GB2437252A - Capsulorhexis custotomes and capsulorhexis forceps with visible scale at tips - Google Patents

Abstract

A visible scale marked on the functional tip of a capsulorhexis cystotome needle or a pair of capsulorhexis forceps. The capsulorhexis cystotome needle may comprise shaft 6, a standard adaptor 5 for attachment to conventional medical syringes and a metric scale 8 marked on the functional tip 7 to visibly assist the surgeon in making a complete circular capsulorhexis of the correct size and position in the anterior lens capsule during cataract surgery. The capsulorhexis forceps may be similarly marked with a visible scale.

Description

<p>Capsulorhexis cvstotomes and capsulorhexis forceps with visible scales

at tip.</p>

<p>Background and problem</p>

<p>The human eye works by focusing images on to the hack of our eye using a lens which sits within the anterior segment of the eyeball. With ageing and in some disease states this lens can become cloudy and opaque resulting in reduced vision. We refer to these opacities as cataracts. There are four main types of cataract depending on the anatomical location of the opacity: nuclear; cortical; posterior sub-capsular; and congenital. All can reduce vision and make the activities of daily living difficult.</p>

<p>Cataract surgery is the method by which cataracts are removed from the eye by extracting the cloudy lens and replacing it with a new synthetic intra ocular lens implant thereby improving the patients vision. The human lens sits within a capsule and in order to remove it we need to gain access through the front of this capsule. This is done is by making a circular tear known as a complete circular capsulorhexis (CCC) in the anterior part of the capsule. The most common way of doing this is to use a capsulorhexis cystotome to initially prick and then tear the anterior capsule from the centre radially and then either using the same capsulorhexis cystotome or a pair of capsulorhexis forceps to teal-a circle in the anterior capsule. After the iCflS has been removed through this opening there remains a capsule Thag' in which to place the new synthetic lens.</p>

<p>In the past the size and centralisation of the CCC on the visual axis has been less important siiice the synthetic lens implants have mainly been of a fixed power. However for more modern multi focal intra ocular lens tmplants it is very Important 10 get the size and Page 1 of 5 2,.</p>

<p>centralisation of the CCC just right for the lens implant This would tend to he a circle of djarncter 5mm centralised on the visual axis. This is because in time after the operation the anterior lens capsule th.at remains tends to go cloudy and can stick to the exposed posterior capsule sometimes distorting the position of the lens. Since the newer multi focal lenses depend on accurate long term positioning a CCC which is either too small or not central may therefore lead to problems with the vision later. It does however follow that a central and circular CCC of an appropriate diameter is beneficial in all types of cataract surgery.</p>

<p>Most experienced cataract surgeons are good at guessing and making the size of the CCC diameter to suite their requirements. However less experienced surgeons and trainees such as myself find this more difficult. Often visual cues such as the pupil diameter are used as a guide/template to the size of the CCC. It erroneously follows that if the pupil is very dilated the surgeon tends to make the CCC too large and if the pupil is small the CCC tends to he too small even though in both cases the relative size of the CCC to the pupil as weighed up in the surgeons mind is probably the same.</p>

<p>Essential features A thorough review of the available capsulorhexis cystotomes and capsulorhexis forceps has revealed several different designs ihr pricking and tearing the anterior capsule and then tearing the CCC, many of which already hold patents. None of these however have marked on their tips a scale so that the surgeon can use these as a visual aid to make the correct size of CCC.</p>

<p>The essential feature ofrny invention is a scale marked on the tip of the capsulorhexis Page 2 of5 3.</p>

<p>cystotome and capsulorhexis forceps so they can he used as a visual aid to make a CCC of a specific diameter to suite the intra ocular]ens size being used. Essentially the scale will act as a ruler SO thai the operating surgeon when looking down the microscope whilst making the CCC can measure the size of CCC he wishes to make. The scale marks could beat intervals measured metrically such as in 0.5mm or 1mm steps, imperial distances or other distances designed to suite the surgeon depending on their preferences. This idea represents an inventive step on the capsulorhexis cyslotorne and capsulorhexis forceps. I feel this invention involves a inventive step which when compared with what is already known it would not be obvious to sonic one with a good knowledge of the subject. I have been modifying my capsulorhexis cystotomes and capsulorhexis forceps in this way and have found it a great help to making CCC of correct diameter. I would like to protect my invention so that I can produce capsulorhexis cystotomes and capsulorhexis forceps incorporating this inventive step.</p>

<p>1 feel it is important to clarify here that every time a different surgical instrument is placed in to the eye during cataract surgery there is an increased risk olintroducing an infection with the instrument which potentially could he sight threatening. For this reason in cataract surgery we try to keep the number of ently and exit times in to and out of the eye to the bare essential minimum, It therefore makes more sense to add ray inventive step to an instrument already being used at the time one is making the CCC such as the capsulorhexis cystotome or capsulorhexis forceps rather than merely introducing another separate instrument to act as a ruler.</p>

<p>The method by which marking of the scale on the instrument is achieved could he one of eil.her painted, engraved or moulded during initial construction. The essential feature is to have a scale oImarks on ihe tip of the instrwnenl which will he visible to the surgeon when Page 3 of</p>

<p>L</p>

<p>he looks at the eye through the microscope during thc formation of the CCC. It is also feasible that if we were aiming for a 5mm diameter CCC then only one mark denoting 5mm from the tip of the instrument would he needed so as to not confuse the surgeon with multiple marks.</p>

<p>In this case it would be possible to make either side of the mark on the instrument a different colour to individually suite to a clients preferences. I would like to clarify that it is not the method of production or presentation of th.e scale marldngs on the instruments, or the structural design of the instruments and material from which the capsulorhexis forceps and capsulorhexis cystotomes are made which I am hoping to patent. Rather I am hoping to patent the actual inventive step of the use of a visible scale on these instruments at i.heir functional tips to act as a visual aid to the surgeon when making the CCC to help make it the correct size. Hopefully the following drawings will explain my inventive step (figures 1-3).</p>

<p>Introduction to drawings</p>

<p>Figure 1 shows a pair of capsulorhexis forceps with a handle I, arms 2, and functional tips 3 which grip the tearing anterior capsule. A. metric scale 4 of either 0.5mm or 1mm gradations depending on which is preferred by the client is visible running from the functional tip 3 back along the arms 2.</p>

<p>Figure 2 shows a capsulorhexis cystotome with standard adaptor 5 for attachment lo conventionally used medical syringes, shaft 6, and functional tip 7 which tears and peels the anterior capsule. A metric scale 8 of either 0.5mm or 1mm gradations depending on which is preferred by the client is visible running from the functional tip 7 back along the shaft 6.</p>

<p>Page 4 01 5 *1 Sib Figure 3 shows a pair of capsulorhexis fbrceps with a handle 9, arms 10, and functional tips 11 which grip the tearing anterior capsule. A visible mark 12 is placed a specific distance e.g. 5mm (but this could be varied to suite the clients choice relative to the intra ocular lens being used) from the functional tip 11 back along the aims 10.</p>

<p>Page 5 of 5</p>

Claims (1)

1. <p>CLAIM S</p>

   <p>1. A visible scale marked on the functional tip of a capsiilorhexis cystotome needle and a pair of capsulorhexis forceps.</p>