NL2026025B1 - Apparatus and method to measure accommodative structure of the eye - Google Patents

Abstract

The present document discloses a novel apparatus and method thereto for imaging and measure the accommodation structure of the eye for, for example, fitting intraoculair lenses. A light source and beam positioning means illuminate 5 the interior of the eye through the sclera thereby back-lighting the accommodation structure, the ciliary mass and sulcus. Different ranges of wavelength of light can accentuate the sulcus and the ciliary mass to be analyzed as distinct bands in the final digital image. The present document discloses a novel apparatus and method thereto for imaging 10 and measure the accommodation structure of the eye for, for example, fitting intraoculair lenses. A light source and beam positioning means illuminate the interior of the eye through the sclera thereby back-lighting the accommodation structure, the ciliary mass and sulcus. Different ranges of wavelength of light can accentuate the sulcus and the ciliary mass to be analyzed as distinct bands in the 15 final digital image.

Description

Apparatus and method to measure accommodative structure of the eye The present invention relates to an apparatus and method to measure the accommodative structure of the eye.

Accurate measurement of the diameter of the sulcus and the ciliary mass of the eye is important for sizing and fitting of intraocular lenses in particular for accommodating intraocular lenses which must accurately fit the anatomy of the eye to function properly, for example, must fit the anatomy of the sulcus and/or the anatomy and diameters of the ciliary mass of the eye, in this document collectively referred to as the accommodation structure. In particular accommodative intraocular lenses positioned in the accommodative structure, lenses change optical power to allow the eye to focus at different distances, require an accurate fit within the accommodative structure.

The sulcus is a wedge-shaped space in between the posterior surface of the peripheral section of the iris and the anterior surface of the ciliary mass. So, the sulcus dimensions are defined by the sulcus-root, the most peripheral rim of the sulcus, the rim at which the iris bends in a posterior direction, with the sulcus-root, in the context of the present document, having a ‘sulcus-root diameter’ transversing the eye, and, a ‘sulcus- width’, which narrows in lateral direction moving outward from the center of the eye due to wedged shape, and, a ‘sulcus- length’ which is defined by the size of the ciliary mass in the lateral direction. In the present document the term ‘sulcus diameter’ or ‘diameter of the sulcus’ refers to the distance of the sulcus-root-to-sulcus root transversing the eye diametrically, meaning transversing the eye through the center of the pupil at the iris plane. In the present document the term ‘ciliary mass diameter’ or ‘diameter of the ciliary mass’ refers to the distance of the tip of the ciliary mass transversing the eye diametrically, meaning transversing the eye through the center of the pupil at the iris plane. The diameter of the sulcus is traditionally established based on, for example, white- to-white, sclera-to-sclera, measurements indicating the border between the iris and sclera of the eye, by a ruler, tape measure, caliper or any other mechanical measuring tool placed on or near the eye, a simple and inexpensive method.

However this method provides an insufficiently accurate estimate for fitting intraocular accommodative lenses because the sizes must be accurate within, say, about 0.1mm because the accommodative amplitude of the ciliary mass is about

0.5mm. Alternatively, the measurement can be by optical coherence tomography, OCT, which provides the required accuracy but which tomography is complex and expensive, and, moreover, a raw digital OCT image requires calculations by complex calibration algorithms because of optical distortions of any optical components of the for example, the cornea of the eye.

