Louise King

Okay, I think most have joined so good evening, my name is Louise King and I'm your presenter this evening. Welcome to our webinar on special lenses, astigmatism, and Callisto. Our expert and presenter is Consultant Ophthalmic Surgeon, Mr Jonathan Aboshiha. This presentation will be followed by a Q&A session. If you'd like to ask a question during or after this presentation, please do so by using the Q&A icon which is at the bottom of your screen, this can be done with or without giving your name. Please note this session is being recorded if you do provide your name. If you'd like to book your consultation, we'll provide contact details at the end of this session. I'll now hand over to Mr Jonathan Aboshiha and I'll hear from you again shortly.

Mr Jonathan Aboshiha

Thank you. Hello everyone, I hope you can all hear me well. Thanks for joining us this evening. We're just going to go through a few topics that might be of interest to anyone who is considering having cataract surgery, particularly if you're thinking about coming to Benenden as bits of equipment and some techniques are pretty unique, at least in my experience in the NHS. That includes state of the art equipment which is partly what we're going to talk about and also a little bit about what that's useful for and how that might affect your choices for lenses, to replace your cloudy lens which is your cataract which we take out during the operation.

So a little bit about me, studied medicine at Cambridge, went to Australia for a few years, ended up doing brains for a bit and then got into eyes spent most of my training when I got back at Moorfields was a consultant briefly and done some research there, my PhD was at UCL which is affiliated with Moorfields and I've done some other training above and beyond the average cataract and clinical training. I've done a couple of fellowships and a few thousand procedures now, time rolls by.

So in this session we're going to cover cataract surgery in its basic forms, astigmatism, what that is and how what we need to do to correct it, toric intraocular lenses and EDOF stroke multi-focal lenses so EDOF is extended depth of focus lenses and they are different to multivocal lenses and talk a little bit about that later something called capsular rhexis, it's a nice Greek term and a product that we use here for our operating called the Callisto operating microscope so obviously caloric surgery and eye surgery is very fiddly and we use an operating microscope and the one we use here is a very state-of-the-art product that I will talk a little bit more in depth about later on and then a little bit at the end about our eye unit and as we said then a question and answer session.

So cataracts what are they well cataract is another word for cloudiness of the lens inside the eye I think it comes from an old term for waterfall I think back many thousands of years ago people thought that there was water in the eye which isn't entirely unsure actually it's probably about 90-98% of the eye cavity is water and that when it became cloudy it was a bit like water bubbling over a book and instead of clear water it was white and opaque and that's why they call it a cataract so the eye or the diagram you can see on the left is your eye or anyone's eye or it's schematic of it cut in half looking from the side and what you can see is the front of the eye, there's something called the cornea and that's really the front clear covering of the eye and then behind that is your iris and the iris is the colour part of the eye that gives people their eye colour to do with melanin which is the same thing that gives us a skin colour and then sitting behind the hole in the middle of the iris which is called the pupil which is the black hole that you see is the lens and the natural lens is made up of little proteins very very carefully organized proteins because as you can tell from everything else in your body it's quite unusual for biological material to be transparent so these tiny little proteins called crystallizes have a very very very highly ordered short-range geometry and that enables the wavelengths of light to go through the lens without being scattered as we get older or from other reasons such as injury diabetes and so forth the short range order of these tiny little proteins is disrupted and they start to scatter like they don't allow this light to pass through the lens so clearly and that is what we call a cataract.

So cataract is a cloudiness of your natural things that existence, the big cavity or space inside the eye of air is called the vitreous humour and that's basically water it's about 98% water and then if you think of the eye as a camera you've got your lens at the front which comprises your cornea and your natural lens and then you've got your photographic film at the back of the eye which is this yellow line and that is your retina and that converts the photons of light into electrical signals which go off through the optic nerve to your brain. In order to see clearly you need to have a clear cornea, clear lens and a functioning, and well, working retina and then all of that needs to go off with some clever electronics into your brain and be processed by the parts of your brain that enable us to perceive vision as well as just sensors so it's quite a complicated little bit of kit we've got but normally works very well. One of the most common things that makes it not work so well is a cataract. Now a cataract is not a disease, it happens to all of us as we get older, some of us a bit younger than others, it's a bit like saying a wrinkles are a disease it is just part of growing up so you haven't got a disease and having it however it is a condition that does have a great impact on our daily life, if it stops us seeing well because we're very visual creatures about a third of our brain input from everything in our body from our taste and our sense and our smell about a third of everything is it's just vision so we are very very visual creatures and we do notice that when our vision declines so the cataracts can affect the vision because they basically scatter light as I was saying earlier the light comes in because here and from the left gets focused probably about two-thirds of the focusing power is in the corner actually not the lens but the clever thing about the natural ends we're born with is it changes shape so you can focus on the distance and you can focus up close when that clear lens becomes cloudy or a cataract everything becomes a bit blurry one of the first things we can notice is a bit of glare that's a very common symptom of cataract also because of the density of the lens.

