SURGICAL VISUAL FIELD ENHANCER AND SURGICAL KNIFE

Abstract

A surgical tool comprising: a tool body for gripping the tool, the tool body having a longitudinal axis and a first end, wherein a vision enhancer extends from the tool body at the first end, the vision enhancer comprising: a tunnel base, and a first tunnel wall extending from the tunnel base at an angle of between 90 and 120 degrees to the tunnel base, wherein the tunnel base and the first tunnel wall form a concave section for the forming of a tunnel through soft tissue.

Claims

1. A surgical tool, comprising: a tool body for gripping the tool, the tool body having a longitudinal axis and a first end, and a vision enhancer that extends from the tool body at the first end, the vision enhancer including: a tunnel base, and a first tunnel wall extending from the tunnel base at an angle of between 90 and 120 degrees with respect to the tunnel base, wherein the tunnel base and the first tunnel wall form a concave section for forming a tunnel through soft tissue.

2. The surgical tool of claim 1, wherein the vision enhancer has a groove extending along a line joining the first tunnel wall with the tunnel base.

3. The surgical tool of claim 1, further comprising a second tunnel wall extending from the tunnel base at an angle of between 90 and 120 degrees with respect to the tunnel base and parallel to the longitudinal axis of the tool body.

4. The surgical tool of claim 3, wherein the vision enhancer has at least two grooves, each groove extending along a line joining one of said tunnel walls with the tunnel base.

5. The surgical tool of claim 1, wherein the concave section formed by the tunnel base and the first tunnel wall defines an inside of the vision enhancer, and wherein the vision enhancer further includes ridges on the outside of the vision enhancer.

6. The surgical tool of claim 5, wherein each ridge has a first end and a second end opposite the first end, where the first end is nearer a centerline of the tunnel base than the second end and is further from the tool body along a longitudinal axis of the vision enhancer than the second end.

7. The surgical tool of claim 1, wherein the tool body further includes a second end opposite the first end, the second end including an edge for separating tissue.

8. The surgical tool of claim 7, wherein the edge for separating tissue has a V-shape when viewed perpendicularly to the longitudinal axis of the tool body.

9. The surgical tool of claim 7, further comprising a guard situated proximal the second end of the tool.

10. The surgical tool of claim 9, wherein the guard has a face facing away from the second end, the face extending at an angle of between 75 degrees and 90 degrees with respect to the longitudinal axis of the tool body.

11. The surgical tool of claim 1, wherein the vision enhancer includes a groove configured to allow the first tunnel wall to pivot relative to the tunnel base.

12. The surgical tool of claim 2, wherein the groove at least partly extends along a longitudinal axis of the vision enhancer and/or the groove is substantially parallel to the longitudinal axis of the vision enhancer.

13. The surgical tool of claim 2, wherein the groove extends along only part of a length of the vision enhancer.

14. The surgical tool of claim 2, wherein the groove is disposed on an outside surface or on an inside surface of the vision enhancer.

15. A surgical knife, comprising: a tool body for gripping the tool, the tool body having a longitudinal axis, a separating end, and a cutting end; wherein the separating end has a blunt tip for separating nerves from ligaments, and wherein the cutting end includes: a blade for cutting a ligament; and a first visual marker proximate the blade.

16. The surgical knife of claim 15, further comprising: a discontinuous change in thickness of the tool, wherein the tool is thicker on the side of the discontinuity further from the blade, the discontinuous change in thickness situated further from the blade than the visual marker; and a gradual change in thickness of the tool extending from the discontinuous change in thickness away from the blade, wherein the thickness of the tool increases with distance from the discontinuous change in thickness in a direction extending away from the blade.

17. The surgical knife of claim 15, wherein the separating end has a second visual marker situated proximate the blunt tip.

18. The surgical knife of claim 15, wherein the first visual marker is disposed on a surface of the surgical knife which is above the blade.

19. The surgical knife of claim 15, wherein the first visual marker is disposed on a surface of the surgical knife which is perpendicular to the blade.

20. The surgical knife of claim 15, wherein at least a portion of the surgical knife defines a curved shape in the longitudinal direction of the surgical knife.

21. The surgical knife of claim 15, wherein the first visual marker is flush with the tool and/or is printed or marked on the tool.

22. The surgical knife of claim 15, wherein the first visual marker includes a protrusion or bump.

23. The surgical knife of claim 27, wherein the second and third visual markers each include a respective protrusion or bump.

