System, method and material composition for use in correction of eye conditions

Abstract

Methods, kits and material composition for use in correction of eye condition are disclosed. This includes a selected three-dimensional patterning on the surface of a cornea of a user. The pattern is selected to provide an optical effect in accordance with a predetermined vision impediment of the user. A dispersion, in the form of a liquid (aqueous solution) comprising nanoparticles, is applied onto said selected three- dimensional pattern such that the nanoparticles are dispersed in incision regions of the pattern. The nanoparticles comprise biocompatible protein based nanoparticles. The dispersion may be used as eye drops thereby allowing the nanoparticles to occupy the etching regions on the cornea, thereby functionalizing and maintaining the visual correction effect of eye condition by said pattern. The present disclosure further provides a method and a kit for ablating the corneal tissue in a selected pattern by using a visual spectrum illumination.

Description

[0001] SYSTEM, METHOD AND MATERIAL COMPOSITION FOR USE IN CORRECTION OF EYE CONDITIONS

[0002] TECHNOLOGICAL FIELD

[0003] The present invention is in the field of visual correction techniques and specifically relates to correction of visual impediments such as myopia, hyperopia, presbyopia, astigmatism, myopia control and other visual impediments.

[0004] BACKGROUND

[0005] Various eye conditions are known as limiting vision. Such eye conditions may generally include nearsightedness (myopia), farsightedness (hyperopia), and aging of the eye (typically associated with (presbyopia). Various techniques are known for providing correction to such eye conditions, including glasses, contact lenses as well as intra-ocular lenses. The lenses used are provided with selected one or more optical powers and / or selected patterns designed for increase of depth of focus of the lens in accordance with user’s eye condition. One of the commonly used approaches to overcome various eye conditions, e.g. presbyopia symptoms, is based on advanced intra ocular lenses technology, through either accommodating IOLS, multifocal IOLS or more recently, IOLs with extended depth of focus.

[0006] Optical power may generally be provided using refractive manipulation of light path. However, diffractive techniques for manipulation of optical path may also provide suitable optical power. Such techniques may include Fresnel zone plates, or rings, providing diffraction of light in a lens-like fashion. Additional light manipulation techniques may utilize light interference for extension of depth of focus.

[0007] For example, US 7,859,769 provides an imaging arrangement and method for extended the depth of focus. The imaging arrangement comprises an imaging lens having a certain affective aperture, and an optical element associated with said imaging lens. The optical element is configured as a phase-affecting, non-diffractive optical element defining a spatially low frequency phase transition. The optical element and the imaging lens define a predetermined pattern formed by spaced-apart substantially optically transparent features of different optical properties. Position of at least one phase transition region of the optical element within the imaging lens plane is determined by at least a dimension of said affective aperture.

[0008] GENERAL DESCRIPTION

[0009] The present invention provides a novel technique for correction of eye conditions causing visual difficulties to users. The present technique provides for applying pattern, selected in accordance with user’s eye condition, on the cornea of the user, and introducing a solution containing nanoparticles (NPs) of selected material composition into the pattern.

[0010] This optical pattern is configured to provide a temporary and targeted correction of the refractive errors without modifying the corneal shape. Generally, the pattern formed on the cornea affects local variation of the refractive index. Although the NPs themselves have a different refraction index than the environment they are applied on, the density of the nanoparticles’ arrangement within the pattern is relatively low such that the averaged local refraction index is almost the same as the one of the solution in which they are placed and they therefore substantially do not affect the optical effect induced by the pattern.

[0011] It should be noted that an effect induced by the nanoparticles' arrangement dispersed in the pattern includes scattering of incident light of visual spectral range, and functionalizing and stabilizing the optical effect of the pattern (which is selected in accordance with vision correction to be applied) due to filling of pattern's incision / etching regions by the nanoparticles. However, the density of the nanoparticles is such that the nanoparticles' arrangement does not change the global refractive index and thus does not affect the refractive effect induced by the pattern structure.

[0012] The selected material composition may generally be provided in the form of eye drops comprising the nanoparticles, that may comprise biocompatible protein chains, e.g., albumin protein chains, e.g. human serum albumin (HSA) or recombinant human serum albumin. Human serum albumin or Recombinant Human Serum Albumin (rHSA) is the most abundance protein in human blood, and offers advantages such as their nontoxicity, non-immunogenicity, water solubility, and biotransformation into harmless materials. As will be described below, the nanoparticles may also be metallic particles with biocompatible polymer shell (e.g., HAS-based shell).

[0013] As indicated above, for example, the nanoparticles may include rHSA. Generally, the material composition of nanoparticles is selected as biocompatible nontoxic material composition having high stability both on shelf and on the user’s cornea. The nanoparticle may be Human Serum Albumin (HSA) based nanoparticles, e.g. rHSA-based nanoparticles; or metallic nanoparticles, such as gold particles that are carried by biocompatible material, e.g. wrapped by the biocompatible material, such as HSA. Preferably, however, the nanoparticles are HAS-based or rHSA-based particles.

[0014] The eye drop formulation may include any suitable nanoparticles, including for example Recombinant Human Serum Albumin nanoparticles, or metallic based nanoparticles, such as gold, which are carried by biocompatible material, e.g. biocompatible polymer shell (e.g., albumin shell). The biocompatible polymer shell (e.g., albumin shell) is typically in the meaning of protein folding around the particle.

[0015] The pattern is a surface relief in the form of a two-dimensional arrangement of spaced-apart incisions / grooves (etched regions) of a certain depth. Thus, the pattern is actually three-dimensional in the meaning that critical dimensions of the pattern are defined by the arrangement of etched regions along the x- and y-axes and the depth of the etched regions.

[0016] Thus, according to a broad aspect, the present invention provides a method for use in correction of eye condition of a subject, the method comprising: forming a selected three-dimensional pattern on a surface of a cornea of the subject; applying a dispersion comprising nanoparticles onto said selected pattern, wherein said nanoparticles are selected to (i) create invariant conditions for one or more of the following: incident illumination of a predetermined spectral range on the cornea, exact locations of the nanoparticles in the pattern and a liquid type of the dispersion, and (ii) exhibit a dominant scattering effect for the incident illumination within said predetermined spectral range.

[0017] The formation of the selected three-dimensional pattern is performed using a pattern formation system including a patterning utility (e.g. etching utility), which controllably operates in accordance with input data comprising pattern data corresponding to correction of vision impediment of a user. The patterning utility may be configured for transmitting selected ultra- sound waves for etching said pattern on the user’s cornea, or may be configured for mechanical etching of the cornea. In some other embodiments, the patterning utility comprises at least one laser unit and beam steering module and is configured for providing optical energy for etching the selected pattern in accordance with operation instructions on cornea of user’s eye. The laser unit may be configured to provide etching at depth of up to single cell layer of the cornea.

[0018] According to some embodiments, the three-dimensional pattern comprises a diffractive pattern. For example, the pattern may comprise Fresnel rings pattern.

[0019] According to some embodiments, the three-dimensional pattern comprises a phase affecting interference pattern. The pattern may for example comprise an extension of depth of focus pattern.

[0020] According to some embodiments, the selected pattern enables optical correction at optical power resolution between 0.1 and 0.3 diopter. Generally, this allows corrections lower than 0.25 diopter, which is the general limit of convention optical correction.

[0021] In some embodiments of the method, said particles are selected to exhibit a maximal scattering effect within the visual range, i.e., 380nm-700nm.

[0022] In some embodiments of the method, said particles are selected to exhibit a maximal scattering effect within a spectrum defined between 450nm-600nm.

[0023] In some embodiments of the method, said nanoparticles are selected to exhibit a maximal absorption effect within the predetermined spectral range.

[0024] In some embodiments of the method, said particles are selected based on their characteristics of one or more of the following: material, size, shape, charge, concentration or any combination thereof. The nanoparticles can be in the shape of a sphere or a rod, and for any given shape their size is selected to obtain the desired result, in particular for obtaining the dominant scattering effect at the desired wavelength or wavelength range. The nanoparticles can be selected such that their shape distribution between sphere and rod is known. For example, the nanoparticles can be selected such that at least X% are spheres and at least Y% are rods and their average size is selected to exhibit the desired effect, such as maximal scattering effect at a wavelength e.g. in the green spectrum., wherein X and Y represent any given number between 0-100. For example, the nanoparticles can be spherical rHSA particles with a diameter of 80nm. In some embodiments of the method, said forming the pattern and applying the dispersion create invariant conditions for a resulted point spread function on a retina of the subject.

[0025] In some embodiments of the method, said applying of the dispersion provides a distribution of at least two or a few nanoparticles on an area of λxλ within said selected pattern, wherein said λ is a wavelength in the visual spectral range, e.g., of about 530 nm. The term about in this context refers to a range of ±30nm.

[0026] In some embodiments, said applying of the dispersion provides a distribution of up to 200 nanoparticles in a λ3volumetric space within incision region of said selected pattern for the nanoparticles of about 80nm size and for λ of about 530nm.

[0027] In some embodiments of the method, said three-dimensional pattern comprises a diffractive pattern.

[0028] In some embodiments of the method, said pattern comprises Fresnel rings pattern.

[0029] In some embodiments of the method, said three-dimensional pattern comprises a phase affecting interference pattern.

[0030] In some embodiments of the method, said pattern comprises an extension of depth of focus pattern.