The sulcus, in particular the peripheral rim of the sulcus, the sulcus-root, is defined by melanin pigment lining of the iris which layer, at the said peripheral rim, bends in a posterior direction, after which the pigment layer aligns, and fades, into the sclera of the eye. The pigment layer contains melanocytes which produce melanin which has light spectral characteristics. The ciliary mass is defined by a mass of elastic fibrogenic tissues with mass comprising muscular fibers collectively referred to as ciliary muscle and contains blood to feed the ciliary muscle. The blood, containing haemoglobin, and muscle fibers have other light spectral characteristics. The apparatus comprises at least one light source, for illuminating the eye, and at least one digital camera, for providing a digital image, and at least one computer, for post-processing the digital image and presenting the digital image on a digital screen and for providing any required digital post-processing of the image. The light source generates specific ranges of wavelengths of light and comprises atleast one beam positioning means to position the light beam versus the eye with the means configured to illuminate the interior of the eye, for example, in the preferred embodiment, illuminates the interior of the eye through the sclera thereby back-lighting the accommodation structure, with, preferably, avoiding illuminating the anterior surface of the iris. In the preferred embodiment the main direction of illumination, of the light beam emitted by the beam positioning means attached to the light source, differs from the direction of the optical axis of the eye so that the light beam largely illuminates the sclera at, or behind, the accommodative structure. In the preferred embodiment the light beam is directed onto the sclera and towards the ciliary sulcus structure an angle largely perpendicular to the surface of the eye at, or behind, the accommodative structure. Such angle prevents said direct illumination of the anterior surface of the iris and also prevents direct illumination of the retina of the eye which allows for application of relatively high intensities of light required due to light loss due to the sclera through which the beam transverses. Such back-lighting and imaging of the accommodative structure also prevents the cornea to distort the image and allows calculation of the accommodative structure directly without correction for image distortions by the optics of the cornea. Such distortion by the cornea is a major disadvantage of any OCT imaging procedures which require digital correction in post-processing of the image with the post-processing based on the optical powers of the cornea such as spherical power, aspherical powers, astigmatism and other optical aberrations. The beam shape projected by the beam positioning means can be a slit- configuration, as in the traditional ophthalmology slit lamp, to provide an elongated slit shaped light beam to be projected on the sclera, or, alternatively, the beam can have an annular shape, for example, a donut shape, to fully illuminate sclera in a ring around the rim of the iris. The beam positioning means can projects at least one disc-shaped spot of light, or, alternatively, bar-shaped spot, or, alternatively, a ‘half-moon’ shaped spot or any other shaped spot onto the sclera to illuminate the interior of the eye. The shape of the light beam is not restricted to said shapes. Note that the light source and positioning means can be fitted to a traditional ophthamological slit-lamp as an add-on arrangement. The retina can be protected from excessive light intensities by, for example, a circular light shield casting a central shadow covering the pupil of the eye or, alternatively, by a contact lens with a central opaque section. All illumination can be continuous or in a flash arrangement and any of the beam positioning means can also be, for example, in a ringlight configuration fitted around the camera lens.

Inthe preferred embodiment the light source provides at least one light beam with the beam comprising at least one range of wavelengths with the range coinciding with at least one absorption spectrum of the ciliary mass which contains said haemoglobin, so with the range, for haemoglobin, preferably including wavelengths within the range of, for example, 400 and 699nm. Note that also other absorption spectra can be included. Alternatively, the light source provides at least one light beam with the beam comprising at least one range of wavelengths with the range coinciding with at least one absorption spectrum of the of the sulcus with the lining of the sulcus comprising melanin, so the wavelengths preferably include wavelengths below 400nm and above 699nm but not restricted hereto.