24. The surgical knife of claim 15, further comprising an internal rib.

25. A surgical kit-of-parts, comprising: a surgical tool, including: a tool body for gripping the tool, the tool body having a longitudinal axis and a first end, and a vision enhancer that extends from the tool body at the first end, the vision enhancer including: a tunnel base, and a first tunnel wall extending from the tunnel base at an angle of between 90 and 120 degrees with respect to the tunnel base, wherein the tunnel base and the first tunnel wall form a concave section for forming a tunnel through soft tissue; and a surgical knife, including: a tool body for gripping the tool, the tool body having a longitudinal axis, a separating end, and a cutting end; wherein the separating end has a blunt tip for separating nerves from ligaments, and wherein the cutting end includes: a blade for cutting a ligament; and a first visual marker proximate the blade.

26. The surgical tool of claim 3, wherein the second tunnel wall is spaced apart from the first tunnel wall in a direction perpendicular to the longitudinal axis of the tool body by a dimension of the tunnel base in the direction perpendicular to the longitudinal axis of the tool body.

27. The surgical knife of claim 17, wherein the separating end has a third visual marker situated proximate the blunt tip.

28. The surgical knife of claim 18, wherein the first visual marker is disposed on a plane defined by the blade.

29. The surgical knife of claim 20, wherein the first visual marker is disposed on the inside of the curved shape.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0064] For a better understanding of the present invention, and to show how the same may be carried into effect, reference will now be made, by way of example only, to the following drawings, in which:

[0065] FIG. 1 shows a general view of a surgical tool according to a first aspect of the present invention.

[0066] FIG. 2 shows a side view of a surgical tool according to a first aspect of the present invention.

[0067] FIG. 3 shows a cross section of a surgical tool according to a first aspect of the present invention, taken across line A-A of FIG. 2.

[0068] FIG. 4 shows a second end of a surgical tool according to a first aspect of the present invention.

[0069] FIG. 5 shows a general view of a surgical knife according to a second aspect of the present invention.

[0070] FIG. 6 shows a side view of a surgical knife according to a second aspect of the present invention.

[0071] FIG. 7 shows a cutting end of a surgical knife according to a second aspect of the present invention.

DETAILED DESCRIPTION

[0072] The surgical tool 10 has a tool body 11, which may be held by a user when the surgical tool 10 is in use. A tool body axis 19 extends through the tool, substantially in line with the longest dimension of the tool. The surgical tool 10 also has a first end 12 and a second end 13.

[0073] The second end 13 of the surgical tool 10 has a separator edge 21. The separator edge extends from the tip of the surgical tool 10 toward the tool body 11. At one point the separator edge 21 splits to form a V-shape. The separator edge is formed so that it can cut tissue when moved to the side, perpendicularly to the tool body axis, in addition to, or alternatively to, a movement along the tool body axis 19.

[0074] In this way, the second end 13 and the separator edge 21 situated at the second end 13 may be used by a surgeon in order to separate tissue.

[0075] When using the surgical tool 10 to separate tissue, a surgeon may apply a force to the tool, in order to penetrate the tissue, along the tool body axis 19. When doing so, the surgeon may wish to rest a finger, thumb or side of the palm on a guard 22, and in particular on a face of the guard 23.

[0076] The guard is therefore situated proximate the separator edge 21 and between the second end 13 and the tool body 11.

[0077] For this reason, the face of the guard 23 is at an angle of between 75 degrees and 90 degrees, preferably between 75 degrees and 80 degrees, to the tool body axis 19 so that the reaction force from the face of the guard 23 can directly oppose the force applied to the surgical tool 10 and the chance of slippage where the hand of the surgeon moves past the guard toward the second end 13 of the surgical tool 10 and the patient can be reduced.

[0078] The first end 12 of the surgical tool 10 has a vision enhancer 14. The purpose of the vision enhancer is to hold apart tissue, which has been separated using the separating edge 21 of the second end 13.

[0079] The vision enhancer 14 has a tunnel base 15, which extends from the tool body 11, and at least 1, preferably 2, tunnel wall(s) 16, which extend from the tunnel base 15. A groove 17 lies along a line joining the tunnel base 15 and tunnel wall(s) 16.