As we get older we can also notice our glasses become more and more short-sighted or out of glasses prescription and normally the safest way to correct that is just with new glasses but at some point regardless of what glasses you put in front of the eye you will not see clearly because the lens inside the eye is cloudy and that's normally the time which we would suggest cataract surgery is something to think about what is astigmatism so you can see in the diagram on the left the cornea which is the clear front surface of the eye in this diagram which is beautifully drawn it is you know a semicircle it's obviously just a cartoon of a real eye none of us are perfect we're not made of machines and therefore we always have a bit of asymmetry in our finger length and our ear height and so forth and our eyes also are not normally perfectly round or at least half of a football you can see here that if you were to cut up in half or even look at the side of a football the red line the curvature of the vertical red line and what we call a meridian that line of curvature would be exactly the same curvature as the horizontal blue line and and that would be completely spherical that would be a non-toric surface and I'll tell you what toric means at the moment but basically toric is another word for a lens that corrects astigmatism has different powers in the in two perpendicular planes will be the vertical and horizontal but not always vertical horizontal so and I with no astigmatism is as steep a curvature in any direction like a football most eyes have a bit of astigmatism and that's best thought of a bit like a rugby ball where you can imagine a rub on your hand or a football in this case that the curvature the red line the vertical meridian is a steeper curvature than the curvature of the blue line or the horizontal meridian so astigmatism is where if you want to think of it in the simplest terms the front of your eye is a bit more rugby ball shaped than perfectly round football shaped why does that matter well beyond a certain amount of astigmatism it actually blurs the vision and that means that you would need something to correct astigmatism and we'll go on to what that something might be sooner or later.

So if you have a lot of astigmatism and you just replace the cloudy lens inside the eye with a perfectly let's say for example say round lens inside the eye then you will still have the astigmatism that might be in the corner at the front of the eye that would need correction some way or other so some of you might have encountered astigmatism before in your glasses prescription from your optician it might look something like this you'll have a number at the front says minus two or plus two or minus 1.5 something like that and that just tells you whether the eye in general is long-sighted by you can see well in the distance but has struggled seeing up close or is short-sighted I.E you can see pretty well up close but it's troubles to see in the distance.

If you have known what we call refractive error then you would just have a prescription of zero and of course you wouldn't have glasses, however as we get older beyond the age of about 45 we also lose the ability as I mentioned earlier of that lens to change shape and so we find it harder and harder to see things as they come closer towards us so we end up needing reading glasses those of you who have some astigmatism in your glasses prescription will notice that there are not just one number which might be plus for a long-sighted and minus for short-sighted but there's a second number and here that number is is three again the plus and the minus just refer to the the strength of the lenses whether they're positive or negative that second number is what determines or the the degree of astigmatism that your glasses are correcting and you'll see after that number there is a little cross and then 90 degrees and that's because if you remember the rugby ball a rugby ball has an angle at which it is a football this is round and whichever way you move it it's the same roundness everywhere and rugby ball obviously has say the pointy bits and they can be at that angle at that angle at that angle at that angle.

