INTRAOCULAR LENSES WITH INTRAOCULAR PRESSURE SENSORS AND METHODS OF MANUFACTURE
20220142768 · 2022-05-12
Assignee
Inventors
Cpc classification
A61B3/16
HUMAN NECESSITIES
A61F2002/1681
HUMAN NECESSITIES
A61F2240/00
HUMAN NECESSITIES
A61L2430/16
HUMAN NECESSITIES
International classification
Abstract
Intraocular lenses with pressure sensors embedded therein, and methods of manufacture.
Claims
1. An intraocular lens (“IOL”) adapted to sense intraocular pressure and adapted for implantation in an eye, comprising: an optic portion disposed in a central region of the IOL; a haptic portion that extends radially outward relative to a periphery of the optic portion, the haptic portion comprising a substrate layer extending radially outward relative to the periphery of the optic portion, wherein the haptic portion also includes an intraocular pressure sensor secured to the substrate layer, the substrate layer also extending radially inward relative to the periphery of the optic portion and through the optic portion, wherein the haptic portion further comprises an electronics module disposed on the substrate layer, wherein the intraocular pressure sensor is disposed in the electronics module.
2. The IOL of claim 1, wherein the optic comprises an anterior optic portion and a posterior optic portion spaced apart from the anterior optic portion by the substrate layer that extends through the optic portion, the anterior optic portion disposed anterior to the substrate layer in the optic portion, and the posterior optic portion disposed posterior to the substrate layer in the optic portion.
3. (canceled)
4. (canceled)
5. The IOL of claim 1, wherein the electronics module further comprises a rechargeable battery and at least one of a microcontroller or an application-specific integrated circuit.
6. The IOL of claim 1, wherein the haptic portion further comprises an antenna secured to the substrate layer.
7. The IOL of claim 1, wherein the optic portion comprises first and second layers, wherein the substrate layer is disposed between the first and second layers in the optic portion.
8. The IOL of claim 1, wherein the optic portion comprises anterior and posterior optic elements comprising a hydrophobic material.
9. The IOL of claim 1, wherein the optic portion comprises anterior and posterior optic elements comprising a hydrophilic material.
10. The IOL of claim 1, wherein optic portion comprises an anterior optic layer with a first refractive index, and the substrate layer that extends through the optic portion having a second refractive index greater than the first refractive index.
11. The IOL of claim 10, wherein the optic portion comprises a posterior optic layer, the substrate layer between the anterior optic layer and the posterior optic layer, wherein the posterior optic layer has a third refractive index that is the same as the first refractive index.
12. The IOL of claim 10, wherein the first refractive index is from 1.42-1.56 and the second refractive index is from 1.45-1.80.
13. (canceled)
14. The IOL of claim 10, wherein an adhesive bonds the anterior optic layer to the substrate layer, wherein the adhesive has a refractive index that is between the first refractive index and the second refractive index.
15. The IOL of claim 14, wherein the adhesive refractive index is a mean of the first refractive index and the second refractive index.
16. The IOL of claim 1, wherein the substrate layer comprises at least one of a polyether, a polyamide, a polyimide, a polyester, or a cyclic olefinic copolymer.
17. The IOL of claim 1, wherein the substrate layer extends radially around the entirety of the periphery of the optic portion.
18. The IOL of claim 1, wherein the substrate layer has a tensile modulus in the range of 2-10 GPa measured at 25° C.
19. The IOL of claim 18, wherein the substrate layer has a melting point in excess of 100° C.
20. The IOL of claim 18, wherein the substrate layer has a glass transition temperature in excess of 75° C.
21. The IOL of claim 1, wherein the substrate layer has a thickness from 5-25 microns and a thickness of the optic portion is from 100-400 microns.
22. (canceled)
23. The IOL of claim 1, wherein the substrate layer comprises at least two layers, at least one of which comprises a cross-linked thermoset and at least one of which comprises a partially crystalline thermoplastic material.