[0031] In some embodiments of the method, said selected pattern enables optical correction between 0.25 and 10 diopters with a resolution of + / - 0.25D.

[0032] In some embodiments, the method further comprises preparing said dispersion prior to said applying, said preparing comprises mixing a liquid with said nanoparticles.

[0033] In some embodiments of the method, said nanoparticles comprise biocompatible protein chains. In some embodiments of the method, said protein chains comprise human serum albumin proteins, and / or recombinant human serum albumin proteins.

[0034] In some embodiments of the method, said forming is carried out according to any one of the below-described embodiments of the method for ablating corneal tissue.

[0035] In another broad aspect of the present disclosure, there is provided a formulation to be applied to an eye of a subject. The formulation comprises nanoparticles dispersed in a liquid forming together a dispersion, wherein a majority of the nanoparticles are selected to (i) create invariant conditions for one or more of: incident illumination in a predetermined (e.g., visual) spectrum on the cornea, concentration of the nanoparticles, the exact locations of the nanoparticles and the liquid, and (ii) exhibit a dominant scattering effect, over absorption, or absorbing effect, over scattering, within said predetermined spectrum when applied on a three-dimensional pattern formed on a cornea of the subject. It is to be noted that the invariant conditions are created by the combined effect of the natural characteristic of the cornea together with the nanoparticles to be applied in the three-dimensional pattern formed on the surface of the cornea.

[0036] The nanoparticles containing substance (macrostructure) may be provided in a solid powder reconstitutable form or in an aqueous carrier as a liquid read-for-use ophthalmological formulation. The aqueous carrier may be any one of water, bacteriostatic water, sodium chloride solutions, glucose solutions, liquid surfactant, pH- buffered solution and others.

[0037] Where the macro structure is provided in an aqueous medium, it may be treated to afford the reconstitutable powder form. The powder form may be obtained by lyophilization or spray drying techniques.

[0038] Preferably, the formulation is in the form of eye drops that can be applied on the surface of the eye, i.e., the cornea.

[0039] Preferably, the nanoparticles in said are selected to exhibit a dominant scattering effect within a visual spectral range when applied on the three-dimensional pattern formed on the cornea of the subject, typically, maximal scattering effect within the visual spectral range. For example, this is the spectral range of 450nm-600nm.

[0040] The nanoparticles are selected based on their characteristics of one or more of the following: material, size, shape or any combination thereof.

[0041] The nanoparticles may be Human Serum Albumin (HSA) based nanoparticles, e.g. rHSA-based nanoparticles.

[0042] According to yet another broad aspect, the present invention provides a kit for use in correction of visual impediments, the kit comprises the above-described pattern formation system and the eye drops comprising the above-described formulation.

[0043] In some embodiments of the kit, the pattern formation system is constituted by any of the below-described embodiments of the kit for ablating corneal tissue.

[0044] The kit may further comprise an instruction manual for operating said patterning utility to form the selected pattern on the user’s cornea and applying the eye drops into the eye. Generally, the technique of the present disclosure allows optical correction to user who is not eligible to modern laser vision correction surgeries as the pattern etching is shallow on the cornea and may be done on thin or weak cornea. Thus, the kit may be suitable for use at home or at eye care professionals’ clinic. Further, the kit and technique enable correction to users who already had cataract surgery as well, enabling additional correction over intra ocular lenses already used by the user.

[0045] The nanoparticles (e.g., made of biocompatible protein chains such as HSA or rHSA) are configured and arranged / dispersed within the pattern for increasing stability of optical effect of said pattern thereby enabling lasting of the optical correction effect, e.g., lasting between a few days and a few months.

[0046] The technique of the present disclosure provides for correction of any one of myopia, myopia control, hyperopia, presbyopia, and astigmatism.

[0047] The present disclosure further provides a method and a kit for ablating a corneal tissue by using an illumination within the visual range spectrum. In order to do that, an energy absorbent material that is capable of interacting with illumination of a selected wavelength, , e.g., thermally absorbing the illumination, to cause an on-spot ablation of the cornea is used. The energy absorbent material is mixed in a liquid in order to be applied on the corneal tissue as eye drops. By ablating the cornea by this unique photo- thermo-chemical reaction, a very low energy can be used and the wavelength that causes the ablation of the cornea is not limited to such wavelengths that are required to interact directly with the corneal tissue. In this process, the wavelength to be used is determined by the energy absorbent material and optionally also its reaction with the cornea.

[0048] In some non-limiting embodiments of the present disclosure, the energy absorbent material is a Fluorescein-based material such as Fluorescein Sodium dye and the selected wavelength is in the visual spectrum. However, it is to be noted that the energy absorbent material can be synthesized or produced to have an absorbance profile in any selected wavelength, whether it is in the visual spectrum or in the IR spectrum.

[0049] Therefore, an aspect of the present disclosure provides a method for ablating corneal tissue or an energy absorbent material for use in a method for ablating a corneal tissue. The method comprises applying a liquid that comprises an energy absorbent material onto the corneal tissue. The energy absorbent material absorbs illumination in an absorbance wavelength or absorbance wavelength range. The absorbance wavelength is a wavelength that the energy absorbent material is suitable to absorb to result in a thermal reaction. It is to be noted that the energy absorbent material may absorb illumination of more than one wavelength. Therefore, the energy absorbent material absorbs illumination of the absorbance wavelength and causes a local photo-thermo- chemical reaction that results in a local ablation of the cornea, After the liquid is applied onto the corneal tissue, the method further comprises illuminating the corneal tissue with an illumination that comprises said absorbance wavelength to result in a selected ablation profile of the corneal tissue. Therefore, this illumination causes a local photo- thermo-chemical reaction that results in a local ablation of the cornea. It is to be noted that the energy absorbent material absorbs can be synthesized so as to have any desired optical features, namely optical absorbance in any desired wavelength.

[0050] It is to be noted that any combination of the described embodiments with respect to any aspect of this present disclosure is applicable. In other words, any aspect of the present disclosure can be defined by any combination of the described embodiments.

[0051] It is further to be noted that all the method embodiments below also apply on the aspect of an energy absorbent material for use in a method for ablating a corneal tissue.

[0052] In some embodiments of the method, said energy absorbent material is a biocompatible organic compound that is suitable for ophthalmological applications.

[0053] In some embodiments of the method, said liquid comprises Fluorescein.

[0054] In some embodiments of the method, said liquid is a Fluorescein Sodium dye.

[0055] In some embodiments of the method, said illuminating comprises focusing said illumination along a selected pattern on said corneal tissue.

[0056] In some embodiments of the method, said selected pattern comprises one or more annular rings or Fresnel rings.

[0057] In some embodiments of the method, the energy absorbent material absorbs energy of said illumination of the visual spectrum.

[0058] In some embodiments of the method, said energy absorbent material absorbs illumination in a plurality of wavelengths or wavelength ranges.

[0059] In some embodiments of the method, said applying occurs about 1-10 minutes before said illuminating.

[0060] The term "about" throughout the application should be interpreted as a deviation of ±20% of the nominal value. For example, if the value is about 10, thus it should be understood to be in the range of 8-12. In some embodiments of the method, said applying occurs about 1 minute before said illuminating.

[0061] In some embodiments of the method, said applying results in a surface of said liquid on the corneal tissue, e.g. creating a liquid basin on the corneal surface.

[0062] In some embodiments of the method, said illuminating results in absorbance of photons of said absorbance wavelength.

[0063] In some embodiments of the method, said absorbance results in a local photo- thermo-chemical reaction that causes the local ablation.

[0064] In some embodiments of the method, said absorbance wavelength is in the visual spectrum, typically between 380nm-750nm.

[0065] In some embodiments of the method, said illumination is of a wavelength between 400nm-650nm.

[0066] In some embodiments of the method, said illumination is of a wavelength of about 390nm.

[0067] In some embodiments of the method, said illumination is of a wavelength of about 435nm.

[0068] In some embodiments of the method, said illumination is of a wavelength of about 530nm.

[0069] In some embodiments of the method, said illuminating is performed by using a laser device.

[0070] In some embodiments of the method, said laser device is a fiber laser.

[0071] In some embodiments of the method, said illumination is continuous wave illumination.

[0072] In some embodiments, the method further comprises, following said illuminating, removing the liquid from the corneal tissue, e.g. by washing the eye with a suitable cleaning agent.

[0073] In some embodiments, the method further comprises applying a dispersion comprising nanoparticles onto said selected ablation profile, wherein said nanoparticles are selected to (i) create invariant conditions for one or more of the following: incident illumination of a predetermined spectral range on the cornea, exact locations of the nanoparticles in the pattern and a liquid type of the dispersion, and (ii) exhibit a dominant scattering effect for the incident illumination within said predetermined spectral range. In some embodiments, the method further comprises any of the above-described embodiments of the method for use in correction of eye condition of a subject.

[0074] Yet another aspect of the present disclosure provides a kit for ablating corneal tissue. The kit comprises a liquid that comprises an energy absorbent material for applying it onto the corneal tissue, wherein the energy absorbent material absorbs illumination in an absorbance wavelength; and an illumination unit configured for illuminating the corneal tissue, when it is applied with said liquid, with an illumination that comprises said absorbance wavelength to result in a selected ablation profile of the corneal tissue. The absorbance wavelength is a wavelength that the energy absorbent material is suitable to absorb to result in a thermal reaction. It is to be noted that the energy absorbent material may absorb illumination of more than one wavelength. The energy absorbent material absorbs illumination of the absorbance wavelength and causes a local photo-thermo-chemical reaction that results in a local ablation of the cornea.

