METHOD AND APPARATUS FOR CHANGING THE PERCEPTUAL COLOR APPEARANCE OF THE IRIS OF A HUMAN'S OR ANIMAL'S EYE

Abstract

The underlying invention comprise a method for changing the human perceptual color appearance of the iris of a human's or animal's eye by selectively decreasing the density of pigments of the anterior stroma layer of the iris, the method comprising the steps of generating a plurality of predefined energy quantities; applying one or more of the predefined energy quantities to the anterior stroma layer, wherein each of the predefined energy quantities is generated and applied such that it ablates at least in part melanocytes of the stroma, wherein the predefined energy quantities at least in part are generated and applied in such a way that ablated tissue generated as an immediate cause of the energy quantities is discharged into the anterior eye chamber such that the discharged tissue can be removed by maintaining a mechanically generated flow of rinsing solution through or within the anterior eye chamber.

Claims

1-15. (canceled)

16. A method for changing the human perceptual color appearance of the iris of a human's or animal's eye by selectively decreasing the density of pigments of the anterior stroma layer of the iris, the method comprising: generating, by a generator module, a plurality of predefined energy quantities; and applying, by the generator module, one or more of the predefined energy quantities to the anterior stroma layer; wherein: each of the predefined energy quantities are generated and applied, such that they ablate, at least in part, melanocytes of the stroma whilst leaving non-melanocyte tissue of at least the stroma essentially undamaged; and the predefined energy quantities are at least in part generated and applied in such a way that ablated tissue or pigment debris, that is generated as an immediate cause of one or more of the applied energy quantities, is discharged into the anterior eye chamber, such that the discharged tissue can be removed by a mechanically generated flow of rinsing solution through or within the anterior eye chamber.

17. The method according to claim 16, wherein the method further comprises: providing a mechanically generated flow of rinsing solution through or within the anterior eye chamber, and thereby removing the tissue/pigment debris from eye by means of the generated flow.

18. The method of claim 17, further comprising one or more than one of the following features: maintaining the mechanically generated flow for a respectively predetermined lapse of time at least during, and/or after applying the predefined quantity of energy to the anterior stroma layer; the mechanically generated flow is also maintained during a predefined lapse of time prior to applying the predefined quantity of energy to the anterior stroma layer; the mechanically generated flow is maintained for at least one predetermined lapse of time in accordance with a respective, predetermined flow rate profile, the predetermined flow rate profile preferably being constant over time, at least for one, optionally for each, lapse of time, wherein at least one of a start and end point of at least one lapse of time optionally being triggered by the generating, and/or applying the predefined quantity of energy; the mechanically generated flow optionally comprising, at least during a predetermined first period of time, a laminar flow, and/or at least during a predetermined second period of time a turbulent flow.

19. The method according to claim 16, comprising the further steps of: partitioning, preferably by a partitioning module, further preferably based on a captured image of the iris, at least a part of the surface area of the anterior stroma layer into a number of predefined surface sections, preferably having a predetermined size, and applying a respective number of predefined energy quantities to one or more surface sections; the predefined surface sections optionally processed in accordance with a predefined succession of surface sections, the predefined succession preferably determined by the partitioning module; the predetermined surface sections, in particular the size of one or more of the predetermined surface sections, and/or the particular succession of surface sections within the processing sequence, and/or the energy content/power of the energy quantity optionally being determined on the basis of the density of pigments, and/or the specific location of the surface area on the iris, and/or the overall size of the iris; wherein at least one parameter of the mechanically generated flow is optionally determined on the basis of one or more of: the specific location of a respectively processed surface section, the particular succession of the surface sections, the density of pigments, the size of a respective surface section, one or more than one parameter related to generating and/or applying the energy quantities.

20. The method according to claim 16, further comprising: wherein at least one or more than one of the predefined energy quantities is generated and applied to the stroma layer as at least one of: one or more electromagnetic waves, in particular electromagnetic wave pulses, the electromagnetic waves preferably generated by a laser device, in particular a pulsed laser device, more particularly by a Q-switched laser device, in particular Q-switched frequency doubled laser device, and one or more mechanical pressure waves, in particular shock or blast waves, preferably induced by cavitation, in particular plasma-induced cavitation, more particularly directly induced by a plasma blast, and/or induced by an electromagnetic wave pulse, the mechanical pressure waves generated within liquid contained in or in direct fluid contact with the anterior eye chamber, and/or wherein the method comprises a step of determining the local pigment density, and/or thickness of melanocyte layer at the anterior stroma layer, wherein generating, and/or locally applying one or more of the energy quantities is carried out in dependence of a respective local density of pigments, and/or local thickness of the melanocyte layer of the anterior stroma layer.

21. The method according to claim 16, at least one or more than one, in particular substantially all, of the energy quantities being generated as electromagnetic wave pulses, in particular for direct application to the iris tissue, by the operation of a laser device, the laser device operated: to generate at least a part of the energy quantities to have a wavelength range between 488 nm to 580 nm, or in a wavelength range between 522 to 541 nm, or with a wavelength corresponding substantially to 532 nm, or in a wavelength range between 976 nm to 1160 nm, or in a wavelength range between 1044 to 1082 nm, or with a wavelength corresponding substantially to 1064 nm; and/or to generate at least a part of the energy quantities with a pulse frequency in the range between 3 Hz and 300 Hz; and/or to generate at least a part of the energy quantities to have a pulse length lying in the range between 2 ns to 6 ns, or corresponding substantially to 4 ns; and/or to generate, by operating or adjusting an optical system of the laser device, a pulsed laser beam for generating at least one or more than one, in particular substantially all, of the energy quantities, the pulsed laser beam having a focusing angle (a) lying in the range between 10 degrees and 18 degrees, optionally between 13 degrees and 16 degrees, further optionally lying substantially at about 14 degrees; wherein the energy quantities are guided from a light emitting element to the optical system via a fiber optical system, preferably having an optical fiber with a fiber-optic core diameter lying in the range between 270 m and 290 m, in particular at about 280 m; and/or to apply the energy quantities to the anterior stroma layer substantially in vertical direction; and/or at least one or more than one, in particular substantially all, of the energy quantities being generated as mechanical wave pulses as a direct cause of a plasma-induced burst pulse generated at least in part by one or more than one of: a direct interaction of a laser pulse with a laser target that is in fluid communication with the intraocular humor; a direct interaction of a laser pulse with a laser target that is placed within the anterior eye chamber; a direct interaction of a laser pulse with rinsing-solution within the anterior eye chamber; and a direct interaction of a laser pulse with the anterior stroma layer, in particular fibrovascular stroma structure of the stroma layer.

