Device for preparing a corneal transplant

Abstract

The invention relates to a device for preparing at least one corneal ring segment of the CAIRS type, comprising at least one base provided with a surface for supporting the corneal ring, which surface is provided with an annular groove shaped to accommodate and model the corneal ring segment. The device optionally comprises a cover provided with at least one opening, the cover being arranged to engage on the base by covering at least the annular groove. In a particular embodiment, the device further comprises a blade holder for engaging on the base. The blade holder comprises a cover provided with a blade and means for the engagement of the cover on the base, thus enabling the cover to rotate about the central axis of the annular groove, with the blade extending opposite a portion of the annular groove.

Description

[0001] DEVICE FOR PREPARING A CORNEAL GRAFT.

[0002] The present invention relates to the field of corneal transplantation, in particular the field of graft preparation used in the treatment of keratoconus, in particular by the technique known as CAIRS (Corneal Allogenic Intrastromal Ring Segment).

[0003] BACKGROUND OF THE INVENTION

[0004] Keratoconus is a progressive, non-inflammatory condition caused by external factors such as allergic reactions or reactions to aggressive environmental conditions: hot, dry climate, strong ultraviolet radiation, or by genetic factors such as a thin cornea. It is characterized by thinning and deformation of the cornea into a cone shape. Vision becomes blurred and distorted. Its prevalence is variable but can affect up to 5% of populations in some regions of the world.

[0005] In the early stages of the disease, vision defects can be corrected by wearing glasses or rigid lenses, which will compensate to some extent for the deformation of the cornea, or by stiffening the corneal tissues by polymerization of the collagen fibers of the stroma (a technique known as Cross Linking). In more advanced stages, keratoconus will be treated surgically.

[0006] Among the surgical techniques used, one of them consists of inserting a ring-shaped or ring-segment implant into a tunnel made on the peripheral edge of the cornea and made in the stroma manually or using a femtosecond laser. The implant, once inserted into the cornea, will exert traction on the collagen fibers which, by spacing out, will reduce the deformation of the cornea, thus improving the refractive properties of the cornea and the patient's visual acuity. The implant can be made of synthetic material such as Polymethyl methacrylate (PMMA). The introduction of a synthetic foreign body, however, has side effects and can cause rejection reactions in the body or even extrusion.Also, in recent years, a new technique has emerged in which the synthetic implant is replaced by an allogeneic graft in the shape of a ring or ring segment taken from the intrastromal tissue of a donor cornea. This technique is designated by the English acronym CAIRS for Corneal Allogenic Intrastromal Ring Segment. The cutting of the graft in a donor cornea is done during the operation. It is delicate and requires great skill from the surgeon. It consists of two main stages:

[0007] - cut a ring in the periphery of a donor cornea, using a femtosecond laser, a scalpel, or a cutting punch;

[0008] - cut with a scalpel or femtosecond laser a segment in the corneal ring of the desired length depending on the anatomy and pathology of the patient.

[0009] The segment thus obtained is then inserted into the tunnel previously drilled in the recipient's cornea. Generally, the operation consists of inserting two segments into two tunnels made in the periphery of the recipient's cornea and diametrically opposed. Although involving few steps, the preparation of the grafts is long and meticulous, which mobilizes the surgeon and increases the duration of the surgical intervention. In addition, it often happens that the segment obtained is not usable (segment of bad size, segment torn during various manipulations, etc.) forcing the operations to be carried out again on a new donor cornea. However, cornea donations are very much lower than the needs.

[0010] In order to facilitate graft handling, recent publications show that an open-air drying step can be added, which further extends the graft preparation time. The development of a ring or ring segment cutting punch as described for example in document US-A-11426307 has made it possible to facilitate and secure the ring cutting steps with a predefined segment size. Despite these improvements, the preparation of corneal ring segments remains delicate, long, tedious and continues to require the use of several corneas if the steps are poorly performed.

[0011] SUBJECT OF THE INVENTION

[0012] The invention aims in particular to at least partially overcome the aforementioned drawbacks by proposing a device making it possible to facilitate the preparation of at least one segment of a CAIRS-type corneal ring.

[0013] SUMMARY OF THE INVENTION

[0014] For this purpose, the invention provides a device for preparing at least one CAIRS-type corneal ring segment comprising at least one base provided with a surface for supporting the corneal ring. The support surface is provided with an annular groove with a central axis normal to the support surface, said annular groove being shaped to accommodate and model the corneal ring segment.

