BACKGROUND

[0001] Intraocular lenses (lOLs) are implantable optical devices for treating cataracts or myopia. lOLs typically replace native crystalline lenses that are cloudy or otherwise discolored due to cataracts. An lOL is surgically implanted by removing the native crystalline lens and then inserting an lOL into the native lens capsule. The World Health Organization estimates that 20 million lOLs were implanted worldwide in 2010 and predicts that 30 million lOLs will be implanted annually by 2020.

[0002] Many current lOLs have a single optical power that is set by the manufacturer. As a result, conventional single-power lOLs have a fixed optical power. This requires practitioners to determine the optical power of single-power lOLs before implantation. The optical power of an lOL, however, may not be correct after implantation because the lOL may not fit properly in the native lens capsule or the eye may change over time. If the optical power of an implanted single-power lOL is not correct, the lOL will need to be replaced with another lOL having a suitable optical power via another surgical procedure. This not only increases the cost of healthcare, but it is also inconvenient for the patients and subject to the normal complications of optical surgical procedures.

BRIEF DESCRIPTION OF THE DRAWINGS

[0003] Many aspects of the present technology can be better understood with reference to the following drawings. The components in the drawings are not necessarily drawn to scale. Instead, emphasis is placed on illustrating clearly the principles of the present technology. Furthermore, components can be shown as transparent in certain views for clarity of illustration only and not to indicate that the component is necessarily transparent. Components may also be shown schematically.

[0004] Figure 1 is a cross-sectional view of an adjustable power intraocular lens in accordance with the present technology. [0005] Figures 2 and 3 are cross-sectional views of the operation of first and second volume control elements, respectively, used in adjustable power intraocular lenses in accordance with the present technology.

[0006] Figure 4 is a cross-sectional view of an adjustable power intraocular lens in accordance with the present technology.

[0007] Figure 5 is a cross-sectional view of an adjustable power intraocular lens in accordance with the present technology.

[0008] Figure 6 is a cross-sectional view of an adjustable power intraocular lens in accordance with the present technology.

[0009] Figure 7 is a plan view of an adjustable power intraocular lens in accordance with the present technology.

[0010] Figure 8A is an isometric view and Figure 8B is a cross-sectional view taken along section A-A of Figure 8A of an adjustable power intraocular lens in accordance with the present technology.

[0011] Figure 9A is an isometric view, Figure 9B is a bottom plan view, and Figure 9C is a cross-sectional view taken along cross-section A-A of Figure 9B that illustrate a modular APIOL in accordance with the present technology.

[0012] Figure 10A is a bottom isometric view of a fixed lens, and Figure 10B is a cross-sectional view taken along section B-B of Figure 10A.

OVERVIEW

[0013] Several embodiments of adjustable power intraocular lenses (APIOLs) in accordance with the present technology are described below with reference to Figures 1 -8. The APIOLs described below are capable of changing the optical power in situ using a non-invasive activation. Although several examples of APIOLs are disclosed with respect to single-power devices, the concept can be applied to accommodating intraocular lenses as well as noted below.

[0014] The disclosed APIOLs provide the ability to selectively change the optical power in situ to adapt the APIOLs to the specific power required by the patient after implantation without removing and/or replacing the APIOLs. For example, several embodiments of APIOLs in accordance with the present technology include first volume control elements that release or expel a transport substance and/or second volume control elements that absorb or otherwise attract and retain a transport substance. The first volume control elements can be shrinking elements or release elements configured to release the transport substance upon non-invasive activation, such as an energy modality that selectively reacts with the first volume control elements. Conversely, the second volume control elements can be swelling elements configured to absorb or otherwise attract and retain the transport substance upon non-invasive activation. In operation, the shrinking elements can be activated to release the transport substance from the APIOL to reduce the optical power, or conversely the swelling elements can be activated to absorb the transport substance to increase the optical power.

