GB2476307A

GB2476307A - Ocular guide device

Info

Publication number: GB2476307A
Application number: GB0922231A
Authority: GB
Inventors: Tom Eke
Original assignee: Norfolk & Norwich University Hospitals Nhs Foundation Trust
Current assignee: Norfolk & Norwich University Hospitals Nhs Foundation Trust
Priority date: 2009-12-21
Filing date: 2009-12-21
Publication date: 2011-06-22
Also published as: WO2011077115A1; GB0922231D0

Abstract

The ocular guide device comprises first and second eyelid engagement means 20, 22 which are adapted to engage an eyelid and are inter-connected by biasing means 24 which may be similar to a speculum. The ocular guide device also comprises a needle guide means 26 which is adapted to guide a needle to the eye. The device may also comprise eyelash guards 15, eyelid receiving means, gripping means 25 and a substrate layer 32 comprising an active agent and/or means for steadying the eyeball. The needle guide means may be one or more guide arms 26, which may be curved to conform to the eyeball.

Description

OCULAR DEVICE

The invention relates to ocular devices for guiding a needle towards and into a patient's eye. In particular, the invention relates to intraocular injection devices, and ocular sampling devices. The invention extends to methods of carrying out an intraocular injection for administering an active agent to a subject's eye, and to methods for obtaining a sample from a subject's eye.

An intravitreal injection is a technique by which a pharmaceutical is injected into the vitreous cavity of a human or animal eye by means of a hypodermic needle attached to a syringe. In recent years, intravitreal injections have become common practice in ophthalmology. Indeed, it is estimated that more than 300,000 intravitreal injections are performed annually in the UK alone. Commonly injected drugs indude steroids (e.g. triamcinolone), and anti-VEGIF drugs (e.g. ranibizumab) for the treatment of wet macular degeneration.

The intravitreal injection is conventionally carried out by a highly trained ophthalmologist. Antibacterial and anaesthetic drops are first instilled into the eye, and then a speculum is used to hold the eyelids open for the rest of the procedure and to keep the eyelashes out of the way. Disposable sterile drapes are positioned around the eye to keep the area clean during the procedure. More anaesthetic is added if required, for example, in the form of a gel. The patient's eyeball is then held stationary either by the patient at the ophthalmologist's request, or using a special instrument by the ophthalmologist. The ophthalmologist then measures a suitable distance from the limbus of the eye (i.e. the border of the cornea and the sclera) using a sterile measure marker, and then delivers the injection through the pars plana of the eye.

The appropriate injection site varies according to the patient and can be anywhere within a ring that measures 3.0 mm to 4.0 mm away from the limbus. For example, in phakic patients, who have natural crystalline lenses, the usual recommendation is for an injection site to be 4.0 mm from the limbus. In an aphakic patient, in which the patient lacks natural crystalline lenses, or in pseudoaphakic patients, in which the natural crystalline lens is substituted with a synthetic lens, the recommended injection site is 3.5 mm from the limbus. Pseudophakic intraocular lenses are used in cataract surgery.

In conventional practice, it may be difficult to measure the distance from the limbus, and place the needle accurately in the pars plana due to inadvertent eye ball movement.

Therefore, there is a need for an apparatus which allows accurate measurement of the distance from the limbus to guide ocular injection and/or sampling. Another disadvantage of the conventional procedure is that it is cumbersome and time-consuming, because each step requires a change of instrument, which requires the presence of an assistant to help the opthalmologist. Therefore, it would be desirable if the procedure can be simplified, for example with a single instrument with combined features that would facilitate all of these steps thereby enabling a safer and more efficient injection or sampling process, that can be safely carried out by one person without an assistant.

Instruments that are specifically designed for each step of the procedure as described above are commercially available. However, these instruments are usually disposable and costly. Therefore, it would be desirable to provide an instrument that reduces waste, and which therefore costs less. Accordingly, there is a need to provide improved devices and methods for carrying out intraocular injections, or taking ocular samples.

The inventor has considered the problems that are currently faced by ophthalmologists when giving intraocular injections and taking ocular samples, and has designed a novel device to facilitate these procedures.

In a first aspect, there is provided an ocular device for guiding a needle to a subject's eye, the device comprising first and second eyelid engagement means each adapted, in use, to engage an eyelid, the engagement means being interconnected by biasing means, which biasing means is adapted, in use, to urge the first and second engagement means apart, and needle guide means adapted to guide a needle to the eye.

Advantageously, the ocular device may be used by an operator (e.g. an ophthalmologist) with one hand, leaving the other hand free, thereby allowing the operator to safely conduct the procedure on the subject's eye on his own without an assistant. For example, an operator can hold the device in position on the subject's eye with their non-dominant hand, leaving their dominant hand free to operate the syringe and direct the needle attached thereto towards the eye.