So the issue with astigmatism is there isn't what we call that axis to the astigmatism and that's the orientation along which the cornea might be steeper or less steep than say perpendicular 90 degrees to that so when you get your prescription you see two numbers the second number after a forward slash that means you've got some astigmatism and you can always check that with your optician's prescription the glass is astigmatism which is what we're just talking about is also sometimes called cylinder just another name for that type of astigmatism and it's to correct the combined astigmatism of the natural lens and the cornea I was saying earlier that the cornea is not normally perfectly symmetrical like a football made in a factory and has the most stigmatism but that also applies to your natural lens most of us again we have a natural lens that isn't perfectly symmetrical and there may be a bit of astigmatism in the lens itself the astigmatism of the lens and the cornea combine to give your glasses as temperatures and that's what they're trying to correct these things in the entire eye. When we do cataract surgery we we take out the natural lens so that means we're also removing any contribution of the natural lens to the eyes total astigmatism and what we've got left then is the corneal astigmatism and we measure that in the clinic in ways that are different to how it's measured by your optician and sometimes people say oh well I've got you're telling me I've got much more astigmatism but in my glasses I don't have very much at all or vice versa, my optician said I have a lot of astigmatism and you're telling me I don't and and that's because all we're doing for surgery is measuring the corneal astigmatism because we're going to by definition remove the astigmatism contribution of your natural cloudy lens of the cataract.

So, what do we do with the remaining cornea astigmatism? Well, we can correct it there's always a simple answer with glasses or almost always nothing is always a medicine unfortunately but almost always you can just correct it with glasses but of course then you have to wear glasses and astigmatism will blur the vision especially if it's significant for all distances so that would probably mean wearing glasses for seeing things in the distance, intermediate which is maybe about half a meter and for near which is a maybe about a foot. So if you have a lot of these things more significant corneal astigmatism the doctor may offer you something called a toric lens and all the toric means is that it will try and correct the astigmatism that's in the cornea by counteracting that with some correction inside the lens implant or what's called an intraocular lens implant or IOL which goes inside the eye and you can see that on the right here and the aim of that is to try and give you better vision without your glasses so that's what toric lenses do and that's at all distances now it doesn't mean you will be able to see at all distances because of course if you have a monofocal toric lens that will correct the astigmatism for distance but the mono focal bit means there's one focal point and that's almost always set for distance so you might need a cheap pair of reading glasses but again the benefit of having a toric monofocal lens would be would mean that your distance vision should be pretty good without your glasses and you don't have to have a toric or astigmatism correction in your reading glasses which means you can just get a sort of buy off the shelf pair from wherever you go for those about one in five people have significant cornea astigmatism we normally Define that as above 1.5 dioptres the D just being stopped as and it's the same units that we saw in that previous example of plus three and minus two and whatever your prescription is they're always in units called dioptres or D for short and normally if that second number is above 1.5 that is likely to have reasonably significant effect on the vision such that you won't have very clear vision unless it's somehow corrected and that would either be with glasses or if you're trying to get rid of your glasses from a toric interlocking lens which is put in to replace the cloudy lenses taken out during the surgery now those little rings trying to highlight something that might be a little bit subtle on the screen which is that this lens because it's a toric lens has some little dots as you can see three dot vertical dots inside each of the red circles and that goes back to the point about the rugby ball having an orientation and the axis of their stigmatism we have to align those dots very carefully with the axis of the astigmatism of the cornea so we have to find what angle we need to put the lenses in and that's really really important otherwise you don't get the healing effect or the corrective effect of the toric lens to counteract the astigmatism in the cornea so the aim of this is to try and reduce your need for glasses or you can get rid of your need for glasses so the options for people who have significant astigmatism normally above about one and a half is of course significant that's cornelisticism so you wouldn't necessarily know you have that until you have your assessment with us or wherever you go because the the measurements that are done are not typically done in the up to opticians so you can have as I just described the toric monofocal lens that corrects these for distance should give you good unaided distance vision but you'll need a pair of readers for near vision and possibly for intermediate vision so that's again about reading distance for near and intermediate is about computer or dashboard when you're driving another option.

The next sort of stage up would be something called a toric EDOF lens so EDOF has extended depth of focus there every choice in medicine has a up and a downside so the up size of the EDOF is they give you good unaided distance vision and also intermediate vision so that might be using your computer on your desk or driving and looking at your dashboard they give you better depth of focus than a standard monofocal lens but you probably still will need glasses for near vision if you're reading a small print on your phone or the newspaper and so forth they're not designed for that some people do get away with eat-off lenses that give them near vision but that's not what we we say they do and then the sort of next level up to try and get a spectacle independent as possible is a toric multifocal lens and the aim of that is to get you out of your glasses so you wouldn't need glasses for your distance or for intermediate or for near that's it so the other thing just to be aware of is I mentioned this number of 1.5 but for multi-focal lenses and and to a lesser degree fit extender depth of focus or eat off lenses we need to correct the astigmatism more carefully so even if your corneal astigmatism is less than 1.5 if you are going for an EDOF or a multi-focal lens you may find that we would recommend a toric version of those lenses to correct any sort of astigmatism because the lenses work best when there's minimal amount of astigmatism left in the cornea which is maximally corrected by the lenses.