22. The method according to claim 16, further comprising: tracking, by a tracking module, in particular an optical tracking module, one or more than one of a position, shape, and movement of the eye or one of the components of the eye, such as the iris or the pupil, relative to a spatial reference point, and applying, at least in part, the generated predefined energy quantities, optionally each of the generated predefined energy quantities, in dependence on the tracking result; and optionally further comprising: inhibiting the generator module and/or inhibiting application of one or more than one energy quantity in case that the tracking result indicates one or more of a change in position, a change in location, a change in shape, and movement, and/or relocating the target setting of the energy quantity in accordance with one or more of a change in position, a change in location, a change in shape, and a movement; and/or the method further comprising at least one or more of the following features: coupling, prior to applying one or more than one of the energy quantities, an eye shielding element to the eye, in particular to the outer layer of the cornea; the eye shielding element implemented and positioned to prevent energy quantities from entering the posterior eye chamber and/or from impinging the retina of the eye; the eye shielding element optionally being implemented in a composite structure comprising an absorption layer for absorbing energy quantities impinging thereon, and an adhesion layer for coupling with the outer cornea layer, in particular by adhesive forces, the absorption layer optionally comprising one or more than one metallic layers, in particular stainless steel layers, and the adhesion layer optionally comprising an open-pored material layer, in particular foamed layer, preferably comprising and/or made from a polyvinyl alcohol material; the eye shielding element being partly, in particular in the adhesion layer, filled with or absorbing natural liquid from the outer side of the cornea thereby adhering to the cornea like for instance a paper tissue or blotting paper would, the eye shielding element optionally having a convex; and/or circular shape, and/or a diameter lying in the range between 0.5 mm and 3 mm, or in the range between 1 mm and 2 mm, or substantially at about 1.5 mm.

23. The method according to claim 16, further comprising: scanning, by a scanning module, at least the iris or sections thereof, and/or the anterior eye chamber at least during application of the energy quantities; and performing one or more than one of the following steps: determining a shape of the iris and/or a track, pathway and/or succession of target points to be impinged with the energy quantities based on the scanning result; storing the scanning result after each predetermined number of applied energy quantities; determining, based on the scanning result, an actual location of impingement or an actual averaged location of impingement respectively indicating an actual location on the anterior stroma layer/the iris where one or more energy quantities indeed impinged on the anterior stroma layer, and optionally tracking the target locations of impingement; controlling, based on the scanning result, the flow of rinsing solution within or through the anterior eye cavity; based on the scanning result, determining a density of pigments, in particular a local density of pigments, in particular a pigment profile, or at least a parameter representative of the density, in particular the local density, of pigments may be determined based on the scanning result, and controlling the generation and/or application of one or more of the energy quantities based at least in part on the density of pigments or the respective parameter; based on the scanning result, determining a change, in particular local change, in the density of pigments, or at least a parameter representative of the change in density of pigments in the anterior stroma layer, and controlling the generation and/or application of the energy quantities based on the determined change of the density of pigments or the respective parameter; generating, based on the scanning result, one or more than one display objects for display on a display screen to an operator executing the method; and optionally providing for display on the display screen operational parameters related to the execution of the method, in particular comprising one or more than one of: one or more than one parameter related to the energy quantities, one or more points of impact (T) of one or more applied energy quantities on the anterior stroma layer, in particular one or more of a one or more past and future points of impact, of energy quantities, a first indication representative of a change, in particular local change, of the density of pigments, and a second indication representative of processed, and/or unprocessed surface areas of the anterior surface of the stroma layer.

24. An apparatus specifically adapted to and set up for changing the human perceptual color appearance of the iris of a human's or animal's eye by selectively decreasing the density of pigments of the anterior stroma layer of the iris, the apparatus comprising: an energy source comprising a generator module that is adapted and set up for generating a plurality of predefined energy quantities of at least one of electromagnetic type and mechanical wave type; a focusing device adapted to and set up for focusing the energy quantities towards the anterior stroma layer of the iris of the eye; a fluid pumping module adapted to and set up for the generation and maintenance of a predefined mechanical flow of rinsing solution through, and/or within the anterior eye chamber; and a controller unit that is programmed and set up for carrying out a method according to at least one of claims 1 to 8, wherein the controller unit is implemented and set up for: operating the energy source and focusing device to apply the generated, predefined energy quantities to a predefined location of the anterior layer of the stroma in such a way that melanocyte tissue of the stroma, that is impinged with the energy quantities is ablated in such a way that it is, at least in part, discharged into the anterior eye chamber as a direct cause of the interaction between the energy quantities and the tissue; and for operating the fluid pumping module to maintain the predefined flow over a lapse of time during, and/or directly after applying the energy quantities to the stroma, such that discharged melanocyte material at least in part is fluidly discharged from the anterior chamber.

25. The apparatus according to claim 24, further comprising one or more than one of the following: a microscope module, optionally implemented as a stereoscopic microscope, arranged and positionable in such a way that an operator operating the apparatus is able to observe at least the anterior surface of the stroma layer of the eye, the apparatus; a slit lamp module comprising a slit lamp and corresponding optical elements allowing the operator/supervisor of the method to throw a sheet of light into the eye/onto the anterior stroma layer, wherein the slit lamp module and microscope module are optionally adapted for mutual interaction thereby implementing a slit lamp microscope for investigating at least the anterior stroma layer of the iris; an eye shielding element implemented and set up for being coupled to the eye, in particular the outer cornea layer in such a way to prevent energy quantities from entering the posterior eye chamber and/or from impinging the retina of the eye, wherein the eye shielding element having one or more than one of: a composite structure having an absorption layer for absorbing energy quantities impinging thereon, and an adhesion layer for coupling with the outer cornea layer, in particular by adhesive and/or cohesive forces in particular to avoid the eye shielding element from being floated away by lacrimal fluid, the absorption layer optionally comprising one or more than one metallic layers, in particular stainless steel layers, and the adhesion layer optionally comprising an open-pored material layer, in particular foamed layer, preferably comprising and/or made from a polyvinyl alcohol material; a convex; and/or circular shape, and/or a diameter lying in the range between 0.5 mm and 3 mm, or in the range between 1 mm and 2 mm, or substantially at about 1.5 mm.