To generate said ranges of wavelengths of light the light source can comprise a combination of at least one broadband light source and at least one fixed wavelength filter, for example, a traditional camera colour filter which filter can be exchanged for other colour filters to generate other ranges of wavelengths, or, alternatively, multiple filters can be applied for combination of different ranges of wavelengths in a single image. Note that a light filtering fluid in the tear film, for example, a standard ophthalmological compound such as fluorescein, or, alternatively, a coloured, contact lens, for example a scleral contact lens, is regarded as a fixed wavelength filter in the context of the present document. Alternatively, to generate said ranges of wavelengths of light, the light source can comprise at least one dedicated light element, such as a LED or a laser. The apparatus can include an illumination combination with at least one light emitting diode, LED, or laser, or, alternatively, an array of LEDs/lasers to provide a broad band light source which band can be narrowed by switching off selected coloured LEDs/lasers. For example, a deep-red array of LEDs/lasers to accentuate the sulcus spectrum in combination with any yellow, blue, and/or green LED/lasers to accentuate the ciliary mass, or any other combination for optimum accentuation. Alternatively, the light source can comprise a combination of at least one broadband light source and at least one tuneable wavelength filter, for example a liquid crystal tuneable filter. The tuneable filter can be, for example, an acousto- optic tuneable filter, or, alternatively, an angle-dependent tuneable filter, or alternatively, a liquid crystal tuneable filter which is electronically controlled and selects a target wavelength or range of wavelengths which selection can be at speeds exceeding 1tkHz. Such apparatus can provide by scanning the ciliary sulcus structure with light wavelengths within at least one relatively narrow band which band can be centered around at least one spectral peak of the ciliary mass, or, alternatively, centered around at least one peak of the sulcus lining, or, alternatively, centered around a combination of at least one spectral peak of the ciliary mass and at least one spectral peak of the sulcus lining. Scanning also provides hitting the precise peaks of the ciliary mass and the sulcus lining. Note that spectral can be individually shifted because of the spectral effects of the individual sclera and other tissues of the individual eye. Scanning over a, generally narrow, range of wavelengths will allow selection of such individual 5 peaks which improves image quality. Alternatively, the light source provides at least one light beam including a combination of at least two ranges of wavelengths with the combination including at least one the range coinciding with the absorption spectrum of haemoglobin and at least one range coinciding with the absorption spectrum of melanin.

Furthermore, the apparatus can also include at least one light polarizing filter, or, alternatively, can comprise at least two polarizing filters in a cross-polarizing arrangement with at least one filter positioned in the incoming light beam, being the beam emitted by the light source and at least one filter positioned in the outgoing light beam, being the beam emitted by the eye. Such polarization can provide absorption of light reflected by tear film and/or corneal surfaces, or, alternatively, at least two polarizing filters can provide cross-polarization for further accentuation of accommodative structures which is a procedure well known for removing ‘noise’, meaning removing non-informational, light signals.

Alternatively, the light source can comprise a broadband light source only with the source comprising no filtering components, for example, as a white light source. A digital camera comprising a colour sensor, for example a sensor fitted with a standard Bayer filter, and with the computer providing, in post-processing, a digital filtration of wavelengths on the, colour, digital image and, alternatively provide for post-processing digital scanning, a digital scanning through narrow bands of wavelengths present in the range of the white light and/or light in the infrared and/or ultraviolet light wavelength ranges.

The camera can include a focusing optical arrangement, for example and generally, a standard macro-camera lens, providing at least one image of the ciliary sulcus structure onto a digital optical sensor to provide translation of the image in a digital image. The macro-camera lens is preferably a lens of a relatively long focal distance to maximize flattening of the image by minimizing aspherical distortions which distortions can affect the accuracy of establishing any size of the accommodative structure during analysis of the images. The camera can also be a ophthalmology slit-lamp camera to which the light source and beam position can be fitted as an add-on arrangement, or, alternatively, the caera can be any technical camera, or, alternatively, a smartphone camera comprising a sensor with a sufficiently resolving sensor and with the lens fitted with an appropriate macro-lens. Furthermore, the camera can be an infrared camera, for example a camera from which the Bayer filter is removed from the camera sensor which sensitizes the camera sensor to infrared light and/or ultraviolet light. However, such procedure can, as the inventors can testify to, void the guarantee of the camera.

The computer provides post-processing the digital image and presenting the digital image on a digital screen and the computer can provide any digital processing of the image, for example, increase resolution of the image, or, alternatively, increase contrast of the image, or, alternatively, any combination of increase of resolution and increase of contrast of the image, all provided in coloured images or, alternatively, in black and white images, as in the IR-images. The digital manipulation can include, for example, also contour attenuation by digital Laplace filtering, and/or interpolation, and/or addition of noise to increase colour depth, followed by digital wavelength selection, pixel-by pixel, if required, for example, based on histograms. Furthermore, as mentioned, the apparatus can include a light source which provides only at least one broadband light source, for example broadband white light, and computer algorithms to provide image post-processing digital filtration for various ranges of wavelengths.