The first and second eyelid engagement means preferably engage the upper and lower eyelids, respectively, and keep the eyelids open under the force of the biasing means.

The needle guide means ensures that the needle is placed on, and advanced at, the correct pre-determined radial distance from the limbus of the eye.

The ocular device may be adapted to be used to carry out an injection into the subject's eye, i.e. administering an active agent or a medicament into the eye. For example, the injection may be administered into the vitreous humor of the eye. Alternatively, the device may be adapted to be used to extract a sample from the subject's eye. For example, a sample may be required following a cataract operation to check for any possible infection prior to giving antibiotics. The operator may wish to take a sample of fluid or cells from a region of the eye, such as from the vitreous humor.

The first and/or second eyelid engagement means may comprise eyelash guard means for preventing the subject's eyelashes from obscuring at least part of the eye during the procedure. Advantageously, the eyelash guard means may also prevent the needle from brushing against the eyelashes on its way towards the eye, which could potentially introduce infection into the eyeball. Thus, it will be appreciated that it is important to keep the lashes out of the way during the procedure. The eyelash guard means may comprise a substantially elongate surface, which is adapted, in use, to be placed adjacent the perimeter of the subject's eyelid such that the subject's eyelashes are disposed therebehind. It is preferred that the eyelash guard means may extend along at least 10%, 20%, 30%, 40%, 50%, 60%, 70%, 80%, 90% or at least 95% of the length of the eyelid. The surface may be substantially planar, or curved at an angle which substantially follows the curvature of the subject's eyelid.

The first and/or second eyelid engagement means may comprise eyelid receiving means adapted to receive at least a portion of the subject's eyelid. The eyelid receiving means may comprise a groove or recess provided in a rearwardly facing side of the eyelash guard means, which groove or recess is suitably sized to receive an eyelid. The eyelid receiving means may be formed between the eyelash guard means and a protrusion, which protrusion extends transversely away from a rearwardly facing side of the eyelash guard means.The term "rearwardly facing" may mean in a direction towards the subject's eye, when the device is in use.

The first and/or second eyelid engagement means may comprise gripping means onto which the operator may grip for controlling the relative positions of the engagement means. Preferably, the gripping means is provided on a forwardly facing side of the eyelash guard means. The term "forwardly facing" may mean extending in a direction away from the subject's eye, when the device is in use. The gripping means may comprise at least one projection, which extends transversely away from the eyelash guard means, and preferably substantially perpendicularly away therefrom, and more preferably away from the subject's eye, when the device is in use. The gripping means may comprise a substantially elongate projection, which may extend in a direction which is substantially perpendicular with the plane of the eyelash guard means. For example, the gripping means may comprise a flange.

The gripping means may comprise an outwardly facing gripping surface, which the operator may grip with his thumb and/or finger of one hand, thereby leaving their other hand free to administer the injection or take the sample. In a first embodiment, the gripping surface may be undulating, or corrugated, or ribbed, such that its surface area is increased, thereby improving the user's grip thereon. In a second embodiment, the gripping surface may comprise, or be coated with a material, which increases friction between the operator's thumb and finger tips and the gripping surface. One example of such a material is rubber. Advantageously, provision of the gripping surface provides the operator with good control over the first and second eyelid retainers, allowing the operator to vary the relative distance therebetween, for their insertion into, and removal from, the subject's eye.

Preferably, when the device is in a rest position, the first and second engagement means are disposed in a substantially parallel and mutually opposing position. When in the rest position, the distance between the engagement means is preferably greater than the distance between the upper and lower eyelids. The biasing means may be made of a material, which allows it to be selectively deformed upon the application of pressure, by the operator, so that the eyelid engagement means may be displaced inwardly (preferably from its rest position) to reduce the distance therebetween to enable their placement adjacent the eyelids. Preferab'y, as the pressure is released, the distance between the engagement means may be increased, and the engagement means move away from each other (i.e. towards the rest position), such that they engage the eyelids.

Advantageously, the subject's eyelids are urged apart by the engagement means, thereby keeping the eye open during the procedure. The biasing means may be a resilient, flexible hinge.

The needle guide means may be arranged, in use, to guide the needle towards the pars plana region of the eye, the standard distance of which is between about 3.5mm and 4mm from the anatomical limbus (i.e. the junction of the iris with the sclera). Hence, in one embodiment, the needle guide means may be arranged, in use, to guide the needle into the vitreous humor. In another embodiment, the needle guide means may be arranged, in use, to guide the needle into the ciliary body. In such embodiments, the needle may be inserted about 2mm from the limbus. Thus, the invention enables consistently more accurate and reproducible ocular injections or sampling compared to conventional instruments.