26. The apparatus according to claim 24, wherein the generator module comprises: a light emitting element, in particular a laser device preferably a Q-switched laser device, more preferably a Q-switched frequency doubled laser device, yet more preferably a Nd:YAG laser device, the laser device operable to generate at least some of the predefined energy quantities, and emit the generated energy quantities in the form of light pulses towards and onto the anterior stroma layer so as to change the density of pigments, wherein the light emitting element, in particular the laser device, is optionally operable or implemented to perform at least one of: emit light, in particular pulsed laser light, in a wavelength range between 488 nm and 580 nm, in particular 532 nm; or in a wavelength range between 976 nm to 1160 nm, or in a wavelength range between 1044 to 1082 nm, or with a wavelength corresponding substantially to 1064 nm; generate light pulses having a duration in the range between 2 ns and 6 ns, in particular 4 ns; generate light pulses having an energy of about 2 mJ; generate light pulses with a pulse frequency in the range between 3 Hz and 300 Hz; generate light pulses having a peak power ranging between 0.1 MW to 0.5 MW; generate a laser spot having a diameter ranging between 200 m and 600 m, preferably in the range of about 400 m; the energy source optionally comprising: an optical system implemented and set up for generating a pulsed laser beam having a focusing angle (a) lying in the range between 10 degrees and 18 degrees, optionally between 13 degrees and 16 degrees, further optionally lying substantially at about 14 degrees, the optical system optionally implemented and set up for applying the energy quantities to the anterior stroma layer substantially in vertical direction; a fiber optical system implemented and set up for guiding energy quantities generated by light emitting element towards the target location (T), the fiber optical system optionally comprising an optical fiber having a fiber-optic core diameter lying in the range between 270 m and 290 m, in particular at about 280 m, wherein the fiber optical system is optionally coupled between the light emitting element and the optical system for guiding energy quantities from the light emitting element located at a remote location to the optical system.

27. The apparatus according to claim 24, wherein the generator module comprises: a pressure wave generator, the pressure wave generator operable to generate at least some of the predefined energy quantities, and emit the generated energy quantities in the form of mechanical pressure waves, in particular shock or blast waves, towards and onto the anterior stroma layer so as to change the density of pigments; wherein the pressure wave generator is optionally operable or implemented to generate the pressure waves by induced cavitation within a liquid that is in liquid contact with the eye liquid as contained in the anterior eye chamber; wherein the induced cavitation is optionally generated by impinging a target object with electromagnetic waves, in particular laser light, preferably pulsed laser light, and/or by an ultrasound source, in particular a piezo generator.

28. A method for use in a non-surgical treatment of the iris of an eye of a human being or an animal, the treatment modifying the perceived color of the iris by selectively decreasing the density of melanin pigments of the anterior stroma layer of the eye, the method further comprising: generating, by a generator module, a plurality of predefined energy quantities; and applying, by the generator module, one or more of the predefined energy quantities to the anterior stroma layer; wherein: each of the predefined energy quantities are generated and applied, such that they ablate, at least in part, melanocytes of the stroma whilst leaving non-melanocyte tissue of at least the stroma essentially undamaged; and the predefined energy quantities are at least in part generated and applied in such a way that ablated tissue or pigment debris, that is generated as an immediate cause of one or more of the applied energy quantities, is discharged into the anterior eye chamber, such that the discharged tissue can be removed by a mechanically generated flow of rinsing solution through or within the anterior eye chamber.

29. A method of treatment using an apparatus in a non-surgical treatment of the iris of an eye of a human being or an animal, the treatment comprising: modifying the perceived color of the iris by selectively decreasing the density of melanin pigments of the anterior stroma layer of the eye; wherein the apparatus comprises: an energy source comprising a generator module that is adapted and set up for generating a plurality of predefined energy quantities of at least one of electromagnetic type and mechanical wave type; a focusing device adapted to and set up for focusing the energy quantities towards the anterior stroma layer of the iris of the eye; a fluid pumping module adapted to and set up for the generation and maintenance of a predefined mechanical flow of rinsing solution through, and/or within the anterior eye chamber; and a controller unit that is programmed and set up for carrying out the method of treatment, wherein the controller unit is implemented and set up for: operating the energy source and focusing device to apply the generated, predefined energy quantities to a predefined location of the anterior layer of the stroma in such a way that melanocyte tissue of the stroma, that is impinged with the energy quantities is ablated in such a way that it is, at least in part, discharged into the anterior eye chamber as a direct cause of the interaction between the energy quantities and the tissue; and for operating the fluid pumping module to maintain the predefined flow over a lapse of time during, and/or directly after applying the energy quantities to the stroma, such that discharged melanocyte material at least in part is fluidly discharged from the anterior chamber.

30. Computer-readable non-transitory storage medium or controller-unit comprising executable instructions which, when executed on a computer or controller-unit cause the computer or controller-unit to execute a method comprising: generating, by a generator module, a plurality of predefined energy quantities; and applying, by the generator module, one or more of the predefined energy quantities to the anterior stroma layer; wherein: each of the predefined energy quantities are generated and applied, such that they ablate, at least in part, melanocytes of the stroma whilst leaving non-melanocyte tissue of at least the stroma essentially undamaged; and the predefined energy quantities at least in part are generated and applied in such a way that ablated tissue or pigment debris, that is generated as an immediate cause of one or more of the applied energy quantities, is discharged into the anterior eye chamber, such that the discharged tissue can be removed by a mechanically generated flow of rinsing solution through or within the anterior eye chamber.