The accommodative structure can be scanned, for example, over time or scanned simultaneously, by a light beam comprising light of wavelengths of, for example, 400-699 nm, the visible green-yellow range, to image the ciliary mass and the sulcus lining, or, alternatively, scanned by any multiple ranges of wavelengths. The accommodative structure can be scanned, subsequently, or, alternatively, simultaneously, by a light beam comprising a range within the red-infrared, RIR, spectral spectrum because melanin effectively absorbs red-infrared, RIR, wavelengths. Or, alternatively, the accommodative structure can be scanned at a number of ranges of wavelength in order to select the best image post-scanning and post-processing digital reconstruction including merging of images, overlay images, taken at different ranges of wavelengths. Scans can be if course also be carried out in shorter wavelengths as far-blue and ultra-violet, UV, ranges. However, for such shorter higher energy wavelengths the amplitude of light and exposure times must be carefully monitored to protect the retina of the eye.

The method for imaging the accommodation structure of the eye, with the structure being the ciliary mass and the sulcus of the eye, can comprise the following steps, not necessarily in such said order, of (a) Adding at least one calibration mark to the eye. The calibration mark can be provided by at least one calibration means on the eye with the calibration mark providing the base for establishing of dimensions and sizes of any component of the accommodative structure, for example the ciliary mass and/or the sulcus. The calibration means can be a physical mark surgically deposited into the eye, for example, at least one, traditional, surgical gentian violet fluid mark of precise dimensions deposited by surgical needle, for example, two dots at a precisely measured distance in the sclera of the eye. Alternatively, the calibration means can be an eye-covering component comprising the physical mark, for example, a mark onto an eye- covering component such as a, for example, scleral, contact lens. Alternatively, the eye-covering component can comprises at least one calibration bar to be included in at least one of the images which can be a small calibration bar or disc of precisely known size, for example, a black, strip of contact lens material which floats on the sclera in the tear film close to the ciliary sulcus structure or, alternatively, the calibration bar is a hand-held calibration bar with such a strip, of any size or shape of known dimensions, mounted, by, for example, sticky tape, on a hand-holder, for example, an extended paperclip to be manipulated, to be positioned on the eye, by the operator, for example onto the sclera adjacent to the rim of the iris as close as possible to the accommodative structure, and, (b) illuminating the eye through the sclera of the eye by the beam positioning means, thereby backlighting the accommodation structure of the eye and preferably avoiding illuminating the anterior surface of the iris, and, (c) imaging, by a digital camera, the accommodation structure of the eye and processing at least one digital image, and, (d) post-processing the at least one digital image, for instance to increase contrast and/or resolution of the digital image and presenting the processed digital image on a digital screen, and, (e) identifying at least one structural marker, such as the ciliary mass or the lining of sulcus of the eye, and, {fl comparing, post-processing, the size of the calibration mark to the size the structural marker to establish the size of the structural marker, and, (g) any combination of the steps listed above can, but not necessarily has to, be automated by computer algorithms.

Figures Figure 1 shows a frontal view of the human eye with the eyelids, 1, 2, the sclera, 3, the iris, 4, the pupil, 5 and the location, 6, under the iris, of the accommodative structure.

Figure 2 shows a schematic cross-cut of the human eye with the cornea, 7, the sclera, 8, the retina, 9, the anterior chamber, 10, and the posterior chamber, 11, the iris, 12, the melanin pigment lining of the iris, 13, the pupil, 14, the lens, 15, the ciliary mass, 16, the sulcus, 17, with the sulcus-root, 18, and, the marked area, the accommodative structure, 19.

