WO2017109250A1 - Ophthalmic lens and set of ophthalmic lenses for correcting presbyopia - Google Patents

Abstract

The invention relates to an ophthalmic lens and set of ophthalmic lenses for correcting presbyopia. The lens comprises a lens body (1) provided with: a central through-hole (2) dimensioned to increase the depth of the distance focus of the eye on which the ophthalmic lens is disposed; and through-holes (3) distributed around the central through-hole (2) to allow nutrients to pass therethrough and also to generate a near focus for the eye, for which purpose the through-holes (3) are distributed along one or more annular regions so that the light diffracted by same generates said near focus. According to the invention, the set of lenses comprises two ophthalmic lenses, one for each of a patient's eyes, which are intended for simultaneous use by the patient to provide binocular vision.

Description

 Ophthalmic Lens and Set of Ophthalmic Lenses for Correction

 OF THE PRESBICIA

Technical sector

The present invention concerns, in general, in a first aspect, an ophthalmic lens for the correction of presbyopia comprising a central through hole to increase the depth of a focus from a distance and through holes distributed around it, and more particularly to an ophthalmic lens whose through holes are distributed by concentric annular regions so that the light diffracted by them generates a near focus.

A second aspect of the invention concerns a set of ophthalmic lenses, comprising two ophthalmic lenses, according to the first aspect, intended for simultaneous use by a patient to provide binocular vision.

Prior art

The treatment of presbyopia or "tired eyesight" has historically been approached from different perspectives, from bifocal and progressive contact lenses and lenses, to multifocal intraocular lenses, all of them to ensure that the patient can see clearly at close distances and intermediate.

The different alternatives for the surgical correction of presbyopia, with their advantages and disadvantages, are described in Charman W.N. "Developments in the correction I heard presbyopia II: surgical approaches". Ophthalmic Physiol Opt 2014; 34: 397 ^ 426.

The most recent alternative is the use of intracorneal implants. Within this type of prosthesis the most popular for its clinical results is KAMRA® (Acufocus, Irving, CA, USA), hereinafter Kamra, which consists of an opaque ring of polyvinylidene fluoride (PVDF) of 3, 8 mm in diameter with a central opening of 1.6 mm (smaller than the pupil diameter) and a thickness of 6 μηι. With this type of implants, and thanks to the pinhole effect produced by the central hole, it is possible to increase the depth of focus of the eye in distance vision, getting to provide good vision at intermediate distances and a barely acceptable vision at short distances. According to the following article: Seyeddain, Orang, et al. "Small-aperture corneal inlay for the correction of presbyopia: 3-year follow-up" Journal of Cataract & Refractive Surgery 38.1 (2012): 35-45, only 12.5% of patients implanted with Kamra were able to do without reading glasses after 2 and 3 years of follow-up: The Kamra has 8,400 randomly distributed micro-holes on its surface, whose only function is to allow the flow of nutrients through it to the corneal stromal cells.

Thus, the Kamra ophthalmic lens meets the characteristics of the preamble of claim 1 of the present invention, since it constitutes the closest antecedent to the invention.

The following patents are related to the Kamra lens or "inlay", or the like: US7404637, US7628810, US7976577, US8287592, US8460374, as well as the following design: USD656526.

In US7628810, which constitutes one of the first documents concerning intracorneal lenses with microperforations, a homogeneous plurality of microperforations arranged in the peripheral part of the lens was proposed. The inventors of the Kamra lens consider the effects of the diffraction of light by the aforementioned microperforations or micro holes to be a problem, since these effects decrease the quality of the image in the retina, so to partially alleviate such effects, they have raised as a better solution, a random distribution thereof, as set forth in US7404637.

In the same sense, in US7976577 it is said that the micro-holes are arranged irregularly on the surface in order to minimize the generation of visible artifacts due to the transmission of light through them, that is to say, the diffracted light, leaving an inner and outer perimeter region substantially free of micro holes.