[0080] The tunnel base 15 and tunnel wall(s) 16 cooperate to form an internal concave surface. This concave surface then has a tunnel space within it. When inserted into a space under the skin, the tunnel wall(s) 16 and tunnel base 15 hold apart the tissue above the space and the tissue below the space so that an empty space is formed. This allows the surgeon to see more clearly the area upon which he or she is operating.

[0081] In order to be put into the surgery area, the vision enhancer must be inserted via an incision in the skin. When this is being done, the tunnel walls 16 may bend or hinge along the groove 17. When in the space under the skin, the tunnel walls will then naturally move back to their position approximately perpendicular to the tunnel base 15 in order to give a sufficiently large tunnel and associated visual field for the surgeon to operate.

[0082] In order to provide the right compromise of flexibility and resilience in the hinging action, the tunnel wall thickness is between 0.75 mm and 1.25 mm, preferably 1 mm and the groove depth is preferably between 0.1 mm and 0.33 mm i.e. 10% to 30% of the tunnel wall thickness. The length of the groove can then be at least 30% of the length of the vision enhancer end, and up to the entire length of the vision enhancer end, optionally half the length of the vision enhancer end.

[0083] These dimensions are appropriate when the surgical tool 10 is made from a polymer, preferably polypropylene, more preferably a polymer comprising polypropylene having a melt flow index of 10 to 70 cm/10 minutes, wherein the polypropylene is selected from polypropylene homopolymer or polypropylene copolymer having comonomer (2-8 carbon atoms) 1-10% by weight.

[0084] The tunnel base 15 has ridges 18. The ridges 18 provide an improved grip for reducing the chance of slippage during surgery. The ridges have a thickness at least 20% of the thickness of the tunnel base and/or tunnel wall, preferably between 20% and 70% of the thickness, more preferably 50%.

[0085] The ridges are angled to the vision enhancer axis 20 as shown in FIG. 3. The angle is between 10 and 60, preferably between 30 and 45.

[0086] While the vision enhancer is shown has having a total of 6 ridges, the number of ridges may be increased or decreased.

[0087] An end of the vision enhancer 14 situated furthest from the tool body 11 should be blunt for preventing injury to tissue, particularly during the insertion of the enhancer. Further, the tunnel wall(s) 16 may have an edge situated away from the tunnel base 15 which is designed for preventing tissue injury and for conforming to the wrist when the vision enhancer 14 is in use. Such an arrangement is shown in FIGS. 1 and 2.

[0088] Turning to the surgical knife 100, the surgical knife 100 has a tool body 101 which may be used by a surgeon to grip the surgical knife 100. The tool also has a separating end 102 and a cutting end 103.

[0089] The separator end 102 has a blunt tip 104, which can be used by the surgeon to separate the transverse carpal ligament from adjacent nerves in order to prevent nerves from being cut when the transverse carpal ligament is cut.

[0090] The width of the blunt tip is preferably between 4.5 mm and 7.4 mm, more preferably 5.9 mm, in order to allow easy insertion into the incision and the carpal tunnel, and optionally into the tunnel created by the vision enhancer 14.

[0091] A second and/or third visual marker 109a, b are situated proximal the blunt end, optionally 40 mm and/or 45 mm from the blunt tip 104. This gives a visual indication to the surgeon when the blunt tip is in the vicinity of the transverse carpal ligament.

[0092] The cutting end 103 has a blade 105 for cutting of the transverse carpal ligament. The blade has an upper and lower cutting end as shown in FIGS. 5, 6 and 7. The thickness of the lower cutting end is between 1.875 mm and 3.125 mm, preferably 2.5 mm and the thickness of the upper cutting end is between 1.95 mm and 3.25 mm, preferably 2.6 mm. Thin cutting sections make visualisation of the surgical area easier due to the transparency of the material.

[0093] The surgical knife 100 has a first visual marker 106 situated proximal the cutting end 103, between 37 mm and 43 mm from the tip of the blade 105, preferably between 38 mm and 41 mm from the tip of the blade 105 more preferably between 39 mm and 40 mm from the tip of the blade 105; in a most preferred embodiment the visual marker 106 is situated about 40 mm from the tip of the blade 105. This allows the surgeon to visually tell when the tip of the blade is in the vicinity of the transverse carpal ligament, since the transverse carpal ligament is usually approximately 40 mm from the incision.