Figure 3 shows an OCT image, a cross-cut, of the accommodative structure with the cornea, 20, the sclera, 21, the anterior chamber, 22, the posterior chamber, 23, the pupil, 24, the lens, 25, the iris, 26, with the anterior surface of the iris, 27, and the posterior surface of the iris, 28, the main melanin pigment lining of the iris, 29, which continues, 30, over the ciliary mass, 31, and thereafter, at the inner lining of the sclera, fades, 32, and, the sulcus, 33, with the sulcus-root, 34. In this Figure, the ciliary mass and the sulcus are digitally accentuated for illustrative purposes. Figure 4 shows the absorption spectrum of haemoglobin, 35, with desired ranges of wavelengths, 36, 37, but not necessarily limited to these ranges, to accentuate the ciliary mass and the absorption spectrum of melanin, 38 to accentuate the lining of the sulcus, preferably the lining of the sulcus-root.

Figure 5 shows a schematic representation of the preferred embodiment of the apparatus to measure dimensions of the accommodative structure of the eye, in particular the ciliary diameter, the distance from the ciliary mass to ciliary mass, transversing the eye, and the sulcus-root diameter, the distance from root to root, transversing the eye. The light source of this embodiment provides at least one beam of selected ranges of wavelengths to be projected onto the sclera with the schematic showing the eye with the cornea, 39, the pupil, 40, the iris, 41, and the accommodative structure including the ciliary mass, 42, and the sulcus, 43, with the apparatus, in this preferred embodiment, comprising a broadband light source, 44, with, in this example, a wavelength filter and a beam positioning means, 45, providing an incoming light beam of selected wavelengths, 46, directed towards the sclera at the location, 47, of the accommodative structure at, this example, an angle parallel to the iris plane with the outgoing light beams, 48, focused by a focusing optical arrangement, 49, onto a digital sensor, 50, which is coupled, 51, to a computer, 52, which computer provides both digital enhancement of the image and which is coupled, 53, to a digital display or screen, 54.

Figure 6 (with Figure 7) shows, as an example, a pre-processed digital image of a section of the accommodative structure. Details of the accommodative structure are not visible except for the sclera, 55, and the iris, 56 and details of the accommodative structure can not be measured with sufficient accuracy.

Figure 7 (with Figure 6) shows the post-processed digital image, by proprietary digital imaging algorithms, of the same section of the accommodative structure with the sclera, 57, the limbus of the eye, 58, sulcus root, 59, and a dark grey/blackish band representing the ciliary mass, 60 and the central section of the iris, 61. Details of the accommodative structure are clearly visible and can therefore be measured with sufficient accuracy. In such final digitalized and digitally enhanced image the combination of the sulcus are and the ciliary mass are projected onto the iris and represented by a band of dark grey to black because the back-light is blocked by the, weak, posterior melanin lining of the ciliary mass followed by the, weak, anterior melanin lining of the ciliary mass followed by blockage by the melanin in the iris, a total of three to four light blocking layers. More centrally the back-light is filtered only by iris and thus shows up in the image as a lighter shade of grey. Note that an image taken along the direction of the optical axis will provide an image with only a single grey band provided by blockage of back-light by a combination of the ciliary mass and the iris. Images at other angles allow for separation of the ciliary mass and the iris which separation can be further increased by multiple imaging with separate wavelengths as set forth elsewhere in this document.

Figure 8 shows a final image from which the diameter of ciliary mass and sulcus root can be established. The image shows, in two diametrically opposed insets, 62, 63, the, in this example corneal, marks for calibration, 64, 65, and the digitally enhanced accommodative structure (see also Figures 6-7). The image shows the dark grey banding, 66, 67, the diameter of the ciliary mass, 68, the diameter of the sulcus-root, 69, and the distance between the arkers, 70. The diameters of the ciliary mass and the sulcus-root can be established based on the prior known distance between the, in this example, corneal markers.