The Kamra lens and the various documents that describe it constitute, therefore, previous teachings that remove the expert in the field from the idea of considering the effects of the diffraction of light by said micro-holes as something beneficial and not as something harmful . It seems necessary to offer an alternative to the state of the art that covers the gaps found therein, providing an ophthalmic lens configured so that the micro-holes, or through holes, not only do not impair the quality of the image in the retina, but also are able to generate a real near focus (something that the Kamra does not do), thus fulfilling an additional function to the passage of nutrients.

Explanation of the invention.

To this end, the present invention concerns, in a first aspect, an ophthalmic lens for the correction of presbyopia which comprises, in a known manner, a lens body provided with:

- a central through hole sized to increase the depth of focus away from the eye in which the ophthalmic lens is arranged; Y

- through holes distributed around said central through hole, provided to allow the passage of nutrients therethrough.

Unlike the ophthalmic lenses known in the state of the art, in the proposed by the first aspect of the present invention the said through holes are provided to fulfill an additional function to that related to allowing the passage of nutrients, said additional function being that of generating a near focus for said eye, for which the through holes are distributed by at least one annular region so that the light diffracted by them generates said near focus.

That is to say, unlike the Kamra lens, where it was considered that the light diffracted by the through holes had harmful effects that should be mitigated, in the ophthalmic lens proposed by the first aspect of the present invention the effects of diffraction of the Light through the through holes is not only not combated but also used and optimized, especially its distribution, to create the aforementioned focus, in order to correct presbyopia.

For a preferred embodiment, the lens proposed by the first aspect of the present invention is a diffractive lens:

- of amplitude, consisting of an opaque material with through holes; - phase, consisting of a transparent material with through holes; or

- amplitude and phase hybrid, consisting of a partially transparent material with through holes.

Advantageously, the through holes are distributed by two or more concentric annular regions. According to an example of embodiment, the through holes are configured, sized and arranged so that part of the light diffracted by them also converges on the aforementioned focus from afar, thus collaborating with the central hole to increase the intensity of light directed to the focus from far. Thus, a multifocal lens designed for at least such near and far foci is constituted, where, by constructive interference, the light diffracted by the lens converges on said foci.

Optionally, the through holes are configured, sized and arranged so that part of the light diffracted by them converges into one or more additional spotlights, preferably including two or more spotlights, thus forming a multifocal lens of more than two spotlights.

Both the central through hole contour and that of the through holes may have any shape, depending on the exemplary embodiment, such as circular, elliptical or irregular.

For another exemplary embodiment, alternative or complementary to the previous one, in addition to the said through holes, the lens of the first aspect of the invention comprises, distributed by said annular regions, other diffractive elements, advantageously porous, which are constituted by at least one of the following optical elements:

- element of transparent optical material, for at least part of the visible radiation, of optical properties different from those of the interstitial material between through holes, and - protruding or indented topology element by at least one of the ophthalmic lens faces.

Optionally, the through holes are configured, sized and distributed for the additional purpose of compensating, at least partially, the aberrations of the eye, in particular those of high order (especially spherical aberration and chromatic aberration).

According to an exemplary embodiment, each of the annular regions where the through holes are located radially follows a periodic or aperiodic distribution.

For an exemplary embodiment, the through holes in each of the annular regions are angularly spaced or follow an aperiodic or irregular distribution.

Preferably, the inner radius of each of the annular regions is defined by the following equation: r _n ² = a ² + ηλ / Α + η ² λ ^2/4 where r _n is the inner radius of the annular region n, n is an integer greater than or equal to one and less than the total number of zones, a is the radius of the central through hole, A is the dioptric power corresponding to the desired fence addition and λ is the design wavelength of the lens within the visible spectrum.

It should be clarified that the addition of near is the difference in dioptric power generated by the near focus and the one generated by the far focus.

According to an exemplary embodiment, the through holes are arranged in concentric annular regions elliptically, such that the axes of the ellipses coincide with the main meridians of an astigmatism eye. The semi-axes of the ellipses are obtained with the previous equation.

