated with an appropriately sized support 100 coupled to intermediate portion 22I so as to produce a protrusion to treat presbyopia, and that the protrusion can be used in combination with additional components of accommodation, such as movement anteriorly of the intermediate portion 22I and the central portion 22C when the eye accommodates, and radially inward elastic force and radially inward movement of the peripheral portion of the lens capsule. The elastic peripheral and outer portions of the lens capsule can move the intermediate and central portions of the lens capsule anteriorly when the eye accommodates, and the elastic peripheral and outer portions of the lens capsule can provide radially inward force and radially inward movement of the peripheral portion of the lens capsule to move the intermediate portion 22I and the peripheral portion 22P anteriorly. The intermediate portion 22I can be coupled to stiffening support 100 with an amount of strain so as to provide appropriate far vision refraction and increased accommodation. The amount of strain of the stiffened intermediate portion may correspond to the stretched lens capsule for far vision, the non-stretched accommodating lens capsule, or amounts of strain in between corresponding to intermediate vision. In many embodiments, the intermediate portion 22I is stiffened when the eye does not accommodate and the lens capsule is stretched, for example when dilated during surgery, such that the intermediate portion 22I and the central portion 22C comprise a curvature and strain corresponding to the non-accommodating stretched lens capsule for far vision of the eye. Alternatively, the intermediate portion 22I can be stiffened with amounts of strain corresponding substantially to the non-stretched capsule when the eye accommodates, for example, such that the intermediate portion 22I and the central portion 22C comprise a curvature and strain corresponding to the non-stretched accommodating lens capsule.
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[0141] The oval support 100 can be used to correct one or more of many types of astigmatism of the eye, such as lenticular astigmatism, or corneal astigmatism, or combinations thereof.
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[0143] The long dimension of the oval annular support 100 can be aligned with the astigmatism of the eye such as with the rule astigmatism, so as to correct the vision of the eye. For example, the long dimension of the oval annular support 100 can be aligned with the steeper substantially vertical axis 12C, and the shorter dimension of the support 100 can be aligned with the flatter substantially horizontal axis 12B. The oval protrusion 23P can have a ratio of the long axis to the short axis so as to correct the astigmatism of the eye when the lens capsule is relaxed with ciliary muscle contraction and the eye accommodates for near vision, or when the lens capsule is stretched with the zonules and the ciliary muscle is relaxed for far vision.
[0144] The stiffened intermediate portion 22I coupled to the oval annular support 100 can induce astigmatism of the lens with toric protrusion 22CP so as to correct the astigmatism of the eye. The oval intermediate portion 22I coupled to annular oval support 100 comprises a shorter inner dimension 112A and a shorter outer dimension 114B. The oval stiffened intermediate portion 22I comprises an elongate inner dimension 112B and an elongate outer dimension 114B. The shorter inner dimension 112A and the elongate inner dimension 114A can define the oval outer boundary of the central portion 22C, such that the central portion 22C comprises an oval shape profile having one or more of an elliptical shape profile, a lentoid shape profile, or an asymmetrical elliptical shape profile. In many embodiments, the oval shape profile corresponds to a toric shape of the protrusion 22CP when the eye accommodates. When the lens capsule moves anteriorly with accommodation of the lens capsule such that central portion 22C comprises protrusion 22CP, the curvature change of the lens capsule can be related to the inner dimensions across the intermediate portion such as shorter inner dimension 112A and elongate inner dimension 112B. The shorter dimension 112A corresponds to a steeper curvature change of the lens capsule when the central portion moves anteriorly, and the elongate dimension 112B corresponds to a less steep change in curvature when the lens capsule moves anteriorly. The flatter curvature change along the axis of the elongate dimension 112B of the oval can correct the with the rule astigmatism along the vertical axis 12C.
[0145] The curvature 22CPC and corresponding elevation profile of the protrusion 22CP can be combined with the shorter inner dimension 112A and the elongate inner dimension 112B so as to determine the amount of optical correction of the protrusion. Alternatively or in combination, the ratio of the shorter dimension to the longer dimension and the elevation of the protrusion 23C can be used to determine the optical correction of the toric protrusion. For example, a patient can have corneal astigmatism with keratometer readings of about 43 D along an axis 180 of degrees and 44 D along an axis of 90 degrees corresponding to a refraction of the eye of about 0 D sphere 1.0 cylinder along an axis of 180 degrees. The dimensions of the short dimension and the long dimension of the oval can be sized to induce astigmatism of the lens to correct the astigmatism of the eye when the eye accommodates. For example the long dimension and the short dimension of the oval support can be sized such that the long dimension corresponds to about +1 D of optical power along axis 12C and the short dimension of the oval corresponds to about +2 D of optical power along axis 12B when the eye accommodates, such that the refraction of the eye with accommodation based on the change in curvature 22CPC of the central potion 22CP is about 2 D along axis 12B and about 2 D along axis 12C.