So, in summary, this invention discloses an apparatus for imaging and measuring the accommodation structure of the eye, the accommodative structure including the ciliary mass and the sulcus of the eye, with the apparatus comprising at least one light source, for illuminating the eye, with the light source comprises at least one beam positioning means configured to illuminate the interior of the eye through the sclera of the eye, thereby back-lighting the accommodation structure, preferably avoiding any illuminating of the anterior surface of the iris, with the main direction of illumination differing from the direction of the optical axis of the eye, and, at least one digital camera, for providing a digital image with the camera arranged to provide an image of the eye with the image including the accommodation structure, and, at least one computer, for post-processing by, for example, merging multiple images and/or processing the digital image by image- enhancing software followed by presenting the digital image on a digital screen. So, post-processing of the digital image by image-enhancing digital software can provide accentuation of the accommodative structure to provide establishment of the sulcus diameter and/or the ciliary mass diameter.

The light source provides at least one light beam with the beam comprising at least one range of wavelengths with the range coinciding with at least one absorption spectrum of the ciliary mass which contains heamoglobin, so the range preferably includes wavelengths within the range of 400 and 699nm. Alternatively, the light source can provide at least one light beam with the beam comprising at least one range of wavelengths with the range coinciding with at least one absorption spectrum of the of the sulcus with the lining of the sulcus comprising melanin, so the wavelengths preferably including wavelengths below 400nm and above 699nm. Alternatively, the light source can provide at least one light beam including a combination of at least two ranges of wavelengths with the combination including at least one the range coinciding with the absorption spectrum of haemoglobin and at least one range coinciding with the absorption spectrum of melanin.

The light source can comprise a combination of at least one broadband light source and at least one fixed wavelength filter, or, alternatively, the light source can comprise at least one dedicated light element, such as a LED or a laser, or, alternatively, the light source can comprise a combination of at least one broadband light source and at least one tuneable wavelength filter. Furthermore, the apparatus can include at least one light polarizing filter which filter can be positioned in the incoming light beam, in between the light source and the eye, or, alternatively, the filter can be positioned in the outgoing light beam, in between the eye and the camera. Also, the apparatus can include at least two polarizing filters, preferably linear polarizing filters, arranged in a cross-polarizing arrangement with at least one polarizing filter positioned in the incoming light beam, in between the light source and the eye and with at least one polarizing filter be positioned in the outgoing light beam, in between the eye and the camera.

The image is optically slightly distorted in frontal images of the eye, especially distortion of the width of greyish bands in the final digital image because of the, almost spherical, bending backward of the sclera. Such distortion can be corrected by (a) the optical arrangement on the camera, by, for example, use of, well known, spherical corrected printing objectives or, alternatively and preferably, (b) be corrected during digital post-processing of the image, by, digital flattening the image based on the spherical bending parameters of the particular eye, or, alternatively, digital flattening based on the spherical bending parameters of the average eye, or, alternatively, (c) apply a correction factor to the said distorted measurements as a last step in the calculations.

The method for imaging the accommodation structure of the eye, with the structure being the ciliary mass and the sulcus of the eye, with the method comprising the steps of (a) adding at least one calibration mark to the eye, and, (b) illuminating the eye through the sclera of the eye, thereby backlighting the accommodation structure of the eye and preferably avoiding illuminating the anterior surface of the iris; golflengtes, and, (c) imaging, by a digital camera, the accommodation structure of the eye and processing at least one digital image,

