Implantable devices and methods for measuring intraocular, subconjunctival or subdermal pressure and/or analyte concentration

Abstract

Methods, apparatus and systems for measuring pressure and/or for quantitative or qualitative measurement of analytes within the eye or elsewhere in the body. Optical pressure sensors and/or optical analyte sensors are implanted in the body and light is cast from an extracorporeal light source, though the cornea, conjunctiva or dermis, and onto a reflective element located within each pressure sensor or analyte sensor. The position or configuration of each sensor's reflective element varies with pressure or analyte concentration. Thus, the reflectance spectra of light reflected by the sensors' reflective elements will vary with changes in pressure or changes in analyte concentration. A spectrometer or other suitable instrument is used to process and analyze the reflectance spectra of the reflected light, thereby obtaining an indication of pressure or analyte concentration adjacent to the sensor(s). The wavelength of the interrogating beam of light may vary to control out potential interference or inaccuracies in the system.

What is claimed is:  
     
         1 . An intraocular pressure sensing system comprising: 
 an implantable optical pressure sensor sized for implantation within the eye, said optical pressure sensor comprising an optical reflecting element which varies relative to changes in intraocular pressure and a window through which light will pass;    a light source useable to pass light through the cornea of the eye and through the window of the pressure sensor such that the light will strike the optical reflecting element;    a receiver/processor which receives light which has reflected from the optical reflecting element and processes such reflected light so as to obtain an indication of intraocular pressure.    
     
     
         2 . A system according to  claim 1  wherein the implantable pressure sensor is attached to a support that holds the implantable pressure sensor in a substantially fixed position within the eye.  
     
     
         3 . A system according to  claim 2  wherein the support comprises a haptic.  
     
     
         4 . A system according to  claim 2  wherein the support comprises a hapic and optic.  
     
     
         5 . A system according to  claim 4  wherein the sensor is mounted on the haptic.  
     
     
         6 . A system according to  claim 4  wherein the sensor is mounted on the optic.  
     
     
         7 . A system according to  claim 2  wherein the support is configured to hold the implantable pressure sensor substantially within the anterior chamber of the eye.  
     
     
         8 . A system according to  claim 2  wherein the support is configured to hold the implantable pressure sensor substantially within the posterior chamber of the eye.  
     
     
         9 . A system according to  claim 2  wherein the support comprises a shunt apparatus that may be implanted in the eye to decrease the intraocular pressure of that eye.  
     
     
         10 . A system according to  claim 2  wherein the support comprises a prosthetic lens that has been implanted in place of the patient's native ophthalmic lens.  
     
     
         11 . A system according to  claim 1  wherein the implantable pressure sensor is attached to a phakic intraocular lens.  
     
     
         12 . A system according to  claim 11  wherein the phakic intraocular lens is constructed to perform a vision correcting function as well as the function of holding the implantable pressure sensor in a substantially fixed position.  
     
     
         13 . A system according to  claim 2  wherein the support holds the implantable pressure sensor within the eye such that light may pass from the light source, through the cornea of the eye and onto the optical reflecting element.  
     
     
         14 . A system according to  claim 1  wherein the implantable optic pressure sensor comprises a Fabry-Perot interferometer pressure sensor.  
     
     
         15 . A system according to  claim 1  wherein the light source is a visible light source.  
     
     
         16 . A system according to  claim 1  wherein the light source is an LED light source.  
     
     
         17 . A system according to  claim 1  wherein the receiver/processor unit comprises a spectrometer.  
     
     
         18 . A method of determining intraocular pressure in a human or veterinary patient, said method comprising the steps of: 
 (A) implanting within the eye an optical pressure sensor that has an optical reflecting element that moves relative to changes in the intraocular pressure of the eye;    (B) using a light source to cast light into the eye such that the light strikes and is reflected by the optical reflecting element; and,    (C) using a receiver/processor to receive light which has reflected from the optical reflecting element and to process such reflected light so as to obtain an indication of intraocular pressure.    
     