[0015] The base according to the invention thus makes it possible to dry a corneal ring or a segment of a corneal ring not only by preserving its arcuate shape but also by shaping said ring segment according to the other dimensions (in thickness and width). The corneal ring segment is thus easier to handle and to insert into the tunnel made in the recipient's cornea and perfectly adapted to the morphology and pathology of the patient.

[0016] Preferably, the annular groove has a flat or rounded bottom U shape or a V shape along a plane parallel to the axis normal to the support surface. The support surface is provided with at least one notch which opens transversely into the groove, said notch being arranged to facilitate gripping of the corneal ring segment.

[0017] The base according to the invention further comprises a chamber extending under the support surface with at least one conduit, a first end of which opens into the chamber and, on the opposite side, a second end opens into the annular groove through at least one orifice.

[0018] Said at least one orifice may be located in the bottom or on the wall of the groove. It is preferably between 0.04 and 0.3 mm, preferably 0.15 mm.

[0019] Furthermore, the base according to the invention comprises means for circulating air in the chamber, the at least one conduit, the at least one orifice and the annular groove. Advantageously, the air circulation means comprise a nozzle for connection to a pump.

[0020] Optionally, the device according to the invention comprises a cover, provided with at least one opening, arranged to engage on the base by covering at least the annular groove to hold the corneal ring in place in the groove during drying.

[0021] According to a particular embodiment of the invention, the device further comprises a blade holder capable of engaging on the base. Said blade holder comprises a cap provided with a blade and means for engaging said cap on the base allowing rotation of the cap around the central axis of the annular groove. The blade here extends opposite a portion of the annular groove. The cap or the base comprise at least one mark and angular graduations centered on the central axis of the annular groove so as to be able to position the blade holder on the base at a predetermined angle around the central axis of the annular groove and so that the blade transfixingly cuts the corneal ring placed in the annular groove to obtain at least one corneal segment.

[0022] Advantageously, the engagement means are arranged such that they allow the blade holder to be engaged on the base between a first position in which the blade holder is partially engaged on the base allowing rotation of said blade holder on the base to determine the angle by aligning the mark with the desired angular graduation and a second position in which the blade holder is fully engaged on the base so that the blade transfixingly cuts the corneal ring along a plane parallel to the central axis in accordance with the previously determined angle. According to the invention, one of the base or the blade holder comprises at least one mark and the other of the blade holder or the base comprises at least angular graduations. Preferably, the base comprises at least angular graduations and the blade holder comprises at least one mark.According to a particular embodiment of the invention, the angular graduations extend radially around the periphery of the stud, around the annular groove. Optionally, they can be marked on a wheel mounted to rotate along the central axis of the base.

[0023] In order to facilitate and secure the cut, the cover has at least one window allowing the surgeon to see a portion of the support surface of the base when the blade holder is engaged on the base. Advantageously, the at least one window is arranged such that the graduations of the base are visible to the surgeon when the blade holder is engaged on the base. Optionally, the at least one window is arranged such that the annular groove of the base is also visible to the surgeon when the blade holder is engaged on the base. Preferably, the at least one window comprises a mark arranged such that the alignment of said mark with the graduations marked on the base is visible to the surgeon.

[0024] According to a particular embodiment, the blade holder comprises at least two windows: a central window for viewing at least part of the annular groove of the base and at least one side window arranged to view the graduations. Thus, the device according to the invention allows the surgeon to quickly and securely prepare at least one segment of corneal ring with the desired dimensions and shape ready to be inserted into the tunnel previously made in the cornea of ​​the recipient patient. In practice, the surgeon will position the corneal ring in the annular groove of the support surface of the base and then in a first step dry the corneal ring in the annular groove. The surgeon can optionally use the cover during this drying step.Drying the corneal ring in the device of the invention not only allows for shaping of said ring by the shape of the annular groove but also for faster and more uniform drying thanks to better air circulation compared to drying in the open air. Once dry and after removing the cover if necessary, the surgeon will, in a second step and without any manipulation of the corneal ring, engage the blade holder on the base, and align the mark and the desired angular graduation (generally 0°) by relative rotation of the blade holder on the base. He will then proceed with a first transfixing cut of the corneal ring by completely engaging the blade holder on the base according to the previously chosen angular graduation.The surgeon will then repeat the operations by determining a second cutting angle by rotating the blade holder relative to the base and then performing a second transfixing cut, thus making it possible to obtain from the corneal ring a segment of the desired length and a residual segment. The operations of determining an angle and cutting can be repeated as many times as necessary to obtain as many segments as desired. The determination of the successive cutting angles is particularly facilitated when the angular graduations are marked on a wheel mounted so as to rotate along the central axis of the base, on the base.Indeed, the first transfixing cut can be made without aligning the mark with a particular graduation, the second cut will then be easily made by aligning an angular graduation (generally zero) with the first cut and then positioning the blade holder mark opposite the desired angular graduation to make the second transfixing cut. This is particularly advantageous when the surgeon wishes to obtain more than one segment of the desired length. Thus, to cut a second segment of the desired length, the surgeon will turn the wheel to align the desired angular graduation, generally zero, with the second transfixing cut previously made and then will make a third transfixing cut by aligning the blade holder mark with the value of the desired graduation, without having carried out any calculation.At the end of this operation, the surgeon will obtain two segments of the desired length and one residual segment from the corneal ring. The surgeon can thus easily cut several segments of the desired length by repeating the steps described above. Alternatively and at the surgeon's discretion, the drying step can be carried out after the corneal ring cutting step. Once the corneal ring segments are cut and dry, they are delicately removed from the annular groove and directly inserted into the tunnel made in the recipient patient's cornea.

