LOADING PLATE FOR OPHTHALMIC LENS

Abstract: A loading plate for use in the insertion of an intraocular lens (20) having a leading haptic (22) and a trailing haptic (24) into a lens injector has a surface recess for the lens and the haptics. The lens (20) is seated in a first, generally circular recess portion and the haptics lie in arcuate second and third recess portions (16, 18) below the plate surface. A deeper linear slot (28) is provided to receive the lower jaw of a pair of forceps, so that the lower jaw can pass over the trailing haptic (24) and below the rear edge of the lens.

Description: LOADING PLATE FOR OPHTHALMIC LENS Field of the Invention: This invention relates to loading plates for use in the insertion of an intraocular lens into a lens injector for subsequent insertion into the eye. Description of the Prior Art : Conventionally, a lens injector is used in combination with a loading plate and a pair of forceps. Initially, the intraocular lens is set on the loading plate. The loading plate is provided with a surface slot and with a number of pins set on the locus of a circle so that the leading haptic and the trailing haptic on the lens are held by the pins. When correctly positioned, the lens overlaps one end of the slot. The lower jaw of the forceps is placed in the slot of the loading plate, making sure that the trailing haptic is below the jaw. With the forceps open, the lower jaw is slid forwards until it strikes the end of the slot . When the lower jaw is thus correctly registered, the forceps are closed, gripping the lens firmly. The lens can then be loaded into the injector. Further details of this procedure are described in our International patent application PCT/GB99/00216 , published as W099/37247. Under some circumstances the upstanding pins used on the conventional loading plate may catch one or other of the haptics. It may also be difficult to position the haptics correctly in relation to the pins . Summary of the Invention: It is an object of the present invention to provide a loading plate of an improved nature which facilitates the loading of a lens which has haptics and which also reduces the risk of one or other of the haptics being wrongly positioned. In accordance with the present invention this is achieved by a loading plate for use in the insertion of an intraocular lens having a leading haptic and a trailing haptic into a lens injector, comprising a plate having a surface recess, the recess having a first portion in which the lens is arranged to be seated and second and third portions in which the leading and trailing haptics respectively are arranged to lie. With this arrangement, the haptics can sit below the surface of the loading plate. The recess portions in which the haptics lie are preferably curved, to receive the leading and trailing haptics respectively, with the curves preferably being symmetrical . A further advantage of the use of recessed channels for the haptics is that the haptics can then be biased automatically towards the outside of the channels, which additionally reduces the risk of adverse contact between the forceps and the haptics . Preferably, the recess includes a linear slot portion for receipt of the lower jaw of a pair of forceps, the slot portion having a greater depth than said first, second and third portions. Brief Description of the Drawings: In order that the invention may be more fully understood, a presently preferred embodiment of loading plate in accordance with the invention will now be described by way of example and with reference to the accompanying drawings . In the drawings : Fig. 1 is a top plan view of the loading plate with its recess ; Fig. 2 is a side view of the loading plate of Fig. 1; Fig. 3 is a view on an enlarged scale of the recess in the loading plate, showing the lens in place; and Fig. 4 illustrates how the lens is picked up from the loading plate using forceps. Description of the Preferred Embodiment: The loading plate, which is indicated generally at 10, is a thin rectangular plate, for example of titanium or a titanium alloy. Midway along the length of the plate there is provided a recess 12 in the upper surface of the plate. The recess 12 has a depth which is approximately half the depth of the plate 10, as can be seen most clearly from Fig. 2. The recess 12 has a generally circular central portion 14 which extends forwards and rearwards as arcuate recess portions 16 and 18 respectively. The arcuate recess portions 16, 18 each extend through an angle of substantially 90°. The configuration of the central portion 14 and arcuate portions 16 and 18 of the recess corresponds generally to the shape of the lens with its haptics which is to be positioned in the recess. As is shown in Fig. 3, when the lens 20 is placed within the central portion 14, the leading and trailing haptics 22 and 24 respectively lie within the respective arcuate portions 16 and 18 of the recess and by their nature lie in contact with the outer wall of the arcuate portions. This is due to the self-biasing nature of the haptics 22, 24. Because the haptics sit in channels, they lie below the surface of the loading plate . At the rearward end of the recess 12 there is provided a linear extension 26 of the arcuate section 18, and also a deeper recess 28 which is of slot-like shape and which extends forwards to a position just below the rearward edge of the lens 20 when the lens is seated in the central portion 14 of the recess. The rear extension 26 and the deeper recess 28 serve as guides for the forceps which are used to pick up the lens from the loading plate. The particular configuration of the recess which is shown in the drawings is not to be regarded as limiting the scope of the invention. Other dimensions and configurations can alternatively be used. Fig. 4 shows how a pair of forceps 30 are used to pick up the lens 20 from the loading plate. The forceps comprise an upper jaw 32 and a lower jaw 34. Each jaw, which is of titanium or a titanium alloy, has a tip insert 36, 38 of PEEK material. The upper tip insert 38 has a stop 40 upstanding from its upper surface. In use, the lens 20 is first placed on the loading plate in the position shown in Fig. 3. The forceps 30 are opened and the lower jaw 34 is placed in the slot 28 in the loading plate, making sure that the trailing haptic 24 is below the jaw. With the forceps open, the lower jaw is slid forwards until the tip insert 38 strikes the forward end of the slot 28. The forceps are then closed, gripping the lens 20 firmly between the tip inserts 36, 38. The lens can then be loaded into the injector for delivery. Holding the lens firmly with the forceps, the leading haptic 22 is placed in a loading guide of the injector and the forceps are slid forwards until the lens is correctly positioned. This is defined by the stop 40 engaging an abutment in the injector. The tips of the forceps are then opened and removed from the injector, leaving the lens in the correct position.

Claims: CLAIMS 1. A loading plate for use in the insertion of an intraocular lens (20) having a leading haptic (22) and a trailing haptic (24) into a lens injector, comprising a plate (10) having a surface recess, the recess having a first portion (14) in which the lens (20) is arranged to be seated and second and third portions (16, 18) in which the leading and trailing haptics (22, 24) respectively are arranged to lie. 2. A loading plate as claimed in claim 1, in which the first portion (14) of the recess is circular and the second and third portions (16, 18) of the recess are arcuate. 3. A loading plate as claimed in claim 2 , in which the curvature of the arcuate recess portions (16, 18) is such that the haptics (22, 24) lie in contact with the respective outer walls of the recess portions. 4. A loading plate as claimed in claim 2 or 3 , in which the arcuate recess portions (16, 18) each extend through an angle of substantially 90°. 5. A loading plate as claimed in any preceding claim, in which the recess includes a linear slot portion (28) for receipt of the lower jaw (34) of a pair of forceps, the slot portion (28) having a greater depth than said first, second and third portions. 6. A loading plate as claimed in claim 5, in which the linear slot portion (28) partially underlies the third portion (18) in which the trailing haptic is arranged to lie and underlies a rear part of the first portion (14) in which the lens is arranged to be seated. 7. A loading plate as claimed in any preceding claim, in which the depth of the first to third portions (14, 16, 18) of the recess is approximately half the thickness of the plate (10) .

Inventors: WALDOCK TERENCE ARNOLD, WALDOCK, TERENCE, ARNOLD
Applicants: DUCKWORTH & KENT LTD, WALDOCK TERENCE ARNOLD, DUCKWORTH & KENT LIMITED, WALDOCK, TERENCE, ARNOLD
Application year: 2000
Main classification: A61F2
IPC codes: A61F2