[0146] The cylinder of the eye can be corrected with many ratios of the long and short dimensions of the oval support 100. For example, an eye having a far vision refraction of 0 D sphere 1 D cylinder at axis of 180 degrees can be corrected with the oval protrusion. The long inner dimension 112B can be aligned along the 90 degree axis and the short inner dimension 112A can be aligned along the 180 degree axis. When the protrusion elevation height is about 50 microns, the oval support may have a long dimension of about 6 mm and a short dimension of about 4.2 mm, as described above with reference to
[0147] As the central and intermediate portions of the anterior lens capsule can move forward together so as to provide optical correction in addition to the curvature 22CPC of the protrusion 22CP, the amount of accommodation and corresponding near vision refraction of the eye can be greater than the amount provided by the curvature 22CPC of protrusion 22CP. Alternatively or in combination, the intermediate portion 22I may be coupled to support 100 so as to provide additional stretching of the outer portion 22O and peripheral portion 22P of the lens capsule as described herein, such that the accommodation can be further increased. Based on the teachings described herein, a person of ordinary skill in the art can conduct additional experiments and computer simulations so as to determine empirically the protrusion height and corresponding sizes and ratios of the short axis and the long axis so as to correct astigmatism when the eye accommodates.
[0148] As a small amount of astigmatism can be tolerated by the patient, the oval support can be used to increase the amount of accommodation of the eye and provide a small amount of astigmatism with acceptable vision, for example about 1 D astigmatism or less.
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[0151] FIG. 2M1 shows a narrow profile configuration for insertion into the eye through the incision with rotation of the support 100 shown in 2L.
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[0153] FIG. 3A1 shows the support 100 as in
[0154] The accommodating IOL 50 may be placed at least partially within the capsule 22. A capsulorhexis surgery may comprise removal of the central optical portion of the anterior lens capsule, for example during cataract surgery, and the tissue of the intermediate portion 22I can be stiffened with the support so as to couple to the intermediate portion and the draw the peripheral portion inward with accommodation as indicated by arrow 40. The coupling of the support to the intermediate portion 22I decreases radial motion of the intermediate portion 22I so as to couple to the peripheral portion with such that the peripheral portion can move the haptic radially inward with force as indicated with arrow 40. The coupling of the stiffening support 100 to the intermediate portion 22I can be performed before, during or after the capsulorhexis, or combinations thereof. For example, the intermediate portion 22I of the anterior capsule can be coupled prior to capsulorhexis such that the curvature and strain of the lens capsule can be maintained. The support can be coupled to the intermediate portion such that the strain and radial position of the intermediate portion correspond to the relaxed capsule of the eye accommodating for near vision, for example. Alternatively or in combination, the support can be coupled with the pupil dilated such that the curvature of natural lens capsule is maintained for far vision, and such that the curvature and strain of the intermediate portion corresponds to the curvature and strain of the stretched lens capsule of the eye. Alternatively or in combination, the intermediate portion can be coupled after capsulorhexis. Following capsulorhexis, a second support can be positioned on the intermediate portion of the posterior capsule as shown above, for example.
[0155] The accommodating IOL 50 may comprise one or more components of know accommodating IOLs. The lens 52 may comprise a rigid material that provides accommodation when the lens 52 moves anteriorly. Alternatively or in combination, the lens 52 may comprise a flexible material that moves and increases curvature when the eye accommodates. Example of lenses having components suited for use in accordance with embodiments as described herein include the Crystalens HD IOL, Focus IOL IOL, Synchrony IOL, and FlexOptic IOL.
[0156] The accommodating IOL 50 can be combined with the oval support as described herein. For example, the accommodating IOL 50 may comprise the flexible material that moves and increases curvature, and the oval support as described above can increase curvature of the accommodating IOL differentially so as to correct astigmatism of the eye.
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[0158]
[0159]
[0160] FIGS. 3E1 and 3E2 show plurality of curved elongate segments aligned on the anterior lens capsule and posterior lens capsule, respectively, so as to vault the lens capsule and increase accommodation. The plurality of curved elongate segments can be used on both the posterior capsular bag and the anterior capsular bag. For example, a first plurality of curved elongate segments can be inserted after the natural lens is removed, and before the IOL is implanted, and a second plurality of curved elongate segments inserted and adhered on the anterior lens capsule, with the first plurality rotationally offset from the second plurality so as to encourage vaulting of the lens capsule. The rotation of the first plurality relative to the second plurality can provide anterior vault during accommodation and posterior vault during non-accommodation, which can increase and amplify the accommodative range of the IOL.
[0161]
[0162]
[0163] As the tissue strain of the intermediate portion of the capsule coupled to the support may be related to both the far vision refraction and accommodation of the eye, an adjustable support can be used to adjust one or more of the far refraction of the eye or the amount of accommodation of the eye.