[0025] Other characteristics and advantages of the invention will emerge from reading the following description of a particular and non-limiting embodiment of the invention.

[0026] BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Reference will be made to the attached drawings, including:

[0028] [Fig. 1] Figure 1 is a schematic view in slight perspective of a base according to the invention;

[0029] [Fig. 2a] Figure 2a is a schematic sectional view along a plane passing through the X axis and in slight perspective detail of the pad comprising the support surface with a U-shaped annular groove with a rounded bottom;

[0030] [Fig. 2b] Figure 2b is a schematic sectional view along a plane passing through the X axis and in slight perspective detail of the pad comprising the support surface with a U-shaped annular groove with a flat bottom;

[0031] [Fig. 2c] Figure 2c is a schematic sectional view along a plane passing through the X axis and in slight perspective detail of the pad comprising the support surface with a V-shaped annular groove;

[0032] [Fig. 3] Figure 3 is a schematic sectional view along a plane passing through the X axis and in slight perspective of a device according to the invention comprising a base on which a cover is engaged;

[0033] [Fig. 4a] Figure 4a is a schematic perspective view showing a blade holder in section along a plane passing through the X axis, engaged on the base, the blade holder mark being aligned with the angular graduation 0 of the base, said base being shown in full and in slight perspective.

[0034] [Fig. 4b] Figure 4b is a schematic perspective view showing a blade holder, in section along a plane passing through the X axis, engaged on the base, the blade holder mark being aligned with the angular graduation 45 of the base, said base being shown in full and in slight perspective.

[0035] [Fig. 5] Figure 5 is a schematic top view of a device according to the invention comprising a base on which a blade holder is engaged;

[0036] [Fig. 6] Figure 6 is an exploded schematic sectional view along a plane passing through the X axis of a device according to the invention comprising a blade holder ready to be engaged on a base.

[0037] [Fig. 7] Figure 7 is a schematic top view of a device according to a particular embodiment of the invention comprising a base on which a blade holder is engaged, the base comprising a graduated wheel and the blade holder at least one central opening and one lateral opening;

[0038] [Fig. 8] Figure 8 is a schematic perspective view showing a blade holder, in section along a plane passing through the X axis, engaged on the base according to a particular embodiment of the invention, the base comprising a graduated wheel and the blade holder at least one central opening and one lateral opening;

[0039] [Fig. 9] Figure 9 is a schematic perspective view of a corneal ring segment prepared using the device according to the invention;