[0015] APIOLs in accordance with present technology can include a container, an optical fluid in the container, and volume control elements in the container. The container can comprise a peripheral component and an optical component. The optical component, for example, can include an anterior optical element and a posterior optical element. The optical elements may be hydrophilic or hydrophobic. The container can comprise a water permeable material. One suitable water permeable material for the container comprises:

a - a hydrophilic acrylic copolymer;

b - Benz 25 UVXTM material manufactured by Benz Research and Development of Sarasota, FL; and

c - C118, CI21 , or CI26 produced by Contamac Ltd. of the UK

Suitable hydrophilic acrylics include, but are not limited to, 2-Hydroxyethyl methacrylate (HEMA). Suitable hydrophobic acrylics include, but are not limited to, 2-Ethoxyethyl methacrylate (EOEMA), polymethyl methacrylate (PMMA), Butyl acrylate, Hexyl acrylate and Hexafluoroisopropyl acrylate. The acrylic, for example, can comprise a cross linker. In some embodiments, the acrylic comprises a cross-linked acrylic polymer. The hydrophilic or hydrophobic polymers may be copolymers of the above.

[0016] The internal optical fluid filling the container can comprise an oil. For example, the oil can have a refractive index greater than that of the aqueous humor. The oil can be capable of holding a saturation volume of water in solution at body temperatures of a human eye. The transport substance can be water. [0017] The volume control elements can include first volume control elements configured to release a transport substance into the optical fluid in the container and/or second volume control elements configured to absorb a transport substance from the optical fluid. The first volume control elements can be shrinking elements that, when activated, release the transport substance into the optical fluid and thereby increase the volume of the transport substance in the fluid chamber. This causes the transport substance concentration within the container to exceed the saturation point such the transport substance is transported out of the container to the aqueous humor by diffusion. The reduction in the transport substance reduces the volume of matter in the container, which in turn reduces the optical power of the optical component. The second volume control elements can be swelling elements that, when activated, absorb the transport substance from the optical fluid. This too causes an imbalance of the transport substance within the container such that additional transport substance is transported from the aqueous humor into the container via diffusion. The increase in the transport substance increases the volume of matter in the container, which in turn increase the optical power of the optical component.

[0018] The first volume control elements, or shrinking elements, can include a first hydrophobic casing containing a volume of the transport substance. For example, the transport substance can be water and the first hydrophobic casing can be wax or a liposome (e.g., a uni-laminar liposome). In one example, the first volume control elements can be wax closed-cell foams containing water.

[0019] The second volume control elements, or swelling elements, can include one or more hydrophilic elements surrounded by a second hydrophobic casing. The hydrophilic elements can include a hydrogel such as acrylic polymers. The second hydrophobic casing can include parylene and/or a hydrophobic acrylic.

[0020] The first and/or second volume control elements can be fixed to the container. In other embodiments, the first and/or second volume control elements can be suspended in the optical fluid.

[0021] The optical component of APIOLs in accordance with the present technology can be a fluid lens comprising the optical fluid (e.g., oil) bounded by the anterior optical element and the posterior optical element. The peripheral component can surround the optical component such that the optical component is a central portion of the container. In some embodiments, one or both of the anterior and posterior optical elements may have an optical power (i.e., a defined curvature in a relaxed unbiased state) such that the optical component has an optical power in a relaxed state. In other embodiments, the anterior and/or posterior optical elements may be flat membranes that have no optical power in a relaxed unbiased state such that the optical component has no power in the relaxed state. The total volume of the optical fluid, transport substance and first and/or second volume control elements within the container can change the curvature, and thus the optical power, of the optical component. More specifically, the optical power increases when the volume of matter within the container increases, or conversely the optical power decreases when the volume of matter within the container decreases.

[0022] The volume of matter within the container is controlled by selectively activating the first volume control elements or the second volume control elements. The first or second volume control elements can be activated by disrupting all or a portion of the hydrophobic casings of the volume control elements. For example, in several embodiments the volume control elements are activated by exposing the volume control elements to a non-invasive activation energy that selectively disrupts either the first hydrophobic casings of the first volume control elements or the second hydrophobic casings of the second volume control elements. The non-invasive activation energy can include laser energy (e.g., light), ultrasound, electrical energy (e.g. , radio frequency), and/or infrared.