Description

[0140] Exemplary embodiments of the invention will now be described in connection with the annexed figures, in which:

[0141] FIG. 1 shows a schematic representation of a human eye together with schematic representations for carrying out the underlying method;

[0142] FIG. 2 shows an enlarged view of a section of FIG. 1, 2 including the iris of the eye;

[0143] FIG. 3 shows a further schematic view of the eye and a schematic embodiment of an apparatus for carrying out the underlying invention;

[0144] FIG. 4 shows a further representation of the human eye together with further details for applying laser pulses in connection with the underlying method;

[0145] FIG. 5 shows a schematic view of the eye and further details of an apparatus for carrying out the underlying invention;

[0146] FIG. 6 shows the enlarged view of FIG. 3 together with an eye shielding element;

[0147] FIG. 7 shows an example flow chart for carrying out a method according to the invention.

[0148] In FIG. 1, a schematic representation of a human eye 1 is presented together with elements or components of an apparatus for carrying out the underlying method.

[0149] As regards the human eye 1, components thereof are described in such an extent which is considered adequate for fully understanding the underlying method.

[0150] The human eye 1 represents an optical system with which real-life objects are imaged via a lens 2 onto the retina 3 of the eye 1. Light incidence into the eye 1, and therefore the amount of light incident on the retina 3, is controlled by a variable aperture represented by a comparatively thin, circular structure in the eye 1, known as the iris 4.

[0151] By a muscular system, the eye 1 is able to vary the diameter and size of the central iris opening, i.e. the pupil 5 and thus the amount of light reaching the retina 3.

[0152] The iris 4 consists essentially of two layers, the so-called stroma layer or stroma 6, which is located at the front (i.e. anterior) of the iris 4 oriented towards the outside of the eye 1, and a layer of pigmented epithelial cells 7 positioned on the back side (i.e. posterior) of the iris 4. The pigmented epithelial cells have the function to absorb incoming light to such an extent that the iris indeed functions as an aperture, defining the diameter of the pupil 5, for the optical system of the eye 1.

[0153] The pigmented epithelial cells comprise melanin as the pigment, which is an efficient light absorber, in particular as regards light in the visible spectrum.

[0154] The anterior stroma layer 8, i.e. the layer of the stroma oriented towards the outside of the eye, i.e. towards the anterior eye chamber 9, may comprise a certain amount of melanocyte cells containing melanin pigment. The amount or density of melanin pigment in the anterior stroma layer 8 is not fixed, and may vary from individuum to individuum.

[0155] Just for the sake of completeness, the anterior eye chamber 9 is delimited to the outside by the cornea 10. The anterior eye chamber 9 defined and located between the iris 4 and the cornea 10 is filled with aqueous humor, wherein aqueous humor is formed in the ciliar body 11 of the eye 1 where it is secreted into the posterior eye chamber 12. From the posterior eye chamber 12 the aqueous humor passes through between the iris 4 and lens 2 into the into the anterior eye chamber 9, from where it is discharged over the Schlemm's Canal 13 of the eye 1.

[0156] The melanin pigments comprised by the melanocytes alter the absorption and reflection behaviour of the iris 4, more specifically of the stroma 6. The melanin pigments, in particular the density of melanin pigments in or of the anterior stroma layer 8 greatly influence the perceived eye color, which is used as a synonym for the perceived color of the iris.

[0157] As a matter of fact, if no or hardly any melanin is present in or on the anterior stroma layer 8, the perceived eye color is blue, whereas with increasing melanin, or melanin-density, the perceived eye color shifts towards green, hazel, and brown. The melanin-density occurring naturally in the anterior stroma layer 8 is determined by the phenotype of the individuum under consideration.

[0158] For some reasons, inter alia driven by aesthetic and/or social forces, there exists the desire to change perceptual eye/iris color from brown, green etc. to blue. Thus, corresponding methods have been developed, for changing the perceptual eye/iris color by removing melanin pigments of the anterior stroma layer of the eye. For example in U.S. Pat. No. 8,206,379 B2, a laser-based approach is described in which melanocyte cells of the anterior stroma layer, containing melanin pigment, are killed, such that the melanocytes and corresponding melanin pigments can be removed by macrophage digestion, and removed from the eye chamber via the so-called Schlemm's Canal depicted in FIG. 1 for convenience with reference sign 13.

[0159] As already discussed, macrophage-based removal of the pigmentation of the anterior stroma layer 8 may adversely affect the operability of the Schlemm's Canal 13, which may lead to increased intraocular pressure, which in turn may impair ocular health.

[0160] The method according to the underlying invention is based on a different approach, which has been found by elaborate investigation of the anterior stroma layer 8 and the pigmentation of the anterior stroma layer 8.

[0161] Specifically, it has been found, that the melanin-containing melanocyte cells of the anterior stroma layer 8 can be ablated by specifically impinging the anterior stroma layer with energy quantities, of for example electromagnetic wave pulses and/or fluidal pressure pulses, or similar, such that the melanocyte cells and corresponding cell debris and pigment is discharged into the aqueous humor of the anterior eye chamber 9 as a direct cause of the applied energy quantity, such that the ablated material can be removed via a mechanically generated flow of rinsing solution through or within the anterior eye chamber 9.

[0162] This process underlying the present invention is schematically indicated and depicted in FIG. 1, showing inter alia applying an energy quantity, by for example one or more laser pulses 14 to the anterior stroma layer 8 such that melanocyte cells 15 bound to the stroma 6 are, as a direct cause of the impinged one or more laser pulses 14, discharged into the aqueous humor/liquid contained in the anterior eye chamber 9. Discharged melanocyte material is depicted with reference sign 16 in FIG. 1.

[0163] The discharged melanocyte material 16 can then be removed from the anterior eye chamber 9, for example, by maintaining a mechanically generated flow of rinsing solution through the anterior eye chamber, which flow is indicated by two arrows 17 in FIG. 1. The flow of rinsing solution 17 may for example be generated by an irrigation device (not explicitly shown in FIG. 1), allowing the generation and maintenance of a, for example, continuous flow of rinsing fluid through the anterior eye chamber 9.