The through holes of each of the annular regions are distributed with a certain density, which can be different in each annular region, to provide an effect equivalent to an amplitude filter that allows obtaining any desired relative intensity between the different foci generated by the lens and / or to correct residual eye aberrations, especially spherical aberration. According to an exemplary embodiment, said annular regions are divided into different adjacent angular sectors, each with a different radial distribution of zones to achieve a greater depth of focus. This aspect is studied in a general way, but only for refractive lenses, in the following reference: de Gracia, Pablo, Carlos Dorronsoro, and Susana Marcos. "Multiple zone multifocal phase designs" Optics letters 38.18 (2013): 3526-3529.

In order to determine the said density of through holes (as well as their size and arrangement), structural criteria are also taken into account, in particular it is taken into account that the interstitial portions of the remaining material between the through holes must be configured, sized and distributed in way to guarantee the structural integrity of the lens. Depending on the exemplary embodiment, the ophthalmic lens of the invention is a contact lens, an intraocular lens (phakic or pseudophakic) or, preferably, an intracorneal lens.

As regards the size of the through holes, according to an embodiment, the largest transverse dimension of the contour of each of the through holes has a value that is between 4 μηι and 300 μηι. When the through holes are circular, said larger transverse dimension refers to their diameter.

As for the size of the central through hole, for an exemplary embodiment, the largest transverse dimension of its contour (ie its diameter, when the hole is circular) has a value that is between 1.0 and 3.5 mm, and The total diameter of the lens is between 3.0 and 26 mm.

According to an exemplary embodiment, in order to improve the efficiency of near focus diffraction, at least some of the through holes of one of the annular regions spatially invade at least one adjacent annular region. For a preferred variant of said exemplary embodiment, the through holes (preferably part thereof) of each annular region invade the two adjacent annular regions between which the annular region is located. Preferably, the ophthalmic lens proposed by the first aspect of the invention comprises only said lens body, which is constituted by a single substrate. For an exemplary embodiment, applicable in the case where the ophthalmic lens proposed by the invention is a contact lens or an intracorneal lens, the anterior part of the ophthalmic lens proposed by the invention is convex and the concave rear face, with the In order to adapt to the shape of the eye. For another embodiment, also applicable in the case where the ophthalmic lens proposed by the invention is a contact lens or an intracorneal lens, the lens is flat, being of a soft material that allows its adaptation to the shape of the cornea .

The material from which the substrate that forms the lens of the invention is made is biocompatible, and, for one embodiment, is colored to resemble the color of the patient's iris or to selectively absorb part of the visible radiation by acting as a filter. color.

Depending on the type of application, the lens object of the first aspect of the invention may be rigid or flexible, be flat or have a certain degree of curvature to adapt to the structure of the attached eye (eg for a contact lens or an implant intracorneal the internal face would be concave and the external face convex), and its profile may have a constant thickness or decrease from the center to the periphery. Depending on the type of application, the thicknesses can vary between 3 μηι and 30 μηι.

The multifocal nature of the lens proposed by the present invention is preferably adapted to presbyte patients of any age, by creating at least one near focus; however, for some embodiments, the lens has some refractive power to compensate for other visual and / or refractive defects. Also, the lens is compatible with other eye surgeries that use femtosecond or excimer lasers, such as LASIK, to correct refractive defects.

In the event that the lens is intracorneal or intraocular, for some embodiments, the lens is transparent to electromagnetic radiation outside the visible range so as not to interfere with diagnostic or therapeutic tests that require observation or treatment of internal structures of the eye. . Also, also in the case that the lens is intracorneal or intraocular, for some embodiments, the lens is composed of a polarizing polymer that absorbs electromagnetic radiation in a particular direction (depending on the orientation) and transmits light in the perpendicular direction. to the previous one (linearly polarized light) to absorb reflections on bright surfaces and reduce glare.

The lens of the present invention creates a close focus, so the need for reading glasses is less than with the Kamra. At large pupillary diameters (greater than the external diameter of the invention, such as those that can occur in night vision), the invention enhances the focus from far away and reduces the intensity of the focus closely so that night vision problems also disappear.