So I mentioned before that we need to align them why do we need to align them well when we're lying down and then when we sit up most people's eyes rotate a few degrees maybe three to five degrees rotating as we sit up now that also changes between people so some people might rotate one way some people might rotate another way some people whose eyes might rotate quite a lot other people's eyes will rotate very little but what we do need to do is find a way to because you're most of the time looking when you're sitting up we need to find a way of marking the axis that the lens needs to go on when you're sitting up however we haven't yet worked out a way to operate when you're sitting up although I think lots of patients would like it but yeah we still need to get you to lie flat on a couch when we're doing the operation and of course then the eye rotates so there's an issue there about how do we make sure we're aligning it to the correct axis when you're sitting up given that when we're measuring it you're lying down and so traditionally what we do is we mark it with ink when you're sitting up in the pre-op room and then you lie down and we know where the marks are for when you're sitting up.

What Benenden has invested quite heavily in his is a state-of-the-art microscope called the Callisto and what that does is use a head up display for the surgeon to perfectly align the toric lens so that allows the surgeon to align the axis orientation of the toric lens to correct the astigmatism perfectly because with every X number of degrees your off axis you lose some of the corrective power of the turret lens and what you want to do is have it you know corrected as as you you expect to really reduce the astigmatism down to a negative amount these head-up displays are pretty cool things when you see them the picture of the bottom is just one in a plane actually came I think originally from spitfire gun site was kind of most primitive one but really it was in the 60s there was a plane called the buccaneer and it was meant to carry nuclear munitions and these pilots were flying very very low very very fast and maybe we'd only see the the target for a you know fraction of a second and so they didn't have time to look up to a bomb site look down to their instruments so that's when I think that was one of the first planes if not the first plane to have something called a head-up display which I'm sure people have seen in TV programs and movies but it's based on the same principle that you know if the eye moves a little bit the surgeon always has the exact angle to put these lenses on you can see those in the top screen there's three blue lines and that's telling you were to align the the lens as you put it in and it actually moves with the eye and it also tracks the the eye as it rotates between lying down and standing up so when you have your pre-assessment the computer talks to the microscope and actually says this is what the eye is aligned when when you're sitting up and that's what we want to know and it actually accounts for that for when you're lying down the surgeons taking down the microscope so it's a very very clever bit of kit and you know there are not that many places I did a bit of research try and work out I think it's less than 15% of our units in the UK have this technology and that's that's mainly because you know the obviously the NHS is not providing toric lenses in the ways that it used to and also it's a very expensive bit of kit but it's an it's a great piece of kit to work with for the surgeons because we're very reassured that patients are getting the absolute best service and that we are allowing those lenses absolutely perfectly to correct their stigmatism so just to run over a little bit of caloric surgery.