and, (d) post-processing the at least one digital image, for instance to increase contrast and/or resolution of the digital image and presenting the processed digital image on a digital screen, and, (e) identifying at least one structural marker, such as the ciliary mass or the lining of sulcus of the eye, and, (f) comparing, post- processing, the size of the calibration mark to the size the structural marker to establish the size of the structural marker, and, (g) the method can also comprise any digital image-enhancing software processing to merge multiple images and to increase resolution and/or contrast of the image. So, the method also comprises any digital merging of multiple images and processing by digital image-enhancing processing to increase resolution and/or contrast of the accommodative structure. Note that largely frontal illumination in combination with frontal imaging can also provide, in some cases, satisfactory images especially with eyes with low iris pigmentation, meaning light blue eyes. So, the method can comprise illuminating the eye by a wide range broadband white light at any angle with the computer providing post-processing digital for selection of at least one range of wavelength and processing by digital image-enhancing processing to increase resolution and/or contrast of the accommodative structure, or, alternatively, the method comprises illuminating the eye at any angle by at least one light beam including a combination of at least two ranges of wavelengths and with the computer providing processing by digital image-enhancing processing to increase resolution and/or contrast of the accommodative structure.

Furthermore, the method can include illuminating the eye through the sclera by a wide range broadband of only white light with the computer providing post- processing digital for selection of at least one range of wavelength which broadband can include at least one range of infrared light and/or ultraviolet wavelength light. The method can also include positioning of at least one light polarizing filter positioned in the ingoing light beam, in between the light source and the eye or in the outgoing light beam, in between the eye and the camera, or, alternatively, the method can include positioning of at least two light polarizing filters in a cross-polarizing arrangement with at least one filter positioned in the incoming light beam, in between the light source and the eye and at least one filter in the outgoing light beam, in between the eye and the camera. Any such application of polarized light can reduce undesired light noise which noise can degrade the digital image by, mainly, reduction of contrast in the image.

The sclera, and thus the sulcus-root, also slightly, say, a 0,05 to 0,1mm, changes in diameter during accommodation. So, the method can include treatment of the eye, prior to the measurements, with any cycloplegia pharmaceutical to widen and stabilize the diameter of the ciliary mass and sulcus-root, or, alternatively, treatment with a pilocarpin pharmaceutical to narrow and stabilize the diameter of the ciliary mass and su;cus-root. Also, the eye can, prior to the measurements, subsequently be treated with a cycloplegia pharmaceutical and a pilocarpin pharmaceutical, or a treatment vice versa, to provide multiple images to establish multiple diameters of the ciliary mass and/or sulcus root. Such procedure can, for example, provide data, pre-operatively and post-operatively, on the accommodative status and accommodative amplitude of the accommodative structure.

Clearly, the method can include digital automation of at least one of the steps, for example, identification of accommodative structures by digital image recognition which recognition can be, over time, optimized by artificial intelligence computer learning procedures.

Claims (22)