     
         19 . A method according to  claim 18  wherein Step (A) comprises implanting the optical pressure sensor such that it is positioned substantially within the anterior chamber of the eye.  
     
     
         20 . A method according to  claim 18  wherein Step (A) comprises implanting the optical pressure sensor such that it is positioned substantially within the posterior chamber of the eye.  
     
     
         21 . A method according to  claim 18  wherein the native ophthalmic lens has been removed from the eye leaving at least a portion of the lens capsule in tact and wherein Step (A) comprises implanting the optical pressure sensor such that it is positioned substantially within at least a remaining portion of the lens capsule.  
     
     
         22 . A method according to  claim 18  wherein the optical pressure sensor is attached to a support that is configured to hold the optical pressure sensor at a substantially fixed position within the eye, and wherein Step (A) comprises implanting the optical pressure sensor and the support such that the optical pressure sensor is thereby held in a substantially fixed position within the eye.  
     
     
         23 . A method according to  claim 22  wherein Step (A) comprises implanting the optical pressure sensor and the support such that the optical pressure sensor is held in a substantially fixed position within the anterior chamber of the eye.  
     
     
         24 . A method according to  claim 22  wherein Step (A) comprises implanting the optical pressure sensor and the support such that the optical pressure sensor is held in a substantially fixed position within the posterior chamber of the eye.  
     
     
         25 . A method according to  claim 22  wherein the support comprises a lens that is adapted to perform a vision correcting function when implanted in the eye and wherein Step (A) comprises implanting the optical pressure sensor and the support in the eye such that i) the optical pressure sensor senses intraocular pressure and ii) the lens at least partially corrects the patient's vision.  
     
     
         26 . A method according to  claim 22  wherein the support comprises a shunt that is designed to drain aqueous humor in a manner that lowers intraocular pressure of the eye and wherein Step (A) comprises implanting the optical pressure sensor and the support in the eye such that i) that the optical pressure sensor senses intraocular pressure and ii) the shunt drains aqueous humor in a manner that lowers intraocular pressure.  
     
     
         27 . A method according to  claim 21  wherein the optical pressure sensor is embedded in or attached to a prosthetic lens, said prosthetic lens being implantable within at least a remaining portion of the lens capsule in place of the previously removed native lens.  
     
     
         28 . A method according to  claim 18  wherein Step (A) comprises positioning the optical pressure sensor in the eye such that, when light is passed from the light source in Step (B), the light will pass through the cornea of the eye and will strike and be reflected by the optical reflecting element.  
     
     
         29 . A method according to  claim 18  further comprising the steps of: 
 (D) implanting in the eye a optical analyte sensor having an optical reflecting element that varies in relation to the concentration or presence of at least one analyte;  
 (E) using a light source to cast light into the eye such that the light will strike and be reflected by the optical reflecting element of the analyte sensor; and,  
 (F) using a receiver/processor to receive light which has reflected from the optical reflecting element of the analyte sensor and to process such reflected light so as to obtain a qualitative or quantitative determination of at least one analyte.  
 
     
     
         30 . A method according to  claim 29  wherein the optical pressure sensor and the analyte sensor are attached to a common support that holds both the optical pressure sensor and the analyte sensor at substantially fixed positions within the eye and wherein Steps (A) and (D) are performed concurrently by implanting the optical pressure sensor, analyte sensor and accompanying support within the eye.  
     
     
         31 . A method according to  claim 29  wherein different light sources are used in Steps (B) and (E).  
     
     
         32 . A method according to  claim 29  wherein the same light source is used in Steps (B) and (E).  
     
     
         33 . A method according to  claim 32  wherein the wavelength of light emitted from the light source is variable and wherein a first wavelength is used in Step (B) and a second wavelength is used in Step (E).  
     
