AU731958B2 - Surgical method and instruments - Google Patents

Description

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AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT Name of Applicant(s): Actual Inventor(s): Address for Service: LEE MUIR LENTON LEE MUIR LENTON CULLEN CO., Patent Trade Mark Attorneys, 240 Queen Street, Brisbane, QId. 4000, Australia.

SURGICAL METHOD AND INSTRUMENTS Invention Title: r Details of Associated Provisional Applications: Nos. PO4273 The following statement is a full description of this invention, including the best method of performing it known to me: THIS INVENTION relates to a method of performing eye surgery and to instruments used in the method. In particular, the invention concerns a method of performing laser assisted intrastromal keratomuleusas (LASIK) surgery and to instruments used in the method.

Laser surgery to correct near sightedness, hypermetropia, myopia and astigmatism involve ablation of the surface of the cornea or surface photo refractive keratectomy. Laser ablation is employed to remove between about to 100 jLm from the surface of the cornea. With such surgery, several days, typically four or five days, must elapse for the cornea to heal before the eye recovers from the effects of the surgery.

LASIK surgery of the eye and in particular, lamella photo refractive keratectomy is preferable over surface photo refractive keratectomy described above. With lamella keratectomy the eye may be uncovered and effectively used •the day after the surgery is conducted.

Lamella keractectomy involves cutting a circular flap from the cornea. The flap remains attached to the surface of the cornea by a short hinge or unsevered portion. Once the flap is formed, it may be moved away to expose a part of the cornea for ablation. To achieve this, the flap is manipulated and .oo* pivoted about the hinge to uncover the area to be ablated. Both prior to cutting the flap from the cornea and after laser ablation is carried out, the eye is irrigated and cleaned of debris and excess fluid is removed. This aspiration and cleaning is particularly tedious with present laser surgery methods and the instruments presently available. Currently, there are no instruments available which provide for easy and effective aspiration and irrigation.

25 A biconvex spatula is currently employed for lifting the corneal flap to expose the stromal bed for laser ablation. This spatula has its anterior surface rounded and smoothly polished while the posterior surface is flat. The slightly convex spatula conforms to the curvature of the cornea and has a semi-sharp dissecting edge at its tip. The spatula is employed for elevating and dissecting the corneal flap. The spatula may also be used for sweeping the stromal bed to remove epithetial cells from the interface. After the flap is repositioned employing the spatula, the spatula may then be used to express excess fluid trapped under the flap and to smooth out the flap and to correctly reposition the flap over the cornea.

It would be preferable to shield the flap from exposure to the laser but the spatula mentioned above is not particularly effective for doing this.

It is an object of the present invention to provide an instrument for use in performing eye surgery which at least minimises the disadvantages mentioned above.

According to one aspect of the invention, there is provided an irrigating instrument having a stem and an irrigating head at one end of the stem, the head having apertures through which an irrigating fluid may be expelled, the head having an underside portion devoid of irrigating apertures.

The head may be substantially circular when viewed in plan, although other shapes are not excluded. The head has an upper face. The upper face may be substantially flat although it is preferred that the upper face be 15 convex.

As mentioned, the underside of the head has a portion devoid of irrigating apertures. Preferably, irrigating apertures are also present in the upper face of the head. The portion of the underside without apertures may be centrally located on the underside of the head. Preferably, the irrigating apertures in the 20 underside are at locations extending around the portion devoid of apertures. The ***head is preferably hollow.

Preferably, the underside is convex in shape.

S: The stem extends outwardly from the head. Preferably, the stem has a first portion extending outwardly from the head and a second portion extending from the first stem portion and upwardly with respect to the head. At least a portion of the stem is hollow and allows irrigating fluid introduced into the stem to be conveyed to the head where it may exit from the irrigating apertures provided in the head. It is preferred that irrigating apertures also be present in the stem. Preferably, the first stem portion has irrigating apertures.

According to a further aspect of the invention, there is provided an aspirating instrument for use in eye surgery, the instrument having a head adapted to extend around a cornea of the eye and into which the cornea may extend, aspirating apertures at spaced intervals around the head and communicating with the interior of the head, a support extending from the head and on which a corneal flap may rest to provide access to a stromal bed of the cornea and a stem extending from the head through which fluid entering the head through the aspirating apertures may be conveyed away from the eye during surgery.