[0075] In some embodiments of the kit, said energy absorbent material is a biocompatible organic compound that is suitable for ophthalmological applications.

[0076] In some embodiments of the kit, said liquid comprises Fluorescein.

[0077] In some embodiments of the kit, said liquid is a Fluorescein Sodium dye.

[0078] In some embodiments of the kit, the illumination unit comprises a controller configured to control the illumination unit, including when to illuminate and along which pattern, so as to focus said illumination along a selected pattern on said corneal tissue. Namely, the controller is configured to perform autonomously the illumination pattern over the cornea.

[0079] In some embodiments of the kit, said selected pattern comprises one or more annular rings or Fresnel rings.

[0080] In some embodiments of the kit, the energy absorbent material absorbs energy of said illumination of the visual spectrum.

[0081] In some embodiments of the kit, said energy absorbent material absorbs illumination in a plurality of wavelengths or wavelength ranges. some embodiments of the kit, said illuminating results in absorbance of photons of said absorbance wavelength.

[0082] In some embodiments of the kit, said absorbance results in a local photo-thermochemical reaction that causes the local ablation. In some embodiments of the kit, said absorbance wavelength is in the visual spectrum, typically between 380nm-750nm.

[0083] In some embodiments of the kit, said illumination is of a wavelength between 400nm-650nm.

[0084] In some embodiments of the kit, said illumination is of a wavelength of about 390nm.

[0085] In some embodiments of the kit, said illumination is of a wavelength of about 435nm.

[0086] In some embodiments of the kit, said illumination is of a wavelength of about 530nm.

[0087] In some embodiments of the kit, said illumination unit comprises a laser device for performing said illumination.

[0088] In some embodiments of the kit, said laser device is a fiber laser.

[0089] In some embodiments of the kit, said illumination is continuous wave illumination.

[0090] In some embodiments, the kit further comprises eye drops comprising a dispersion to be applied to said selected ablation profile to functionalize and stabilize the optical effect of the pattern, the dispersion comprising nanoparticles selected to (i) create invariant conditions for one or more of: incident illumination of a predetermined spectral range on the cornea, exact locations of the nanoparticles in the pattern and a liquid type of the dispersion, and (ii) exhibit a dominant scattering effect for the incident illumination within said predetermined spectral range.

[0091] In some embodiments, the kit further comprises any of the above-described embodiments of the formulation to be applied to an eye of a subject.

[0092] BRIEF DESCRIPTION OF THE DRAWINGS

[0093] In order to better understand the subject matter that is disclosed herein and to exemplify how it may be carried out in practice, embodiments will now be described, by way of non-limiting examples only, with reference to the accompanying drawings, in which:

[0094] Fig. 1A schematically illustrates a kit for use in eye vison correction technique of the present disclosure; Fig. IB exemplifies the principles of preparation of dispersion including nanoparticles, according to the technique of the present disclosure;

[0095] Fig. 1C schematically illustrates a system for use in correction of eye condition according to some embodiments of the present disclosure;

[0096] Fig. 2 exemplifies Fresnel zone plate pattern suitable for correction of eye condition by adding / subtracting optical power;

[0097] Fig. 3 and Fig. 4 exemplify eye correction patterns associated with extension of depth of focus of the eye’s lens;

[0098] Fig. 5 exemplifies desolvation process of albumin proteins according to some embodiments of the invention;

[0099] Figs. 6A and 6B show size and electric (zeta) potential measurement of nanoparticle produced according to some embodiments of the invention;

[0100] Figs. 7A to 7C show TEM, cryo-TEM microphotographs and size distribution histogram of the HAS core NPs;

[0101] Figs. 8A and 8B show FTIR spectroscopy of HSA core NPs carrying maghemite nanoparticles according to some embodiments of the invention, Fig. 8A shows FTIR results and Fig. 8B focuses on peaks in the absorption spectrum of the Maghemite carrying HSA nanoparticles;

[0102] Figs. 9A and 9B show X-ray photoelectron (XPS) spectra of the crude HSA (Fig. 9A) and HSA NPs described herein (Fig. 9B);

[0103] Fig. 10A to 10D show morphology and the size distribution measurements of the hybrid HSA / CAN-y-Fe2O3nanoparticles were characterized using TEM, cryo-TEM, and HR-SEM;

[0104] Figs. 11A to 11D show measurement of amount of selected elements using HR- SEM image (Fig. 11A) and line scan analysis of HSA NPs for Carbon (Fig. 11B), Oxygen (Fig. 11C and Iron (Fig. 11D) according to some embodiments of the invention;

[0105] Fig. 12 shows reflection measurement from hyper reflecting iron particles embedded in the HAS NPs illustrating the NPs within the etched regions of the cornea; and

[0106] Figs. 13A and 13B show measured variation in optical power of pigs’ eyes provided by applying selected pattern on the eyes and providing eye drop solution according to some embodiments of the invention. Figs. 14A-14B are block diagrams exemplifying non-limiting embodiments of the kit for ablating a corneal tissue according to an aspect of the present disclosure.

[0107] Figs. 15a-15b show ex-vivo porcine eye images for eye placed in a custom- made container (Fig. 15a), and the contained connected to a rotatory step motor and fixated on an optical post (Fig. 15b).

[0108] Figs. 16a-16c show an experimental Setup, where Fig. 16a shows eye placed in a custom-made contained with fiber tip placed close; Fig. 16b shows a top view of Fig. 16a illustration; and Fig. 16c shows a scheme of the optical setup.

[0109] Figs. 17a-17k show eye images, wherein Figs. 17a-17h show bright-field images of various sections of the eye that was illuminated with the laser (The images were taken after surgically removing the corneal layer), Fig. 17i shows the photo of the eye after laser treatment, Fig. 17j shows a photo of an eye before laser treatment and Fig. 17k shows a photo of the eye after laser treatment showing no trace of ablation.

[0110] Figs. 18a-18b show eye 5 Microscopic Images wherein Fig. 18a shows bright- field microscopic image of the cornea surface of Eye No. 5 after ablation; and Fig. 18b shows a fluorescent confocal image of the same eye with Lecia Confocal Microscope with a 20X objective lens.

[0111] Figs. 19a-19o show eye 5 Z-stack confocal Images being Z-stack confocal microscopy images of Eye 5 from depth Z=0 to Z= 184 pm. The fluorescent signal is seen only to a depth of 160 pm.

[0112] Figs. 20a-20d show eye 6 and 7 Microscopic Images, wherein Fig. 20a shows bright-field microscopic images of Eye No. 6 with 1.25x of the cornea surface; Fig. 20b shows confocal image of the whole Eye No. 6; Fig. 20c shows confocal image of Eye No. 7 with the width of the ablation of 300 pm and depth of 247 pm; and Fig. 20d shows reflection mode image of Eye No. 7 in the same field of view.

[0113] Figs. 21a-21b show eye 8 Microscopic Images, wherein Fig. 21a shows bright- field microscopic images of Eye No. 8 with 1.25x of the cornea surface; and Fig. 21b shows confocal image of the whole Eye No. 8 before cutting with the width of the ablation of 570 pm and depth of 465 pm.

[0114] DETAILED DESCRIPTION OF EMBODIMENTS

[0115] The technique of the present disclosure provides for correction of visual impediments such as myopia, myopia control, hyperopia and presbyopia. Fig. 1A schematically illustrates a kit 10 for implementing the technique of the eye vision correction according to the present disclosure. The kit 10 includes a pattern formation system 20; and eye drops 50. The pattern formation system 20 includes a patterning utility 30 configured and controllably operable to create a selected three-dimensional pattern on user's eye cornea. To this end, the patterning utility 30 is operable by a controller 40 which provides to the patterning utility input data indicative of the prestored pattern data corresponding to vision impediment of the specific user.

[0116] The patterning utility may be of any known suitable type, for creating a two- dimensional arrangement of spaced-apart incisions / grooves of a certain depth thus forming a three-dimensional pattern. The patterning utility may be configured to utilize operation instructions to create the pattern on cornea of user’s eye by applying ultrasound waves or via mechanical etching or via laser-based etching.

[0117] In the description below, such patterning utility is at times referred to as "etching utility", but it should be understood that the principles of the technique of the present disclosure are not limited to this specific example.

[0118] The eye drops 50 are configured as a formulation in the form of a dispersion including nanoparticles dispersed in a liquid. The majority of the nanoparticles are selected such that, when the eye drops are applied on the three-dimensional pattern formed on a cornea of the subject, the nanoparticles create invariant conditions for incident illumination in a predetermined (e.g., visual) spectrum on the cornea and / or concentration of the nanoparticles and / or the exact locations of the nanoparticles and the liquid. Also, the majority of the nanoparticles are selected such that, when the eye drops are applied on the three-dimensional pattern, the nanoparticles exhibit a dominant scattering effect, over absorption, or absorbing effect, over scattering, within the predetermined spectrum.

[0119] It should be noted that the nanoparticles' parameters, such as shape and size, are selected to provide a desired scattering-absorption ratio ensuring that the nanoparticles respond to incident light of certain spectra (visual spectra for the purposes of the present disclosure) as scatterers rather than absorbers. In this connection, it should be understood that scattering and absorption properties of the nanoparticle are defined by the scattering and absorption resonance peaks, which in turn are defined by the nanoparticle size and shape, where a generally spherical nanoparticle has one scattering resonance peak and one absorption resonance peak, while a rod-like nanoparticle has 2 scattering and 2 absorption resonance peaks.