I might have seen this if you saw my last talk it takes about 10 to 15 minutes on average sometimes a bit quicker sometimes a bit longer we make little incisions in the cornea which is the clear part of the front we do the capsular rhexis which is variably spelled because two hours or one half from the Greek I'll talk about that in a second then you'll hear a little bit of noise buzzing noise and that's the fake emulsification that's the ultrasound probe that goes in to break up the Cloudy lens into little pieces a bit like when you play Trivial Pursuit and you sort of always say it's the opposite of that you're not trying to put all the little segments into the pie you're trying to break it up into little segments and end up with an empty cartridge so then you hear a bit of irrigation aspiration that's just water going in and out of the eye more noise and then probably the most interesting bit from anyone undergoing the procedure is when the lens goes in that's a bit of the light show the lens is rolled up like a little taco and as it unfolds you get this lovely Kaleidoscope effect then we put some antibiotics inside the eye seal up the wounds and we cover the eye with a transparent Shield so you can see here some of the steps I was just talking about the capsular rhexis just is a rex is something as Greek for tearing or ripping a little hole it's a little bit more precise than that in the very very thin membrane that contains the natural lens which is called the capsule so people sometimes ask how does the new lens stay in place well it stays in place the same way the old lens did it goes into this very very thin transparent bag or the capsule and that's the fiddly bit of the surgery then as I said there's the fako tip which is breaking up the cloudy lens which we call the Cataract with the ultrasound energy and then you can see a little diagram of the folded up lens going into the eye and then it unfolds and voila you can see again so the capsular rhexis is making it open in a very very thin transparent bag it's it's iPhone is always you know like to brag but the only surgeons that operate on the basement membrane that it's so thin it's the it's the layer that cells sit on it's about one thousandth of an inch or less than that it really really is a very tiny thing and adding to its smallness is the fact it's transparent so it's probably the fiddliest bit of the surgery and you're trying to make an opening in the front of that bag it's called variably a capsule or a bag that's just a a thin membrane that contains the Cloudy lens you need to make sure it's circular it's central and it's the correct size the three C's so normally we just a terrible pun here eyeball that diameter of the opening at 5.5 millimetres now you can imagine trying to eyeball obviously get better with it with experience but you know eyeballing the difference between five and six millimetres is you know that that's a an acquired skill and there are better ways to do it and I'll come on to that in a moment so one of the times it can be quite hard is that as surgeons we do many many hundreds if not thousands of these procedures and so we get used to these things kind of a procedural memory but if the eye is particularly big or small and that's normally people who are short-sighted they have bigger than average eyes or long-sighted they have smaller than average eyes then you normally say oh it's about so far away from the iris and I judge that's about 5.5 but that can be quite misleading if someone has a very big eye or a very small eye and probably a few percent of people do have really really big really really small eyes so how can we mitigate that problem why do why would we want to well the reason is that little opening needs to be all of those things that I was talking about if it's too big or too small or off-centre or not circular that can cause problems that can increase the amount of cloudiness behind the lens it can cause the lens to sit off the centre of the vision it can and that can have a particular effect if it's a multi-focal lens or rhetoric lens it can also cause if it's too small the membrane to start shrinking around that opening so you really want it to be the right size and before this kind of technology there were some instruments to try and help you do it but basically almost all surgeons were just you know judging it by a kind of experience so what's improved now with this new microscope well the Callisto microscope again using the head-up display projects an image the perfect sizing position of this capsular rhexis so you actually can be guided so you set your parameters and you know you want to be you want a 5.5 millimetre rhexis so you want to be making that opening in this very delicate clear membrane in between the blue circles and again if you use patient move or the surgeon has to move to microscope those blue lines will track and always be in exactly the right place so that's really a game changer and super helpful for the surgeon to make sure that you have a really good outcome and the lens is exactly where it needs to be so no longer the need just to eyeball the eyeball that's my terrible pun for the presentation over.

Just to say that you know I'm very proud to work at Benenden, I've been at some big hospitals, and you know Benenden has a CQC Outstanding rating which is you know it's not easy to get. I think only about eight percent or less than 10% of NHS acute core services have got that level rating and it's it's just a lovely friendly place and I really enjoy working here and I think with patients I've treated here really enjoyed coming here it's a nice place to be and and everyone's happy and so I'm very proud to you know toot that horn or blow the banner or whatever whatever the phrase is so yeah it's a really lovely place to be and I think that's really important for everyone to be happy it's very supportive and and you're not you're not a number you're not processor you're a person it's kind of how I remember the best bits of the NHS 20 years ago. Obviously, we do a medical and social history just to ask the details we need for the procedure to go ahead, we check some basic things like your blood pressure and what your vision's like and the pressure in your eye. There are some other investigations so that biometry one is the one where we're measuring the astigmatism amongst many other things including the size of your eye and those are the main factors that go into deciding what power lens implant you need because everybody needs a different strength lens for the shape and size of their eye and we also do some other more advanced scans something called a pentacam which measures in great detail thousands and thousands of points at the front of your eye so that we can get a really good impression of what shape your eye might be and what kind of astigmatism etc you might need correcting because the thing is whenever you measure anything in medicine there's always some error and so the more you can measure it and the better tools you have to measure it with the more you minimize that error and we do a scan or no OCT scan which is basically an ultrasound with light over the back of the either retina to make sure that photographic film is healthy you'll then have all of that done by the team here and then you'll come in and see one of the Consultants, I think there's three of us now that are doing these lenses Benenden, we'll talk to you about the results of the scans what lenses might be a good idea for you what lenses might not because it's not the case that everybody should or can have a multi-focal or rhetoric lens everyone's different it's it's a surprising somebody said once that you get bored of doing cataracts but it's really quite remarkable how different everyone's eyes are for essentially the same organs so we then talk to you about the results. We'll talk to you a little bit about the surgery, tell you about the risks unfortunately you have to do that as part of life but yeah it is incredibly safe surgery it's one of the you know not many operations in in medicine have 98% 99% success rates so I would just but that's partly because we're so meticulous in in measuring everything before we go ahead and start the operation then we have a chat with you about the type of lens implants and what you want to do a big part of cataract surgery you know in the old days it was about making sure you could see it you know somehow whether that's the glasses or contacts or whatever now a lot of it is about you know asking people what they want from it you know do they like orienteering and it really frustrates them every time they look down on a map they've got water on their glasses those sort of things so that's called the refractive outcome it's you know what do you want to be able to see without your glasses or with your glasses and where do you want your focusing to be so that's really where cataract surgery has moved into rather than just safely removing the lens but you know leaving you with a huge prescription your glasses and then we talked about consent you sign the consent form and then you get booked in for surgery. It's a little bit quicker just the way of things if you are going down what we call the special lens route and that would include anything from a toric monofocal which is just correcting your astigmatism all the way through the EDOFs and the multifocal which may or may not have the correction in them as well and of course we've got a really good support team and 24-hour phone line if you have any questions or concerns.