DETAILED DESCRIPTION

[0023] Figure 1 is a cross-sectional view schematically illustrating an APIOL 100 having a peripheral component 1 10 and an optical component 120. The peripheral component 1 10 and the optical component 120 together can define a container, or just the peripheral component can define the container. The peripheral component 1 10 can be an annular outer compartment that completely surrounds the optical component 120, or the peripheral component 1 10 can be discrete outer segments that extend around only a portion of the optical component 120. The peripheral component 1 10 can have interior volume 1 12 that is in fluid communication with the optical component 120. In other embodiments, however, the interior volume 1 12 of the peripheral component 1 10 can be fluidically isolated from the interior of the optical component 120. The peripheral component 1 10 can be stiffer than the optical component 120 such that changes in volume occur to a greater in the optical component 120 than in the peripheral component 1 10.

[0024] The optical component 120 can have an anterior optical element 122 coupled to an anterior portion of the peripheral component 1 10, a posterior optical element 124 coupled to a posterior portion of the peripheral component 1 10, and a fluid chamber 126 between the anterior optical element 122 and the posterior optical element 124. The anterior optical element 122 can be a first membrane, and the posterior optical element 124 can be a second membrane. The first and second membranes can have an optical power (e.g., have a set or minimum curvature) or they can have no optical power in a relaxed, unbiased state (e.g., horizontal in Figure 1 ). The fluid chamber 126 can be filled with an optical fluid 128 such that the anterior optical element 122, the posterior optical element 124 and the optical fluid define a fluid lens 130. In operation the optical fluid 128 can fill both the peripheral component 1 10 and the fluid chamber 126 to impart the desired curvature to the anterior optical element 122 and/or the posterior optical element 124 to provide the desired optical power to the optical component 120. The optical component 120 can have a single power or it can be an accommodating fluid lens in which the optical power changes in response to movement of the muscles of the native eye.

[0025] The APIOL 100 can further include first volume control elements 140 and/or second volume control elements 160. The first volume control elements 140 can be shrinking elements or release elements configured to disgorge or otherwise release a transport substance using a first non-invasive activation modality. Conversely, the second volume control elements 160 can be swelling elements configured to absorb or otherwise attract and retain a substance using a second non-invasive activation modality. The first and second non-invasive activation modalities can be one or more types of energy, such as laser radiation, ultrasonic energy, radio frequency (RF) energy or infrared radiation, that selectively activates one or both of the first and second volume control elements 140 and 160. In several embodiments, the first non-invasive activation modality activates only the first volume control elements 140 and the second noninvasive activation modality activates only the second volume control elements 160 such that the first and second volume control elements 140 and 160 can be activated independently of each other. For example, the first volume control elements 140 can be activated by one type of energy (e.g., laser energy), while the second volume control elements 160 can be activated by a different type of energy (e.g., RF energy). In a different example, the first and second volume control elements 140 and 160 can be activated by a common type of energy at different wavelengths or frequencies. In this example the first volume control elements 140 can be activated by a type of energy at a first wavelength or frequency (e.g., laser energy in a first bandwidth) and the second volume control elements 160 can be activated by the same type of energy at a second wavelength or frequency (e.g., laser energy in a second bandwidth). The second bandwidth is sufficiently different than the first bandwidth to avoid joint activation of the first and second volume control elements. In other embodiments, a single non-invasive activation modality can activate both the first volume control elements 140 and the second volume control elements 160. Upon activation, the first and second volume control elements 140 and 160 can become first and second activated elements 142 and 162, respectively.

[0026] The optical fluid 128 and the transport substance (not shown in Figure 1 ) are selected to maintain a desired equilibrium within the fluid chamber 126 with respect to the aqueous humor of the native eye. The transport substance is selected to transport through the walls of the peripheral component 1 10, the anterior optical element 122, and/or the posterior optical element 124 via osmosis to maintain the desired equilibrium between the optical fluid 128 and the transport substance within the fluid chamber 126. In several embodiments, the optical fluid 128 is an oil that can sustain a solubilized water content of greater than a few percent and the transport substance is water. As a result, the first volume control elements 140 (e.g., shrinking elements) provide a water source within the APIOL 100, whereas the second volume control elements 160 (e.g., swelling elements) provide a sink for water. As the internal volume is a changed by activating either the first volume control elements 140 elements or the second volume control elements 160, the volume of the matter in the fluid chamber 126 changes and thereby adjusts the power of the optical component 120 in situ. In general, when the internal volume of matter in the fluid chamber 126 increases the optical power increases, and conversely when the internal volume of matter in the fluid chamber 126 decreases the optical power decreases.