Conclusions An apparatus for imaging and measuring the accommodation structure of the eye, the accommodation structure comprising the ciliary mass and sulcus of the eye, the apparatus comprising: a. at least one light source for illuminating the eye; b. at least one digital camera for providing a digital image; c. a computer for post-processing the digital image and displaying the digital image on a digital screen; d. wherein the light source comprises at least one beam positioning means arranged to illuminate the inside of the eye through the sclera of the eye, thereby illuminating the accommodation structure from behind, preferably avoiding illuminating the anterior face of the iris; e. wherein the main direction of illumination is different from the direction of the optical axis of the eye; and f. wherein the device is configured to provide an image of the eye, the image comprising the accommodation structure. Apparatus according to claim 1, wherein the light source is at least one light beam! which ray comprises at least one range of wavelengths coincident with at least one absorption spectrum of the ciliary mass comprising hemoglobin, thus preferably comprising the range of wavelengths in the range of 400 and 699 nm. Apparatus according to claim 1, wherein the light source provides at least one light beam, which beam comprises at least one range of wavelengths coincident with at least one absorption spectrum of the sulcus, wherein the coating of the sulcus comprises melanin, such that the wavelengths are preferably wavelengths include less than 400 nm and greater than 699 nm. An apparatus according to any preceding claim, wherein the light source provides at least one light beam comprising a combination of at least two ranges of wavelengths, the combination comprising at least one range coincident with the absorption spectrum of the hemoglobin, and comprises at least one region that coincides with the absorption spectrum of melanin. Apparatus according to any one of the preceding claims, wherein the light source comprises a combination of at least one broadband light source and at least one fixed wavelength filter. Apparatus according to any one of claims 1-4, wherein the light source comprises at least one suitable light element, such as an LED or a laser. Apparatus according to any one of claims 1-4, wherein the light source comprises a combination of at least one broadband light source and at least one adjustable wavelength filter. An apparatus according to any one of the preceding claims, wherein the apparatus also comprises at least one polarizing filter for light, which is arranged in the incident light beam, between the light source and the eye. An apparatus according to any one of the preceding claims, wherein the apparatus also comprises at least one polarizing filter for light, which is arranged in the exiting light beam, between the eye and the camera. An apparatus according to any preceding claim, wherein the apparatus comprises at least two polarizing filters for light, in a crossed polarization arrangement, wherein at least one filter is arranged in the incident light beam, between the light source and the eye, and at least one filter is arranged in the exiting light beam, between the eye and the camera. A method of imaging the accommodation structure of the eye, the structure being the ciliary mass and the sulcus of the eye, the method comprising the steps of: a. adding at least one calibration marker to the eye; b. illuminating the eye through the sclera of the eye, illuminating the accommodation structure from behind, and preferably preventing the anterior face of the iris from being illuminated; c. imaging by a digital camera the accommodation structure of the eye and processing at least one digital image; d. post-processing the digital image by image-enhancing software, for example to increase the contrast and/or resolution of the digital image, and displaying the processed digital image on a digital screen; e. identifying at least one structural marker, such as the ciliary mass or a section of the coating of the sulcus of the eye, preferably the suicus root; f comparing the size of the calibration mark with the size of the structure mark to determine the size of the structure mark. The method of claim 11, wherein the method also comprises digitally merging a plurality of images, and processing by digital image-enhancing processing to increase the contrast and/or the resolution of the accommodation structure. The method of claim 11 or 12, wherein the method comprises illuminating the eye through the sclera by a wide-area broadband white light, wherein a selection of at least one region of wavelength is made during post-processing of the digital image. A method according to any one of claims 11 to 13, wherein the method comprises positioning at least one light polarizing filter disposed in the incident light beam, between the light source and the eye, or in the exiting light beam, between the eye and the camera. A method according to any one of claims 11-13, wherein the method comprises positioning at least two polarizing filters for light in a crossed polarization arrangement, wherein at least one filter is arranged in the incident light beam, between the light source and the eye , and at least one filter is arranged in the exiting light beam, between the eye and the camera. A method according to any one of claims 11-15, wherein the wide range of the broadband light comprises at least one range of infrared light and/or ultraviolet light. A method according to any one of claims 11-16, wherein the eye is treated with a medicament for cycloplegia prior to the procedure to widen the diameter of the ciliary mass and the suicus root. A method according to any one of claims 11 to 18, wherein the eye is treated with the drug pilocarpine prior to the measurements to constrict and stabilize the diameter of the ciliary mass and the sulcus root. A method according to any one of claims 17 or 18, wherein prior to the measurements the eye is treated sequentially with a drug for cycloplegia and the drug pilocarpine, in particular to provide different images in order to obtain different diameters of the ciliary mass and/or determine the suicus root. The method of any of claims 11-19, wherein the method comprises illuminating the eye at an angle by at least one light beam comprising a combination of at least two wavelength regions and wherein during post-processing of the digital image a selection of at least one wavelength region is made, comprising the step of processing by digital image enhancing processing, to increase the resolution and/or contrast of the accommodation structure. A method according to any one of claims 11-19, wherein the method comprises illuminating the eye at an angle by at least one light beam comprising a combination of at least two wavelength ranges and wherein during post-processing, e.g. by digital imaging improving processing, the resolution and/or the contrast of the accommodation structure is increased. A method according to any one of claims 11-21, wherein at least one of the steps of the method is digitally automated.