[0094] The surgical knife 100 initially maintains its thickness, then gradually increases in thickness with increasing distance from the tip, before reaching a discontinuity in the change of thickness. This discontinuity can also be considered as a discontinuous change in thickness 107, where the surgical knife 100 is thicker on the side of the discontinuous change further form the cutting end 103. The tool body then again has a gradual change in thickness 108 with the tool body becoming thicker as the distance from cutting end 103 increases, as shown in FIG. 7.

[0095] The discontinuous change and gradual change in thickness 107, 108 have the effect of giving a physical notification to the surgeon that the depth of insertion of the surgical knife 100 is beyond that which is usually required for cutting of the transverse carpal ligament. For this reason, the step change is situated between 43 mm and 48 mm from the tip of the blade 105, preferably between 44 mm and 47 mm from the tip of the blade 105, more preferably between 45 mm and 46 mm from the tip of the blade 105; in a most preferred embodiment the step change is situated 45 mm from the tip of the blade 105 and the gradual change in thickness 108 extends to a point between 48 mm and 53 mm from the tip of the blade 105, preferably between 50 mm and 53 mm from the tip of the blade 105, more preferably between 51 mm and 52 mm from the tip of the blade 105; in a most preferred embodiment, the gradual change in thickness 108 extends to a point 52 mm from the tip of the blade 105.

[0096] These distances are selected based on collected data, which found that the width of the transverse carpal ligament is between 38 mm and 39 mm in 90 to 95% of cases.

[0097] The surgical tool 10 and the surgical knife 100 may be formed by an injection moulding process. In this process the surgical tool 10 and surgical knife 100 may each be formed in two separate parts and inserted together subsequently.

[0098] For example, the surgical tool 10 or surgical knife 100 may be manufactured partially from a hard polymer and partially from a soft rubber in order to make the tool easier to grip, while maintaining adequate structural stiffness. It is noted that other material combinations are available, but that the two-part manufacture allows a greater range of properties to be obtainable for the tool 10 or knife 100.

[0099] During such a process, the products of the process are liable to suffer from shrinkage. This can be reduced by the surgical knife 10 or surgical tool 100 comprising an internal rib.

[0100] The rib may be formed such that one part of the product has an internal rib and the second part has a corresponding recess, such that the internal rib of the first part is inserted into the corresponding recess of the second part.

[0101] The surgical tool 10 and surgical knife 100 cooperate such that in use the surgical tool 10 may be used to separate tissue and then to form a tunnel, with the surgical knife 100 being inserted via said tunnel in order to separate the nerves and ligament and to cut the ligament.

[0102] Apart from the two aforementioned exemplary embodiments, which teach the manner in which the invention may be carried into effect, further alternative embodiments are possible. In particular, there are a number of variations which are possible, as may be appreciated by those skilled in the art.

[0103] For example, the vision enhancer 14 may not comprise a groove; the vision enhancer 14 may have a material which is weakened along a line between a tunnel wall 16 and the tunnel base 15. This would facilitate the bending of the vision enhancer as required.

[0104] In another embodiment, the ridges 18 on the vision enhancer 14 may not be present. A frictional coating may be provided by a rubberised coating on the tunnel base 15.

[0105] In a further exemplary embodiment, the vision enhancer may have an asymmetric arrangement, with only a single tunnel wall being present.

[0106] The surgical tool 10 may have no guard 22, or a guard with no face 23 perpendicular to the tool body axis 19. In this case, the tool might have ridges or a soft rubber coating in order to facilitate sufficiently strong gripping without risk of slipping of the surgeons hand during the procedure.

[0107] It is noted that all of the positions of visual markers and/or physical markers are exemplary and have been chosen by the inventors as the anatomical match of the average carpal tunnel syndrome patient population. Differing positions of such markers are possible, such as for surgery performed on children or smaller adults.

[0108] Even though in the above embodiments the first tunnel wall and/or the second tunnel wall extend from the tunnel base at an angle of between 90 and 120 degrees, this requirement is purely optional, and, therefore, the any of the embodiments may be modified so that they do not necessarily satisfy this requirement such that the above angle does not necessarily fall within this range.

[0109] Accordingly, the present disclosure provides, as a general aspect, a surgical tool comprising: a tool body for gripping the tool, the tool body having a longitudinal axis and a first end, wherein a vision enhancer extends from the tool body at the first end, the vision enhancer comprising: a tunnel base, and a first tunnel wall extending from the tunnel base, wherein the tunnel base and the first tunnel wall form a concave section for the forming of a tunnel through soft tissue.