So, I think that's me done. Sorry if I did it too quickly, I will hand over to Louise for the Q&A. 

Louise King

Thank you, that was really interesting. I don't think you were too quick at all.

We have some questions to go through. The first is someone says they've been considering cataract surgery but heard that you can’t to get them done if you've had laser eye surgery in the past, is this true? 

Mr Jonathan Aboshiha

Not true, but it's definitely something to be aware of. So laser eye surgery is increasingly common and one of the things it does is we have to use mathematical formulas to predict where your focus will be after the cataract surgery and that's how we decide what power of lens so you put in all these parameters into the into the machine say that the length of your eye the curvature of your cornea the depth of the front of the eye the thickness lots of different things and they all go into lots of different formulas mathematical formula and then we work out what's the most likely lens to give you, focus where you want when you've had laser eye surgery say to correct remove your glasses something like Lasik is a common one the presuppositions that go into that formula are less secure and what I mean by that is the chances that you'll be spot on for the focus afterwards are less, it doesn't. So lots of people have cataract surgery but you you know if you've had laser what we call laser vision correction in the past to helping young people are very short-sighted they say I don't know about my glasses and they have laser vision correction either lays it with a flap or without a flap then you just have to be aware the predictability of focus is not as accurate it's still pretty accurate and they're a good formula that account for that but the most important thing is you must tell the surgeon and the team that you see that you've had laser. The only the real big surprises happen when people say no I've never had laser and then you do it and then they get a kind of surprise and then they said afterwards oh actually yeah I did have that thing 10 years ago to 20 years ago to remove my glasses so just let them know there are things we can do to accommodate people who've had laser vision correction but we need to know it and the other things that's really important is to work out whether you had it to correct what's called myopia or hyperopia that means alongside short-sightedness or long-sightedness so the easiest question is you know before you had it were you trying to see better in the distance and then you had the laser and you could see well in the distance without your glasses so we you would need to know if at all possible the laser vision correction was done to correct short-sightedness or long-sightedness.

Louise King

Okay, thank you. Okay, if a patient is nervous can they be anaesthetized during eye surgery or if not can any other kind of medication be given to sedate a very nervous patient? 

Mr Jonathan Aboshiha

That's a good question. So everyone's anesthetized to a degree because that we do it under something called a local anaesthetic and that means that in the old days when I started I was on lists where every single person was you know put under a general anaesthetic but they're they're a risks to that in of itself and it's not the most efficient way or pleasant way to do it. So most all the surgery here we do is under local anaesthetic and that means drops on the eye like when you come for your examination and then little injection inside the eye which you do to stop from a bit of stinging and that works really well people they don't have any horrible hangover from general anaesthetic. We can give sedation, we can give a tablet here at Benenden and that normally calms people down a little bit, we don't do it routinely for everyone because the issue with sedation is some people can react it's a bit like having a little dram of whiskey or something, you know some people have empty stomach and you're affected it can make you know away with the fairies and when you're having an operation under a local anaesthetic and the doctor says okay turn to the left or stop moving or look up you need to comply as it were all you know do what's asked of you so if you're really nervous most people almost everybody I've ever operated on has said it's it was worth thinking about it than having it done and the best thing is not to think about what's having done you say I'm on the bench, I always tell people I'm on the beach, I'm looking through a hat at the Sun or go to a happy place but we do give out some oral sedation here. People who are really really anxious and it's just it's just something we can do if you ask for it so if you feel you need it you really are terrified then just ask when you're here and they can do that for you.