[0164] Maintenance of the flow of rinsing solution and applying the laser pulses 14 in order to ablate the melanocytes and discharge them directly into the anterior eye chamber 9 may, for example, be executed by trained medical staff, not requiring the intervention of a medical professional.

[0165] By removing the melanocytes of the anterior stroma layer 8, the perceptual color of the eye 1 may be changed from a brown/green shade or color towards blue. Further, by conducting the method such that the melanocyte material is directly discharged into the anterior eye chamber 9, the melanocyte material can be removed by maintaining the flow of rinsing solution 17, thereby avoiding impairments of the naturally occurring exhaust processes for the aqueous humor over the Schlemm's Canal 13.

[0166] Beyond that, by directly removing the melanocytes, the pigment density of the anterior stroma layer 8 may be changed instantaneously, meaning that the result of pigment removal may be directly checked or monitored, which may lead to more efficient, and overall shortened procedures for changing the perceptual eye color to a respectively desired color.

[0167] FIG. 2 shows an enlarged view of the iris 4 and stroma 6 region of the eye as shown in FIG. 1. Specifically, FIG. 2 shows one or more laser pulses 14 applied to and impinging on the anterior stroma layer 8. As a direct consequence of applying the one or more laser pulses 14, melanocyte cells 15, which under normal conditions are bound to the anterior stroma layer 8, are, by the direct action of the one or more laser pulse 14, directly discharged into the aqueous humor/liquid/aqueous humor rinsing solution mixture that is present in the anterior eye chamber 9. The discharged melanocyte cells and melanocyte material 16 may be flushed away and out of the anterior eye chamber 9 by the mechanically generated flow 17 of rinsing solution generated through/across the anterior eye chamber 9.

[0168] In order to obtain adequate and/or improved removal of the discharged melanocytes 16, it is possible to maintain the mechanically generated flow 17 of rinsing solution for a predetermined lapse of time during, prior to, and/or after applying the predefined energy quantities, e.g. the one or more laser pulses 14.

[0169] The flow of rinsing solution 17 may be provided according to a predetermined profile, in particular flow rate profile, which may be constant over time, or which may vary according to a predefined time course. Variations of the profile may for example correspond or synchronized with the pulse rate and/or with the density of pigments of a respective area of the stroma 6 where the energy quantities are respectively applied.

[0170] Further details of a corresponding apparatus 18 configured for and set up for carrying out a method as has been previously discussed are described below in connection with FIG. 3.

[0171] FIG. 3 shows a schematic view of the eye 1, and beyond that a schematic representation of components of the apparatus 18 which is adapted to and set up for changing the human perceptual color appearance of the iris of a human's or animal's eye.

[0172] The apparatus 18 comprises as an energy source or energy module for generating a plurality of predefined energy quantities a laser device 19 having a laser source 20 for generating predefined laser pulses 14. Via a not explicitly shown focusing device, for example involving an optical system, the laser device 19 is operable to direct and apply the generated predefined laser pulses 14 to the anterior stroma layer 8 of the iris 4. The laser device in particular may comprise a target setting device for setting a corresponding target point/area where the generated laser pulses 14 shall impinge.

[0173] The predefined laser pulses 14 are generated and applied in such a way that melanocyte cells 15 of the anterior stroma layer 8 are directly discharged (in particular: burst off), by the action of the laser pulses 14, into the aqueous humor or liquid or aqueous humor/rinsing solution mixture or rinsing solution contained in the anterior eye chamber 9.

[0174] For example, the laser device, which may for example be a Q-switched frequency doubled Nd:YAG laser, may be set up for generating laser pulses in the wavelength range of about 532 nm, having a pulse length of about 4 ns, and a pulse energy of approximately 2 mJ. A pulse frequency of the laser device may lie in the range between 3 Hz and 300 Hz, for example. The focusing device and/or target setting device/unit may be adapted and set up for generating laser spot sizes in a diameter range of about 500 m.

[0175] The apparatus further comprises a fluid pumping module 21 that is adapted and set up for maintaining the predefined mechanical flow 17 through the anterior eye chamber 9. The flow 17 may for example correspond to a continuous flow in which, via a pair of irrigator elements 22, for example, rinsing solution is supplied and drained from the anterior eye chamber 9. By the mechanical flow 17 thus generated, it is possible to remove ablated and discharged melanocytes and melanocyte material from the anterior eye chamber 9, which in particular leads to the advantages as described in more details hereinabove.

[0176] As is indicated in FIG. 3, the apparatus 18 may comprise one or more controller units 23 that is/are specifically programmed and set up for controlling the components of the apparatus 18 in accordance with any suitable method according to the invention as described herein.

[0177] As an example, the controller unit 23 may be programmed and set up such that a mechanically generated flow as described hereinabove can be maintained, such as for example in accordance with a predefined flow profile defined for at least one of the time prior to, during, and/or after applying the one or more energy quantities, e.g. laser pulses 14, to the anterior stroma layer 8 of the iris 4.

[0178] Further, the one or more controller units 23 may be coupled to the laser device 19, in order to generate and apply the predefined laser pulses 14 to the anterior stroma layer 8 of the iris 4 as described herein.

[0179] The one or more controller units 23 may be set up such that, for example by adequately controlling a focusing/target setting device, one or more of the generated laser pulses 14 are directed/applied to a predefined location/area of the anterior stroma layer 8.

[0180] As depicted in FIG. 3, the apparatus 18 may comprise a microscope and/or scanning module 24, which may be coupled to and correspondingly set up for being controlled by the one or more controller units 23, wherein the one or more controller units 23 may be programmed and set up for adequately controlling the operation of the corresponding modules 24.

[0181] The microscope and/or scanning module 24, which may in embodiments be divided into a separate microscope module and a separate scanning module, may comprise a stereoscopic microscope, that is arranged and positionable such that an operator operating the apparatus 18 is able to observe at least the anterior stroma layer 8 of the stroma 6.

[0182] The microscope may further or in the alternative be adapted such that electronic/digital imaging of eye 1, inner components thereof, in particular at least the anterior stroma layer 8, is possible/enabled.