[0110] Even though in the above embodiments, the vision enhancer has a groove extending along a line joining the first tunnel wall and the tunnel base, and optionally another groove extending along a line joining the second tunnel wall and the tunnel base, the groove or grooves may be located anywhere on the vision enhancer.

[0111] Accordingly, the present disclosure provides, as a general aspect, that the vision enhancer comprises a first groove configured to allow the first tunnel wall to pivot relative to the tunnel base.

[0112] The present disclosure also provides, as a further general aspect, that the vision enhancer comprises a second groove configured to allow the second tunnel wall to pivot relative to the tunnel base.

[0113] The first groove and/or the second groove may be configured to allow the first tunnel wall and/or the second tunnel wall to pivot relative to the tunnel base upon insertion of the vision enhancer into an incision, where the incision may be a carpal tunnel incision.

[0114] The first groove and/or the second groove may at least partly extend along the longitudinal axis of the vision enhancer (vision enhancer axis 20). The first groove and/or the second groove may be substantially parallel to the longitudinal axis of the vision enhancer (vision enhancer axis 20).

[0115] The first groove and/or the second groove may extend along only part of the length of the vision enhancer.

[0116] The first groove and/or the second groove may be disposed on the outside surface of the vision enhancer. Such a location may aid in the pivoting of the tunnel walls relative to the tunnel base, whilst still maintaining the structural integrity of the vision enhancer when inserted.

[0117] The first groove and/or the second groove may be disposed on the inside surface of the vision enhancer.

[0118] In any of the embodiments, the first visual marker (first visual marker 106) may be disposed on a surface of the surgical knife which is above the blade, and, optionally, the first visual marker may be disposed to intersect the plane defined by the blade.

[0119] In any of the embodiments, the first visual marker (first visual marker 106) may be disposed on a surface of the surgical knife which is perpendicular to the blade.

[0120] In any of the embodiments, at least a portion of the surgical knife defines a curved shape in the longitudinal direction of the surgical knife. The first visual marker (first visual marker 106) may be disposed on the inside of the curved shape.

[0121] In any of the embodiments, the first visual marker (first visual marker 106) may be flush with the tool.

[0122] In any of the embodiments, the first visual marker (first visual marker 106) may be printed or marked on the tool.

[0123] In any of the embodiments, the first visual marker (first visual marker 106) may be configured such that it is proximate a carpal tunnel incision when cutting the transverse carpal ligament during carpal tunnel surgery.

[0124] In any of the embodiments, the discontinuous change in the thickness of the tool (discontinuous change in thickness 107) may be configured such that it provides physical notification to the surgeon that the depth of insertion of the surgical knife is beyond that which is required for cutting of the transverse carpal ligament during carpal tunnel surgery.

[0125] In any of the embodiments, the first visual marker (first visual marker 106) may comprise a protrusion or bump. Additionally or alternatively, the first visual marker (first visual marker 106) may be configured such that it provides physical notification to the surgeon that the depth of insertion of the surgical knife is so that the tip of the blade is proximate the transverse carpal ligament during carpal tunnel surgery, and/or may be configured such that it provides physical notification to the surgeon that the depth of insertion of the surgical knife is so that the tip of the blade has cut the transverse carpal ligament during carpal tunnel surgery.

[0126] In any of the embodiments, the second visual marker (second visual marker 109a) and/or the third visual marker (third visual marker 109b) may comprise a protrusion or bump. Additionally or alternatively, the second visual marker (second visual marker 109a) and/or the third visual marker (third visual marker 109b) may be configured such that it provides physical notification to the surgeon that the depth of insertion of the surgical knife is so that the blunt tip is proximate the transverse carpal ligament during carpal tunnel surgery.

[0127] All of the above are fully within the scope of the present invention, and are considered to form the basis for alternative embodiments in which one or more combinations of the above-described features are applied, without limitation to the specific combinations disclosed above.

[0128] In light of this, there will be many alternatives which implement the teaching of the present invention. It is expected that one skilled in the art will be able to modify and adapt the above disclosure to suite its own circumstances and requirements within the scope of the present invention, while retaining some or all technical effects of the same, either disclosed or derivable from the above, in light of his comment general knowledge in this art. All such equivalents, modifications or adaptations fall within the scope of the invention hereby defined and claimed.