24-37. (canceled)
38. An intraocular lens (“IOL”) adapted to sense intraocular pressure and adapted for implantation in an eye, comprising: an optic portion disposed in a central region of the IOL; a haptic portion that extends radially outward relative to a periphery of the optic portion, the haptic portion comprising a substrate layer extending radially outward relative to the periphery of the optic portion, wherein the haptic portion also includes an intraocular pressure sensor secured to the substrate layer, the substrate layer also extending radially inward relative to the periphery of the optic portion and through the optic portion, wherein the substrate layer comprises at least two layers, at least one of which comprises a cross-linked thermoset and at least one of which comprises a partially crystalline thermoplastic material.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0039]
[0040]
[0041]
[0042]
[0043]
[0044]
[0045]
DETAILED DESCRIPTION
[0046] The present disclosure relates to field of Intraocular Lenses (“IOLs”) that include a sensor, including manufacturing processes thereof. In some embodiments a sensor is coupled to a haptic surface of the IOL, ensuring that the sensor is not within the optic zone such that it does not significantly affect the optical performance or stability of the IOL in the eye. Preferably, the sensor is an intraocular pressure sensor.
[0047] Regular and frequent monitoring of intraocular pressure is critically important during the immediate post-operative period, following cataract surgery. In the long run, regular monitoring of intraocular pressure is required to track continued efficacy of pressure controlling medications and monitor compliance. Both of these needs require introduction of an implanted, intraocular pressure sensor that can wirelessly transmit data to an external unit without any involvement of the patient.
[0048] Preferably, the IOP sensor assembly is mounted on the body of the IOL. The sensor assembly (which may be referred to herein as an implantable wireless intraocular pressure sensor assembly or WIPSA) can comprise the sensor, an electronic controller, a memory to store IOP data and telemetry algorithms that may be customized for each patient or animal implanted with a IOP sensor, an antenna and a radiofrequency (RF) module that performs telemetry transmitting data on intraocular pressure generated by the intraocular pressure sensor to an external monitoring unit (which may be referred to herein as an external interrogating device, or EID). Exemplary implantable devices and external units, including their design, are described in WO 2017/210316, which is incorporated by reference herein.
[0049] An exemplary structural model of a telemetry link 4 between an internal device 6 and an external interrogating device 2 is shown in
[0050] The maximum operating range of such a telemetry link is shown in Table 2.
[0051] In some uses, the implants are implanted in canines and are used to monitor canine IOP. In such instances, the EID is preferably adapted such that it can be attached to the collar worn by the dog, or it is clipped on to its vest or other similar clothing. In such a configuration, the EID may be programmed to automatically activate the implanted sensor assembly initiating data collection and transmission without requiring intervention by the owner of the canine. A study was performed to measure the average distance of the EID from the WIPSA for a number of common dog breeds that are found among household pets. The data are presented in Table 1. Comparison of these data with the range of operating parameters of a passive telemetry link shown in Table 2 indicate that the minimum distance over which wireless data transfer has to be carried out is about 15 cm, and should be in a range of 15.0+/−3.0 cm. This requirement makes it necessary to have an indigenous power source in the sensor assembly, in order to maintain the RF power in the EID at a safe level, and remain in compliance with regulatory requirements in all operating situations. Consequently, the implantable device preferably includes a rechargeable power source (e.g., battery) or some other power source that is controlled by a power management module, and that is recharged wirelessly by the same external unit using the same wireless data transfer module. The external unit has a wireless data exchange and power transfer module powered by a rechargeable battery that can be recharged on a regular basis by any electrical power outlet.
TABLE-US-00001 TABLE 1 Distance of a dog collar from the eye in selected canine breeds. distance collar - distance collar - std- # breed weight (kg) eye (inch) eye (cm) dev (cm) Small average <15 kg 4.3 10.9 3.0 maltese 5 3.5 8.9 shih tsu 8 3.5 8.9 dachshund 9 4.5 11.4 bichon frise 10 5 12.7 border terrier 10 4 10.2 japanese chin 10 3 7.6 cocker spaniel 13 6.5 16.5 Medium average 15-22 kg 4.7 11.9 3.9 beagle 15 5 12.7 miniature poodle 15 3 7.6 blue heeler 22 6 15.2 Large average >22 kg 5.7 14.5 4.4 taz 25 4 10.2 golden retriver 30 6.5 16.5 matie 30 6 15.2 baorador 31 8 20.3 Total corgi 33 4 10.2 3.8 average — 4.8 12.3
TABLE-US-00002 TABLE 2 Parameters of the telemetry link in FIG. 2 and their values. Symbol Parameter Description Value Unit d Reader coil wire diameter 0.50 mm ID.sub.1 Inner diameter of reader coil 30.0 mm n.sub.1 Number of turn of the reader coil 2 1 L.sub.11 Self-inductance of the reader coil 256.2 nH R.sub.11 Reader coil wire resistance at 191 mΩ operating frequency d
Sensor coil wire diameter 40 μm ID.sub.2 Inner diameter of sensor coil 6.0 mm n.sub.2 Number of turns of the sensor coil 16 1 L
Self-inductance of the sensor coil 3.384 μH R.sub.22 Sensor coil wire resistance at 6.615 Ω operating frequency
Typical sensor capacitor value 6.0 pF
Telemery link reference frequency 35.323 MHz z.sub.min Minimum coupling distance 10 mm z.sub.max Maximum coupling distance 40 mm
indicates data missing or illegible when filed
[0052] When considering designs for an intraocular lens comprising a pressure sensor, there are a variety of design pathways for integration of a sensor assembly into an IOL. An exemplary first design is to dispose the sensor assembly into or onto the optic portion, and the antenna positioned around the periphery of the optic, as shown in exemplary
[0053] In the embodiment in
[0054] An alternative design that addresses the downside of having electrical components disposed in the optic path (e.g., like in
[0055] Referring to the embodiment shown in
[0056] The multilayer intraocular lens 20 is comprised of two or more layers throughout, at least one of these layers comprising a relatively soft, cross-linked optic material, which may be an acrylic thermoset or a cross-linked polysiloxane. Another layer comprises a relatively stiff material that is selected on the basis of its ability to function as a substrate for electronics and the antenna assembly, as described above.