The stem preferably has a first portion extending outwardly from the head and a second portion extending from the first stem portion and upwardly of the head. Preferably, the stem is hollow along its entire length. It is preferred that the stem be located on an opposite side of the head to the flap support.

The head is preferably annular in shape and contoured to rest against the conjunctiva with the cornea located within and encircled by the head. The aspirating apertures are preferably present on just an upper face of g is the annular head and at spaced locations around the head.

The support may be fixed relative to the head and extend outwardly and downwardly of the head. During surgery, the corneal flap is folded over to expose the stromal bed and rests against the support. In this way, the flap is held spaced from the adjacent portion of the conjunctiva and less likely to be 20 contaminated with foreign matter. Rather than having the support fixed to the head against relative movement with respect to the head, the support may be pivotally mounted to the head. In this way, when the aspirating instrument is placed onto the eye, the support is free to move into contact with the eye and its movement is governed by the natural contour of the eye. Where the head is annular in shape, the support may be located diametrically opposed to the stem.

According to another aspect of the invention, there is provided a spatula for manipulating a corneal flap during eye surgery, the spatula having a head with a free leading end and a trailing end, a stem extending from the trailing end and upwardly of the head, the head having a sole portion with an outwardly and downwardly curved shape, the head having an intermediate portion between the leading and trailing ends of a substantially greater width than the ends, and the free end is stepped relative to the remainder of the head and terminates in a reduced thickness portion with an arcuate shape.

It is preferred that the head have an upper surface opposed to the sole and which has an outwardly and upwardly curved shape.

The arcuate edge is preferably semi-sharp and may be employed for dissecting tissue of the eye.

According to a further aspect of the invention, forceps are provided having a pair of arms pivotally coupled to each other at a location between their ends with each arm having a handle at one end and jaw at the other end, each said jaw terminating in a tip and having a forward contact portion and rearwardly spaced recessed portion such that when the forceps are operated the contact portions may be brought into contact with each other and the recessed portions provide clearance for the tissue being grasped by the 15 forceps.

The handles are preferably substantially flat and the users thumb and forefinger may engage against the handles for pivoting the arms of the forceps. Preferably, the arms are biased so that the jaws are normally spaced apart and the bias needs to be overcome to bring the contact portions of the :00 jaws against each other. A spring, either a leaf or coil spring, may provide this o 20 bias.

According to another aspect of the invention, there is provided a S• method of eye surgery comprising the steps of: Cutting a corneal flap from the cornea; Positioning an aspirating instrument such as the one described above against the eye; Using either forceps such as the one described above or the spatula mentioned above to hinge the corneal flap to one side to expose the stromal bed and to cause the flap to extend over the support of the aspirating instrument; Conducting laser ablation on the stromal bed; Employing an irrigating instrument such as the one mentioned above to irrigate the eye; Removing excess irrigating fluid from the eye with the aspirating instrument; Returning the corneal flap so that it extends over the stromal bed and employing the aperture free portion of the underside of the irrigating instrument to smooth out the corneal flap and to express excess fluid trapped under the flap; and Properly repositioning the flap over the cornea.

Preferably, the irrigating instrument is used to irrigate and clean the eye prior to the cutting of the corneal flap and the aspirating instrument is employed to remove excess fluid during this initial cleaning process.

emlydOnce the stromal bed has been laser ablated, the spatula may be employed for sweeping the stromal bed for removing epithelical cells from the interface. The irrigation instrument may be used to flush the stromal bed and excess fluid may be removed by the aspirating instrument.

.i 15 The forceps, spatula or the aspirating instrument may be employed to reposition the comrneal flap over the cornea. Preferably, the aspirating instrument is employed for this purpose. The aspirating instrument may be moved laterally across the eye to reposition the flap.

Once the flap is repositioned the sole or underside of the irrigating S: 20 instrument may be used to smooth out the flap and expel excess fluid from under the flap. The spatula may also be used for this purpose.

Once the surgery is complete, the periphery of the flap reattaches itself to the cornea and if at some future stage further ablative surgery is required the forceps may be used to partially sever the flap again from the cornea with a hinge remaining connecting the flap to the cornea.