Louise King

Okay, is it the patient's choice to have either their mono focal EDOF or their multifocal lens or is it the surgeon's recommendation?

Mr Jonathan Aboshiha

Everything is the patient's choice so that's the paternalistic model of medicine is gone so even whether you have surgery or not you know that's another thing I found is that I've been told by X that I need a calorie operation you need it when you feel because they're your eyes and you live with the consequences that you feel that you'll benefit. Most people occasionally other people will say you need it for you know you really should have it done but some people are terrified of surgery and there are other people who have what we think is completely normal vision and they still have characters so it's a choice for every person to make individually there are some eyes where they wouldn't be suitable for multi-focal lenses and that's why we do a quite in-depth work up or even occasionally for toric is quite unusual so we would always advise you what we think are suitable options and then you choose from them that would be the proper way to do it.

Louise King

Related to that, I've actually had a question someone's had a detached retina a few years ago would they be able to go for the toric multifocal lens?

Mr Jonathan Aboshiha

Yes, that's a good question. So yeah you can, there's no reason inherently not to do that if you've got a fair bit of astigmatism and you want it corrected detached records can happen spontaneously so I don't know if that's what happened with your case it's a very unlikely but possible side effect of any cataract surgery so we tell you about the risks and benefits of that and what to look out for but as long as you're reference attachment repair went well and you can see well then there's no reason not to have a toroid lens to correct if you've got a fair bit of astigmatism so yeah there's no there's no reason not to have that corrected afterwards.

Louise King

Okay, had a couple of questions about driving, how soon can you drive after the operation?

Mr Jonathan Aboshiha

Excellent question, so yeah legally you can drive when you can read a number plate at 20 meters, we would probably normally advise people for a week or two afterwards don't to do that but partly because the eye is still healing and most of the time we don't put stitches in the wounds anymore, they just self-heal but if you were to be sort of shunted really hard or had a whiplash or something like that it's probably not worth driving for the rest a week or two so normally we advise people not to do that just for a couple of weeks after the surgery just to allow the it it's more of a peace of mind thing 

Louise King

Okay, what level of intraocular pressure would make the procedure difficult?

Mr Jonathan Aboshiha

So above a pressure of something called of 21 is considered abnormal but many people might have a pressure of 22-23 and that's incidental even high 20s some people aren't treated if you had a really high pressure then you would need to go and be assessed by a glaucoma specialist in glaucoma is the condition where you have a high pressure in the eye and over time that wears away on the optic nerve at the back of your eyes you lose your peripheral visual field. So if you've got high pressure, the best thing is first of all to get that checked out by eye pressure specialist or somebody they're called glaucoma specialists and they will start you want to draw up to lower the pressure one of the good things about cataract surgery is in the medium to long term it does actually lower your pressure a little bit but it can put the pressure up in the first few weeks afterwards partly because of the drops and so if you came here and you had a particularly high pressure we would probably ask for you to be reviewed by a glaucoma specialist to make a decision about whether you had glaucoma or not and if you needed treatment before we then went tone and had a chat with you about what lenses you wanted in your cataract surgery.

Louise King

Okay, thank you. Just a few more this person's had their assessment, and they went for an ordering lens they were told they had astigmatism and now thinking maybe they should have gone for a toric lens can they change their mind I assume they can check this before they've had it, I assume.