[0057] Two issues related to the design of a multilayer intraocular lens need to be addressed in order to obtain an implant that provides excellent optical resolution and mechanical characteristics, in particular bending, flexing behavior, as well as shape memory and fatigue resistance required of a foldable intraocular implant that will be expected to function for more than 20 years. The first of these design issues relates to the mismatch in refractive index between the materials comprising the haptics and the optics layers. The second issue is related to the high modulus and hence stiffness of the material comprising the haptic layer relative to the material comprising the optics layer.
[0058] Refractive index (“RI”) of foldable acrylic or silicones commonly utilized in intraocular optic fabrication range from 1.42-1.44 for silicones, 1.44-1.49 for hydrophilic acrylics and from 1.44-1.56 for hydrophobic acrylics. In any of the embodiments herein, the RI of one or more optical components can therefore be from 1.42-1.56.
[0059] The haptic layers herein that are adapted to function as transparent PCB substrates typically have a relatively high refractive index, such as in the range from 1.45-1.80, measured at 535 nm.
[0060]
[0061] Bonding the optic materials 51 (e.g., acrylic) to the haptic material 53 can be accomplished by acrylic adhesives, silicone adhesives, or hot melt adhesives, for example. Either a one part or two-part adhesive may be used. A two-part adhesive may be thermally polymerizable or it may be photopolymerizable.
[0062] After the blank has been prepared by bonding two acrylic buttons to the haptic film substrate as shown in views 54A and 54B, the assembly can be mounted on a block and diamond turned to form the biconvex optic based on computation of the optimum radii of curvature and base thickness of the acrylic layers, as described herein. Optics of any power may be machined, although for canine applications, a single power, 41D is preferred. Well known IOL power calculation algorithms can be used to calculate the power of the IOL needed.
[0063] In some embodiments, the optic components comprises a hydrophilic material. The hydrophilic material is preferably a cross-linked network of hydrophilic monomers, with an equilibrium water content of 5% to 50%, preferably 10% to 30%, more preferably 15-20%. In these embodiments, bonding of the hydrophilic optic component(s) and the haptic layer is preferably accomplished by developing an interpenetrating network anchored on both surface through siloxane, ester or amide linkages, as an example only, using silane coupling reaction or click chemistry.
[0064] After the optics have been machined, as shown in views 56A and 56B, the part is cleaned, and is then ready for deposition of the electronics, which occurs at step 57. The optic area is preferably masked during electronic deposition in order to avoid damage to the optics. A mask made of a metal or silicon or a poly-silicate film may be used to protect the acrylic optics during the deposition and assembly of the electronics.
[0065] Placement of the sensor assembly can include deposition of the antenna using a chemical vapor deposition process, a flip chip assembly followed by wire bonding of the microcontroller, the IOP sensor, the battery and the electronics that are mounted directly on the haptics substrate, as shown in the top and side views of parts 58A, 58B, and 58C. The profile of the haptic layer 53 is shown in
[0066] The IOL thus formed is next coated by chemical vapor deposition with a multilayer hermetically sealing coating, for example, comprising or consisting of alternate layers of SiOx and Paralyene C. Each layer of such a coating may be, in some embodiments, 0.5-1.5 microns in thickness. Up to 16 layers may be applied, with the outermost layer being either Paralyene C or SiOx, depending on whether a hydrophilic or a hydrophobic optic surface is desired. The hermetic seal is not applied on the surface of a hydrophilic optic material (if the optic is made from a hydrophilic material), but is still necessary to provide added biocompatibility to the haptic layer. Any hydrophilic optic material herein would not receive a hermetic sealing thereon.