[0040] DETAILED DESCRIPTION OF THE INVENTION With reference to Figures 1 to 9, the present invention relates to a device for preparing at least one segment S1, S2 of a CAIRS C type corneal ring. The device according to the invention comprises at least one base 1 particularly illustrated by Figures 1, 2a, 2b, 2c and 3. According to one embodiment of the invention, the base 1 of the device is arranged to rest on the work surface and comprises a central crown 1.2 comprising two surfaces of revolution around a central axis X, namely an external surface 1.2a and an internal surface 1.2b parallel to each other, connected to each other by a flat upper surface 1.2c, orthogonal to the axis X and therefore parallel to the work surface. The internal surface 1.2b defines a cylindrical housing capable of receiving a stud 1.3 also cylindrical with a circular section. Here, the central crown 1.2 is surrounded by a circular rim 1.1 arranged around the central crown 1.2 opposite its external surface 1.2a to form between them a ring-shaped gutter 1.4. The stud 1.3, particularly illustrated by figures 2a, 2b and 2c has a tubular shape closed at one end by a partition having an upper surface forming a support surface 2 of the corneal ring C. The stud 1.3 delimits a chamber 3 located under the support surface 2 when the stud 1.3 is inserted into the central crown 1.2, the center of the support surface 2 is then located on the axis X. The stud 1.3 is inserted into the central crown 1.2 in such a way that the support surface 2 of the stud 1.3 is flush with the flat surface 1.2c of the central part 1.2 so as to form a substantially continuous circular surface. It is specified that the edges, surfaces and parts located in the immediate vicinity of the work surface are referred to as "lower" and the edges, surfaces and parts opposite it are referred to as "upper". The support surface 2 of the pad 1.3 comprises a groove 4 which has an annular shape with a central axis normal to said support surface 2 and coincident with the axis X, said annular groove is shaped to accommodate and model the corneal ring C. The width of the groove 4 is thus defined as a function of the dimension of the corneal ring C intended to be placed in the groove 4 so that the groove 4 is slightly wider than the corneal ring C to have a clearance between the corneal ring C and the inside of the groove 4. Here, by way of illustration, the width of the groove 4 is at least 0.55 mm, preferably greater than or equal to 1.1 mm. The groove 4 here has a diameter of 5 mm for the small diameter and 6.6 mm for the large diameter. In addition, the bottom of the groove 4 is shaped to model the corneal ring C during the drying step. It is preferably U-shaped with a flat bottom as illustrated in Figure 2.b or rounded as illustrated in Figure 2.a, or V-shaped as illustrated in Figure 2.c.The person skilled in the art is able to define the diameters, width and depth of the groove according to the dimensions (diameters, width and thickness) of the corneal ring to be received. Generally, the width of the groove 4 is between 0.55 mm and 1.1 mm and its depth is between 0.4 mm and 1 mm. The support surface 2 is also provided with at least one notch 5 which opens transversely into the groove 4 and which is arranged to facilitate the gripping of the corneal ring C or the corneal ring segment S1, S2.The person skilled in the art will be able to define the shape, dimensions and number of notches 5 necessary to facilitate the passage of the surgeon's instruments, in particular, the depth of each notch 5 will be slightly greater than that of the groove 4 and its length slightly greater than the width of the groove 4 so as to be able to grasp with forceps or a hook for example, the ring or the corneal segment by sliding, through one of the notches 5, one of the first branches of the forceps against the bottom of the groove 4 under the ring or the corneal segment, the other branch of the forceps pinching the opposite face or inserting the hook under the ring or the corneal segment. Here, each notch 5 is more or less oblong in shape with a width of approximately 0.6 mm, a length and a depth at least equal to the width and depth of the groove. The base 1 further comprises a chamber 3 extending under the support surface 2, here formed by the pad 1.3 which is hollow.The base also comprises conduits 4.2, a first end of which opens into the chamber 3 and a second end of which opens into the groove 4 via an orifice 4.1. The orifices 4.1 are indifferently located on the bottom and / or on the walls of the groove 4. A person skilled in the art will be able to adjust the number of orifices (one could be sufficient), their shape and their size according to the dimensions of the groove 4. Here, the orifices are circular in shape and have a diameter between 0.04 mm and 0.3 mm and are distributed uniformly on the bottom and the walls of the groove 4. The base 1 of the device of the invention may further comprise means for circulating air in the chamber 3, the conduits 4.2 and the orifices 4.1 of the groove 4. According to the particular embodiment of the invention, the air circulation means comprise a connection end piece 6 to a pump (not shown).A pump is understood to mean any manual, pneumatic or electrical device for blowing or sucking air. For example, the connecting tip 6 can be connected to a bulb or to a conventionally used electric pump, for example, it can be a pump of the “ACP system” type marketed by the company Moria. Here, the air is blown by the pump, passes into the connecting tip to be dispersed in the chamber 3 then passes through the conduits 4.2 until it opens into the groove 4 via the orifices 4.1 to dry the ring or the corneal segment placed in the groove 4. A person skilled in the art is able to define the flow rate and the pressure of air delivered as well as the duration so that the drying of the ring or the corneal segment is improved without it being moved outside the groove 4 or damaged. For illustration, a pump that delivers an insufflation of 200 mmHg can be used.The base 1 can be made of any material, preferably a sterilizable material. The support surface 2 and the annular groove 4 are made of a non-adherent material such as, for example, polytetrafluoroethylene (or Teflon®): this can be the material forming the stud 1.3 or the material of an upper coating of the stud. Drying the ring or the corneal segment placed in the groove of the device not only reduces the drying time but also allows a corneal segment SI, S2 to be obtained shaped like an arc of a circle and whose section in the thickness is U-shaped with a flat or rounded bottom or V, as is respectively illustrated in Figure 9, which facilitates its insertion into the tunnel made in the cornea of ​​the recipient patient.