     
         34 . A method according to  claim 29  wherein different receiver/processors are used in Steps (C) and (F).  
     
     
         35 . A method according to  claim 29  wherein the same receiver/processor is used in Steps (C) and (F).  
     
     
         36 . A method according to  claim 35  wherein at least one setting on the receiver/processor is variable and wherein at least one first setting of the receiver/processor is used in Step (D) and at least one second setting of the receiver/processor is used in Step (F).  
     
     
         37 . A method according to  claim 29  wherein the analyte sensor is adapted to measure or to detect glucose and wherein Step (F) comprises obtaining a qualitative or quantitative determination of glucose.  
     
     
         38 . A system for intraocular, subconjunctival or subdermal analyte determination, said system comprising: 
 an optical sensor sized for intraocular, subconjunctival or subdermal implantation, said sensor comprising an optical reflecting element which varies relative to changes in the amount or concentration of the analyte and a window through which light will pass;    a light source useable to pass light through the cornea, conjunctiva or skin such that the light will strike and be reflected by the optical reflecting element;    a receiver/processor which receives light that has reflected from the optical reflecting element and processes such reflected light to obtain a qualitative or quantitative determination of the analyte.    
     
     
         39 . A system according to  claim 38  wherein the optical sensor further comprises a membrane through which the analyte will pass and wherein the optical reflecting element varies in response to the amount or concentration of the analyte that has passed through the membrane.  
     
     
         40 . A system according to  claim 38  wherein the analyte is glucose.  
     
     
         41 . A system according to  claim 38  wherein the osmotic pressure, osmolality and/or osmolarity of a biological fluid varies with the concentration of the analyte in that fluid and wherein the optical reflecting element varies in response to changes in the osmotic pressure, osmolality and/or osmolarity of a biological fluid indicative of changes in the analyte concentration in that fluid.  
     
     
         42 . A system according to  claim 38  wherein the light source is a visible light source.  
     
     
         43 . A system according to  claim 38  wherein the light source is an LED light source.  
     
     
         44 . A system according to  claim 38  wherein the receiver/processor comprises a spectrometer.  
     
     
         45 . A method of qualitative or quantitative determination of an analyte within the body of a human or veterinary patient, said method comprising the steps of: 
 (A) implanting an optical analyte sensor at an intraocular, subconjunctival or subdermal location within the patient's body, said analyte sensor having an optical reflective element that varies in response to the presence of or changes in the concentration of the analyte;    (B) using a light source to cast light through the cornea, conjunctiva or skin of the patient such that the light will strike and be reflected by the optical reflecting element; and,    (C) using the receiver/processor to receive light which has reflected from the optical reflecting element and to process such reflected light so as to obtain a qualitative or quantitative determination of the analyte.    
     
     
         46 . A method according to  claim 45  wherein Step (A) comprises implanting the optical analyte sensor such that it is positioned substantially within the anterior chamber of the eye.  
     
     
         47 . A method according to  claim 45  wherein Step (A) comprises implanting the optical analyte sensor such that it is positioned substantially within the posterior chamber of the eye.  
     
     
         48 . A method according to  claim 45  wherein the native ophthalmic lens has been removed from the eye leaving at least a portion of the lens capsule in tact and wherein Step (A) comprises implanting the optical analyte sensor such that it is positioned substantially within at least a remaining portion of the lens capsule.  
     
     
         49 . A method according to  claim 45  wherein Step (A) comprises implanting the optical analyte sensor such that it is positioned substantially within or beneath the skin.  
     
     
         50 . A method according to  claim 45  wherein Step (A) comprises implanting the optical analyte sensor such that it is positioned substantially within or beneath the cornea of an eye.  
     
     
         51 . A method according to  claim 45  wherein Step (A) comprises implanting the optical analyte sensor such that it is positioned substantially within or beneath the conjunctive of an eye.  
     