The needle guide means may comprise a guide arm which extends laterally inwardly from at least one or both of the eyelid engagement means, the or each guide arm defining the position of the eye into which the needle should be inserted, such as into the pars p/dna. Preferably, the or each guide arm extends substantially along the same plane as the eyelid engagement means.

In one embodiment, the guide arm may extend away from a region of the eyelid engagement means, which region is disposed between the subject's nose and iris. In another embodiment, the guide arm may extend away from the other side of the eyelid engagement means, which is disposed on the other side of the iris. In yet another embodiment, the guide means may comprise at least two arms extending away from one or both eyelid engagement means. For example, the guide means may comprise one guide arm on each side of the first (e.g. upper) engagement means, or on each side of the second (e.g. lower) engagement means. Alternatively, the guide means may comprise a left' guide arm on one engagement means (e.g. lower), and a right' guide arm on the other engagement means (e.g. upper), or any other permutation/combination thereof. It will also be appreciated that the device may be inserted upside-down so that the guide arm is disposed on the other side of the eye.

The guide arm may comprise a first side wall, which is curved such that its profile corresponds to the curvature of at least a portion of the eye's limbus. The arm may therefore stabilise the position of the eyeball during the procedure, thereby preventing inadvertent ocular damage. The curved profile of the first side wall may be designed to follow the curve of the anatomical limbus. The guide arm may be between about 5mm and 10mm in arc length, preferably between about 6mm and 9mm in length. The guide arm may be between about 2mm and about 6mm wide, and provides a measurable distance from the limbus and the position of the region of the eye into which the needle is to be inserted, for example the pars plana. For intravitreal injections into the adult human eye, the standard distance is either 3.5mm or 4mm from the limbus, and thus, the guide arm may be about 3.5 or 4mm wide.

The guide arm may have a second side wall, which has a curved profile and which is substantially parallel to the limbus, and which corresponds to, and thereby defines, the position of the region into which the needle is to be inserted, such as the pars plana.

The second side wall of the guide arm may therefore provide a guideline into which the needle may be inserted.

The device may comprise a substrate layer, which layer is adapted, in use, to be placed against the anterior surface of the eyeball, the layer comprising an active agent, which may impart its effect on the eyeball when placed adjacent thereto. In use, the substrate layer may abut at least a portion of the limbus, and stabilise the position of the eyeball during the procedure. The substrate layer also helps to steady the globe such that the needle is more likely to be inserted in the correct place since there is less chance of eye movement.

The substrate layer may be disposed underneath and, preferably adjacent the guide arm.

Preferably, the substrate layer extends beyond a peripheral edge of the guide arm, and preferably beyond the second side wall of the guide arm. In embodiments where the second side wall of the guide arm defines the position of the pars plana, the substrate layer will also be disposed at least adjacent the pars plana. The substrate layer may be attached to the underside of the guide arm and/or at least one of the eyelid engagement means. For example, the substrate layer may comprise a sponge or the like, which may have been pre-soaked with an active agent. The active agent may be any pharmaceutical, for example an anaesthetic solution, which is intended to reduce the pain of the injection, an antibacterial agent, such as povidone-iodine solution, or an antibiotic.

In embodiments where the device does not comprise a substrate layer, it may comprise means for steadying the eyeball. For example, the eyeball steadying means may comprise an undulating surface which abuts the anterior surface of the eyeball and holds it in position.

The guide arm and/or the substrate layer may be curved with respect to its hori2ontal plane, such that it forms a curved or concave lower surface, which contacts the anterior surface (i.e. the conjunctiva) of the eyeball. The angle or radius of curvature of the curved lower surface may be substantially the same as the curvature of the eye ball or globe (which is approximately 24mm in diameter in an adult) such that, when the device is in use, the lower surface of the guide arm and/or substrate layer closely abuts the surface of the eye ball. Preferably, therefore, the curvature of the curved lower surface is that of a circle whose radius is the same as the eye being treated, e.g. about 12mm for adults.

The inventor has also provided a kit for use by operators to simply carry out intraocular injections, or for taking ocular samples.

Thus, in a second aspect of the invention, there is provided a kit for carrying out an intraocular injection or for intraocular sampling, the kit comprising the device of the first aspect, and a syringe and needle.

The device in the kit of the second aspect may comprise a substrate layer, which has preferably been pre-soaked with active agent. The active agent may comprise a pharmaceutical, for example an anaesthetic solution, an antibacterial agent, or an antibiotic, or any combination thereof.

The device of the first aspect, or the kit of the second aspect, may be used for conducting an intraocular injection, or for taking an intraocular sample.

