Device for preparing a corneal graft

Abstract

The invention relates to a device for preparing at least one segment of a corneal ring of the CAIRS type comprising at least one base provided with a surface for supporting the corneal ring provided with an annular groove shaped to receive and shape the segment of the corneal ring. Optionally, the device comprises a cover, provided with at least one opening, arranged to engage on the base by covering at least the annular groove. According to a particular embodiment, 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 extending opposite a portion of the annular groove. FIGURE OF THE ABSTRACT: Fig. 4a

Description

Title of the invention: Device for preparing a corneal graft.

[0001] 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).

[0002] BACKGROUND OF THE INVENTION

[0003] 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 certain regions of the world.

[0004] 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.

[0005] Among the surgical techniques used, one of them consists of inserting an implant in the form of a ring or a segment of a ring 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: .

[0006] - cutting a ring in the periphery of a donor cornea, using a laser femtosecond, a scalpel, or a cutting punch;

[0007] - cut with a scalpel or femtosecond laser a segment in the ring of cornea of ​​the desired length depending on the patient's anatomy and pathology.

[0008] 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.

[0009] Although there are few steps, preparing grafts is long and meticulous, which requires the surgeon's time and increases the duration of the surgical procedure. In addition, it often happens that the segment obtained is not usable (segment of the wrong size, segment torn during various manipulations, etc.), forcing the operations to be carried out again on a new donor cornea. However, cornea donations are far below 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 overcome at least in part 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. Summary of the invention

[0013] For this purpose, according to the invention, there is provided a device for preparing at least one segment of a corneal ring of the CAIRS type comprising at least one base provided with a surface for supporting the corneal ring. The supporting surface is provided with an annular groove with a central axis normal to the supporting surface, said annular groove being shaped to accommodate and model the corneal ring segment.

[0014] The base according to the invention thus makes it possible to dry a corneal ring or a corneal ring segment 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.

[0015] Preferably, the annular groove has a U or 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.

[0016] The base according to the invention further comprises a chamber extending under the support surface with at least one conduit of which a first end opens into the chamber and on the opposite side a second end opens into the annular groove through at least one orifice.

[0017] 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.

[0018] 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.

[0019] 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.

[0020] 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 extends here 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.

[0021] 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 placing the mark opposite 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, the base preferably comprises at least one mark and the blade holder preferably comprises at least the angular graduations. The graduations are arranged such that in none of the positions marked by the angular graduations, the blade is not opposite an orifice of the annular groove when the blade holder is fully engaged on the base to cut the corneal ring. In order to facilitate and secure the cut, the hood has at least one opening allowing the surgeon to see part of the support surface of the base when the blade holder is engaged on the base.

[0022] Thus, the device according to the invention allows the surgeon to quickly and safely 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 makes it possible to obtain an annular segment shaped by the shape of the annular groove but also faster and more uniform drying thanks to better air circulation compared to drying in the open air.Once dry and after possible removal of the cover, the surgeon will in a second step and without any manipulation of the corneal ring engage the blade holder on the base, determine a first angle by placing the mark and the angular graduation in relation by relative rotation of the blade holder on the base. He will then proceed to a first transfixing cut of the corneal ring by fully engaging the blade holder on the base according to the previously determined angle. The surgeon will then repeat the operations by determining a second cutting angle by rotating the blade holder relative to the base and then by making a second transfixing cut thus making it possible to obtain two segments from the corneal ring. The operations of determining an angle and cutting can be repeated as many times as necessary to obtain as many segments as desired.Alternatively, and at the surgeon's discretion, the drying step can be performed after the corneal ring cutting step. Once the corneal ring segments are cut and dry, they are gently removed from the annular groove and directly inserted into the tunnel made in the recipient patient's cornea.

[0023] Other characteristics and advantages of the invention will emerge from reading the following description of a particular and non-limiting embodiment of the invention. Brief description of the drawings

[0024] Reference will be made to the accompanying drawings, among which:

[0025] [Fig.l] [Fig.l] is a schematic view in slight perspective of a base according to the invention;

[0026] [Fig.2a] [Fig.2a] is a schematic sectional view along a plane passing through the axis X and in slight perspective detail of the plot including the support surface with a U-shaped annular groove;

[0027] [Fig.2b] [Fig.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 V-shaped annular groove;

[0028] [Fig.3] [Fig.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;

[0029] [Fig.4a] [Fig.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.

[0030] [Fig.4b] [Fig.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 mark of the blade holder being aligned with the angular graduation 45 of the base, said base being shown in full and in slight perspective.

[0031] [Fig.5] [Fig.5] is a schematic top view of a device according to the invention comprising a base on which a blade holder is engaged;

[0032] [Fig.6] [Fig.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.