[0027] Figure 2 schematically illustrates the operation of the first volume control elements 140, and more specifically releasing or expelling the transport substance (e.g., water) from the first volume control elements 140 to reduce the optical power of the optical component 120. In this aspect of the present technology, an energy source 170 produces a non-invasive activation energy 172 that interacts with the first volume control elements 140 such that the first volume control elements 140 release or otherwise expel the transport substance. As the transport substance is released from the first volume control elements 140, the transport substance over-saturates the internal fluid or optical fluid 128 within the APIOL 100. The excess transport substance passes through the wall of the peripheral component 1 10 and/or the optical elements 122, 124 of the optical component 120 into the surrounding aqueous humor. The internal volume of the APIOL 100 is therefore reduced by the volume of transport substance that transports out of the APIOL 100. Since the peripheral component 1 10 of the APIOL 100 is structurally stiffer than the optical component 120, the volume of the optical component 120 changes more than that of the peripheral component 1 10. The decrease in volume of the optical component 120 decreases the optical power of the optical component 120.

[0028] Figure 3 schematically illustrates the operation of the second volume control elements 160, and more specifically absorbing or otherwise collecting the transport substance (e.g., water) in and/or on the second volume control elements 160 to increase the optical power of the optical component 120. In a specific example of the present technology, the optical power of the APIOL 100 increases by the sequestration of water into the second volume control elements 160. More specifically, the transport substance is absorbed into the second volume control elements 160 from the optical fluid, and the second volume control elements 160 swell to occupy more volume. The transport substance removed from the optical fluid is replaced by the same type of substance from the aqueous humor which passes through the peripheral component 1 10 and/or the optical component 120 from the surrounding aqueous humor into the optical fluid. This brings the chemistry of the optical fluid back to its equilibrium level (e.g., wateroil equilibrium ratio). The internal volume of the APIOL 100 is therefore increased by the volume of water which has been absorbed into the second volume control elements 160 within the APIOL 100. Since the peripheral component 1 10 of the APIOL 100 is structurally stiffer than the optical component 120, the volume of the optical component 120 increases and thereby increases the optical power of the optical component 120. [0029] Figure 4 is a cross-sectional view illustrating aspects of the optical component 120 in greater detail. The anterior optical element 122 and the posterior optical element 124 can define a container or structural portion of the APIOL 100. As illustrated, both membranes are thin and flat in a relaxed unbiased state (e.g., platelike) and provide no optical power to the optical component 120 in this state. As the internal volume of the APIOL 100 increases, the membranes flex into roughly spherical curvatures. The high refractive index optical fluid 128 between the membranes, in combination with the optical elements 122 and 124, thereby forms the fluid lens 130 which has an optical power. The optical power of the fluid lens 130 increases as the volume of the optical fluid 128 in the fluid chamber 126 increases. In other embodiments (not shown), one or both the anterior optical element 122 and the posterior optical element 124 may have a curvature in a relaxed unbiased state such that they comprise an optical power. In still other embodiments, one of the anterior optical element 122 or posterior optical element 124 may be stiffer and or thicker than the other (not shown).