[0041] Optionally and as illustrated in Figure 3, the device according to the invention may comprise a cover 7 arranged to engage on the base 1 by covering at least the ring or the corneal segment placed in the annular groove 4 to hold the ring or the corneal segment in place in the groove 4. The cover 7, here of tubular shape of revolution, has a circular upper wall 7.1 having a central axis X2 and a tubular wall 7.2 extending downwards from a periphery of said upper wall 7.1. When the cover 7 is engaged on the base, the central axis X2 of the cover 7 coincides with the axis X of the base 1, the upper wall 7.1 is opposite the support surface 2 of the base 1 and the tubular wall 7.2 is opposite the external surface 1.2a of the central ring 1.2 of the base 1. The upper wall 7.1 of the cover 7 is preferably pierced with openings 8 allowing the progress of the drying and shaping of the corneal ring or segment to be monitored. The openings also allow air to circulate. A person skilled in the art is able to define the shape, position and dimensions of the openings. The openings, here for illustration purposes, are ten in number (but only one could be sufficient), oblong in shape and positioned in radii of a circle whose center is on the X axis.

[0042] According to the particular embodiment of the invention particularly illustrated by Figures 4 to 8, the device further comprises a blade holder 10. The blade holder 10 comprises a cylindrical cover 11 having a central axis X3 with an upper end forming a bottom 11.1 partially open by at least one window 12 and an annular lower end 11.2, the two ends being connected by an edge 11.3, the junction between the at least one window 12 and the edge 11.3 forming a shoulder 14. The cover 11 further comprises a blade 13 fixed in such a way that it extends in a direction substantially parallel to the axis X3 and opposite a portion of the groove 4 of the base 1 to have a transfixing cutting function of the corneal ring C. Here, the blade 13 is fixed by a tubular support 13.1 which extends projecting and in the center of the bottom 11.1 to inside the hood 11.The person skilled in the art will be able to determine the width, the height of the blade 13 as well as the shape of its tip in such a way that the cutting edge of the blade enters the groove 4 and can go to the bottom thereof. By way of illustration, the blade 13 has a cutting edge of a shape complementary to that of the groove 4: straight or rounded when the bottom of the groove 4 is U-shaped with a flat or rounded bottom, V-shaped when the bottom of the groove 4 is V-shaped. The cover 11 also comprises means for reciprocal engagement of the cover 11 on the base 1, here respectively formed by the edge 11.3 of the blade holder 10 and the external surface 1.2a of the central crown 1.2 of the base 1 allowing rotation of the cover 11 around the coincident central axes X, X3. The reciprocal engagement means 11.3, 1.2a are arranged in such a way that they allow the blade holder 10 to be engaged on the base 1 between a first position in which the blade holder 10 is partially engaged on the base 1 allowing rotation of said blade holder 10 on the base 1 to adjust the cutting angle and a second position in which the blade holder 10 is fully engaged on the base 1 so that the blade 13 transfixingly cuts the corneal ring or segment placed in the groove 4 of the base 1 according to the previously determined angle. A person skilled in the art may provide on the base 1 and / or the blade holder 10 means for positioning the blade holder 10 relative to the base 1. As a non-limiting example, the gutter 1.4 may be provided with at least one spring. When the blade holder 10 is partially engaged on the base 1, the spring is not compressed and the blade 13 is not in contact with the support surface 2.To perform the cutting of the corneal ring C, the surgeon will exert pressure on the cover 11 of the blade holder 10 to fully engage the blade holder 10 on the base 1 by compressing the spring and thus perform the cutting. A person skilled in the art is able to produce and position the positioning means such that in a first position, the blade 13 of the blade holder 10 is not in contact with the support surface 2 when the surgeon determines the cutting angle and that in a second position, the blade 13 performs a transfixing cut of the corneal ring. One of the cover 11 or the base 1 further comprises at least one mark 15a, 15b and the other of the cover 11 or the base 1 comprises angular graduations 16 centered on the central axis X of the annular groove 4 so as to be able to position by rotation the blade holder 10 on the base 1 to adjust the cutting angle around the central axis X of the groove 4.According to the particular embodiment of the invention, the cover 11 comprises a first mark 15a marked on the bottom 11.1 opposite a window 12 and a second mark 15b, as a reminder of the first, on the shoulder 14. The marks 15a and 15b are aligned and mark the position of the blade 13. The angular graduations 16 are centered on the axis X. They extend radially on the periphery of the stud 1.3 around the annular groove 4. Here they are located on the upper surface 1.2c of the central crown 1.2 of the base 1 and arranged according to the radii of the circle forming the external contour of the upper surface 1.2c which is centered on the axis X. Optionally and as illustrated by figures 7 and 8, the angular graduations 16 can be marked on a wheel 1.5 mounted to rotate about the central axis, on the crown 1.2. The wheel.