[0067] The IOL can then be coated with a hydrogel coating, comprising one or more layers of a biocompatible hydrogel, of thickness in the range of, for example, 25-50 microns. The coating may comprise, for example, polyethylene glycol mono-acrylate or polyethylene glycol diacrylate. The biocoating is applied by dipping or spraying the IOL with a monomer formulation comprising a photo-initiator such as Ethyl (2,4,6-trimethylbenzoyl) phenyl phosphinate (TPO-L). If such a coating is applied to the IOL, the coating is required to be dehydrated prior to sterilization by exposure to ETO or another chemical gas sterilant. Preferably, dehydration is carried out by maintaining the lens in a vacuum oven at 45 C (40-50 C) overnight. The IOL is then inspected, packaged and sterilized prior to shipment at step 62 and 64.
[0068] The optic components herein (such as components 51) may be made of a hydrophilic optic material. Referring again to
[0069] As set forth above, the haptic, or substrate, layer (e.g., layer 53 in
[0070] A second consideration related to the mechanical design of the multilayered IOL is the stiffness of the haptic layer (e.g., layer 53). The haptic layer material that support the electronics and the antenna are generally stiff, having a relatively high melting point in excess of 100 C, a glass transition temperature in excess of 75 C, and a tensile modulus in the range of 2-10 GPa measured at 25 C. This layer is bonded to the optic components (e.g., components 51), which are relatively soft, which may have glass transition temperatures in the range of 0-20C, and tensile moduli in the range 0.5-100 MPa.
[0071] The overall haptic portion thickness, including any electronics or sensor housings secured to the haptic layer, will generally be in the range from 0.125 mm-0.500 mm, depending on the tensile moduli of the materials comprising the haptic and the optic layers.
[0072] The thickness of the relatively rigid haptic substrate (which may be herein referred to as the haptic layer) is generally from 5 microns-25 microns, while the thicknesses of the relatively more flexible optical component (which may be referred to herein as the optic layer) is in the range of 0.100 mm-0.400 mm. Standard IOLs may have haptic thicknesses in the range of 0.4 mm to 0.5 mm.
[0073] In some embodiments, such as that shown in
[0074] Any of the optical components herein may comprise a hydrophobic material. The hydrophobic acrylic material may be a cross-linked thermoset including acrylate and methacrylate derivatives (e.g., mono or multifunctional monomers with an acrylate or a methacrylate moiety as terminal or pendant groups), may have a refractive index in the range of 1.44-1.52 at 530 nm, and may have a glass transition temperature in the range 0 C to 25 C. It may be polymerized using thermal or photochemical initiators.
[0075] Any of the substrate layers herein utilized for deposition of sensor assembly, antenna and formation of haptics may be a thermoset or a thermoplastic material of relatively high melting temperature in the range 100-250 C, glass transition temperature exceeding 45 C, a tensile modulus not to exceed 5 GPa, and an elongation at break exceeding 25%. It should be transparent, and preferably colorless. It may comprise a polyester, a polyether, a polysulfone, a polyamide, a polyimide or cyclic olefinic polymers or copolymers, or Paralyene. It may be a single or a multilayer film.
[0076] The IOL created by the exemplary process in
[0077] In the embodiment in
[0078] In the embodiment in
[0079] In the embodiment in
[0080] In the embodiment in
[0081] In the embodiment of
[0082] In any of the embodiments herein the substrate layer can have a tensile modulus in the range of 2-10 GPa measured at 25 C.
[0083]
[0084]
[0085] In the exemplary method 80 shown in
[0086] If a hydrophilic optic material is used, then the haptic layer with the assembled electronics is first coated with a hermetically sealing multilayer coating, prior to bonding the optic layer to the haptic layer.
[0087] The resulting multilayer intraocular lens according to the method of
[0088] In the embodiments herein, the optic portion is free of electronics and an antenna that may interfere with light passing through the optical path. It may be acceptable for one or more of electronics or an antenna to extend to a very small degree on the optic portion without substantially interfering with light passage through the optic path. If the disclosure herein thus states that the optical path is void of electronics and antenna, it may include a very minor degree in overlap between electrical components and the optic path.