[0183] The microscope and/or scanning module 24, for example a scanning unit, may be configured and set up for capturing an image, i.e. a digital image, of at least the iris 4 or a part thereof, for example a section that is intended for being impinged with one or more laser pulses 14 in order to change the perceptual color of that section. The captured image may be processed and used for partitioning at least a part of the surface area of the anterior stroma 8 layer into a number of surface sections.

[0184] The scanning unit may for example be programmed to define surface areas of essentially similar size and/or shape and/or pigment density. Having defined suitable/corresponding surface areas, the one or more controller units 23 may be operated to apply a respective number of predefined laser pulses 14 to one or more of the surface sections to thereby remove the melanin pigment density in accordance with a method as described herein in connection with the invention.

[0185] The one or more controller units 23 may be programmed such that the predefined surface sections are processed (in particular: impinged) with laser pulses 14, in accordance with a predefined succession of surface sections.

[0186] The predefined succession of surface sections (in particular: surface areas) may for example be determined by a partitioning module (not explicitly shown). The partitioning module may for example be programmed to determine the predetermined surface sections, e.g. their size, and/or the particular succession of surface sections within the processing sequence, on the basis of the captured image and/or on the basis of a determined density of pigments extracted for example from the captured image.

[0187] Further, the energy content/power of the energy quantities to be applied to a respective surface section may in embodiments be determined on the basis of the captured image and/or the density of pigments. Further, the specific location of the surface area on the iris 4, and/or the overall size of the iris 4, and/or the specific size of the surface sections may be used as parameters for defining and setting up characteristics of the pulses 14 to be applied to respective surface sections.

[0188] In embodiments where particular surface sections are determined, it is possible to determine or calculate at least one parameter of the mechanically generated flow on the basis of or in accordance with the specific location of a respectively processed surface section. As an example, locations near the inner border of the iris 4 defining the outer circumference of the pupil 5 may require a different flow rate/profile than surface regions lying on the outer rim of the iris 4.

[0189] Further, in case that particular surface sections are determined, parameters associated with the flow 17 and/or associated with the generation and application of the one or more energy quantities may be determined/calculated based on the particular succession of the surface sections, and/or based on the density of pigments within the surface sections, and/or based on the size of a respective surface section.

[0190] With one or more of the above options, it is in particular possible to adapt the ablation of melanin pigments to the particular configuration of the underlying iris 4, thereby reducing the risk for possible irritations of the tissue of the anterior stroma layer 8. Further, the above options, which make it possible to take account of specificities of a corresponding iris structure/shape and/or pigment density, are particularly suitable for automating the procedure of changing the perceptual color appearance of the eye.

[0191] The microscope and/or scanning module 24 may in embodiments comprise a tracking unit, or may be constructed to implement a corresponding tracking module, that is able to track the actual position, and/or shape, and/or movement of the eye 1, or one or more of the components of the eye 1 such as the iris 4, pupil 5 or others, relative to a spatial reference point.

[0192] Such a tracking function may advantageously be used for optimizing the step of applying the generated laser pulses 14, in general the generated energy quantities, to the anterior stroma layer 8. Specifically, the apparatus 18 may be configured, e.g. programmed, to track the location of the respective eye 1, and to apply the energy quantities, i.e. the laser pulses 14, in dependence of the tracking result.

[0193] For example, application of a laser pulse 14 may be inhibited (in particular: blocked) in case that the tracking result indicates that the position of the target position for the laser pulse 14 has changed, for example more than a given threshold value.

[0194] Corresponding shifts/movements in the target position may also be induced by a change in the shape of the iris 4, for example in case that the iris 4 unexpectedly dilates.

[0195] Inhibiting the application of the laser pulses 14 in case of a detected inappropriate movement of the iris 4, i.e. of the target position, may help avoiding possible damages to the anterior stroma layer 8, or other parts of the eye 1, such for example the eye's vitreous body, or even retina 3.

[0196] In embodiments, the apparatus 18, for example a focusing unit/module or the like, may be programmed such that the target location T of the energy quantity, e.g. laser pulse 14, is relocated/shifted in accordance with, in particular synchronous to, one or more of a change in position, a change in location, a change in shape, and a movement of the iris 4, or the observed component of the eye 1, respectively.

[0197] With such a setup, for example, minor shifts of the target location T, lying for example below or within a predetermined threshold, may be compensated. A corresponding threshold may be dependent on the exact location of the target location T, wherein near the inner edge of the iris 4 defining the pupil 5, the threshold may be smaller than further away from the pupil 5.

[0198] In embodiments, the apparatus 18 may further be programmed/set up, such that at least the iris 4 or sections thereof, and/or the anterior eye chamber 9 is/are scanned (in particular: recorded), for example at least during a time interval when the energy quantities, e.g. laser pulses 14, are applied to the anterior stroma layer 8.

[0199] The scanning function may be implemented with the microscope and scanning module 24, wherein it shall be mentioned that a separate scanning unit or the like may be present, and correspondingly implemented, set up, and/or programmed.

[0200] Scanning respective sections at least during application of the energy quantities may be accompanied by further operational modes based on and/or supported by the scanning result. The scanning result may for example comprise an image of the scanned section, wherein for example the respective target location T where the energy quantities impinge on the anterior stroma layer 8 may be comprised by the image and/or indicated within the image.

[0201] Implementing the scanning may be accompanied by a functionality/an operational mode in which the scanning result, e.g. a scanned or recorded image, is stored in a datastore after each predetermined number of applied energy quantities, e.g. laser pulses 14. The predetermined number may range from one to any suitable number, allowing for example the establishment of a processing history representative for the obtained color change.

[0202] Implementing the scanning may be accompanied by a functionality/an operational mode in which the actual location T of impingement, indicating a location on the anterior stroma layer 8 where the one or more energy quantities (14) actually impinged on the anterior stroma layer 8, may be determined on the basis of the scanning result.

[0203] Alternatively or in addition, the target location T may be marked (in particular: identified by a particular mark) in for example a captured image, or in the imaging result of the iris 4.

[0204] Further embodiments may involve an operational mode in which the actual locations of impingement and/or the target locations T are tracked. Corresponding results of tracking/marking may be provided for display to an operating user on a display (not shown) of the apparatus 18.