An obvious disadvantage of the reduced monovision diameter is that the illuminances in the retina (in the macules of both eyes) are uneven. The ratio of the two illuminances changes as the natural diameter of the pupil varies (there being relative intensity differences of 5 to 1) when changing external lighting conditions. This raises the problem that patients may suffer from disturbances in the perception of relative movement of objects (Pulfrich effect, see: Charman WN "Developments in the correction of presbyopia II: surgical approaches". Ophthalmic Physiol Opt 2014; 34: 397 ^ 426) in addition to possible ocular motility problems. The lens of the first aspect of the invention can be implanted (or arranged superficially, if it is a contact lens) in both eyes, so that these problems do not exist. If implanted in a single eye, the amount of light it receives is greater than with the Kamra and the potential Pulfrich effect would be much less obvious.

According to a recent study with 32 patients (Seyeddain O, Hohensinn M, Riha W et al. "Small-opening cornea inlay for the correction of presbyopia: 3-year follow-up." J Cataract Refract Surg 2012; 38: 35-45 ), as mentioned in a previous section, only 12.5% of patients implanted with Kamra were able to do without reading glasses after 2 and 3 years of follow-up. In addition, at 3 years 15.6% of those operated with Kamra reported severe night vision problems.

A second aspect of the invention concerns a set of ophthalmic lenses for the correction of presbyopia, comprising two ophthalmic lenses according to the first aspect of the invention, one configured for the dominant eye of a patient and the other for the non-eye. dominant, the aforementioned two ophthalmic lenses being provided for simultaneous use by said patient to provide binocular vision, unlike the Kamra implant, which only includes a lens that must be disposed unilaterally in the non-dominant eye of the patient. By means of this set of two lenses, the aforementioned problems related to Pulfrich effects and ocular motility are avoided.

Brief description of the drawings

The foregoing and other advantages and features will be more fully understood from the following detailed description of some embodiments with reference to the attached drawings, which should be taken by way of illustration and not limitation, in which:

Figure 1 shows the ophthalmic lens of the first aspect of the present invention, for two embodiments, illustrated in view a) schematically and in view b) in a more realistic manner;

Figure 2a shows another embodiment of the lens proposed by the first aspect of the present invention, where the through holes are arcs constituting ring segments, in this case both the central opening and the through holes have been illustrated in white and the rest of the regions in black, although the latter are not necessarily opaque (neither in this nor in the rest of the attached figures), and may even be made of a transparent material depending on the embodiment;

Figure 2b illustrates an exemplary embodiment of the lens of the first aspect of the invention, for which the lens body is made of a material transparent to visible radiation, and the through holes are configured, sized and distributed with a certain density , which is different in each annular region, to provide an effect equivalent to an amplitude filter that allows obtaining any desired relative intensity between the different foci generated by the lens and / or to correct residual ocular aberrations, especially spherical aberration, the spherical aberrations being annular regions divided into different adjacent angular sectors, in particular in four sectors (delimited by the dashed lines shown in the figure) in which the radial distribution of the zones is different to provide an increased depth of focus closely. Figures 3a and 3b respectively illustrate, in their left views, the lens object of the first aspect of the present invention for an exemplary embodiment for which it is a diffractive lens of amplitude and the Kamra lens, and, in its right views, respective graphs of PSF (English "Point Spread Function", or impulse response) normalized axial vs. blur showing the intensities of the foci, for different wavelengths, inside the eye, obtained for the corresponding lenses.

Detailed description of some embodiments

In Figures 1, 2 and 3a five examples of embodiment of the ophthalmic lens for the correction of presbyopia proposed by the first aspect of the invention are illustrated, which comprises, as can be seen in the figures, a lens body 1 equipped with:

- a central through hole 2 sized to increase the depth of focus away from the eye in which the ophthalmic lens is arranged; Y

- through holes 3 distributed around said central through hole 2, intended to allow the passage of nutrients therethrough and to generate a near focus for the eye, for which the through holes 3 are distributed by several concentric annular regions so that the light diffracted by them generates the aforementioned focus closely.

The diffraction of the light generated by the central hole 2 and the holes 3 distributed in the annular zones creates at least two foci, so that the lens as a whole behaves like a multifocal diffractive lens (preferably) of amplitude.