[0120] Accordingly, for the purposes of the present disclosure, the size and shape of the nanoparticle of a given material composition are selected such that (1) the center of the scattering resonance peak is at the desired wavelength (e.g., wavelength of green spectra, e.g., about 530nm), and the peak width is relatively wide, and (2) the amplitude of scattering at sais spectral peak is much higher than that of the absorption.

[0121] For example, according to the Mie model, nanospheres with a diameter d have a resonance peak at a wavelength of k-es that can be determined according to the following relation:

[0122] For nanorods, there are two peaks that correspond to each of the two different cross section dimensions of the rod. According to the Rayleigh model, the ratio between the scattering and the absorption cross section of the nanoparticles is given by: where κ is a constant, λ is the wavelength of the illumination, and V is the volume of the nanoparticle.

[0123] It should be noted that the invariant conditions are created by the combined effect of the natural characteristic of the cornea together with the nanoparticles being applied in the three-dimensional pattern formed on the surface of the cornea.

[0124] Thus, the kit can be used as follows: the patterning utility is operated as described above to form the selected three-dimensional pattern on a surface of a cornea; and the eye drops are used to apply the above-described dispersion onto the pattern.

[0125] The formation of the selected three-dimensional pattern is performed using a patterning utility (e.g. etching utility), which controllably operates in accordance with input data indicative of vision impediment of a user.

[0126] The patterning utility may be configured for transmitting selected ultra- sound waves for etching said pattern on the user’s cornea, or may be configured for mechanical etching of the cornea. In some other embodiments, the patterning utility comprises at least one laser unit and beam steering module and is configured for providing optical energy for etching the selected pattern in accordance with operation instructions on cornea of user’s eye. The laser unit may be configured to provide etching at depth of up to single cell layer of the cornea.

[0127] As illustrated schematically in Fig. IB in self-explanatory manner, the pattern data, as well as data indicative of operational spectral range (typically visual range in the specific application of eye drops), is used to select optimal formulation (dispersion) including the nanoparticles. This includes nanoparticles' material composition, size and shape of nanoparticles, as well as the amount / concentration of the nanoparticles in a liquid. The selection of the nanoparticles is aimed at providing desired result of the combined effect of the pattern with nanoparticles, in particular to obtain the dominant scattering effect at the desired wavelength or wavelength range thus functionalizing and stabilizing the optical effect of the pattern itself.

[0128] It should be understood that the selection of the formulation data can be performed automatically using a computerized system which utilizes data in a specific database. Such data may include scattering vs absorption properties of nanoparticle of a given material composition and any given shape and size.

[0129] Fig. 1C is a schematic illustration of a system 100 defining the operation of the pattern formation system 20 for its further use in kit 10 for correction of eye condition as described above. The system 100 may generally be configured as a computer system, while being associated with the pattern formation system 20 to provide output pattern data to be stored in a storage utility 400 of the pattern formation system 20 (e.g. in the controller 40 of system 20). The system 100 thus includes a processing utility 200, and also typically includes input / output utilities and user interface that are not specifically shown in the figure.

[0130] In the present not limiting example, the patterning utility 30 is exemplified as including an etching utility 300 configured and operable to form a pattern by properly applying laser radiation. The etching utility 300 includes a laser unit 310 and a beam steering unit 320. The operation of the etching utility is described below.

[0131] The processing utility 200 may generally include one or more processors and further include one or more hardware or software modules such as correction pattern module 210. The correction pattern module 210 is configured for receiving and processing input data indicative of the epithelium thickness, the required optical correction for a user’s eye (each eye may require different optical correction), such as ocular wavefront or autorefractometer, and for determining, or retrieving from a storage utility (e.g. external database), a selected three-dimensional pattern (as described above) suitable for the optical correction. The processing utility 200 is further configured for generating the pattern data forming operational instructions for the patterning utility for etching the selected pattern on cornea of the user to provide the selected optical correction. The processing utility 200 generates and transmits the pattern data (instructions) to the etching utility 300 for providing optical radiation and directing it for generating the selected pattern on cornea of a user’s eye.

[0132] Figs. 2, 3 and 4 exemplify schematically three possible patterns selected in accordance with eye condition of the user. Fig. 2 shows Fresnel zone plate pattern including a plurality of concentric rings of varying widths; Figs. 3 and 4 exemplify patterns selected for extension of depth of focus, e.g. suitable for correction of presbyopia. Generally, the optical characteristics of such patterns and the exact configuration of each pattern can be determined in accordance with selected eye correction, e.g. optical power required for correction, or required increase of depth of focus.

[0133] Generally, the etching utility 300 is configured to apply the selected patterns as incision(s) / ablation onto the epithelial layers of the cornea, the Bowman layer or in the anterior corneal stroma. The etching may generally be provided using optical etching with selected wavelength ranges, ultra-sonic etching and / or mechanical incision of the cornea. For simplicity the etching utility is exemplified herein as optical etching utility 300 configured with laser light source and beam steering unit 320. The laser light source 310 is configured to provide optical radiation at wavelength and power suitable for etching within epithelial cell, Bowman layer or anterior corneal stroma later and the steering unit 320 is configured for varying path of the output light beam to enable projection of the selected pattern on the user’s cornea. Operation speed of the steering unit 320 and power of the light source unit 310 are selected to provide light etching of the cornea, typically, within superficial epithelial layers, e.g. at depth of single cell layer, Bowman layer or anterior corneal stroma.

[0134] More specifically, the pattern is generally to be etched within the epithelial layer or right underneath. It should also be noted that the selected optical pattern can be effectively stamped within the epithelial layers of the cornea.

[0135] As indicated above, the pattern is selected to provide the desired optical effect to enable correction of visual impediments. The nanoparticle-containing dispersion, when applied to the pattern, actually functionalizes / activates and stabilizes (provide lasting) this optical effect. As also described above, the eye drop solution (formulation / dispersion), includes selected nanoparticles having refractive index different than that of the cornea and / or tears around the eye and the dispersion is applied to the pattern such that the nanoparticles are arranged / dispersed within the pattern (incision / ablation region(s) of the pattern) with a substantially low density (i.e. such that the nanoparticles' arrangement does not affect the refractive effect induced by the structure of the pattern).

[0136] An effect induced by the nanoparticles' arrangement being dispersed in the pattern includes scattering (or scattering and absorption) of light of the spectral range of interest (e.g. visual spectral range) being incident on the nanoparticles located within the incision / etched regions of the pattern, and this functionalizes and stabilizes the optical effect of the pattern (which is selected in accordance with vision correction to be applied) due to filling of pattern's incisions / etched regions by the scattering nanoparticles.

[0137] More specifically, the nanoparticles' material composition is selected such that for a given size and shape of the nanoparticle it exhibits a dominant scattering (over absorption to thereby prevent undesired heating effects in the eye) for incident illumination of a predetermined (e.g. visual) spectral range; and the arrangement of the nanoparticles is of a substantially low density.

[0138] For example, a few nanoparticles for a region of xλ area within the pattern (generally at least 2 nanoparticles, e.g., 4 nanoparticles, for the visible range). This provides that just a few nanoparticles are needed to be dispersed in the pattern (i.e. low concentration of the nanoparticles in the eye drops). By such selection of the nanoparticles for a given pattern, invariant conditions is provided for the pattern with nanoparticles on the cornea for incident illumination in a predetermined spectrum, namely, the combined effect of the natural characteristic of the cornea, the pattern, and the nanoparticles' dispersion in the pattern creates the invariant conditions for the resulted point spread function on a retina of the subject.

[0139] Generally, the amount of nanoparticles needed to be dispersed in the pattern and their arrangement in the pattern depend inter alia on the critical dimensions of the pattern, e.g. the depth, the diameter and width of the ablations. Considering for example, a pattern including ring(s), the width relates to the width of the ring itself (e.g., 375 microns for the case of presbyopia treatment), and the diameter relates to the external diameter of the pattern, e.g., 3mm.

[0140] The inventors have shown that with the relatively low density of the selected nanoparticles (i.e., nanoparticles being mostly scattering for the visual selected range), the nanoparticles operate as scatterers not affecting / modifying the refractive optical effect induced by the pattern structure itself, but functionalizes and stabilizes this pattern's effect due to the optical effect of scattering induced by the nanoparticles. For example, considering substantially spherical nanoparticles of a diameter of about 80 nm, and operational wavelengths of the visual spectral range (e.g., λ=530 nm), the arrangement of nanoparticles in the pattern is such that a λ3volumetric space in the pattern comprises up to 200 nanoparticles.

[0141] As described above, the eye drop formulation may include any suitable nanoparticles, including for example HAS-based nanoparticles (e.g., Recombinant Human Serum Albumin nanoparticles), or metallic based nanoparticles, such as gold, which are carried by biocompatible material, e.g. biocompatible shell (e.g., albumin shell), i.e., protein folding around the particles.

[0142] It should be noted that the particles of the eye solution are configured to provide the optical effect of the inscribed pattern to be steady in time. More specifically, the nanoparticles, being locked inside the pattern (inside the incision / etching regions) at a specific depth of the etching, functionalize / activate the pattern and preserve the pattern shape “optically active”, thus maintaining the optical effect of the pattern to provide the optical effect to last from a few days to a few months.