Therefore, in a third aspect of the invention, there is provided the device of the first aspect, or the kit of the second aspect, for use in intraocular injection or for intraocular sampling.

Preferably, the intraocular injection comprises an intravitreal injection.

Preferably, the intraocular sample comprises an intravitreal sample.

The inventor has also devised a method for guiding a needle into the interior of an eye (preferably, the vitreous humor), a method for administering a pharmaceutical into a patient's eye, and a method for taking a sample from the eye.

Hence, in a fourth aspect, there is provided a method for guiding a needle into the interior of a subject's eye, the method comprising the steps of:- (i) positioning the device of the first aspect, or the kit of the second aspect, on a subject's eye; and (ii) guiding a needle via the guide means until the tip of the needle is positioned in the interior of the eye.

In a fifth aspect, there is provided a method of administering, to a subject in need of treatment, a composition comprising an effective amount of a medicament for treating a condition of the subject's eye, the method comprising the steps of:- (i) positioning the device of the first aspect, or the kit of the second aspect, on a subject's eye; (ii) guiding a needle coupled to a syringe containing the composition via the guide means until the tip of the needle is positioned in the interior of the eye; and (iii) expelling the composition into the interior of the eye.

In a sixth aspect, there is provided a method of taking a sample from a subject's eye, the method comprising the steps of:- (i) positioning the device of the first aspect, or the kit of the second aspect, on a subject's eye; (ii) guiding a needle coupled to a syringe until the tip of the needle is positioned in the interior of the eye; and (iii) drawing a sample from the interior of the eye into the syringe.

Step (i) of the methods of the fourth, fifth and sixth aspects may comprise urging the eyelid engagement means closer together against the force of the biasing means such that the distance therebetween is reduced such that they may be placed adjacent the eye.

This may be achieved by positioning a thumb and/or a finger for grasping each eyelid engagement means, and preferably the gripping means thereof, and then gently applying pressure thereto. Step (i) may comprise positioning the device adjacent the subject's eyeball with the first and second eyelid engagement means, and preferably the eyelid receiving means, substantially aligned with the upper and lower eyelids. The method -10 -may then comprise gradually decreasing the pressure that is applied to the eyelid engagement means, thereby allowing them to return, under the force of the biasing means, to the rest position. The method may comprise allowing the eyelid engagement means to engage the eyelids, which are received in the grooves thereof. The method may comprise positioning the subject's eyelashes behind the eyelash guard means.

Once the eyelids have been engaged, the method may comprise placing the guide arm so that it contacts the anterior surface of the subject's eye. Step (i) may comprise arranging the guide arm such that the first side wall thereof contacts at least a portion of the limbus of the subject's eye. Step (i) may further comprise arranging the guide arm such that a concave lower surface thereof contacts the curvature of the globe of the eye ball. Hence, the lower curved surface of the guide arm contacts the conjunctiva, thereby fixating the globe.

In embodiments where the device comprises a substrate layer, this layer may also be placed against the eyeball. Hence, step (i) may comprise arranging the substrate layer such that it contacts at least a portion of the limbus of the subject's eye. Step (i) may further comprise arranging the substrate layer such that a concave lower surface thereof conforms with the curvature of the globe of the eye ball.

The method may comprise leaving the device in position on the eye for at least 1 Os, 20s, 30s, 40s, 50s, or 60s, or more, in order to allow the active agent in the substrate layer to act on the eye. For example, in one embodiment, the active agent may comprise anaesthetic. Once the eye has been anaesthetised, step (ii) of the method may then be carried out.

Step (ii) may comprise placing the needle along a guideline formed by the guide arm, and preferably the second sidewall thereof which denotes the position of the eye into which the needle is to be inserted, for example the pars plana. Step (ii) may comprise inserting the needle into the sclera, and urging it substantially perpendicularly into the eye, for example as far as the vitreous humor or the ciliary body regions of the eye.

-11 -Step (iii) of the method of the fifth aspect may then be carried out, in which the composition is released into the subject's eye. The medicament may be any active agent which is suitable for treating a condition or disease of the eye, which may for example be administered into the vitreous cavity by means of injection. For example, the medicament may be a a pharmaceutical, for example an antibiotic, or an anti-angiogenic agent, an anti-inflammatory agent.

Alternatively, step (iii) of the method of the sixth aspect may be carried out, in which the sample is extracted from the interior of the eye into the syringe. The sample may comprise fluid and/or cells, for example from the vitreous humor or ciliary body.

The methods preferably comprise a step of withdrawing the needle (and preferably the syringe) away from the subject, preferably together in one movement. The methods may then comprise removing the device from the subject's eye. This may be achieved by applying pressure to the eyelid engagement means, and preferably the gripping means thereof, such that they are urged towards each other against the force of the biasing means, thereby disengaging the eyelids from the eyelid receiving means.