In the embodiments of Figure 1, the through holes 3 are circular and are distributed over several annular regions, in a much larger number in view b) (both of holes 3 and of annular regions), which corresponds to a case more realistic application than that of sight a).

In contrast, in the embodiments of Figure 2a, the through holes 3 are arc portions into which each annular region is divided.

Figure 2b illustrates another embodiment of the lens of the first aspect of the invention, for which the annular regions divided into different adjacent angular sectors, in particular in four sectors (delimited by the dashed lines shown in the figure) in which the radial distribution of the zones is different to provide an increased depth of focus closely. The through holes in each of the annular regions are distributed with a variable density in each annular region, to provide an effect equivalent to an amplitude filter.

In order to validate the efficiency of the lens proposed by the present invention, the present inventors have performed a series of simulations with both the lens of the present invention and the Kamra lens, according to the configurations illustrated in the left views of said figures. , whose results are illustrated by the graphs of the right views of such figures.

In Figures 3a and 3b they respectively illustrate, in their left views, the lens object of the first aspect of the present invention for an exemplary embodiment for which this is a diffractive lens of amplitude with a diameter of the central hole of 1, 2 mm and an external diameter of 3.3 mm, and the Kamra lens with a diameter of the central hole of 1.6 mm and an external diameter of 3.8 mm and, in its right views, respective graphics of normalized axial PSF versus blur showing the intensities of the foci, for different wavelengths (450 nm, 550 nm and 650 nm), inside the eye with a pupil of 3.8 mm diameter, obtained for the corresponding lenses.

In particular, in the right views of Figures 3a and 3b, comparative results of the intensities of the foci are shown, for different wavelengths, inside the eye with a cornea of 43 D of average power, for the "inlay" Kamra (Figure 3b) and for an exemplary embodiment of the lenses object of the present invention (of amplitude lens) calculated for an addition of 3 diopters (Figure 3a). It can be seen that, due to diffraction, the lens of the invention generates closely focused foci corresponding to an addition of three diopters and that the foci corresponding to 450 nm (blue) and 650 nm (red-orange) are axially separated near a diopter . On the other hand, as shown in Figure 3b, the "inlay" Kamra has no near spotlights. In that range of wavelengths, the longitudinal chromatic aberration of the eye is approximately the same value but of the opposite sign (see: Vinas, M., Dorronsoro, C, Cortes, D., Pascual, D., & Marcos, S. (2015). "Longitudinal chromatic aberration of the human eye in the visible and near infrared from wavefront sensing, double-pass and psychophysics." Biomedical optics express, 6 (3), 948-962), so, for focus closely with polychromatic illumination, the chromatic aberration would be partially compensated. On the other hand, the far focus generated by the lens of the invention for the design wavelength (550 nm) is a 92% more intense than for the Kamra inlay, which is an additional advantage, since in addition to improving near vision, the lens of the invention provides far better vision than that provided with the Kamra inlay . It can be seen, therefore, that the lens proposed by the present invention clearly improves the performance offered by the Kamra lens, optimizing the vision of nearby objects and ensuring a wide range of clear vision between near and far objects (greater than that achieved with known lenses). The aforementioned benefits are even better for the set of lenses of the second aspect of the present invention, since, unlike the Kamra lens, the proposed set allows the application of lenses in both eyes of a patient without creating binocular vision problems. A person skilled in the art could introduce changes and modifications in the described embodiments without departing from the scope of the invention as defined in the appended claims.