[0030] Figure 5 illustrates an APIOL 500 in accordance with the present technology. The APIOL 500 is similar to the APIOL 100 described above, and like reference numbers refer to like components. The APIOL 500 is different than the APIOL 100 in that the peripheral component 1 10 and the optical component 120 of the APIOL 500 are fluidically isolated from each other by a barrier 510. The barrier 510, for example, can be a hydrophilic membrane. In such an embodiment, the barrier 510 constrains debris ("D") associated with the activation of the first and/or second volume control elements 140, 160 from entering the fluid chamber 126 of the optical component 120. In some such embodiments, the membrane 510 may be continuous between the peripheral component 1 10 and the optical component 120, as illustrated in Figure 5. Whereas in other embodiments the membrane 510 may contain channels or large pores 512 (shown in dotted line) which prevent or otherwise inhibit the debris D from passing into the optical component 120 while allowing the optical fluid 128 to pass to/from the fluid chamber 126. This embodiment is expected to be useful for providing an adjustable accommodating fluid lens in which the optical component 120 increases/decreases optical power as the native eye acts upon the peripheral component 1 10 to pump fluid into or withdraw fluid out to the fluid chamber 126 (see, e.g., International Application No. [Insert 120974.8012 WO00], which is incorporated herein by reference). [0031] Figure 6 is a cross-sectional view illustrating an APIOL 600 in accordance with the present technology in which the optical component 120 is surrounded by a deformable barrier 610. The APIOL 600 is similar to the APIOLs 100 and 500 described above, and like reference numbers refer to like components. The fluid in the peripheral component 1 10, which includes the first and second volume control elements 140, 160, acts on the deformable barrier 610. In some embodiments, the deformable barrier 610 is bellows. In operation, the optical fluid 128 may have a more standard low solubility for water, and vacuoles of water released from the first volume control elements 140 diffuse to the outer surfaces of the peripheral component 1 10 that communicate with the aqueous humor.

[0032] Figure 7 is a plan view of an APIOL 700 in accordance with the present technology in which like reference numbers refer to like components with respect to Figures 1 -6. The APIOL 700 has a peripheral component 710 and the optical component 120 in the center of the peripheral component 710. The peripheral component 710 has a first compartment 714 containing a fluid and the first volume control elements 140, and the peripheral component 710 has a second compartment 716 containing a fluid and the second volume control elements 160. The APIOL 700 accordingly differs from the APIOLs 100, 500 and 600 in that the first volume control elements 140 are isolated from the second volume control elements 160 in the first and second compartments 714 and 716, respectively.

[0033] Figure 8A is an isometric view and Figure 8B is a cross-sectional view taken along section A-A of Figure 8A of an APIOL 800 in accordance with the present technology. The APIOL 800 also isolates the first volume control elements 140 from the second volume control elements 160, but the APIOL 800 uses multiple compartments. More specifically, the APIOL 800 has a peripheral component 810 that completely surrounds the optical component 120, and the peripheral component 810 has a plurality of first compartments 814 configured to contain separate volumes of the first volume control elements 140 and a plurality of second compartments 816 configured to contain separate volumes of the second volume control elements 160. Each of the APIOLs 700 and 800 can have a connecting barrier between the compartments containing the volume control elements and the optical component 120. In such embodiments, deformation of the connecting barrier driven by activation of the volume control elements 140, 160 adjusts the peripheral volume of the optical component 120 of the APIOLs 700 and 800.

[0034] The first volume control elements 140 can have a thin outer wall and a volume of the transport substance within the thin outer wall. For example, the first volume control elements 140 can have a thin wax shell and a small volume of water encased within the shell. In other embodiments, the first volume control elements 140 can have water encased by a liposome shell, such as a uni-laminar liposome shell having of a bilayer lipid outer membrane. In other embodiments, the first volume control elements 140 can be a closed-cell wax foam with water in the voids of the closed-cell foam.

[0035] The second volume control elements 160 can comprise of an outer surface of hydrophobic material encasing either a hydrophilic material or a material which can diffuse or otherwise pass through the optical fluid 128 and/or some portion of the peripheral wall of the APIOL. For example, the second volume control elements 160 described herein can include a small volume of a dehydrated hydrogel encased in a thin layer of wax, a parylene coating, or a layer of an amphiphilic material such that the hydrophilic head groups are presented as the outer surface of the hydrogel and the hydrophobic tail groups are presented outwardly to the environment forming a micelle. The second volume control elements 160 can also be a closed-cell wax foam wherein the voids within the foam contain hydrogel.