[0164]
[0165]
[0166]
[0167]
[0168] The adjustable support having the at least one structure 132 may comprise one or more of many components so as to adjust the support. The support may comprise a shape changing material to adjust the dimension across the support when the support is treated with energy. The shape changing material may comprise a heat sensitive material to stiffen the support when the support is coupled to the intermediate portion. The shape changing material comprises one or more of a metal or a polymer.
[0169] The adjustable support may comprise a polymer such as an elastomeric material, for example, and the at least one structure may comprise a plurality of metal bands deposited in layers on the support, for example, such that cleavage of one of the structure can adjust the support radially. The at least one structure 130 of the adjustable support may comprise layers of polymer, and the layers of polymer can be arranged in a progressively stiffer membrane arrangement, such that inner layers comprise more stiffness than outer layers. An inner layer of the at least one structure 132 can be severed so as to release an amount of contractual force so as increase the dimension across the support. Alternatively, the at least one structure may comprise a second component having pre-loaded configuration opposite a first component comprising inner layer, such that cutting of the first component of the at least one structure allows the second component to move the support inward radially and decrease strain of the intermediate portion such that the dimension across the intermediate portion is decreased and so as to increase stretching and corresponding force of the outer portion of the lens capsule. The decrease in dimension across the intermediate support may adjust the far refraction of the eye toward myopia, for example, and may increase accommodative force so as to provide increased amounts of accommodation, for example.
[0170]
[0171] Experimental and Computer Modeling
[0172]
[0173] The capsule was modeled with finite element shells having a uniform thickness of about 30 um. The intermediate portion of the lens capsule corresponding to the location of the support was constrained such that the radial position remained fixed but was allowed to move along the axis of the coordinate system, as described herein. The force profile of the lens capsule for the normal lens was scaled to be about 6 g. The lens profile in the non-stretched lens condition corresponding to accommodation was used to determine the fixed radial position of the lens capsule corresponding to the location of the support. This fixed radius condition corresponds to placement of the ring when the eye accommodates, for example adhering the ring to the eye when the eye accommodates. Alternatively or in combination, the tissue can be coupled to the stiffening support 100 such that the radial distance of the intermediate portion is fixed at a radial distance corresponding to an at least partially stretched lens capsule, for example. The support 100 can be adjusted, and may comprise a ring adhered to the eye when dilated and adjusted as described herein. Although the initial determined force was somewhat higher for the normal lens capsule, for example about 30 g, this elevated force can be related to modeling of the lens capsule with uniform thickness. Based on the teachings described herein, a person of ordinary skill in the art can model the lens capsule with varying thickness and material properties to determine the force profile for the stiffening ring.
[0174] With the non-stiffened capsulorhexis, the inward force of the lens capsule corresponding to accommodation decreased to about 4, 3 and 2 grams with capsulorhexis diameters of 4, 5 and 6 mm respectively. With the stiffened capsulorhexis having the fixed radius of the capsulorhexis edge corresponding to a rigid support coupled to the intermediate portion of the lens capsule, the inward force of the lens capsule corresponding to accommodation increased to 6.5, 6.8 and 7.2 grams, with capsulorhexis diameters of 4, 5 and 6 mm respectively.
[0175] The unexpected result of these calculations indicate that stiffening of the intermediate portion of the capsule with the support as described herein can increase accommodative force following capsulorhexis as compared to non-stiffened capsulorhexis. These calculations also indicate that stiffening of the intermediate portion of the normal lens capsule can increase redistribute forces of the lens capsule so as to increase the amount of accommodation of the natural lens.
[0176] A person of ordinary skill in the art will recognize many adaptations and variations on simulations and calculations that can be performed so as to determine empirically the properties of the support and resulting accommodation of the lens capsule, such as finite element analysis, finite difference analysis, and dimensional analysis to determine the response of the lens to the support coupled to the intermediate portion as described herein.
[0177] Experiments and simulations can be performed to determine the profile of the support so as to stiffen the intermediate portion of the lens capsule. For example, additional studies can be performed to determine the affect of dilation when the support is adhered to the lens capsule, and effectiveness of adjusting the support to adjust refraction, for example.
[0178] Following experimental simulations in vivo measurement can be performed on living eyes. The change in refraction and accommodation can be measured so as to ensure that the amount of accommodation increases by at least about 1D for at least about 3 months in a primate animal model and the refraction can be measured so as to ensure that the refraction changes by no more than about 2 D, for example no more than about 1D with at least 1D of increased accommodation, for example.
[0179] Clinical trials can be performed to determine the amount of accommodation increased with the tissue stiffening as described herein.
[0180] Based on the teachings described herein a person of ordinary skill in the art can determine the profile and modulus of the support and adhesives and structures suitable for coupling to the capsule so as to stiffen the intermediate portion of the capsule and increase accommodation.
[0181] While the exemplary embodiments have been described in some detail, by way of example and for clarity of understanding, those of skill in the art will recognize that a variety of modifications, adaptations and changes may be employed. Hence the scope of the present invention shall be limited solely by the claims.