TECHNICAL FIELD

The present invention relates to a nozzle tip for an intraocular lens injector. The intraocular lens injector is used for injecting an intraocular lens into an eye of a patient.

BACKGROUND OF THE INVENTION

One of the operative treatments used to treat cataract is a method of removing a crystalline lens from an eye of a patient and then injecting an intraocular lens in place of the crystalline lens. The majority of first generation intraocular lens' (lOLs) were manufactured from rigid PMMA and were implanted into the eye using forceps through large (5-6 mm) incisions. The large incision size increased the risk of infection and could lead to induced changes in the shape of the cornea and also potentially cause astigmatism of the eye after the operation. To prevent such disadvantages, a next generation of foldable lOLs was developed that could be introduced into the eye through a reduced incision size (2-4 mm) using an injector.

To inject the intraocular lens, the following steps are usually performed: first making an incision in the eye; fragmenting and aspirating a clouded crystalline lens through the incision; and then injecting the intraocular lens into the eye through the incision to implant it in place of the crystalline lens. In current lens injectors, the foldable intraocular lens is held in a housing of the injector and is pushed toward the tip of the injector while being folded into a smaller shape. Thereafter, the folded intraocular lens is pushed out of the tip of the injector inserted in the eye through the incision and is spread (unfolded) and placed in the eye.

IOL injectors usually have an injector tip. This usually consists of a hollow, cannula-type needle, having a smooth bore down which the IOL can pass into the eye, through the cornea. The injector tip may be straight or bevelled. Bevelling has been carried out in order to provide a 'sharpened' edge which assists with inserting the tip into the incision, so as to better deliver the IOL to the inside of the eye. Some existing IOL injector tips have a straight bevel at the tip as shown in Figure 1 . lOLs typically comprise a lens portion and a pair of resilient haptics extending outwardly from opposite sides of the periphery of the lens portion. The haptics aid in locating the IOL in a correct position in the eye and in maintaining the IOL in that correct position. It is an object of the invention to reduce surgically induced astigmatism and the risk of endophthalmitis when delivering an lOL to the eye.

SUMMARY OF THE INVENTION

This invention addresses a requirement for an lOL injector nozzle tip that is curved to match the curve of the cornea, thus aiding the effectiveness of wound assisted surgery.

One technique for inserting the lOL into the eye is to press the injector tip against the incision and use the incision tunnel as an extension of the injector tip bore. This technique allows smaller incisions to be used as the injector itself does not have to enter the corneal tunnel. Smaller incisions benefit the patient by reducing surgically induced astigmatism and the risk of endophthalmitis.

Thus, in a first aspect, the present invention provides an injector tip for an lOL injector, said injector tip comprising a hollow tube having an end with a curved concave surface which is adapted to correspond to the curvature of the cornea.

Thus, in a second aspect, the present invention provides an injector tip for an lOL injector, said injector tip comprising an obliquely truncated tube, wherein the truncated surface is open and concave in at least one plane.

In a third aspect, the present invention provides an injector tip for an lOL injector, said injector tip comprising a tube with a concave hollow bevel.

The present invention further provides an lOL injector comprising an lOL injector tip as defined herein.

The present invention further provides a kit of parts comprising an lOL injector and an lOL injector tip as defined herein.

It will be appreciated for each of the aspects of the invention the profile of the tip is shaped such that it is capable of contacting the cornea along substantially the whole end surface of the tip. This allows the injector tip surface to engage with the surface of the cornea, thereby distributing the pressure which is applied evenly. It also effectively allows a seal to be created between the injector tip and the eye, thus enabling accurate and effective delivery of the lOL into the eye, without having to insert the injector tip into the corneal tunnel. Thus, the surface of the injector tip has a scooped profile, rather than a straight profile, at least in one plane.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a side view of the prior art IOL injector tip.

FIG. 2 shows a side view of one embodiment of a device according to the present invention.

FIG. 3 shows an end view (down the longitudinal axis of the injector tip) of one embodiment of a device according to the present invention.

FIG. 4 shows a side view of one embodiment of a device according to the present invention.

FIG. 5 shows a side view of one embodiment of a device according to the present invention. DETAILED DESCRIPTION OF THE INVENTION

General

The term "comprising" encompasses "including" as well as "consisting" e.g. a device "comprising" X may consist exclusively of X or may include something additional e.g. X + Y. The term "about" in relation to a numerical value x means, for example, + 10%.

The word "substantially" does not exclude "completely". Where necessary, the word "substantially" may be omitted from the definition of the invention.

Preferably, the injector tip has an open truncated surface, such that the curvature of the cross-section, along at least one plane which is axially disposed along the tube, approximates the curvature of the eye.

Preferably, in at least one plane, one extremity of the tip extends further than a point disposed 180° at another extremity of the tip.

Preferably, the axis normal to the curvature of the bevel is not coaxial with the cylindrical bore of the injector tip and/or the body of the IOL injector. Preferably, the radial axis of the curvature of the bevel is not coaxial with the cylindrical bore and/or body of the injector tip.