[0143] Generally, protein-based NPs, often used as drug carrier particles, may be of high interest for the eye drop solution, based on high stability during storage, and biocompatibility, e.g. being non-toxic and non- antigenic. Albumin proteins provide macromolecular carrier that has been shown to be biodegradable, non-immunogenic, non-toxic, and metabolized in vivo.

[0144] In some embodiments of the invention the nanoparticles may include Human Serum Albumin (HSA, 66.5 kDa). HSA may be preferred since it is the most abundant plasma protein (35-50 g / L human serum) and has an average half-life of 19 days in the blood and is thus used in the following. However, it should be noted that the nanoparticles of the present invention may typically be associated with any albumin type protein including various animal serum and / or synthetic or recombinant albumin. Generally, albumin contains 35 cysteinyl residues forming one sulfhydryl group and 17 disulfide bridges. HSA is robust towards pH, it is stable in the pH range of 4-9. Further, HSA can be heated at 60 °C for up to 10 h.

[0145] The inventors of the present invention have identified a technique enabling to provide and characterize HSA-based nanoparticles (NPs) having robust and controllable particle size. The technique utilizes a nanofabrication method by the processes of desolvation and cross-linking-with Divinyl Sulfone (DVS) as exemplified in Fig. 5. During the desolvation process, spheric protein NPs are formed and then hardened / stabilized by cross-linking promoted by DVS. In this context, a covalent Michael reaction occurs between the free nucleophilic functional groups of the HSA protein and the strong electrophilic bifunctional DVS reagent, resulting in intra- and / or inter-chain bonds within the NPs. The preparation of such HSA NPs may offer the availability of a variety of free functional groups on their surface that may be used for further second step functional modifications.

[0146] In some examples, the nanoparticles may be based on hybrid organic / inorganic nanosystem consisting of HSA NPs that encapsulated with metallic nanoparticles (gold nanoparticles or maghemite (y-Fe2O3) nanoparticles). The hybrid organic / inorganic nanosystems including HSA NPs that encapsulated hydrophilic (NH4)2Ce(lV)(NO3)6 (are modified by Ceric Ammonium Nitrate (CAN), named as CAN maghemite or CAN-y-Fe2O3NPs, have also been fabricated and characterized. Several suitable nanoparticles have been produced and characterized, being nanoparticles variations / species and / or nanoparticles associated with intermediate production stages according to the present technique, as exemplified in the following.

[0147] Example 1 - HSA Core Nanoparticles Fabrication

[0148] HSA Core Nanoparticles Fabrication HSA (50.0 mg) was dissolved in 1.0 mL of purified water (ddH2O). Ethanol was added during the desolvation process to get a total volume of 5.0 mL for a final HSA concentration of 10 mg / ml. 140.0 pL of DVS (5% w / w in EtOH) was added to induce protein chain cross -linking. The cross-linking process was performed by stirring the suspension for 1 hour at 55 °C followed by 20 minutes in an ultra- sonication bath. The resulting HSA nanoparticles were then purified by three cycles of differential centrifugation (at conditions of 13,500 rpm, 60 min, 4 °C) and were then re-dispersed to the original volume of ddH2O. Each redispersion step was performed in an ultra-sonication bath for 10-15 min. To enable long-term storage and to avoid agglomeration, the nanoparticles were stored in a refrigerator at 4 °C.

[0149] Example 2 - HSA Core Nanoparticles characterization

[0150] The resulting HSA core NPs were further characterized by various combined analytical, spectroscopic, and microscopic methods. Figs. 6A and 6B show analysis of size distribution (Fig. 6A) and charge distribution (zeta potential, Fig. 6B) of the nanoparticles. The resulting fabricated HSA NPs show NP hydrodynamic size (DLS) of 149.56+1.8 nm and a strong negative zeta (electric) potential of -35.4+2.4 mV. Additionally, the nanoparticles show small dispersity, associated with polydispersity index (PDI) value of 0.17.

[0151] Figs. 7A to 7C show TEM, cryo-TEM microphotographs and size distribution histogram of the HSA core NPs. These measurements indicate formation of spherical and substantially homogeneous HSA core NPs with an average size of 23.05+5.3nm.

[0152] Additional measurement of the nanoparticles has been performed for determining cross-linking of the HSA polymeric chains by the DVS reagent. Figs. 8A and 8B show FTIR spectrum measurement showing structural differences between standard HAS G2 and Maghemite carrying HSA nanoparticles G1 as described herein. Fig. 8A shows relative intensity measured along the spectrum between 4050cm1and 550cm1, Fig. 8B focuses on a region marked by rectangle in Fig. 8A and specifically shows peaks in the absorption spectrum Gl. The structural differences between the particles are exemplified by the FTIR absorption peaks variations are generally assigned to the presence of DVS in the core HSA NPs. The spectral difference between both the crude HSA and the HSA NP spectra can readily be seen in Fig. 8B at the range of 800- 1100 cm1. The figure shows several peaks in the HSA NP spectrum Gl that do not appear in the standard HSA FTIR spectrum G2. The first peak at 880 cm1corresponds to the stretching vibrations of the C-S bonds. The two other peaks appearing at 1047 and 1083 cm1can be attributed to the stretching vibrations of the sulfoxide groups (R- S=O).

[0153] Additionally, X-ray photoelectron (XPS) spectroscopy was used to confirm the participation of this electrophilic DVS reagent during the HSA polymeric chain crosslinking. Figs. 9A and 9B show XPS spectra of the crude HAS (Fig. 9A) and HAS NPs described herein (Fig, 9B). The XPS analysis of HSA NPs shows that the S element is present in two oxidation states, i.e., a first state corresponding to the R-S species (Binding Energy of BE = 164.0 eV) and the second state is at a higher binding energy, typically of 168.5 eV, corresponding to the SO2sulfoxide groups originating from the DVS sulfone group. This peak at 168.5 eV did not appear in the XPS analysis of the starting crude HSA protein.

[0154] The main functional groups, generally including the primary amine (NH2) and the carboxylic groups (COOH), have been successfully quantified using a UV-sensitive Kaiser Test (1,3 -diaminopropane use for EDC-activated COOH group amidation / derivatization). Both the obtained differential EDC and the non-EDC-based Kaiser results revealed that for 1.0 g of HSA NPs, there are 0.632 and 1.127 millimole of both the NH2 and the COOH groups, respectively. (These quantified surface functionalities enable the future uses of HSA NPs as a biocompatible biodegradable drug carrier, as it allows further binding of additional therapy and / or tumor and diseased cell targeting agents).

[0155] Example 3 - CAN Maghemite Nanoparticle Preparation

[0156] The CAN Maghemite NP preparation was executed in a two-step procedure which included basic co -precipitation of two types of Fe2+ / 3+salts. This procedure yielded magnetite (Fe3O4) NPs as the less oxidized starting NP material that was then oxidized by mono-electronic oxidant cerium ammonium nitrate (CAN) and surface modified by (CeLn)3 / 4+cation / complex NP surface doping, to obtain 6.61+2.04 nm-sized positively charged (+45.7 mV)

[0157] Example 4 - Hybrid CAN Maghemite- Containing HSA Nanoparticles Preparation

[0158] To provide the desired nanoparticle structures, having suitable refractive index for affecting vision in accordance with selected pattern on the cornea, both of the nanoscale components of HSA and NPs were assembled for CAN-y- Fe2O3NPs to be entrapped into HSA nanocomposite particles during this same DVS- mediated NP fabrication / component cross-linking. For this purpose, the hybrid CAN maghemite containing HSA nanoparticles were prepared by procedure identical to the one described above for HSA NPs. In brief, to HSA (50.0 mg in 1.0 mL of ddH2O), CAN-y- Fe2O3NPs were added at weight ratio of 25:1, and incubated for 1 hour at room temperature followed by a desolvation and cross-linking process. The resulting composite nanoparticles were then purified by three cycles of differential centrifugation (13,500 rpm, 60 min, 4°C), magnetically decanted (using a strong external magnet) and re-dispersed into the original volume of ddH2O. At each performed re-dispersion step, the reaction vessel was placed in a low power ultra-sonication bath for 15 min before processing. For a long-term storage and to avoid agglomeration, the nanoparticles were stored in a refrigerator (4°C).

[0159] It should be noted that the weight ratio between both HSA and CAN-y-Fe2O3NPs phases has been found to be 25:1 for an optimal encapsulation of a maghemite composition into a HSA nano shell. Generally, the weight ratio may be in the range between 15:1 and 40:1.

[0160] The DLS hydrodynamic diameter, the size distribution, and the electric potential values of the corresponding composite particles, have been determined. A DLS hydrodynamic diameter of 130 nm was measured with a poly dispersity index below 0.3. An electric potential analysis was also performed in order to check the colloidal stability of the resulting hybrid NPs (the entrapment method) towards an aggregation control, meaning that composite particles were always found to be negatively charged with an average electric potential value of -25 mV.