[0129] There is provided: [0130] 1. A surgical tool comprising: [0131] a tool body for gripping the tool, the tool body having [0132] a longitudinal axis and a first end,

[0133] wherein a vision enhancer extends from the tool body at the first end, the vision enhancer comprising: [0134] a tunnel base, and [0135] a first tunnel wall extending from the tunnel base at an angle of between 90 and 120 degrees to the tunnel base so that the first tunnel wall extends substantially or generally in a plane parallel to the plane defined by the longitudinal axis of the tool body (tool body axis 19) and the longitudinal axis of the vision enhancer (vision enhancer axis 20), or so that the first tunnel wall tapers inwardly towards the inside of the vision enhancer moving away from the tunnel base, [0136] wherein the tunnel base and the first tunnel wall form a concave section for the forming of a tunnel through soft tissue. [0137] 2. A surgical tool comprising: [0138] a tool body for gripping the tool, the tool body having [0139] a longitudinal axis and a first end,

[0140] wherein a vision enhancer extends from the tool body at the first end, the vision enhancer comprising: [0141] a tunnel base, and [0142] a first tunnel wall extending from the tunnel base at an angle of between 90 and 120 degrees to the tunnel base, wherein the angle is the angle defined between (i) a first plane that includes the longitudinal axis of the vision enhancer (vision enhancer axis 20), and which first plane is perpendicular to a second plane defined by the longitudinal axis of the tool body (tool body axis 19) and the longitudinal axis of the vision enhancer (vision enhancer axis 20), and (ii) the outside of the first tunnel wall, [0143] wherein the tunnel base and the first tunnel wall form a concave section for the forming of a tunnel through soft tissue. [0144] 3. The surgical tool of statement 1 or 2, wherein the vision enhancer has a groove extending along a line joining the first tunnel wall and the tunnel base. [0145] 4. The surgical tool of statement 1, 2 or 3, further comprising a second tunnel wall extending from the tunnel base at an angle of between 90 and 120 degrees to the tunnel base and parallel to the longitudinal axis of the tool body, the second tunnel wall preferably being spaced from the first wall, in a direction perpendicular to the longitudinal axis, by the dimension of the tunnel base in that direction. [0146] 5. The surgical tool of statement 4, wherein the vision enhancer has at least two grooves, each groove extending along a line joining one of said tunnel walls and the tunnel base. [0147] 6. The surgical tool of any preceding statement, wherein the concave section formed by the tunnel base and the first tunnel wall defines an inside of the vision enhancer, and wherein the vision enhancer further comprises ridges on the outside of the vision enhancer. [0148] 7. The surgical tool of statement 6, wherein one end of each ridge nearer a centreline of the tunnel base is further from the tool body along the vision enhancer axis than an opposite end of the ridge. [0149] 8. The surgical tool of any preceding statement, wherein the tool body further comprises a second end, an edge for separating tissue being situated at the second end. [0150] 9. The surgical tool of statement 8, wherein the edge for separating tissue has a V-shape, in plan view, and/or side view, as viewed perpendicularly to the longitudinal axis of the tool body. [0151] 10. The surgical tool of statement 8 or 9, further comprising a guard situated proximal the second end of the tool. [0152] 11. The surgical tool of statement 10, wherein the guard has a face facing away from the second end, the face being at an angle of between 75 degrees and 90 degrees, optionally between 75 degrees and 80 degrees, to the longitudinal axis of the tool body. [0153] 12. The surgical tool of any preceding statement, wherein the vision enhancer comprises a groove configured to allow the first tunnel wall to pivot relative to the tunnel base. [0154] 13. The surgical tool of statement 3, 4, 5 or 12, wherein the groove or each groove at least partly extends along the longitudinal axis of the vision enhancer and/or wherein the groove or each groove is substantially parallel to the longitudinal axis of the vision enhancer. [0155] 14. The surgical tool of statement 3, 4, 5, 12 or 13, wherein the groove or each groove extends along only part of the length of the vision enhancer. [0156] 15. The surgical tool of statement 3, 4, 5, 12, 13 or 14, wherein the groove or each groove is disposed on the outside or inside surface of the vision enhancer. [0157] 16. The surgical tool of any one of statements 1 to 15, further comprising an internal rib.