[0043] 1.5 here comprises a flat upper surface 1.5c on which the angular graduations 16 are marked, an opposite lower surface 1.5d joined by two lateral surfaces 1.5a and 1.5b. A person skilled in the art is able to assemble the wheel 1.5 and the crown 1.2 so that not only is the wheel rotatable about the central axis X but also that the upper flat surface 1.5c of the wheel forms with the upper surface 1.2c of the crown 1.2 and the support surface 2 of the stud 1.3 a continuous surface, preferably substantially flat. For example, the crown 1.2 may comprise an L-shaped annular guide 1.6 formed in a hollow in the surface 1.2c of the crown 1.2 and which accommodates the wheel 1.5 in rotation. Here, rotation is possible simply by sliding the surfaces 1.5a and 1.5d inside the guide

[0044] 1.6 and the surface 1.5b against the stud 1.3. A person skilled in the art will be able to define the shape of the guide 1.6 and, in a complementary manner, the shape of the surfaces 1.5d, 1.5a and 1.5b so as to allow the rotation of the wheel 1.5 and the stability of the position of the wheel 1.5 once it has been selected by the surgeon. Here, the guide 1.6 comprises an inner rim 1.6a forming a rail to accommodate a complementary rim 1.5e cut out in the surface 1.5a of the wheel 1.5. A person skilled in the art will be able to provide means for locking the position.

[0045] The person skilled in the art will be able to produce the marks 15a, 15b and the angular graduations 16 in such a way that they are perfectly legible. Thus, they can be marked, printed and / or engraved and / or produced in relief. The interval of the angular graduations 16 can, for example, be defined every 5 degrees, with a numerical mention every 15 degrees from 0 to 345. For a corneal ring of 7.75 mm diameter D, the angle ot of 5° thus represents a length 1 of corneal segment of 0.34 mm (l=IID.a / 360). The outline of the graduations 16 can be of different length depending on whether the angular graduations 16 are accompanied by an angle value mark or not. Here, the angular graduations 16 accompanied by an angle value mark are represented by a line substantially longer than the line representing the angular graduations 16 at intervals. Advantageously and when the graduations 16 are marked on the upper surface 1.2c of the central crown 1.2, the person skilled in the art will ensure that in none of the positions marked by the angular graduations 16, the blade 13 is opposite one of the orifices 4.1 opening into the groove 4 when the blade holder 10 is engaged on the base 1. In addition and as stated previously, the cover 11 has at least one window 12, preferably arranged opposite the marks 15a, 15b to see a part of the flat surface 1.2c of the base 1 marked with the angular graduations 16 when the blade holder 10 is engaged on the base 1. Optionally, the window 12 is arranged so that the groove 4 of the base 1 is also visible when the blade holder is engaged on the base. Preferably, and as illustrated by figure 7, the cover 11 comprises at least two windows (here four), at least one side window 12.1 (here three) allowing the surgeon to see the angular graduations 16 and a central window 12.2 allowing him to see (and possibly hold or manipulate) the ring or the corneal segment placed in the annular groove 4. In order to facilitate the positioning of the blade holder relative to the base and to make it more precise, the first mark 15a marked on the bottom 11.1 is opposite the central window 12.2 and the second mark 15b, as a reminder of the first, on the shoulder 14 opposite the lateral window 12.1. The marks 15a and 15b are aligned and mark the position of the blade 13.

