The invention relates to an ophthalmic device for intravitreal administration of a substance into a human or animal eye by means of a needle, comprising a support structure having a lower surface for contacting the conjunctiva of the sclera, the lower surface being provided with an aperture for receiving the needle.
In ophthalmology, a medical substance can be injected into the corpus vitreum to treat eye diseases such as intraocular inflammation, macular edema, retinal new vessel formation as in proliferative diabetic retinopathy and choroidal neovascularisation as in age-related macular degeneration. The injection is performed by a needle that is usually pierced through the sclera at the so-called pars plana at a distance of approximately 3.5 mm from the limbus being the corneoscleral transition zone.
The position where the needle is to be inserted into the sclera is usually determined on the basis of the ophthalmologist's visual assessment and the aid of a measuring device. A needle that is inserted at an incorrect position or at an incorrect angle may cause complications, such as intraocular hemorrhage, lens damage leading to cataract, retinal perforation and detachment. Further, eyelids are kept open by separate fixation elements to avoid that a blinking movement of the patient's eye interferes with the insertion of the needle. However, the application of such eyelid fixation elements is uncomfortable for the patient.
It is an object of the invention to provide an ophthalmic device according to the preamble wherein at least one of the disadvantages mentioned above is counteracted. In particular, the invention aims at providing an ophthalmic device according to the preamble that increases the safety, the surgical simplicity and/or the patient comfort of the intravitreal injection procedure. Thereto, the support structure further comprises a substantially tapering part directed away from the lower surface and the device also comprises a channel provided in the tapering part wherein a first end of the channel forms the aperture in the lower surface.
By providing the tapered part including the channel, contact of the eyelid margin with the injection site is avoided. As a result, the device according to the invention provides an antiseptic effect. A further antiseptic effect may be obtained by guiding droplets, such as a disinfectant, e.g. povidon iodine, through the channel towards the injection site, thus increasing the safety of the injection procedure. Obviously, also other droplets, such as an anesthetic, e.g. cocaine, can be guided through the channel. Optionally, the droplets are fed to the conjunctiva via a passage formed by the second end of the channel, towards a second substantially tapering part serving as a receptor, both tapering parts being oriented in an opposite way forming an hour-glass shape.
It is further noted that the channel structure guides the needle through the device into the eye in a predetermined orientation, preferably perpendicular with respect to the lower surface of the support structure, thereby preventing damage caused by poor orientation of the needle. In addition, the channel structure enables setting a predetermined maximum penetration depth of the needle, e.g. 5 mm into the vitreous body. To that end, an appropriate needle and channel geometry and dimensions can be chosen to set the maximum penetration depth accurately, thereby preventing undesired extremely deep penetration of the needle into the eye.
The all-in-one design of the ophthalmic device according to the invention further simplifies the procedure in such a way that the skills required to perform the intravitreal procedure are greatly reduced. To precisely identify the injection site which is at the pars plana, the size of the lower surface may act as a measuring device. Thereto, the distance between the needle guiding channel aperture and the edge of the support structure lower surface can be chosen to have a predetermined distance, e.g. exactly 3.5 mm. When the lower surface edge is placed on the sclera, tangent to the limbus, the needle channel being directed away from the cornea towards the conjunctival fornix, the penetration site will be precisely through the pars plana.
Further, the all-in-one design of the device according to the invention renders the need to insert an eyelid speculum superfluous since there is no need to grasp the conjunctiva with forceps. The lower part of the device prevents contact of eyelids with the injection site or needle as the surface of the circumference of the lower part of the device that will make contact with the conjunctiva, is serrated. The device being controlled through a hand piece can thus be used to stabilize and control the eyeball.
Moreover, by providing the tapered part with the channel, a structure is obtained that provides a relatively comfortable and effective protection against the eyelids when the needle is received in the aperture. Here, the eyelids can contact the tapered part in an ergonomic way without reaching the needle and the penetration site. Further, due to the presence of the channel, the needle may be inserted towards the aperture of the lower surface, even when the eyelids are in semi-closed position.
In an advantageous embodiment according to the invention, the support structure further comprises a second substantially tapering part, wherein the tapering parts are oriented in an opposite way forming an hour-glass or diabolo shape. By providing the second substantially tapering part, the needle can easily and safely be guided towards the channel in the first substantially tapering part. In principle, the device can also be implemented without the second substantially tapering part, e.g. in order to obtain a very compact device.
In a further advantageous embodiment according to the invention, the needle forms an integral member of the device so that operation of the device can further be simplified.
The invention also relates to an intravitreal method of administrating a substance into a human or animal eye.
Other advantageous embodiments according to the invention are described in the following claims.
By way of example only, embodiments of the present invention will now be described with reference to the accompanying figures in which
It is noted that the figures show merely a preferred embodiment according to the invention. In the figures, the same reference numbers refer to equal or corresponding parts.
The needle 5 is movable in a pre-determined range in a direction D through the channel 7, along the axis of the channel 7. In particular, the movement of the needle 5 is stopped at two end positions of the pre-determined range by one or more stoppers to control the movements of the needle 5. Preferably, in a retracted position, the needle does not extend through the aperture 4 to avoid damage or injuries. Further, in a distal position, the needle may penetrate through the sclera 12. A stopper can e.g. be implemented by providing the needle 5 with an integrated member 21 that abuts against the housing 20 when the pre-determined distal position has been reached. Similarly, a pre-defined retracted position can be defined. However, the pre-defined range can also be open at the retracted position, thereby allowing that the needle 5 is removed from the housing 20 of the device 1 relatively easily.
The device 1 further comprises an elastic element 22, e.g. implemented as a spring element, for exerting a backward pulling force on the needle 5 in a direction away from the lower surface 3 of the support structure 2, so as to obtain a device that normally has a retracted needle 5 when no manual pulling forces are exerted on the needle 5, thereby further enhancing the safety of the device 1. In
The ophthalmic device 1 according to the invention therefore facilitates keeping the eye open, fixing the sclera, determining the pars plana and piercing the needle using a single instrument.
The invention is not restricted to the embodiments described herein. It will be understood that many variants are possible.
Other such variants will be obvious for the person skilled in the art and are considered to lie within the scope of the invention as formulated in the following claims.
Number | Date | Country | Kind |
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2002379 | Dec 2008 | NL | national |
Filing Document | Filing Date | Country | Kind | 371c Date |
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PCT/NL2009/050808 | 12/28/2009 | WO | 00 | 12/21/2011 |