A "subject" may be a vertebrate, mammal, or domestic animal, and is preferably a human being.

All of the features described herein (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined with any of the above aspects in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

For a better understanding of the invention and to show how embodiments of the same may be carried into effect, reference will now be made, by way of example, to the accompanying diagrammatic drawings, in which:-Figure 1 shows a schematic plan view of one embodiment of a device according to the invention in position on a patient's eye. The device engages the patient's upper and -12 -lower eyelids to allow an operator to carry out an intravitreal injection or to extract a sample from the eye; Figure 2 shows a partial cross-sectional side view of the device shown in Figure 1 along axis B-B in position on the patient's eye; Figure 3 shows a partial cross-sectional side view of the device shown in Figure 1 along axis A-A in position on the eye; and Figure 4 shows a perspective side view of the device shown in Figure 1 in position on the eye. The view is taken from the side of the patient's nose.

Example

Figures 1 to 4 illustrate various views of a device of the invention, referred to herein as a speculum 2, in position on a patient's eye 4 to allow an operator to carry out an intravitreal injection or to take a sample from the eye 4. The injection can be used to administer, to the vitreous humor of the eye 4, any active pharmaceutical agent, such as a steroid (e.g. triamcinolone), or an anti-VEGF drug (e.g. ranibizumab), etc. The sample which may be taken from the patient's eye 4 can be vitreous fluid, possibly including cells dispersed therein.

Referring to Figure 1, the patient's eye 4 includes an inner pupil 6 through which light passes to the retina (not shown), and a coloured iris 8 which surrounds the pupil 6.

The white region which makes up the rest of the eye 4 is referred to as the sclera 10, and the junction between the circumference of the iris 8 and the white sclera is known as the limbus 12. Figure 1 also illustrates the patient's eyelashes 14 which extend from the patient's upper and lower eyelids 16, 18.

The speculum 2 includes a first eyelid retainer 20, which, in use, engages with the upper eyelid 16, and a second eyelid retainer 22, which, in use, engages with the lower eyelid 18. The design of the retainers 20, 22 is shown in more detail in Figure 3. As shown in Figure 1, the first and second eyelid retainers 20, 22 each consists of a slightly curved -13 - (or planar if not too long) eyelash guard 15, which ensures that the patient's eyelashes 14 do not get in the way during the injection or sampling procedure. The eyelid retainers 20, 22 are connected to each other by a resilient, flexible hinge 24, which biases the retainers 20, 22 (and eyelash guards 15) outwardly, such that the patient's eyelids 16, 18 are urged apart, thereby keeping the eye 4 open during the procedure.

Elongate flanges 25 extend perpendicularly away from the eyelash guards 15 of the first and second eyelid retainers 20, 22, and provide gripping surfaces onto which the operator can apply pressure with his/her fingers in order to urge the retainers 20, 22 towards each other. This enables the operator to displace the retainers 20, 22 inwardly to reduce the distance therebetween, to thereby disengage them from the eyelids 16, 18.

The hinge 24 of the device 2 may be made of injection-moulded flexible plastic, which allows it to be selectively deformed upon application of pressure, by the operator, on to the flanges 25.

As shown in Figure 1, a short guide arm 26 extends laterally inwardly from the second eyelid retainer 22 (which engages the lower eyelid 18) along the same plane as the retainer 22. The guide arm 26 has a first side wall 28, which is curved such that its profile corresponds to, and abuts with, the curvature of the eye's limbus 12. The guide arm 26 is about 2 mm to 5 mm wide, and provides a measurable distance of about 2 mm to 5 mm from the limbus 12 into the pars plana region 29 of the eye 4 into which the intravitreal injection should be administered. The pars plana 29 is denoted in Figure 1 by a circumferential band disposed between a pair of concentric rings at approximately 3 mm and 4.5 mm from the limbus 12. The guide arm 26 has a second side wall 30, which also has a curved profile which is parallel to the limbal wall 28, and which corresponds to, and thereby defines the position of the pars plana 29. The side wall 30 therefore provides a guideline along which the injection may be made into the pars plana 29. However, it should be appreciated that injections or sampling need not always be carried out into the parspiana region 29 of the eye. The width of the guide arm 26 will therefore correspond to the distance from the limbus 12 into which the injection or sampling needle should be inserted. Thus, in another -14-embodiment, the guide arm 26 can be about 1-2 mm wide, for example for insertion into the eye's ciliary body.

It will be appreciated that the position of the guide arm 26 can be either on the inner or outer region of the eye 4 with respect to the iris 8. Furthermore, in another embodiment, the speculum 2 is able to hold the eyelids 16,18 wide open such that an injection can be administered, or a sample be taken, at the top or bottom of the eye, i.e. above or below the iris 8 and limbus 12, rather than just in the interpalpebral zone (i.e. between the lids 16, 18).