     
         52 . A method according to  claim 45  wherein the optical pressure sensor is attached to a support that is configured to hold the optical analyte sensor at a substantially fixed position within the body and wherein Step (A) comprises implanting the optical analyte sensor and the support such that the optical pressure sensor is thereby held in a substantially fixed position within the body.  
     
     
         53 . A method according to  claim 52  wherein Step (A) comprises implanting the optical analyte sensor and the support such that the optical analyte sensor is held in a substantially fixed position within the anterior chamber of the eye.  
     
     
         54 . A method according to  claim 52  wherein Step (A) comprises implanting the optical analyte sensor and the support such that the optical analyte sensor is held in a substantially fixed position within the posterior chamber of the eye.  
     
     
         55 . A method according to  claim 52  wherein the support comprises a lens that is adapted to perform a vision correcting function when implanted in the eye and wherein Step (A) comprises implanting the optical analyte sensor and the support in the eye such that i) the optical analyte sensor senses at least one analyte and ii) the lens at least partially corrects the patient's vision.  
     
     
         56 . A method according to  claim 52  wherein the support comprises a shunt that is designed to drain aqueous humor in a manner that lowers intraocular pressure of the eye and wherein Step (A) comprises implanting the optical analyte sensor and the support in the eye such that i) that the optical analyte sensor senses at least one analyte and ii) the shunt drains aqueous humor in a manner that lowers intraocular pressure.  
     
     
         57 . A method according to  claim 48  wherein the optical analyte sensor is embedded in or attached to a prosthetic lens, said prosthetic lens being implantable within at least a remaining portion of the lens capsule in place of the previously removed native lens.  
     
     
         58 . A method according to  claim 45  wherein Step A comprises positioning the optical analyte sensor in the eye such that, when light is passed from the light source in Step (B), the light will pass through the cornea of the eye and will strike and be reflected by the optical reflecting element.  
     
     
         59 . A method according to  claim 45  wherein Step A comprises positioning the optical analyte sensor in the eye such that, when light is passed from the light source in Step (B), the light will pass through the conjunctiva of the eye and will strike and be reflected by the optical reflecting element.  
     
     
         60 . A method according to  claim 45  further comprising the steps of: 
 (C) implanting in the eye a optical pressure sensor having an optical reflecting element that varies in relation to changes in intraocular pressure;  
 (D) using a light source to cast light into the eye such that the light will strike and be reflected by the optical reflecting element of the pressure sensor; and,  
 (E) using a receiver/processor to receive light which has reflected from the optical reflecting element of the pressure sensor and to process such reflected light so as to obtain a measurement of intraocular pressure.  
 
     
     
         61 . A method according to  claim 60  wherein the analyte sensor and the pressure sensor are attached to a common support that holds both the analyte sensor and the pressure sensor at substantially fixed positions within the body and wherein Steps (A) and (C) are performed concurrently by implanting the analyte sensor, pressure sensor and accompanying support within the body.  
     
     
         62 . A method according to  claim 60  wherein different light sources are used in Steps (B) and (D).  
     
     
         63 . A method according to  claim 60  wherein the same light source is used in Steps (B) and (E).  
     
     
         64 . A method according to  claim 63  wherein the wavelength of light emitted from the light source is variable and wherein a first wavelength is used in Step (B) and a second wavelength is used in Step (E).  
     
     
         65 . A method according to  claim 60  wherein different receiver/processors are used in Steps (D) and (F).  
     
     
         66 . A method according to  claim 60  wherein the same receiver/processor is used in Steps (D) and (F).  
     
     
         67 . A method according to  claim 66  wherein at least one setting on the receiver/processor is variable and wherein at least one first setting of the receiver/processor is used in Step (D) and at least one second setting of the receiver/processor is used in Step (F).  
     
     
         68 . A method according to  claim 45  wherein the analyte sensor is adapted to measure or to detect the presence of a concentration of glucose and wherein Step (F) comprises obtaining a qualitative or quantitative determination of glucose.