[0046] Thus, to cut a corneal ring C previously placed in the groove 4 of the support surface 2 of the base 1, the surgeon will engage the blade holder 10 a first time by placing the marks 15a, 15b of the blade holder 10 and the angular graduation 16, generally marked with “0”, of the base 1, visible through at least one window 12.1, 12.2, then the surgeon will fully engage the blade holder 10 until the blade 13 comes into contact with the bottom of the groove 4. In this position, the blade 13 makes a first transfixing cut of the corneal ring C.In a second step, the surgeon will slightly raise the blade holder 10 to return it to the partially engaged position and thus completely disengage the blade 13 from the corneal ring C before performing a rotation until the marks 15a, 15b are placed opposite the chosen angular graduation 16 and then re-engage the blade holder 10 on the base 1 until the blade 13 comes back into contact with the bottom of the groove 4 to perform a second transfixing cut and thus easily obtain a corneal segment SI of the desired length and a segment Sr corresponding to the rest of the corneal ring C.All of these operations can be repeated by positioning the marks 15a, 15b opposite the angular graduation 16 chosen to correspond to the desired length of the corneal segment S2 and then by re-engaging the blade holder 10 on the base 1 until the blade 13 comes back into contact with the bottom of the groove 4 to make a third transfixing cut and thus easily obtain a corneal segment S2 of the desired length. At the end, the surgeon has two segments SI and S2 of the desired length (SI and S2 may have identical lengths or not) and a third segment Sr corresponding to the remainder of the corneal ring C. In other words, the lengths of the three segments SI, S2 and Sr define the perimeter of the corneal ring C. The succession of these operations to produce corneal segments is all the easier when the angular graduations 16 are marked on a wheel 1. 5 .Indeed, the surgeon by rotating the wheel 1.5 can then align the chosen graduation (generally the zero graduation) with the mark 15a, 15b of the blade holder corresponding to the second cut, then rotate the blade holder until the mark 15a, 15b is aligned with the desired graduation to make a third cut and so on as many times as necessary without having to make any calculations. Thus, at the end, the surgeon can easily cut out as many segments of the desired length SI, S2 from the corneal ring C and obtain a residual segment Sr by repeating the steps described above.

[0047] The device according to the invention therefore allows the surgeon to obtain at least one corneal segment S1, S2 of the desired length from a corneal ring C by limiting the manipulations of the ring and the corneal segment, as illustrated in Figure 9. Indeed, once the corneal ring C is placed in the groove 4, the successive cuts are made without any manipulation of either the ring or the segment. Once the drying and cutting steps have been carried out, it is sufficient to recover the segment or segments which are then ready to be directly grafted into the cornea of ​​the recipient patient.

[0048] The device according to the invention thus makes it possible to dry, shape according to the shape of the groove and cut at least one corneal segment SI, S2 of desired length from a corneal ring C quickly while limiting handling. In addition, the corneal segment SI, S2 obtained is perfectly adapted in shape and length to the recipient's eye and easier to insert into the tunnel made in the eye of the recipient patient. The device according to the invention also allows the surgeon to carry out the drying and cutting steps independently of each other and in the order he wishes.

[0049] Of course, the invention is not limited to the embodiment described but encompasses any variant falling within the scope of the invention as defined by the claims. In particular, the stud 1.3 can be removable and can thus be changed to be adapted to the diameter of the corneal ring C without having to modify the other elements of the base 1 or be in one piece with the base. The person skilled in the art can thus provide that the cover 7 is universal and covers the groove 4 whatever its diameter. Of course, the blade holder 10 must be chosen to be compatible with the groove 4 of the support surface 2 so that the corneal ring C can be cut by the blade 13.

[0050] The orifices 4.1 of the groove 4 may be provided only on the bottom of the groove 4 or only on the walls of the groove 4 or present on both the bottom and the walls of the groove 4. All the orifices 4.1 may have identical diameters or may be of different diameters depending on their position. A person skilled in the art will be able to determine the number, shape, position, size and density of the orifices depending on the diffusion of the air in the groove 4 that he wishes to obtain. In particular, they may be substantially circular, oblong, square, slot-shaped or form a mesh.

[0051] According to the embodiment of the invention, the air is blown but it can also be sucked in.

[0052] The base 1 comprises air circulation means comprising a connection tip to a pump but it is also possible that the base 1 is not connected to a pump and that the air circulation between the chamber 3, the conduits 4.2 and the orifices 4.1 is passive. The entry of air into the chamber 3 can then be achieved through passages provided in the circular rim 1.1.

[0053] The base 1 comprises air circulation means but alternatively, the air circulation means can be fitted to the cover 7. The connection tip to the pump is then placed in the center of the cover 7. The air blown or sucked by the pump will be delivered via the connection tip through the cover 7 onto the support surface 2. The air will then pass through the orifices 4.1 of the groove 4, through the conduits 4.2 to arrive in the chamber 3 from which it will be evacuated through openings provided for this purpose. A person skilled in the art will know how to adapt the cover 7 if it is used to diffuse the air.

[0054] The upper flat surface 1.5c of the wheel 1.5 forms with the upper surface 1.2c of the crown 1.2 and the support surface 2 of the stud 1.3 a continuous surface, preferably substantially flat, but the upper surface 1.5c of the wheel can also be hollow or protrude from the upper surfaces 1.2c and support 2.