[0205] Implementing a corresponding scanning function may in embodiments involve to have a functionality in which, based on the scanning result, the flow of rinsing solution within or through the anterior eye chamber 9 (in particular: eye cavity 9) is controlled. Here, an automated adaption of the operational parameters to the respectively prevailing individual situation may be obtained.

[0206] Further, the density of pigments, in particular a local density of pigments, in particular a pigment profile, or at least a parameter representative of the density/density profile of the pigments of the anterior stroma layer 8 may be determined based on the scanning result. For example, a scanned image of the anterior stroma layer 8 may be processed for determining/identifying a description of the distribution of pigments over at least the respectively treated surface area.

[0207] Based on the determined pigment density, or the respective parameter, respectively, as has already been mentioned, the generation and/or application of one or more of the energy quantities may be controlled.

[0208] In embodiments, the apparatus 18 may be implemented, set-up, and/or programmed to be operable to generate, based on the scanning result, one or more than one display objects, and the display objects may be provided for display on a display screen of the apparatus 18 to an operator executing the method for changing the perceptual color appearance of the eye 1.

[0209] In case that a corresponding display screen (not shown) may be present, embodiments may involve that operational parameters related to the execution of the method, in particular comprising one or more of: one or more parameters related to the energy quantities, one or more target locations T and/or actual locations of incident, a first indication representative of a change, in particular local change, of the density of pigments, and a second indication representative of processed, and/or unprocessed surface areas of the anterior surface of the stroma layer 8, are displayed on the display screen, e.g. in such a way that user-guidance as regards the overall execution/performance/

[0210] implementation of the method may be obtained. User guidance in particular may improve human-machine interaction thereby further improving operational safety of the appliance 18.

[0211] In embodiments, in particular as indicated in FIG. 3, the apparatus 18 may comprise, in particular as an optional element, a slit lamp module 25, implemented as a conventional slit-lamp, and configured to be operated with the remaining components of the apparatus 18 such that an operating user and/or a corresponding microscope/scanning unit 24 is able to observe/monitor at least the anterior stroma layer 8, by means of a sheet of light generated by the slit-lamp and thrown onto the observed section of the eye 1. With this design, the laser pulses 14 may be applied substantially or mainly in a horizontal direction, meaning that the optical axis A of the eye 1 under consideration may be oriented horizontally, meaning that a corresponding person may sit upright during the change of the eye color.

[0212] The sheet of light may for example be generated by corresponding optical elements allowing the generation and projection the sheet of light.

[0213] FIG. 4 shows a further representation of the human eye 1 together with further details for applying laser pulses 14 in connection with the underlying method and embodiments of the invention. Specifically, applying the laser pulses 14 may involve an optical system 26 that is implemented and adapted to generate a pulsed laser beam having a focusing angle a.

[0214] The focusing angle a may lie in the range between 10 degrees and 18 degrees, optionally between 13 degrees and 16 degrees, and may further optionally lie substantially at about 14 degrees.

[0215] The optical system may be part of a focusing device, wherein the optical system may include one or more than one lenses or lens systems for generating the focused laser beam.

[0216] Using such a focused laser beam has the advantage that the energy density at the cornea 10 can be kept comparatively small so as to avoid impairment of the cornea 10 by laser pulses passing through on their way to the anterior stroma layer 8 for ablating melanocyte cells 15.

[0217] By using the proposed focusing angles, it has been found out that the distance between the cornea 10 and the anterior stroma layer 8, being about 1.2 mm, is sufficient to have an energy density at the level of the cornea 10 that does not negatively affect the cornea 10, and to have an energy density at the anterior stroma layer 8 that is sufficient to ablate the melanocyte cells 15 or melanocyte pigments.

[0218] FIG. 5 shows a schematic view of the eye 1 and further details of an apparatus for carrying out the underlying invention. In the embodiment shown in FIG. 5, the laser device 19 is and may positioned and located remote from the eye 1, wherein laser pulses 14 generated by the laser device 19 are guided by a flexible fiber optical system 27 from the laser source 20 towards the optical system 26 used for focusing the laser pulses 14 under the focusing angle a, which may lie between 10 degrees and 18 degrees, onto the anterior stroma layer 8 of the eye 1.

[0219] The fiber optical system may comprise an optical fiber (not explicitly shown) with a fiber-optic core diameter lying in the range between 270 m and 290 m, in particular at about 280 m.

[0220] Providing such a fiber optical system and a remote laser device 19 has the advantage that the orientation of the optical axis of the eye 1 during the procedure of changing the eye color may be selected within a comparatively broad range. In particular, the optical axis A of the eye 1 may be oriented vertically during the procedure of changing the eye color, meaning that a corresponding human being may be placed horizontally on a table, which may be advantageous for restricting overall movements of the human being, including eye and/or head movements during the procedure.

[0221] The optical system 26 may be provided in connection with a microscope 28 enabling the user and/or device applying the method to investigate the eye and/or anterior stroma layer during the whole procedure.

[0222] FIG. 6 shows the enlarged view of FIG. 3 together with an eye shielding element 29 which may in embodiments of the invention provided together with the proposed apparatus and together with carrying out the method.

[0223] In particular, the eye shielding element 29 may be implemented and configured to be able, when properly played on the outer layer or side of the cornea 10, to absorb energy quantities, in particular energy quants, such as laser pulses, that have been generated and directed to the eye 1 in order to ablate melanocyte cells 15 or melanocyte pigments. Such an eye shielding element 29 may be of advantage in case that a sudden eye movement shifts the actual target location of respective energy quantities off the stroma 6, meaning that such energy quantities would, without the eye shielding element 29, hit and possibly affect the retina 3, for example.

[0224] The eye shielding element 29 as shown in FIG. 6 comprises a composite structure comprising an absorption layer 30 for absorbing energy quantities 14 intended for ablating melanocyte cells 15 and impinging thereon. The eye shielding element 29 further comprises an adhesion layer 31 configured and set up for being coupled with the outer cornea layer 32 by adhesive forces.

[0225] The absorption layer 30 may comprise one or more than one metallic layers, such as stainless steel layers. The adhesion layer 31 may comprise an open-pored, adhesive material layer, such as a foamed layer, for example comprising and/or made from a polyvinyl alcohol material. The foam layer may be advantageous for obtaining a stable positioning of the eye shielding element 29 on the outer cornea layer 32 which in general includes a liquid film.