Particular preferred embodiments of the invention will now be described with reference to the drawings in which: Figures la, b, c and d are side, front, plan and perspective views of a spatula according to an embodiment of the invention; Figure 2 is a perspective view of forceps according to an embodiment of the invention; _Figure 3 is a perspective view of part of an aspirating instrument according to an embodiment of the invention; and, Figures 4a, b, c and d are plan, side, inverted plan and front views of an irrigating instrument according to an embodiment of the invention.

With reference to Figures la, b, c and d, the spatula 10 will be described. The spatula 10 has a head 11 and a stem 12. The head 11 has a free leading end 13 and a trailing end 14. Sole portion 15 is contoured as shown in Figure lb. Intermediate portion 16 is of a greater width than the ends 13 and 14. The upperside 17 is curved and this side meets with the sole portion 15 to define lateral edges 18, 19.

Free end 13 terminates in a semi sharp edge 20 and is stepped at 21.

21. Figure 2 shows a view of forceps 30. The forceps 30 have two arms 31 and 32 terminating in flat handles 33, 34 at one end and jaws 35, 36 at the other end. Hinge 37 connects the arms to each other. A spring (not shown) biases the jaws apart.

Each jaw has a forward contact portion 38, 39 terminating in semisharp edges and a rearwardly spaced recessed portion 40, 41.

The aspirating instrument 50 has an annular head 51 with aspirating apertures 52, a support 53 is hinged at locations 54, 55 to the head. The head 20 is hollow and has a stem 56 extending from it. The stem 56 is hollow and communicates with the interior of the head to allow a source of suction applied to the stem to draw fluid through the apertures 52 and through the stem.

The irrigating instrument 60 of Figures 4a, b, c and d has a head 61 and a stem 62. The stem has a first portion 63 and a second portion 64.

Irrigating apertures 65 are present in the head both in the upper surface, along the stem portion 63 and over part of the underside of the head as shown in Figure 4c. The head and the stem are hollow to allow irrigating fluid to be introduced into the stem to be expelled through apertures 65. A central region of the underside of the head is devoid of apertures for reasons previously mentioned.

The spatula of Figure 1 has multiple uses as previously mentioned and because of its width may be used to shield the hinge which connects the 8 corneal flap to the cornea from laser irradiation during laser ablation of the stromal bed.

The irrigating instrument may be used to irrigate and clean the eye as well as to smooth and reposition the flap over the stromal bed after surgery.

The aspirating instrument not only allows excess fluid to be removed from the eye, but also supports the flap during laser ablation and may be used to reposition the flap over the comea after ablation and irrigation.

**0 o• *o •o

Claims (6)

1. A spatula for manipulating a corneal flap during eye surgery, the spatula having a head with a free leading end and a trailing end, a stem extending from the trailing end and upwardly of the head, the head having a sole portion with an outwardly and downwardly curved shape, the head having an intermediate portion between the leading and trailing ends of a substantially greater width than the ends, and the free end is stepped relative to the remainder of the head and terminates in a reduced thickness portion with an arcuate sharpened edge.

2. The spatula of claim 1 wherein the head has an upper surface opposed to the sole and which has an outwardly and upwardly curved shape.

3. A method of eye surgery when using the spatula of claim 1 or claim 2, which method comprises the steps of: Cutting a corneal flap from the cornea and hinging the 15 corneal flap to one side using said spatula to expose the stromal bed; Conducting laser ablation on the stromal bed; S Irrigating the eye; o.oo Removing excess irrigating fluid from the eye; and 20 Returning the corneal flap so that it extends over the stromal bed, smoothing out the corneal flap to express excess fluid trapped under the flap and properly repositioning the flap.

4. The method of claim 3 wherein the spatula is used for sweeping the stromal bed for removing epithelical cells after laser ablation.

5. The method of claim 3 or claim 4, wherein the spatula is used to reposition the flap.

6. A spatula for manipulating a corneal flap during eye surgery substantially as hereinbefore described with reference to any one of figures 1 a, b, cord. DATED this 8 t h day of February 2001 LEE MUIR LENTON By His Patent Attorneys CULLEN CO.