As further shown in Figure 1, disposed underneath and adjacent the guide arm 26, there is provided a thin sponge layer 32, which has been pre-soaked with anaesthetic solution, and which is intended to make the injection less painful for the patient. In some embodiments, the sponge layer 32 has been soaked with anti-bacterial, antibiotic or some other solution containing an active agent, or a mixture thereof. The sponge layer 32 is attached to the underside of the guide arm 26 and a portion of the eyelid retainer 22 by adhesive. Clearly, the sponge layer 32 should not interfere with engagement of the second eyelid retainer 22 with the lower eyelid 18.

Referring now to Figure 2, there is shown a side view of the speculum 2 in position on the patient's eye 4. When viewed from the side, the anterior portion of the eye 4 can be seen as having a lobed profile which is created by the curvature of the cornea 36.

Behind the iris 8 there is provided a lens 38, which focuses the light onto the retina, and behind the lens 38 there is disposed the vitreous humor 40 into which the active agent can either be injected via the pars plana 29, or from which a biopsy or sample may be extracted, by needle 48 of a syringe 46. Figure 2 also shows the guide arm 26, which projects away from, but along the same plane as, the second eyelid retainer 22 (not shown). Arrow Y' illustrates the width of the arm 26, which is between about 2mm and 5mm, i.e. the distance of the pars plana 29 from the limbus 12. The first side wall 28 of the arm 26 can be seen closely abutting the limbus 12 of the eye 4. The second side wall 30 of arm 26 provides the guideline defining the position of the pars plana 29, into which the injection is administered or through which the sample is taken. The -15 -Figure also shows, disposed underneath the guide arm 26, the sponge layer 32 which may be soaked with anaesthetic and/or other active agent. The sponge 32 also closely abuts the limbus and stabilises the position of the eyeball during the injection, thereby minimising the risk of inadvertent ocular damage which might otherwise be caused by movement of the eye 4 during the procedure.

As can be seen in Figure 2, the guide arm 26 and the sponge layer 32 are both curved with respect to their horizontal plane, such that they form concave lower surfaces 33, which contact the anterior surface of the eyeball 4. The angle or radius of curvature of the curved lower surfaces 33 is substantially the same as the curvature of the eye ball or globe, which is approximately 24mm in diameter, such that, when the speculum 2 is in use, the lower surface 33 of the arm 26 and/or sponge layer 32 closely abut the surface of the eye ball (i.e. the conjunctiva, which is the transparent soft layer overlying the hard white sclera 10). Thus, the curvature of the curved lower surfaces 33 is that of a circle whose radius is the same as the eye, i.e. about 12mm.

Referring to Figure 3, there is shown an alternative view of the speculum 2 engaging the eye 4, showing the first and second eyelid retainers 20, 22 in more detail. Flanges 25 can be seen extending away from each eyelash guard 15 portion of the retainers 20, 22.

Each flange 25 has an outwardly facing gripping surface 40 onto which the operator grips with his thumb and/or finger of one hand leaving his dominant hand to operate the syringe 46. In one embodiment, the outer surface 40 of the flange 25 undulates, or is ribbed, in order to increase its surface area, and therefore improve the user's grip on the flanges 25. In another embodiment, the gripping surface 40 is made of, or coated with, a rubber material etc, which increases the friction with the operator's thumb and finger tips. The operator therefore has excellent control over the first and second eyelid retainers 20, 22, and therefore the relative distance therebetween for their insertion into, and removal from, the patient's eye. A curved protrusion or lip 44 extends transversely away from each eyelash guard 15. A recess or groove 4 is formed between the protrusion 44 and eyelash guard 15, which groove 47 is suitably si2ed to receive an eyelid 16, 18, and eyelashes 14. Hence, in use, the operator ensures that patient's -16 -eyelids 16, 18 are positioned in the grooves 47 and pulled open under the biasing effect of the hinge 24.

Referring to Figure 4, there is shown a perspective view of the eye 4 with the speculum 2 inserted. The eyelid retainers 20, 22 can be seen engaging the upper and lower eyelids 16, 18, and the eyelash guards 15 are shown preventing the eyelashes 14 from extending substantially over the sclera 10. The Figure shows the guide arm 26 extending over the sclera 10 with side wall 28 following the curvature of the limbus 12, and side wall 30 defining the position of the pars plana 29.