[0161] Reference is made to Figs. 10A to 10D showing morphology and the size distribution measurements of the hybrid HSA / CAN-y-Fe2O3nanoparticles were characterized using TEM, cryo-TEM, and HR-SEM. Figs. 10A and 10B show respectively TEM and cryo-TEM images of respectively the HSA NP phase (slightly less contrasting grey area) containing entrapped and strongly contrasting CAN maghemite NPs, which can be readily visualized and identified (dark spots) within the HSA phase. Hence, electron dense metallic NPs were successfully incorporated into the surrounding HSA matrix, while distributions of the CAN maghemite NPs between the particles and within each particle were found to be quite homogeneous, which likely arose from promoting interactions between the positively charged CAN-y-Fe2O3NPs and the negatively charged HSA phase. NP crystallinity has been further confirmed by TEM / S elected- Area Electron Diffraction (SA ED) as shows in Fig. 10D, in addition, the nanoparticles size distribution by TEM was also measured in Fig. 10C revealing an average size of 44.6+4.18 nm.

[0162] Figs. 11A to 11D show HR-SEM image (Fig. 11A) and line scan analysis for Carbon (Fig. 11B), Oxygen (Fig. 11C) and Iron (Fig. HD) amounts obtained in a scanning transmission electron microscopy (STEM) mode. The can lines for analysis of the elements are marked as L1-L3 respectively for Carbon, Oxygen and Iron. The figure shows that CA maghemite NPs were present as fully encapsulated clusters in the HSA matrix, while the HSA phase appeared as surrounding clouds. The line-scan elemental analysis is based on Energy Dispersive X-ray Spectroscopy (EDS) validates that the CAN-y-Fe2O3NPs encapsulation mainly arose within the resulting HSA nanocomposite particles. Indeed, there is a simultaneous presence of iron (top-right), carbon (bottomleft), and oxygen (bottom-right) elements. The peak of the iron element is much thinner than the others, thus demonstrating the encapsulation of CAN-y-Fe2O3NPs into HSA NPs. Additionally, Fig. 12 shows reflection of iron particles embedded in the HSA NPs. As shown, from reflection of iron particles the HAS NPs are located within the incision region of the cornea enhancing the etched pattern.

[0163] ICP-AES elemental analyses were also carried out in order to confirm iron encapsulation during the hybrid NP formation. ICP measurements demonstrated an entrapment efficiency of 95% of elemental iron into the HSA phase. Additional concentration measurements of both the hybrid NPs and the CAN-maghemite NPs revealed that the weight percentage of the CA -maghemite NPs phase is nearly 40% out of the total weight of corresponding hybrid NPs.

[0164] Thus, the present technique utilizes solution formulation including biocompatible protein chains, e.g., albumin based NPs, e.g., rHSA based NPs, and / or CAN-y-Fe2O3nanoparticles with biocompatible protein shell, e.g., albumin shell (rHSA shell), as eye drops, such that when the nanoparticles are dispersed in the selected etched patterns on the user cornea being located in the incision regions of the pattern, they, do to scattering effect with respect to incident light of a predetermined spectral range, provide functionalization and stability of the refractive effect induced by the pattern structure. The nanoparticles generally remain on the cornea for time period between a few days to a few months enabling correction of the user eye condition in accordance with optical operation of the selected pattern. The inventors have conducted tests on porcine and rabbits eyes validating the optical effect of the etched pattern and selected nanoparticles for correction of optical vision impediment.

[0165] To this end, refractive error of hundreds of fresh pig eyes were measured with both, an automated refractometer and a wavefront abberometer before and after realization of a corneal superficial pattern and then after instillation of eye drops filled with the selected nanoparticles at a specific known concentration of between O. lmg / ml and 15mg / ml. The nanoparticles’ concentration used in this example was l Omg / ml. In these ex-vivo experiments, both myopia and presbyopia correction were tested. The patterns were performed to the porcine corneas either using mechanical stamper, built with a 3-D printer with a calibrated optical pattern or assisted by laser.

[0166] The laser assisted pattern performed in this example provides the superficial ablation onto the cornea in order to let the nanoparticles penetrating the cornea, and thus enable desired optical power variation determined by the pattern. For myopia correction, the pattern itself was selected to be an optimized non-binary Fresnel plate zone diffractive pattern providing in this specific experiment an optical correction of 3 diopters. For presbyopia, an extended depth of focus pattern was used to achieve an increase depth of focus of 1.5D equivalent addition. The optical power of the porcine eye system was measured and recorded 5 times at each time points of the experiment, as followed: Baseline optical power, immediately after the pattern was etched into the cornea, after application of the eye drop into the pattern, and then at 5min, lOrain, 20min and 30min after the eye drops instillation into the pattern. The various measures were conducted to avoid bias due to large standard deviation.

[0167] Thus, after selection of the desired pattern in accordance with required optical correction, the 3 D-dimensional pattern was applied to the cornea. When the pattern is etched on the cornea, the eye was washed with eye drop solution including human serum albumin nanoparticles conjugated with Cy5 to enable their identification through confocal fluorescence microscope and histopathology.

[0168] Reference is made to Fig. 13A and 13B showing optical power variation results on pig eyes corrected using the above-described technique. Fig. 13A illustrates the outcomes of 3 diopters myopic correction over 64 pig eyes obtained with the technique of the present disclosure. As seen in Fig. 13A, there is no refractive change induced immediately after the creation of the pattern (“Pattern” in the graph) whereas the refractions change according to the planned correction upon addition of the nanoparticles (“NP’s” in the graph) into the pattern. The results were similar in in vivo and ex-vivo models, the changes in refraction only occur once the pattern is filled with the recombinant human serum albumin nanoparticles. Fig. 13B shows similar results for an extended depth of focus treatment, suitable for presbyopia correction. The “defocus” metric is based on through focus visual Strehl Ratio and is measured for assessing the effect produced by the Extended Depth Of Focus (EDOF) element (pattern of surface relief) etched on the corneal epithelium and optically activated by rHSA nanoparticles. As a control parameter, the inventors also analyzed the changes in the overall spherical component of the eye (the “sphere”) and the overall refraction of the optical system (“spherical equivalent”). As shown in Fig 13A, the applied 3 diopters myopic pattern combined with the nanoparticles’ eye drops provided a mean correction of - 3.12±0.58 diopter at the last measurements (30mn post nanoparticles instillation), whereas the change induced solely by the creation of the myopic pattern into the eye (without nanoparticles) was not statistically significant (0.ID±0.13). In Fig 13B a generated increase in depth of focus of 1.22±0.2D for presbyopia correction was observed, without significant change in the overall sphere and spherical equivalent of the eye, respectively -0.08D and -0.04D. The defocus measured in the presbyopia testing is based on through focus visual Strehl Ratio.

[0169] Accordingly, as shown, the use of selected pattern applied / etched on the cornea providing a selected vision correction effect (refractive effect) with suitable eye drops containing sufficient concentration of nanoparticles selected as described above such that, when the nanoparticles are located / dispersed in the incision regions of the pattern they induce scattering effect with respect to light of a predetermined spectral range (typically visual range) to functionalize the optical effect of the pattern and allow it to be lasting for reasonably long period enable correction of various eye conditions. The technique of the present invention is thus minimally invasive. Generally, the pattern may be diffractive (e.g. Fresnel zone plate / rings) or configured to introduce light interference enabling extension of depth of focus of the eye.

[0170] Typically, the eye drops and corresponding nanoparticles as described here may be suitable for use in various additional conditions. For example, the eye drops solution described herein may be used for treatment of Dry eye disease (DED) where the nanoparticles provide lubrication to the eye operating as synthetic tears. DED represents a heterogeneous group of conditions with tear film insufficiency and signs and / or symptoms of ocular surface irritation. These conditions may be associated with various factors, including for example Meibomian gland dysfunction (MGD).

[0171] The use of the nanoparticles containing eye drops as described herein may be used for creating biological bond with the molecules of lipid composing the lipid layers of a user’s eye. This results in both, greater stability of the tear film as well as longer effect on the corneal surface. Further, it should also be noted that the above described nanoparticles, being in eye drop solution may be used as drug delivery carriers. Generally, the anatomical barriers and physiological clearance mechanisms on the ocular surface presents challenges for development of ocular drug delivery devices. More invasive methods, such as intravitreal injections, can improve the ocular bioavailability of therapeutic agents but often result in vision-threatening side effects.

[0172] The use of the selected nanoparticles described herein may enhance the ocular bioavailability of one or more suitable therapeutic agents (e.g. drugs, proteins, peptides for example). The above-described nanoparticles may provide major potential advantages, including for example improving of the penetration / bioavailability / delivery of any bioactive agent in deeper tissue for curing more severe affection such as bacterial, fungal or parasitic infection. Additional major advantage is associated with improving the bioavailability, which may lead to a significant decrease of eye-drops instillations frequency in chronic diseases such as glaucoma or dry eye diseases, as well as a potential external controllable drug delivery by portable device.

[0173] Thus, the present invention provides eye drop material composition containing desired (relatively low) concentration of nanoparticles of selected size and shape, e.g., biocompatible protein chains (preferably HSA-based) or carrying metal based nanoparticles with biocompatible protein shell (e.g., albumin shell) enabling the nanoparticles' arrangement of relatively low density within the pattern to functionalize and maintain / stabilize the optical effect for which the pattern structure is designed. The eye drop composition is thus used in combination with suitable patterning applied to cornea of a user’s eye for providing activation, lasting and stabilized selected optical correction to various eye conditions.