[0036] The volume control elements 140, 160 described above can be activated by controllably disrupting the shells or outer coating layers thereby allowing a controlled amount of the contained material to access the local environment. Such energy may be one or any combination of laser energy, ultrasound, electrical energy including RF, and infrared energy. In some embodiments, the disruption is accomplished by the delivery of laser energy to the volume control elements. In some embodiments, the first volume control elements 140 and the second volume control elements 160 are activated by different wavelengths of laser energy or different frequencies of ultrasonic or electrical energies. For example, a first wavelength of laser energy is used to activate the first volume control elements 140, while a second different wavelength of laser energy is used to activate the second volume control elements 160. Such selectivity may be built into the volume control elements by controlling the absorbance of the coating material and or the size of the volume control element. In alternative embodiments, the first and second volume control elements 140, 160 may be compartmentalized such that they can be addressed separately as described above with reference to Figures 7, 8A and 8B.

[0037] Figure 9A is an isometric view, Figure 9B is a bottom plan view, and Figure 9C is a cross-sectional view taken along cross-section A-A of Figure 9B that illustrate a modular APIOL 900 in accordance with the present technology. Referring to Figures 9A and 9B, the APIOL 900 has an accommodation structure 910, a fixed lens 930, first volume control elements 140, and second volume control elements 160. Referring to Figure 9C, the accommodating structure 910, for example, can have a first component 91 1 defining an anterior portion and a second component 912 defining a posterior portion. The first and second components 91 1 and 912 are assembled to form an outer fluid reservoir 914, a channel 916, and an inner fluid chamber 918 in fluid communication with each other. The outer fluid reservoir 914, channel 916 and inner fluid chamber 918 are filled with an optical fluid and transport substance in solution, which flow between the outer fluid reservoir 914 and the inner chamber 918 via the channel 916.

[0038] The accommodating structure 910 can have an accommodating optical element 920 (e.g. , an accommodating fluid lens) having a first optical component 921 defining an anterior side of the inner fluid chamber 918 and a second optical component 922 defining a posterior side of the inner fluid chamber 918. The first and second optical components 921 and 922 can be flexible membranes that do not have an optical power, or in other embodiments one or both of the first and second components 921 and 922 can be flexible lenses that have an optical power. In operation, fluid flows between the outer fluid reservoir 914 and the inner chamber 918 in response to the movement of the ciliary muscles of the native eye. For example, when the ciliary muscles relax, the capsular bag pushes against the outer fluid reservoir 914, which in turn causes fluid to flow into the inner chamber 918 and deflect the first optical component 921 anteriorly. This increases the thickness of the accommodating optical element 920. Conversely, when the ciliary muscles contract, the capsular bag is pulled radially outward such that the force exerted against the outer fluid reservoir 914 decreases allowing the higher- pressure fluid in the inner chamber 918 to flow into the outer fluid reservoir 914. This decreases the thickness along the optical axis (e.g., curvature) of the accommodating optical element 920.

[0039] The APIOL 900 includes flow-through features 950 that enhance the rate and ease with which Ophthalmic Viscosurgical Devices (OVDs) used during the implantation of AIOLs can be removed from the natural lens capsule. The APIOL 900 can have three outer flow-through features 950. The outer flow-through features 950 can be detents, such as a recess, distributed circumferentially along the perimeter of the outer fluid reservoir 914. In the illustrated embodiment, the flow-through features 950 are formed in regions of the first and second components 91 1 and 912. Although three outer flow-through features 950 are illustrated, other embodiments may comprise less or more than illustrated. The outer flow-through features 950 may additionally constrain rotation of the APIOL 900 in the eye.

[0040] The APIOL 900 additionally comprises a fixed lens assembly 930. The fixed lens assembly 930 illustrated in Figure 9C includes an optical portion 932, a skirt 934 extending from the optical portion 932, and passages 936. The optical portion 932 has a fixed power which may comprise an asymmetrically powered lens or other lens as explained herein, and the passages 936 are holes, slots, orifices, etc., that pass through the skirt 934 and extend into a perimeter region but not the optical portion 932.