The injector tip preferably has a tube having a non-planar opening, preferably an asymmetric, non-planar opening.

The radius of the curvature of the bevel may vary. Thus, the bevel may have one or more straight sections (at least in one plane). Preferably, at least 50%, more preferably at least 60%, more preferably at least 70%, more preferably at least 80%, more preferably at least 90%, more preferably at least 95% of the circumference of the bevel has a concave profile in at least in one plane which is axially disposed to the tube.

The outer diameter of the injector tip is preferably in the range of 1 .5-5mm, preferably 2- 4mm, preferably 2.5-3.5mm. The injector tip preferably comprises an open mouth with an inner diameter of no more than 4.0mm, more preferably no more than 2.0, more preferably no more than 1 .8mm, preferably about 1 .4mm.

The radius of curvature of the bevelled surface is preferably in the range of 1 mm-30mm, more preferably 1 .5mm-20mm, more preferably 2-10mm. The radius of curvature of the bevelled surface may vary. Preferably, at least 50% of the surface of the bevelled edge has a radius of curvature in the ranges set out above.

In a preferred embodiment, the outer diameter of the injector tip is about 1 .8mm.

In a preferred embodiment, the inner diameter of the injector tip is about 1 .4mm.

In a preferred embodiment, the angle of curvature radius of the bevel is about 2mm. Preferably, the point of the bevelled tip which extends furthest away from the injector body when in use (the distal tip) is disposed between 0.01 and 3mm further along the axial length of the tip than the point of the bevelled tip which extends least away from the injector body when in use (the proximal tip).

The injector tip preferably comprises a tubular body. The tubular body preferably has a smooth bore. The tubular body may be tapered or straight sided or a mixture of tapered and straight sided sections. The tubular body is preferably 10-60mm in length.

Preferably, the injector tip is formed (and presented) separately from the body of the injector device (as opposed to being formed integrally therewith). In this embodiment, the injector tip is preferably provided with a coupling capable of reversibly or irreversibly engaging with the body of the injector device. The coupling may comprise a lock, for example, a twist or push lock which engages the body of the injector device. This allows the bore of the injector tip to be correctly and securely aligned with the bore of the injector device.

The injector tip and/or the portion of the tip that contacts the surface of the cornea may comprise a soft material such that it is conformable to the shape of the surface of the cornea. In this embodiment, the injector tip or a portion of it may comprise a material having an elastic modulus of between 500 kPa and 2000 kPa. The material preferably comprises or consists essentially of a thermoplastic elastomer.

The open end of the tube of the injector tip is preferably smooth, such that damage to the surface of the eye is minimised. The IOL injector body preferably comprises a body having a bore which is capable of accommodating an intraocular lens, and a rod which is capable of pushing said intraocular lens out of the bore and into the eye.

As mentioned above, the injector tip is the part of the injector device through which the intraocular lens may be expelled from the device. The injector tip may be presented separately to the injector body, or may be formed integrally therewith.

The injector tip, when attached or formed with the injector body, is preferably substantially co-axial with the body bore of the injector body. The injector tip is preferably substantially axially co-linear with the body bore of the device.

The injector tip preferably comprises a bore having a radial cross-sectional area which is on average smaller than the average radial cross-sectional area of the body bore. Preferably, the bore of the injector tip has a tapering radial cross-sectional area which decreases towards distal end of the injector tip (i.e., the tip through which the intraocular lens is delivered into the eye).

The injector tip may have portions that are symmetrically or asymmetrically tapered. The injector tip is preferably tapered towards its open end in order to present a smaller radial cross-sectional area at the tip.

The injector tip may comprise a guide which can be used to control the rotation of the rod within the device. The guide may be axially co-linear with the IOL injector body bore.

The rod may be provided with a portion at one of its ends which is adapted to be contacted by a user. For example, the rod may be provided with a flattened or plate-like section which may be contacted by a users thumb and/or finger(s), such that the rod may be pushed and/or pulled moved along the body bore.

Preferably, the injector device comprises a lens receiving portion, hereinafter referred to as a load chamber. Preferably, the load chamber is located in or on the body of the device. Preferably, the load chamber is located adjacent to the injector tip of the device. Preferably, the load chamber enables easy insertion of an intraocular lens into the device. Preferably, the load chamber enables the intraocular lens to be folded and/or rolled into a configuration suitable for delivery into the eye. Preferably, the load chamber of the device comprises a loading port. Said loading port preferably has a first, open configuration, wherein the intraocular lens may be loaded into the device, and a second, closed configuration, wherein the intraocular lens is loaded within the device. The load chamber may be formed integrally with the device, or may comprise a cartridge which may be loaded into the device.

The load chamber preferably has an open proximal end and a distal end aligned with the body bore and the injector tip.