[0174] Reference is now being made to Figs. 14A-14B, which are block diagrams exemplifying non-limiting embodiments of the kit for ablating a corneal tissue according to an aspect of the present disclosure. Fig. 14A exemplifies a kit 1400 that comprises a liquid that contains an energy absorbent material 1402. The liquid 1402 can be contained in a container, such as a bottle or a tube or a single-use packaging. The energy absorbent material is selected to interact with certain illumination wavelength, i.e. an absorbance wavelength, so as to result in a very accurate ablation of the corneal tissue, e.g. by causing an explosive ablation. Therefore, the energy absorbent material absorbs illumination in an absorbance wavelength to thermos-chemically react with the cornea. The liquid 1402 is intended for application onto a corneal tissue of a subject to form a layer of energy absorbent material-containing liquid in some portions of the cornea of the subject. The kit 1400 further comprises an illumination unit 1404 for providing an illumination that comprises said absorbance wavelength. The absorbance wavelength may be in the IR or visual spectrum as long as it interacts with the liquid 1402 on the corneal tissue to result in a desired ablation of the cornea. The illumination unit 1404 can be controlled to result in the desired illumination pattern and profile, namely the pattern on the cornea along which the illumination is applied. By that, a desired ablation pattern is formed on the corneal tissue of the subject.

[0175] Fig. 14B differs from the example of Fig. 14A by including in the illumination unit 1404 a laser 1406 and a control unit 1408. The laser 1406 is the illumination device that provides the desired illumination on the cornea. In this example, the laser is controlled by a control unit 1408 that executes a desired illumination pattern on the corneal tissue of the subject. The desired illumination pattern to be executed by the control unit 1408 can be personalized according to the subject's specific characteristics. Namely, for each subject, a different illumination pattern and profile is executed, which may be different pattern along the cornea and also may be illumination with different illumination wavelength profile.

[0176] Example 5 - Enhanced Ablation of Cornea Dopped with Fluorescein Dye using Visible Wavelength Laser

[0177] Materials and Methods

[0178] Preparation of the porcine eye specimens

[0179] Fresh porcine eyes were obtained from a local CRO (Lahav CRO, Israel). Porcine eyes are anatomically similar to human eyes and are easily obtained in large numbers and in excellent and reproducible biological conditions. Enucleations were performed at the facility and used within 4 hours of enucleation. Each eye was placed in a rotatory cylindrical container as shown in Fig. 15a. The cylindrical container was connected to a rotatory step motor operated using an Arduino board. The container was fixated on an optical post using a clamping structure shown in Fig. 15b to maintain the eye in a forward-facing position, like in a person that is sitting and looking straight.

[0180] Experimental Setup

[0181] The experimental setup is shown in Figs 16a-16c. It consisted of a 532 nm CW (of maximum power 800 mW) a single mode fiber laser. The fiber tip was placed very close to the tip of the eye (at a distance of less than 1 mm). The step motor was controlled by an Arduino board. The speed of the motor could be varied. The aim was to rotate the eye while the laser is on to ablate a circle on the cornea with a predefined radius.

[0182] Fluorescein dye

[0183] Fluorescein was extracted from a clinically used strips (BIO FLUORO, Img Fluorescein Sodium [C20H1005.2Na.2H20] USP strips (LOT FL15G1605, CE 0434)) that were soaked in saline, with a resulting concentration of 4.68 mg / ml. This is the clinical concentration from a clinical strip and an amount of water usually used to moisten the strip during the clinical application of the dye. The dye is a clinically used solution, approved by the FDA for topical application (NDA 208582), with safety established for all ages, including pediatric patients. A single application of the dye solution similar to the common clinically accepted practice is sufficient to create the photoablation effect, with the excess of the dye washed away by the tears with no need for extra wash. The dye was either applied as usual eye drops (i.e., 1 drop that creates a tear-film-like coverage of the corneal surface) 1 min before the laser procedure or in a larger amount, i.e., soaking the corneal surface with an excessive amount of dye that created a liquid basin on the corneal surface for 1 min, until the eye was placed in the forward-facing position and immediately underwent the laser procedure.

[0184] Ablation Principle

[0185] The interaction of laser photons with corneal tissue can be classified into three main principles based on how the photon energy is deposited on the tissue molecules. When the photon flux is sufficiently high to heat the substrate by conversion of electronic excitations into vibrational energy, it is termed thermal ablation. Photochemical ablation occurs when the damage is extremely low due to the localization of the energy. The process happens at a very fast rate, because of which the energy conversion doesn't create vibrating molecules which causes a heating effect. The third principle is termed explosive ablation, which is similar to thermal ablation, however, it is a controlled process that does not rely on a heated particle to ablate the surroundings. This type of ablation occurs at a fast time scale, in which the energy is transformed into kinetic energy, at the same time causing no damage to un-irradiated tissues, this is based on the effect of enhancing the laser energy absorbance by introducing dopants into the tissue. The addition of fluorescein (an organic dye) into the tissue as an energy absorbent dopant leads to effective ablation by visible 485 nm light.

[0186] Chemical structure of fluoresceine (F) can be written as indicated in Scheme 1.

[0187] Scheme 1: Chemical structure of fluoresceine.

[0188] Previous studies show that in dark the fluoresceine leads to a formation of a stable semi-fluorescein radical (S*) which is through a simple one electron transfer (see scheme 2).

[0189] Scheme 2: Chemical structure of stable semi-fluorescein radical.

[0190] It has been reported that the dye when irradiated with 390 nm light, due to the photochemical reduction form a product leucoflurescein (LH)26as shown in scheme 3.

[0191] Scheme 3: Chemical structure of lecoflurescein. This is due to the flow of photocurrents during the reduction process. The ablation is enhanced by this photochemical reaction that occurs. Here we use the same principle to treat the cornea with an eye- safe fluorescein sodium dye to enhance the absorption properties of the tissue for achieving an explosive ablation.

[0192] Microscopy

[0193] Confocal imaging of the whole mount porcine eyeball was performed using the Lecia Confocal STED Microscope with a magnification of 20X.

[0194] The whole cornea was surgically excised and examined using a bright field microscope (Leica LMD) with a magnification of 1.25X.

[0195] Results and Discussion

[0196] In the first set of experiments, the corneal surface was illuminated using a 532 nm fiber-coupled laser, as shown in Figs 16a-16c. For each power setting, the step motor was rotated at a speed of either 2 mm / s or 4 mm / s. A total of 800 mW in steps of 50 mW was applied. No corneal ablation was produced (Table 1, Eye No. 1-4). Furthermore, no ablation was observed when the cornea was illuminated with 800 mW in a single point, with no rotation.

[0197] Figs. 17a-17k show an example of different regions of the whole cornea, indicating no ablation following the laser illumination (Figs. 17a-17h). Figs. 17j and Fig, 17k show the high-resolution images of the eye before and after laser treatment indicating no ablation.

[0198] In the second set of experiments, the eyes were treated with a freshly prepared solution of clinically used fluorescein dye solution. After 1 minute with the dye that was applied as usual eye drops (see Methods), the eye was illuminated with the laser at a speed of 2 ms / exposure steps at maximal power. An ablation of the cornea was produced, as shown in Figs. 18a-18b (Eye No. 5). Fluorescent confocal microscopy of the whole eye was used to measure the width and depth of the ablation. For this example, the measurements were 36 pm and 180 pm, respectively (see Figs. 19a-19o for Z-stack images from depth Z=0 to Z= 184 pm. The fluorescent signal is seen only to a depth of 160 pm.).

[0199] The same procedure was repeated on another eye, Eye No. 6, that was soaked in fluorescent dye solution (see Methods). An ablation with a width of 123 pm and depth of 100 pm was produced. Figs. 20a and 20b show, respectively, the bright-field microscopic image with 1.25x of the corneal surface and the confocal image of thew whole Eye.

[0200] In the third set of experiments, the exposure time was increased to 4 ms / exposure step by changing the speed of the motor. The microscopic images are shown in Fig. 20c (showing confocal image of Eye No. 7 with the width of the ablation of 300 pm and depth of 247 pm), Fig. 20d (showing reflection mode image of Eye No.

[0201] 7 in the same field of view), and Fig. 21a (showing bright-field microscopic images of Eye No. 8 with 1.25x of the cornea surface), and Fig. 20b (showing confocal image of the whole Eye No. 8 before cutting with the width of the ablation of 570 pm and depth of 465 pm).

[0202] The complete experimental results are consolidated in Table 1.

Claims

CLAIMS:

1. A method for ablating a corneal tissue, comprising: applying a liquid that comprises an energy absorbent material onto the corneal tissue, wherein the energy absorbent material absorbs illumination in an absorbance wavelength; illuminating the corneal tissue, following said applying, with an illumination that comprises said absorbance wavelength to result in a selected ablation profile of the corneal tissue.

2. The method of claim 1, wherein said energy absorbent material is a biocompatible organic compound.

3. The method of claim 1 or 2, wherein said liquid comprises Fluorescein.

4. The method of claim 3, wherein said liquid is a Fluorescein Sodium dye.

5. The method of any one of claims 1-4, wherein said illuminating comprises focusing said illumination along a selected pattern on said corneal tissue.

6. The method of claim 5, wherein said selected pattern comprises one or more annular rings or Fresnel rings.

7. The method of any one of claims 1-6, wherein the energy absorbent material absorbs energy of said illumination of the visual spectrum.

8. The method of any one of claims 1-7, wherein said applying occurs about 1-10 minutes before said illuminating.

9. The method of any one of claims 1-8, wherein said applying results in a surface of said liquid on the corneal tissue.

10. The method of any one of claims 1-9, wherein said illumination is of a wavelength between 400nm-650nm.

11. The method of claim 10, wherein said illumination is of a wavelength of about 390nm (the term "about" in the claims should be understood as ±20nm).