[0041] Referring to Figure 9C, the fixed lens assembly 930 has an engagement feature 938, such as an annular groove, that extends around the skirt 934, and the first component 91 1 of the accommodating structure 910 has a thickened region 939, such as an annular protrusion (e.g., a ledge) that extends radially inwardly. The fixed lens assembly 930 can be attached to the accommodating structure 910 by engaging the continuous thickened region 939 of the first component 910 with the engagement feature 938 of the fixed lens assembly 930. In other embodiments (not shown), the thickened region 939 and the engagement feature 938 may be discontinuous features (e.g., segmented or other recesses or protrusions that extend around less than the full circumference of the fixed lens assembly 930 and the accommodating structure 910). Such a discontinuous thickened region 939 and engagement feature 938 are desirable to maintain a particular radial alignment between the fixed lens assembly 930 and the accommodating structure 910, such as when the fixed lens assembly 930 comprises a toric lens or other asymmetrical lens. Alternatively, the groove may be in the fixed lens assembly 930 and the protrusion on the accommodating structure 910.

[0042] The fixed lens assembly 930 can be implanted after the accommodating portion 910 has been implanted. This is expected to be advantageous because the accommodating portion 910 can be implanted and then a fixed lens assembly 930 with the desired power can be selected and implanted later based on the actual post-implant optical power of the accommodating portion 910. The fixed lens assembly 930 can also be removed after being attached to the accommodating structure 910. This is advantageous if the fixed lens assembly 930 that was initially implanted is not correct or was damaged while being inserted into the accommodating structure 910.

[0043] The APIOL 900 can further include a square-shaped annular region 951 that inhibits cell migration from the periphery of the patient's capsule to the optical part of APIOL 900 (shown in Figure 9C at the posterior most region of the lens). Such cell migration could cause post-surgery opacification of the optical system.

[0044] Referring to Figures 9B and 9C, the APIOL 900 includes the first and second volume control elements 140 and 160 in the outer fluid reservoir 914. As a result, when the first or second volume control elements 140 or 160 are activated, the volume of matter in the outer fluid reservoir 914 decreases or increases, respectively, as described above. The change in volume of matter in the outer fluid reservoir 914 accordingly changes the volume in the accommodating optical element 920, which in turn adjusts the power of the APIOL 900 as described above. This is expected to be useful even in the APIOL 900 that has a removable fixed lens assembly 930. For example, even though the fixed lens assembly 930 can be implanted after the accommodating structure 910 has been implanted or removed if not appropriate, activating the first or second volume control elements 140 or 160 can be used to further adjust the optical power of the APIOL 900 if needed.

[0045] Figure 10A is a bottom isometric view of a fixed lens 1030, and Figure 10B is a cross-sectional view taken along section B-B of Figure 10A. The fixed lens 1030 is similar to the fixed lens 930 used in the modular accommodating APIOL 900 described above in Figures 9A-9C. The fixed lens 1030, however, includes the first and second volume control elements 140 and 160 either in lieu of or in addition to having the volume control elements 140 and/or 160 in the container. The fixed lens 1030 is itself an adjustable power lens. For example, referring to Figure 10B, the fixed lens 1030 includes an anterior optical element 1032, a posterior optical element 1034, and a fluid chamber 1036 filled with an optical fluid and a transport substance. In operation, the first and/or second volume control elements 140 and/or 160 are exposed to a noninvasive activation energy to either decrease or increase the volume of matter in the fluid chamber 1036 and thereby adjust the optical power of the fixed lens 1030 as described above with respect to Figures 1 -8B.

[0046] One embodiment of an oil suitable for the optical fluid 128 described above may be compounded by combining volumes of the following materials. Both equilibrium water content and refractive index can be adjusted by varying the proportions of the following components:

Phenylmethylcyclosiloxane. Rl 1 .545

N-(triethoxysilylpropyl)-0-Polyehylene oxide urethane, Rl 1 .45

(HYDROXYETHYLENEOXYPROPYLMETHYLSILOXANE)-(3,4- DIMETHOXYPHENYLPROPYL)METHYLSILOXANE-DIMETHYLSILOXANE TERPOLYMER, RU 1 .505