[0033] [Fig.7] [Fig.7] is a schematic perspective view of a ring segment corn prepared using the device according to the invention; DETAILED DESCRIPTION OF THE INVENTION

[0034] With reference to Figures 1 to 7, the present invention relates to a device for preparing a segment SI, S2 of a corneal ring of the CAIRS C type. The device according to the invention comprises at least one base 1 particularly illustrated by Figures 1, 2a, 2b and 3. According to a particular 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 planar 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 plot 1.3, particularly illustrated by figures 2a and 2b 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 ring 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 ring 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, parts located in the immediate vicinity of the work surface are referred to as "lower" and the edges, surfaces, 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 and which 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 such 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, for a corneal ring with a diameter between 6.5 mm for the smallest diameter and 8 mm for the largest diameter, with a width of the groove 4 of 0.85 mm, the clearance between the corneal ring C and the inside of the groove 4 is 0.05 mm on each side. In other words, for a width of the groove 4 of 0.85 mm, the groove 4 has a diameter of 6.4 for the small diameter and 8.1 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 or V shaped.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 0.75 mm and 1 mm and its depth is between 0.5 mm and 0.9 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 SI, 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 stud 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 through 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 know how 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 tip 6 for connecting to a pump (not shown). By pump is meant any manual, pneumatic or electrical device for blowing or sucking air. For example, the connection 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 connection 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.The 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. By way of illustration, a pump can be used which delivers an insufflation of 200 mmHg. 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. The drying of the ring or the corneal segment placed in the groove of the device makes it possible not only to reduce the drying time but also to obtain a corneal segment shaped in an arc of a circle and whose section in the thickness is U-shaped as illustrated by [Fig.7] or V, which facilitates its insertion into the tunnel made in the cornea of ​​the recipient patient.

[0035] Optionally and as illustrated by [Fig. 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 C or the corneal segment S1, S2 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 crown 1.2 of the base 1. The upper wall 7.1 of the cover 7 is preferably pierced with openings 8 making it possible to control the progress of the drying and modeling of the ring or the corneal segment. The openings also allow the circulation of air. 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 one could be enough), oblong in shape and positioned as radii of a circle whose center is on the X axis.

[0036] According to the particular embodiment of the invention particularly illustrated by figures 4 to 6, 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 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 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: V-shaped when the bottom of the groove 4 is V-shaped, and rounded when the bottom of the groove 4 is U-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 cuts in a transfixing manner the ring or the corneal 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 . By way of 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 comeal 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 comeal 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 are here 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 X axis.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 made in relief. The interval of the angular graduations 16 can, for example, be defined every 5 degrees, with a numerical indication every 15 degrees from 0 to 345. For a corneal ring with a diameter D of 7.75 mm, the angle a of 5° thus represents a length 1 of corneal segment of 0.34 mm (l=nD.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.Preferably, the graduations 16 are arranged in such a way 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.

[0037] 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 marked 0 of the base 1, visible through the window 12, opposite each other, 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 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 make a second transfixing cut and thus easily obtain a corneal segment S2 of the desired length.

[0038] The device according to the invention therefore allows the surgeon to obtain at least one corneal segment S2 of the desired length from a corneal ring C by limiting the manipulations of the ring and the corneal segment, as illustrated by [Fig.7]. 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 these have been made, it is sufficient to recover the segment which is then ready to be grafted.

[0039] The device according to the invention thus makes it possible to dry, shape according to the shape of the groove and cut a corneal segment SI, S2 from a corneal ring C quickly while limiting handling. In addition, the corneal segment S2 obtained is perfectly adapted in shape and length to the eye of the recipient 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.

[0040] 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.

[0041] 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. Obviously, 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.

[0042] The groove 4 has a U-shaped or V-shaped bottom, but the bottom may have other shapes for example a rectangular shape. 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 both on 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.

[0043] According to the embodiment of the invention, the air is blown but it can also be sucked in.

[0044] The base 1 comprises air circulation means comprising a nozzle for connection to a pump, but it is also possible for the base 1 not to be connected to a pump and for the air circulation between the chamber 3, the conduits 4.2 and the orifices 4.1 to be passive. The air can then enter the chamber 3 via passages provided in the circular rim 1.1.

[0045] The base 1 comprises air circulation means but alternatively, the air circulation means can be fitted to the cover 7. The connection end piece 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 end piece 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.

[0046] 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.

[0047] Here, the marks 15 are traced 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.

[0048] The means for reciprocal engagement of the blade holder 10 on the base 1 comprise position 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 position means comprise a spring but it could be by piston, a notch or stop system and / or a color marking.

[0049] 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 has been 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 CAIRS type corneal ring segment (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 or 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 an orifice (4.1).

5. Device according to claim 3, wherein 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 orifice (4.1) is between 0.04 mm and 0.3 mm, preferably 0.15 mm.

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

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

9. A device according to any one of claims 4 to 8, comprising a cover (7) which is provided with openings (8) and which is arranged to engage on the base (1) by 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 for reciprocal engagement (11.3, 1.2a) 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 a predetermined angle around the central axis (X) of the annular groove (4) and so 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) are arranged in such a way that, in none of the positions marked by the graduations, the blade (13) is opposite an orifice (4.1) of the annular groove (4) when the blade holder (10) is engaged on the base (1).

12. Device according to any one of claims 10 and 11, 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).

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