The use of the eyelid speculum 2 to perform an intraocular injection or to extract a sample from the eye 4 will now be described with reference to the Figures. The operator first positions his thumb and/or fingers for grasping the flanges 25 on each retainer 20, 22, and then gently applies pressure thereto. This squeezes the ends of the retainers 20, 22, which are distal to the hinge 24, against the force of the hinge 24 closer together such that the distance therebetween is reduced. The speculum 2 is then positioned nearer the patient's eyeball with the eyelid retainers 20, 22 generally aligned with the upper and lower eyelids 16, 18. The operator then carefully positions the lips 44 on the inside of the eyelid margin, and then gradually decreases the pressure that is applied to the flanges 25, thereby allowing the retainers 20, 22 to return, under the biasing force of hinge 24, to their original position. The result is that the eyelid retainers 20, 22 engage the eyelids 16, 18, which are received in the grooves 47. The eyelashes 14 are retained behind the eyelash guards 15.

Once the eyelids 16, 18 have been engaged, the operator ensures that the guide arm 26 and sponge 32 abut the conjunctiva of the eyeball 4. This is facilitated due to the curvature of their curved lower surfaces 33. The speculum 2 is then left in position for several seconds in order to allow the anaesthetic (or other active agent) in the sponge 32 to act on the eye 4. Once the eye 4 has been suitably anaesthetised, the operator is then ready to administer the intraocular injection or take the sample using his/her dominant hand. If carrying out an injection, active agent (e.g. steroid) is first taken up by the syringe 46, and its needle 48 is then carefully placed along guideline 30 formed -17 -by the outer facing sidewall 30 of the guide arm 26, which denotes the position of the pars plana 29. The needle 48 is then carefully inserted into the sclera 10, and urged perpendicularly into the eye 4, as far as the vitreous humor 40, at which point the pharmaceutical agent is released. Once the agent has been released, the needle 48 and syringe 46 are withdrawn. If taking a sample, the needle 48, which is attached to an empty syringe 46, is inserted into the pars plana 29 as far as the vitreous humor 40, at which point fluid and/or cells are then drawn up into the syringe 46.

To remove the eyelid speculum 2, pressure is again applied to the two flanges 25 such that the two eyelid retainers 20, 22 are urged closer together, thereby disengaging the eyelids 16, 18 from the grooves 47. The operator then carefully lifts the speculum 2 including the sponge 32 and guide arm 26 away from the eye 4.

Advantages of the speculum 2 reside in the effective and painless manner in which the upper and lower eyelids 16, 18 can be urged open and maintained in the open position during the procedure. The device 2 may be operated with the user's non-dominant hand, leaving his/her dominant free to administer the injection or to take a sample.

The device 2 is a single instrument that combines eyelid retainers specuum 20, 22, eyelash guards 15 and a measuring guideline to facilitate safer and more efficient intraocular injections or sample extraction from the eye. The instrument 2 enables consistently more accurate and reproducible injections or sampling compared to conventional practice, and involves less equipment. The anaesthetic sponge 32 provides improved pain control at the pars plana 29, and also abuts the conjunctiva/sclera 10 to steady the eyeball and limit unwanted ocular movement, thereby avoiding eye damage.

Claims

-18 -Claims 1. An ocular device for guiding a needle to a subject's eye, the device comprising first and second eyelid engagement means each adapted, in use, to engage an eyelid, the engagement means being interconnected by biasing means, which biasing means is adapted, in use, to urge the first and second engagement means apart, and needle guide means adapted to guide a needle to the eye.
2. A device according to claim 1, wherein the device is adapted to be used to carry out an injection into the subject's eye.
3. A device according to claim 1, wherein the device is adapted to be used to extract a sample from the subject's eye.
4. A device according to any preceding claim, wherein the first and/or second eyelid engagement means comprises eyelash guard means for preventing the subject's eyelashes from obscuring at least part of the eye during the procedure.
5. A device according to claim 4, wherein the eyelash guard means comprises a substantially elongate surface, which is adapted, in use, to be placed adjacent the perimeter of the subject's eyelid such that the patient's eyelashes are disposed therebehind.
6. A device according to any preceding claim, wherein the first and/or second eyelid engagement means comprises eyelid receiving means adapted to receive at least a portion of the patient's eyelid.
7. A device according to claim 6, wherein the eyelid receiving means comprises a groove or recess provided in a rearwardly facing side of the eyelash guard means, which groove or recess is suitably si2ed to receive an eyelid.