Claims

one . - Ophthalmic lens for the correction of presbyopia, comprising a lens body (1) equipped with: - a central through hole (2) sized to increase the depth of focus away from the eye in which the ophthalmic lens is arranged; Y - through holes (3) distributed around said central through hole (2), provided to allow the passage of nutrients therethrough; the ophthalmic lens being characterized in that said through holes (3) are provided to fulfill an additional function relative to allowing the passage of nutrients, said additional function being to generate a near focus for said eye, for which the through holes (3) are distributed over at least one annular region (4) so that the light diffracted by them generates said focus closely. 2. - Ophthalmic lens according to claim 1, characterized in that it is a diffractive lens: - of amplitude, constituted by an opaque material (5) with through holes (3); - phase, consisting of a transparent material (5) with through holes (3); or - amplitude and phase hybrid, consisting of a partially transparent material (5) with through holes (3). 3. - Ophthalmic lens according to claim 1 or 2, characterized in that the through holes (3) are distributed by two or more concentric annular regions (4). 4. Ophthalmic lens according to claim 1, 2 or 3, characterized in that the contour of the central through hole (2) has a circular, elliptical or irregular shape. 5. Ophthalmic lens according to claim 4, characterized in that said through holes (3) are configured, sized and arranged so that at least part of the light diffracted by them also converges in said focus from afar. 6. Ophthalmic lens according to any one of the preceding claims, characterized in that the contour of said through holes (3) has a circular, elliptical or irregular shape. 7. Ophthalmic lens according to any one of the preceding claims, characterized in that, in addition to said through holes (3), the lens comprises, distributed by said annular regions (4), other diffractive elements, which are constituted by at least one of the following optical elements: - element of transparent optical material, for at least part of the visible radiation, of optical properties different from those of the interstitial material (5) between through holes (3), and - protruding or indented topology element by at least one of the ophthalmic lens faces. 8. - Ophthalmic lens according to claim 7, characterized in that said optical elements are porous. 9. - Ophthalmic lens according to any one of the preceding claims, characterized in that each of the annular regions (4) where the through holes (3) are radially follows a periodic or aperiodic distribution. 10. - Ophthalmic lens according to claim 9, characterized in that the through holes (3) of each of the annular regions (4) are angularly spaced or follow an aperiodic or irregular distribution. eleven . - Ophthalmic lens according to any one of the preceding claims, characterized in that the through holes (3) are located in concentric annular regions elliptically, so that the axes of the ellipses coincide with the main meridians of an astigmatism eye. 12. - Ophthalmic lens according to any one of the preceding claims, characterized in that the through holes (3) of each of the annular regions (4) are distributed with a certain density, which is variable between each annular region, to provide an effect equivalent to an amplitude filter that allows to obtain any intensity desired relative between the different foci generated by the lens and / or to correct residual eye aberrations. 13. - Ophthalmic lens according to any one of the preceding claims, characterized in that the annular regions (4) are divided into different adjacent angular sectors, each with a different radial distribution of areas to increase depth of focus. 14. - The ophthalmic lens according to any one of the preceding claims, characterized in that the inner radius of each of said annular region is as follows: r _n ² = a ² + ηλ / Α + η ² λ ^2/4 where r _n is the internal radius of the annular region n, n is an integer greater than or equal to one and less than the total number of zones, a is the radius of the central through hole, A is the dioptric power corresponding to the desired fence addition and λ is the design wavelength of the lens, within the visible spectrum. 15. - Ophthalmic lens according to any one of the preceding claims, characterized in that it is a contact lens, an intracorneal lens or an intraocular lens. 16. - Ophthalmic lens according to claim 15, characterized in that the major transverse dimension of the contour of each of said through holes (3) has a value that is between 4 μηι and 300 μηι. 17. - Ophthalmic lens according to claim 15 or 16, characterized in that the major transverse dimension of the contour of the central through hole (2) has a value that is between 1.0 and 3.5 mm, and the total diameter of the lens is between 3.0 and 26 mm. 18. Ophthalmic lens according to any one of the preceding claims, characterized in that at least some of the through holes (3) of one of the annular regions spatially invade an adjacent annular region, in order to improve the diffraction efficiency of the near focus. 19. Ophthalmic lens according to any one of the preceding claims, characterized in that it comprises only said lens body (1), which is constituted by a single substrate. 20.- Set of ophthalmic lenses for the correction of presbyopia, comprising two ophthalmic lenses according to any one of the preceding claims, one configured for the dominant eye of a patient and the other for the non-dominant eye, said two ophthalmic lenses being said. intended for simultaneous use by said patient to provide binocular vision.