[0055] According to the embodiment of the invention, the corneal ring C is first dried on the base 1 and then cut by engaging the blade holder 10 on the base 1, but the surgeon can choose to carry out the steps in the reverse order, that is to say to first proceed with the cutting of the corneal segment C with the blade holder 10 and then the drying and shaping step. He can also distinguish the steps and use the device according to the invention only to dry and shape the corneal segment or ring or only to cut it.

[0056] Here, the marks 15 are drawn on the blade holder 10 and the angular graduations 16 on the base 1 but the reverse is also possible, that is to say that the marks 15 are marked on the base and the graduations 16 on the blade holder 10. The person skilled in the art will know how to adapt the marks and angular graduations accordingly. The blade holder 10 here comprises two marks 15a, 15b, but there could only be one. If the person skilled in the art considers it useful, marks can also be marked on the base 1, for example in alignment with the angular graduation 0 and / or the most used graduations.

[0057] The reciprocal engagement means of the blade holder 10 on the base 1 comprise positioning means allowing the surgeon to "feel" the position of the blade holder 10 between the partially engaged position and the fully engaged position. Here, the positioning means comprise a spring but it could be by piston, a notch or stop system and / or a color marking.

[0058] Alternatively, the blade 13 may be retractable with a retracted position upon rotation of the blade holder 10 to determine the angle and in a developed position for transfixing cutting of the corneal ring C or the corneal segment S once the angle is determined. For example, the blade may be equipped with a push button or a lever which allows the blade to be extended (developed position) and / or entered (retracted position) once the blade holder 10 is engaged on the base 1.

Claims

CLAIMS 1. Device for preparing a segment of a corneal ring of the CAIRS type (S), comprising at least one base (1) provided with a support surface (2) for the corneal ring (C), said support surface (2) comprising an annular groove (4) which has a central axis (X) normal to said support surface (2) and which is shaped to accommodate and model the corneal ring or the corneal segment.

2. Device according to claim 1, in which the annular groove (4) has a U shape with a flat bottom or a rounded bottom or a V shape along a plane parallel to the axis normal to the support surface.

3. Device according to claim 1, wherein the support surface (2) is provided with at least one notch (5) which opens transversely into the groove (4) and which is arranged to facilitate gripping of the corneal ring or the corneal segment.

4. Device according to claim 1, in which the base (1) comprises a chamber (3) extending under the support surface (2) and at least one conduit having a first end opening into the chamber (3) and opposite a second end opening into the groove through at least one orifice (4.1).

5. Device according to claim 4, in which at least one orifice (4.1) is located in the bottom or on a wall of the annular groove (4).

6. Device according to claim 4 or 5 wherein the at least one orifice (4.1) is between 0.04 mm and 0.3 mm, preferably 0.15 mm.

7. Device according to any one of the claims 4 to 6, wherein the base comprises means for circulating air in the chamber (3), the conduits, the at least one orifice (4.1) and the annular groove (4).

8. Device according to claim 7, in which the air circulation means comprise a connection end piece (6) to a pump.

9. A device according to any one of claims 3 to 7 comprising a cover (7) which is provided with openings (8) and which is arranged to engage on the base (1) covering at least the annular groove (4) to hold the corneal ring or the corneal segment in place in the annular groove (4).

10. Device according to any one of the preceding claims, comprising a blade holder (10), said blade holder comprising a cover (11) provided with a blade (13), and means (11.3, 1.2a) for reciprocal engagement of the cover (11) on the base (1) allowing rotation of the cover (11) around the central axis (X) of the annular groove (4), the blade (13) extending opposite a portion of the annular groove (4), one of the blade holder (10) or the base (1) comprising at least one mark (15a, 15b) and the other of the blade holder (10) or the base (1) comprising angular graduations (16) centered on the central axis (X) of the annular groove (4) so as to be able to position the blade holder (10) on the base at an angle predetermined around the central axis (X) of the annular groove (4) and that the blade (13) transfixingly cuts the corneal ring (C) to obtain at least one corneal segment.

11. Device according to claim 9 or 10 taken in dependence on any one of claims 4 to 8, in which the graduations (16a, 16b) extend radially on the base (1) on the periphery of the stud (1.3) around the annular groove (4).

12. Device according to claim 11 in which the graduations (16a, 16b) are marked on a wheel (1.5) mounted to move in rotation along the central axis X of the base (1) • 13. Device according to any one of claims 10 to 12, in which the cover (11) has at least one window (12) allowing a part of the support surface to be seen when the blade holder 10 is engaged on the base (1) • 14. Device according to claim 13, in which the cover (11) has at least two windows (12.1; 12.2) allowing one to see the graduations (16) and the other at least part of the annular groove (4).

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