12. The method of claim 10, wherein said illumination is of a wavelength of about 435nm (the term "about" in the claims should be understood as ±20nm).

13. The method of claim 10, wherein said illumination is of a wavelength of about 530nm (the term "about" in the claims should be understood as ±20nm).

14. The method of any one of claims 1-13, wherein said illuminating is performed by using a laser device.

15. The method of claim 14, wherein said laser device is a fiber laser.

16. The method of any one of claims 1-15, wherein said illumination is continuous wave illumination.

17. The method of any one of claims 1-16, comprising, following said illuminating, removing the liquid from the corneal tissue.

18. The method of any one of claims 1-17, wherein said illuminating results in absorbance of photons of said absorbance wavelength.

19. The method of claim 18, wherein said absorbance results in a local photo- thermo-chemical reaction.

20. The method of any one of claims 1-18, wherein said absorbance wavelength is in the visual spectrum.

21. A kit for ablating a corneal tissue, comprising: a liquid that comprises an energy absorbent material for applying it onto the corneal tissue, wherein the energy absorbent material absorbs illumination in an absorbance wavelength; an illumination unit configured for illuminating the corneal tissue, when it is applied with said liquid, with an illumination that comprises said absorbance wavelength in a selected ablation profile of the corneal tissue.

22. The kit of claim 21, wherein said energy absorbent material is a bio -compatible organic compound.

23. The kit of claim 21 or 22, wherein said liquid comprises Fluorescein.

24. The kit of claim 21, wherein said liquid is a Fluorescein Sodium dye.

25. The kit of any one of claims 21-24, wherein the illumination unit comprises a controller configured to control the illumination unit, so as to focus said illumination along a selected pattern on said corneal tissue.

26. The kit of claim 25, wherein said selected pattern comprises one or more annular rings or Fresnel rings.

27. The kit of any one of claims 21-26, wherein the energy absorbent material absorbs energy of said illumination of the visual spectrum.

28. The kit of any one of claims 21-27, wherein said illumination is of a wavelength between 400nm-650nm.

29. The kit of claim 28, wherein said illumination is of a wavelength of about 390nm.

30. The kit of claim 28, wherein said illumination is of a wavelength of about 435nm.

31. The kit of claim 28, wherein said illumination is of a wavelength of about 530nm.

32. The kit of any one of claims 21-31, wherein said illumination unit comprises a laser device for performing said illumination.

33. The kit of claim 32, wherein said laser device is a fiber laser.

34. The kit of any one of claims 21-33, wherein said illumination is continuous wave illumination.

35. The kit of any one of claims 24-34, wherein illuminating results in absorbance of photons of said absorbance wavelength.

36. The kit of claim 35, wherein said absorbance results in a local photo-thermo- chemical reaction.

37. The kit of any one of claims 21-36, wherein said absorbance wavelength is in the visual spectrum.

38. A kit for use in correction of an eye condition of a subject, the kit comprising: a pattern formation system configured and operable to utilize predetermined pattern data to form a corresponding three-dimensional pattern on a surface of a cornea of the subject selected to apply an optical effect correcting the eye condition; and eye drops comprising a dispersion to be applied to said pattern to functionalize and stabilize the optical effect of the pattern, the dispersion comprising nanoparticles selected to (i) create invariant conditions for one or more of: incident illumination of a predetermined spectral range on the cornea, exact locations of the nanoparticles in the pattern and a liquid type of the dispersion, and (ii) exhibit a dominant scattering effect for the incident illumination within said predetermined spectral range.

39. The kit of claim 38, wherein said nanoparticles are selected to exhibit a maximal scattering effect within a visual spectral range.

40. The kit of claim 39, wherein said nanoparticles are selected to exhibit a maximal scattering effect within a spectrum defined between 450nm-600nm.

41. The kit of claim 38, wherein said nanoparticles are selected to exhibit a maximal absorption effect within a visual spectral range.

42. The kit of claim 38, wherein said nanoparticles are selected based on their characteristics of one or more of the following: material, size and shape.

43. The kit of claim 38, wherein said three-dimensional pattern is configured as a diffractive pattern.

44. The kit of claim 38, wherein said pattern comprises Fresnel rings pattern.

45. The kit of claim 38, wherein said three-dimensional pattern comprises a phase affecting interference pattern.

46. The kit of claim 38, wherein said three-dimensional pattern comprises an extension of depth of focus pattern.

47. The kit of claim 38, wherein said three-dimensional pattern is selected to enable optical correction between 0.25 to 10 diopters at optical power resolution + / - 0.25D.

48. The kit of claim 38, wherein said nanoparticles comprise biocompatible protein chains.

49. The kit of claim 48, wherein said protein chains comprise albumin proteins- based nanoparticles.

50. The kit of claim 49, wherein said albumin proteins-based nanoparticles comprise human serum albumin and / or recombinant human serum albumin.

51. The kit of claim 38, wherein said nanoparticles comprise metallic nanoparticles with biocompatible polymer shell.

52. The kit of claim 51, wherein said biocompatible polymer shell is human serum albumin based shell and / or recombinant human serum albumin based shell.

53. A method for use in correction of eye condition of a subject, the method comprising: forming a selected three-dimensional pattern on a surface of a cornea of the subject; applying a dispersion comprising nanoparticles onto said selected pattern, wherein said nanoparticles are selected to (i) create invariant conditions for one or more of the following: incident illumination of a predetermined spectral range on the cornea, exact locations of the nanoparticles in the pattern and a liquid type of the dispersion, and (ii) exhibit a dominant scattering effect for the incident illumination within said predetermined spectral range.

54. A method for use in correction of eye condition of a subject, the method comprising: providing the kit of claim 38; operating the pattern formation system to form a selected three-dimensional pattern on a surface of a cornea of the subject; applying the dispersion to said pattern, thereby functionalizing and stabilizing the optical effect of the pattern.

55. The method of claim 54, wherein said forming and applying create invariant conditions for a resulted point spread function on a retina of the subject.

56. The method of claim 54, wherein said applying of the dispersion provides a distribution of at least two nanoparticles on an area of 'kx within incision regions of said selected pattern, wherein said k is a wavelength of the predetermined spectral range.

57. The method of claim 54, wherein said applying of the dispersion provides a distribution of up to 200 nanoparticles in a λ3volumetric space within incision region of said selected pattern for the nanoparticles of about 80nm size and for λ of about 530nm.

58. The method of claim 54, further comprising preparing said dispersion prior to said applying, said preparing comprises mixing a liquid with said nanoparticles.

59. A formulation to be used in eyedrops to be applied on a three-dimensional pattern on a surface of cornea of a subject's eye, comprising: nanoparticles dispersed in a liquid forming together a dispersion, wherein a majority of the nanoparticles are selected such that said nanoparticles, when applied on the three-dimensional pattern formed on the cornea and being located within incision regions of the pattern, they (i) create invariant conditions for one or more of: incident illumination in a predetermined spectral range on the cornea, exact locations of the nanoparticles and a type of said liquid, and (ii) exhibit a dominant scattering effect or absorbing effect for said incident illumination of the predetermined spectral range, thereby providing functionalization and stability of an optical effect of vision correction for which said three-dimensional pattern is designed.

60. The formulation of claim 59, wherein said nanoparticles are selected to exhibit a dominant scattering effect within a visual spectral range when applied on the three- dimensional pattern formed on the cornea of the subject.

61. The formulation of claim 60, wherein said nanoparticles are selected to exhibit a maximal scattering effect within the visual spectral range.

62. The formulation of claim 61, wherein said nanoparticles are selected to exhibit a maximal scattering effect within the spectral range defined between 450nm-600nm.

63. The formulation of claim 59, wherein said nanoparticles are selected based on their characteristics of one or more of the following: material, size, shape or any combination thereof.

64. The formulation of claim 59, wherein said nanoparticles comprise human serum albumin (HAS) based nanoparticles and / or recombinant human serum albumin (rHSA) based nanoparticles.

65. The method of any one of claims 53-58, wherein said forming is carried out according to the method of any one of claims 1-17.

66. The method of any one of claims 1-17, further comprises applying a dispersion comprising nanoparticles onto said selected ablation profile, wherein said nanoparticles are selected to (i) create invariant conditions for one or more of the following: incident illumination of a predetermined spectral range on the cornea, exact locations of the nanoparticles in the pattern and a liquid type of the dispersion, and (ii) exhibit a dominant scattering effect for the incident illumination within said predetermined spectral range.

67. The method of claim 66, further comprises the method of any one of claims 56- 58.

68. The kit of any one of claims 21-37, further comprising eye drops comprising a dispersion to be applied to said selected ablation profile to functionalize and stabilize the optical effect of the pattern, the dispersion comprising nanoparticles selected to (i) create invariant conditions for one or more of: incident illumination of a predetermined spectral range on the cornea, exact locations of the nanoparticles in the pattern and a liquid type of the dispersion, and (ii) exhibit a dominant scattering effect for the incident illumination within said predetermined spectral range.

69. The kit of any one of claims 21-37, further comprises the formulation according to any one of claims 59-64.

70. The kit of any one of claims 38-52, wherein the pattern formation system is constituted by the kit of any one of claims 21-37.

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