[0226] The eye shielding element 29 may having a convex; and/or circular shape, and/or may have a diameter lying in the range between 0.5 mm and 3 mm, or in the range between 1 mm and 2 mm, or substantially at about 1.5 mm.

[0227] The apparatus 18 and method has been described in connection with the figures as comprising a laser device 19 for generating and applying the energy quantities. In embodiments, the apparatus 18 may comprise either as an alternative or in addition to the laser device a pressure wave generator, in particular a corresponding pressure wave generator module (not explicitly shown).

[0228] The pressure wave generator may be operable, set up and programmed to generate and emit energy quantities in the form of mechanical pressure waves, in particular shock or blast waves, towards and onto the anterior stroma layer so as to change the density of pigments in a way similar to that as described in connection with laser pulses 14. Such a pressure wave generator may be operable, set up and programmed to generate the pressure waves by induced cavitation within a liquid that is in liquid contact with the eye liquid as contained in the anterior eye chamber 9.

[0229] The induced cavitation may for example be generated by impinging a solid state target with electromagnetic waves, in particular laser light, preferably pulsed laser light, or other forms of energy such as but not restricted to ultrasound energy. In accordance with the invention, the mechanical pressure waves may be generated and applied to the anterior stroma layer 8 in such a way that melanocyte cells of the anterior stroma layer 8 are ablated in the corresponding area of impact and, as a direct response, are, at least in part, discharged into the liquid contained in the anterior eye chamber 9, such that the melanocytes, corresponding cellular material and pigment contained therein can be removed by the flow 17 maintained by the fluid pumping module 21.

[0230] The procedure of removal of the melanocyte material essentially corresponds to the removal as described in connection with laser-based ablation. The only difference is the way of applying energy of the anterior stroma layer 8. Essentially the same advantages and effects as regards the change in the perceptual color appearance of the eye 1 may be obtained. Hence, reference is made to the discussion above.

[0231] It shall be noted, that electromagnetic-based, in particular laser-based, and/or pressure-wave-based ablation may be used as alternatives or jointly, wherein the combined use may allow a finer adjustment to respective individual needs as regards the density of pigments in a respective area of interest of an iris 4 of interest.

[0232] Reference is now made to FIG. 4 showing an example flow chart for carrying out a method according to the invention. The method for changing the perceptual color appearance of the iris 4 may comprise the following steps:

[0233] positioning 401 an eye 1 relative to a generator module 19 configured, set up and programmed for generating a plurality of predefined energy quantities 14, in particular laser pulses 14 and/or pressure waves;

[0234] operating 402 the generator module 19 to generate the plurality of predefined energy quantities 14, the energy quantities 14 defined such that interaction with melanocyte cells 15 of the anterior stroma layer 8 leads to melanocyte cell ablation 16;

[0235] directing and applying 403 the generated energy quantities 14 to the anterior stroma layer 8 of the eye 1, wherein the anterior stroma layer 8 comprises a non-zero density of melanin-pigments 15, and, by applying the energy quantities 14, discharging the melanocyte cell material at least in part into liquid contained within the anterior eye chamber 9; and

[0236] removing 404 the melanocyte cell material 16 by maintaining a flow of rinsing liquid 17 through/within the anterior eye chamber 9.

[0237] The proposed sequence of steps in particular is efficient in removing melanin pigment from the anterior stroma layer 8 thereby shifting perceptual color appearance of the iris 4/eye 1 towards blue. The proposed method steps may be carried out at least in part in an automated manner, allowing their execution by trained medical staff.

[0238] It has been shown, that the proposed method and apparatus are well suitable in obtaining the underlying object of the invention. In particular, the proposed method as such represents a non-chirurgical method of changing eye color, wherein the proposed method, in particular each single step of the method, and the apparatus, in particular each single unit or module of the proposed apparatus, are particularly suitable for use in non-surgical treatments of the iris for changing the perceptual color appearance of the iris.

[0239] Finally it shall be noted, that the proposed method may be provided as computer-executable instructions stored on a computer-readable storage medium, wherein the computer-executable instructions are defined such that a corresponding apparatus when executing the instructions carries out the proposed method for changing eye color.

[0240] In summary, the underlying invention is directed to a method for changing the human perceptual color appearance of the iris of a human's or animal's eye by selectively decreasing the density of pigments of the anterior stroma layer of the iris, the method comprising the steps of generating a plurality of predefined energy quantities; applying one or more of the predefined energy quantities to the anterior stroma layer, wherein each of the predefined energy quantities is generated and applied such that it ablates at least in part melanocytes of the stroma, wherein the predefined energy quantities at least in part are generated and applied in such a way that ablated tissue generated as an immediate cause of the energy quantities is, at least in part, discharged directly into the anterior eye chamber such that the discharged tissue can be removed by maintaining a mechanically generated flow of rinsing solution through or within the anterior eye chamber.

REFERENCE SIGNS

[0241] 1 eye [0242] 2 lens [0243] 3 retina [0244] 4 iris [0245] 5 pupil [0246] 6 stroma [0247] 7 pigmented epithelial cells [0248] 8 anterior stroma layer [0249] 9 anterior eye chamber [0250] 10 cornea [0251] 11 ciliar body [0252] 12 posterior eye chamber [0253] 13 Schlemm's Canal [0254] 14 laser pulse [0255] 15 melanocyte cell [0256] 16 discharged melanocyte cells/material [0257] 17 flow of rinsing solution [0258] 18 apparatus [0259] 19 laser device [0260] 20 laser source [0261] 21 fluid pumping module [0262] 22 irrigator elements [0263] 23 controller unit [0264] 24 microscope and scanning module [0265] 25 slit lamp module [0266] 26 optical system [0267] 27 fiber optical system [0268] 28 microscope [0269] 29 eye shielding element [0270] 30 absorption layer [0271] 31 adhesion layer [0272] 32 outer cornea layer [0273] 401-404 operational steps [0274] a focusing angle [0275] A optical axis [0276] T target location