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8. A device according to either claim 6 or claim 7, wherein the eyelid receiving means is formed between the eyelash guard means and a protrusion, which protrusion extends transversely away from a rearwardly facing side of the eyelash guard means.
9. A device according to any preceding claim, wherein the first and/or second eyelid engagement means comprises gripping means onto which the operator may grip for controlling the relative positions of the engagement means.
10. A device according to claim 9, wherein the gripping means comprises at least one projection, which extends transversely away from the eyelash guard means.
11. A device according to either claim 9 or claim 10, wherein the gripping means comprises a substantially elongate projection, which extends in a direction which is substantially perpendicular with the plane of the eyelash guard means.
12. A device according to claim 11, wherein the gripping means comprises an outwardly facing gripping surface, which the operator grips with his thumb and/or finger of one hand.
13. A device according to claim 12, wherein the gripping surface is undulating, or corrugated, or ribbed.
14. A device according to any preceding claim, wherein the gripping surface comprises, or be coated with a material, which increases friction between the operator's thumb and finger tips and the gripping surface.
15. A device according to any preceding claim, wherein, when the device is in a rest position, the first and second engagement means are disposed in a substantially parallel and mutually opposing position.

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16. A device according to claim 15, wherein, when in the rest position, the distance between the engagement means is greater than the distance between the upper and lower eyelids.
17. A device according to any preceding claim, wherein the biasing means may be made of a material, which allows it to be selectively deformed upon the application of pressure, by the operator, so that the eyelid engagement means are disp'aced inwardly to reduce the distance therebetween to enable their placement adjacent the eyelids.
18. A device according to claim 17, wherein, as the pressure is released, the distance between the engagement means is increased, and the engagement means move away from each other, such that they engage the eyelids.
19. A device according to any preceding claim, wherein the biasing means is a resilient, flexible hinge.
20. A device according to any preceding claim, wherein the needle guide means is arranged, in use, to guide the needle towards the pars plana region of the eye.
21. A device according to any preceding claim, wherein the needle guide means is arranged, in use, to guide the needle into the vitreous humor.
22. A device according to any preceding claim, wherein the needle guide means is arranged, in use, to guide the needle into the ciliary body.
23. A device according to any preceding claim, wherein the needle guide means comprises a guide arm which extends laterally inwardly from at least one or both of the eyelid engagement means, the or each guide arm defining the position of the eye into which the needle should be inserted.
24. A device according to claim 23, wherein the guide arm extends substantially along the same plane as the eyelid engagement means.

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25. A device according to either claim 23 or claim 24, wherein the guide arm comprises a first side wall, which is curved such that its profile corresponds to the curvature of at least a portion of the eye's limbus.
26. A device according to any one of claims 23 to 25, wherein the guide arm has a second side wall, which has a curved profile, and which corresponds to, and thereby defines, the position of the region into which the needle is to be inserted.
27. A device according to any preceding claim, wherein the device comprises a substrate layer, which layer is adapted, in use, to be placed against the anterior surface of the eyeball, the layer comprising an active agent, which may impart its effect on the eyeball when placed adjacent thereto.
28. A device according to claim 27, wherein, in use, the substrate layer abuts at least a portion of the limbus.
29. A device according to either claim 27 or claim 28, wherein the substrate layer extends beyond a peripheral edge of the guide arm.
30. A device according to any one of claims 27 to 29, wherein the substrate layer comprises a sponge or the like, which may have been pre-soaked with the active agent.
31. A device according to any one of claims 27 to 30, wherein the active agent is a pharmaceutical, for example an anaesthetic solution.
32. A device according to any one of claims 23 to 31, wherein the guide arm and/or the substrate layer is curved with respect to its hori2ontal plane, such that it forms a curved or concave lower surface, which contacts the anterior surface of the eyeball.
33. A kit for carrying out an intraocu'ar injection or for intraocular sampling, the kit comprising the device according to any one of claims 1 to 32, and a syringe and needle.

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34. The device of according to any one of claims 1 to 32, or the kit according to claim 33, for use in intraocular injection or for intraocular sampling.
35. A method for guiding a needle into the interior of a subject's eye, the method comprising the steps of:- (i) positioning the device according to any one of claims 1 to 32, or the kit according to claim 33, on a subject's eye; and (ii) guiding a needle via the guide means until the tip of the needle is positioned in the interior of the eye.
36. A method of administering, to a subject in need of treatment, a composition comprising an effective amount of a medicament for treating a condition of the subject's eye, the method comprising the steps of:- (i) positioning the device according to any one of claims 1 to 32, or the kit according to claim 33, on a subject's eye; (ii) guiding a needle coupled to a syringe containing the composition via the guide means until the tip of the needle is positioned in the interior of the eye; and (iii) expelling the composition into the interior of the eye.
37. A method of taking a sample from a subject's eye, the method comprising the steps of:- (i) positioning the device according to any one of claims 1 to 32, or the kit according to claim 33, on a subject's eye; (ii) guiding a needle coupled to a syringe until the tip of the needle is positioned in the interior of the eye; and (iii) drawing a sample from the interior of the eye into the syringe.