Preferably, the injector tip is substantially light transparent or light translucent, or comprises light transparent and/or light translucent portions to enable the user to see the intraocular lens when pushed through the device. Preferably, the IOL injector and the injector tip are adapted such that the intraocular lens may be observed from the point of loading until the point of delivery of the lens.

Preferably, the rod is made from an opaque material, such that it can be seen by a user in situ.

Different parts of the injector tip and/or other parts of the IOL injector device may comprise different coloured materials or patterning. For example, the tip of the rod or a portion thereof may be coloured or patterned in order that its tip may be clearly seen by a user.

The injector tip of the present invention may be constructed from any suitable materials. The injector tip preferably comprises one or more polymers. For example, a non-limiting list of suitable polymers that can be independently used to form one or more parts of the device of the present invention includes polyacetals, polyamides, polyimides, polyesters, polycarbonates, polysulphones, polyamide-imides, polyamide-esters, polyamide ethers, polycarbonate-esters, polyamide-ethers, polyacrylates; elastomers such as polybutadiene, copolymers of butadiene with one or more other monomers, butadiene-acrylonitrile rubber, styrene-butadiene rubber, polyisoprene, copolymers of isoprene with one or more other monomers, polyphosphazenes, natural rubber, blends of natural and synthetic rubber, polydimethylsiloxane, copolymers containing the diphenylsiloxane unit; polyalkylmethacrylates, polyethylene, polypropylene, polystyrene, polyvinylacetate; polyvinylalcohol, and polyvinylchloride.

The injector tip of the present invention may comprise or consist of flexible materials, thus reducing the impact on the surface of the eye and improving conformity therewith. The flexibility (or stiffness as it is also known) test is preferably carried out according to ISO 9626, Appendix C. Using this test, the injector tip preferably has a deflection in the range of 0.1 mm to 3 mm, more preferably 0.25-2 mm, for example, 0.5-1 mm.

Preferably, injector tip of the present invention comprises or consists of resilient materials, thus improving conformity with the surface of the eye. In use, the method of delivering an intraocular lens to the eye preferably comprises placing an intraocular lens in the load chamber, inserting the rod into the proximal end of the body bore, bringing the injector tip into contact with an incision in the eye, and urging the intraocular lens from the load chamber through the internal bore of the injector tip. The intraocular lens is urged out of the open mouth of the injector tip and into the eye by the rod.

The injector tip is preferably presented in a package. The package is preferably sealed and internally sterile. The package may contain saline solution. The package may contain plastics, foil or may be an appropriately sealed glass vial.

As the injector tip is preferably presented separately to the body of the injector, at the time of surgery, a user of the injector device, such as a nurse or a surgeon, simply opens the package containing the injector tip (and any other packages containing the other parts of the injector device) and attaches the parts together. The injector device is then ready to deliver the IOL from the injector device and into an eye.

Preferably, the injector tip is injection moulded. Preferably, the curved bevel is created by a curved plate on the mould tool.

With regard to Figure 1 , this shows a side view of an IOL injector tip 1 according to the prior art. The injector tip 1 has a tapering body 2, terminating in a straight sided end section 3. End section 3 is the end of the tip which contacts the surface of the cornea in use. The end section 3 has a straight bevelled edge 4. The opposite end of the injector tip has a twist or push lock coupling section 5, which is adapted to engage with the body of an IOL injector device.

With regard to Figure 2, this shows side view of an IOL injector tip 1 according to the present invention. The injector tip 1 has a tapering body 2, terminating in a straight sided end section 3. End section 3 is the end of the tip which contacts the surface of the cornea in use. The end section 3 is open and has a concavely curved bevelled edge 4, through which the IOL emerges when pushed out of the device. The opposite end of the injector tip has a twist or push lock coupling section 5, which is adapted to engage with the body of an IOL injector device. The opening of the end section is circular in cross-section when viewed along the longitudinal axis of the injector tip 1 , although it may have an elliptical or non-circular cross-section if desired. The concavely curved bevelled edge 4 has a tip 6 which is the furthest extremity of the injector tip (the distal tip), whereas the part of the tip 7 is the surface of the open end of the injector tip which extends least towards the cornea in use. Thus, the injector tip retains a 'sharp' point 6 with which to engage the incision in the cornea if necessary, or to position the tip against the corneal incision. In the plane shown, the curved bevelled edge of the injector tip 4 has a section 8 which has a greater curvature, i.e., a smaller radius, than section 9.

Figure 3 is an end view of the injector tip of Figure 2. The tapered body 2 terminates in the concave bevelled surface 4. The coupling section 5 has a flat wall section 10 that is connected to the tapered surface 2 by a curved section 1 1 . The open end of the injector tip comprises a bore 12 through which the IOL emerges when pushed out of the injector tip towards the cornea.

Figure 4 is a side view of an alternative injector tip to that shown in Figure 2, but having a curved bevel 4 having a constant radial curvature.

Figure 5 is a side view of an alternative injector tip to that shown in Figure 4, but having a increased curvature of the bevel compared to that shown in Figure 4, i.e. a bevel having a smaller radius of curvature.