Mr Jonathan Aboshiha

Yeah, I that's what I'm not sure about yeah so if you've had the lens put in then it's tricky I mean you can do anything you want, as I said before, there's everything's possible in medicine fortunately or unfortunately but you know whether it's a good idea it's quite risky removing lenses once because they're folded up in this little taco shape and they unfold you've got to kind of either refold them or cut them and they're a risk to that especially if they've been in the eye for a while so if you already had the surgery I probably wouldn't advise doing it if you've been into the there are other things you might be able to do but if you've just been into the clinic and said I'd have the standard one and then you feel actually I'm kind of would rather have the the toric I always advise people you know you you have the result of this the rest of your life so it's always worth just going we have special lens clinics here just to talk it through with somebody and then you know the options and then you know people tend to feel a bit happier when they've known all the options and said okay that's for me you might still say no I don't want the toric but at least you discuss it through the pros and the cons and then you don't have that position where you know I've seen that with a couple of people who've you know weren't really told in the NHS that multifocal lenses were possible and then they had the standard lenses and then they've seen a neighbour or a friend sort of you know playing golf and doing their scorecard without glasses and they said you know I didn't know that was an option legally. Now even in the NHS you should be told of all the options of all lenses even if they're not offered and there is a cost to them so I think it's worth if you're thinking about it you know it doesn't cost you anything but a bit of time to come and have a chat and then you can say yep that's what I want to go for or no I'll stick with the with the standard lenses.

Louise King

I believe this person was on the waiting list.

Mr Jonathan Aboshiha

So yes, they can change them yes. So if they're on the waiting list then I mean it's a bit difficult I'll be seeing because everyone's got a tiny or everyone's got a bit of astigmatism but the question is whether it's enough to sort of start thinking about toroid lenses and without looking at your degree of these things I wouldn't know I suppose if you want to be 100 safe just get another appointment and worst case you'll come in and they'll say no you don't need one.

Louise King

Okay, thank you. This person they have a cataract in one eye and apparently the other eye they've been told has 100% vision is it worth therefore considering cataract surgery?

Mr Jonathan Aboshiha

Yes, absolutely. Yeah, we normally only operate on eyes that have a problem that's sort of the medical legal indication for cataract surgery is normally when you as a patient say that my vision's blurry and that may well happen in one eye many years before the other eyes so I think that's completely reasonable to do that the the only issue is if you're having multi-focal lenses because they can give you some Halos and you might notice them more if your eyes are you're comparing one multiple lens of the natural lens so sometimes that's a little bit of a think around but you know many people do that as well and they're quite happy so definitely if you feel there's a problem with your eye it's worth doing the thing I also say is if you don't feel there's a problem with your eye don't have surgery and it's a silly being pressuring to say but you know it's incredibly safe surgery but all surgery is a risk and and I would never counsel a patient to have an operation when they say I've got no problems my vision I've got no glare I've got no worries about anything I'm just doing it because someone told me I cataract well just you know it's when you you feel there's a visual problem most people who come here and say yeah I've got low vision or glare they're the two main problems yeah, but one eye is fine. Yes, you can definitely do one eye.

Louise King

Okay, thank you. um do people need to be referred by the NHS or can they come directly?

Mr Jonathan Aboshiha

My understanding is if you're a Benenden Health member you would have to get a referral through your GP, which is just to say your local waiting time which unfortunately is pretty easy now given the state of the waiting list and the NHS. If you if you're a private, fully private patient, you know either paying or with your private insurers, then you can just ring up the private team at Benenden and they will book you an appointment. 

Louise King

Yes, that's right. This person says from the presentation they now understand why they need specs for reading, their biggest problem is sunlight, it's painful would an operation be possible to correct this? 

Mr Jonathan Aboshiha

Yeah, so that's the most common your first sort of indication that you're getting a bit of cataract is is this glare and that's because as those little proteins that are perfectly all ordered in your clear lens start to sort of become less ordered through time, you know just just like getting wrinkles they start to interfere with the light passing through and it starts to scatter more so the biggest sort of example people notice normally is driving in the evenings or at night the car headlights although these new I think it's Xenon headlights are just awful for all of us I think I mean I've been through days of the halogens I actually there's an option to finally mention that there's actually an option on the operating microscope to turn the very state-of-the-art microscope into a halogen effect light and I've looked at both of them one of them is horrific bright blue and so I always turn it down into the kind of slightly softer candle light of the of the of that of the halogen but yeah the glare is normally a sign that you're cataracts are getting on and and that's the reason some people have 20-20 vision and they have the surgery done for glare about probably about 10 years ago you weren't able to do that but the NH this and nice and and we'll be able to look after the recommendations realize that you know just reading letters on a chart is not vision. Vision is many things and and if you've got what we call disabling there or bothersome glare then that's a reason to do cataract surgery because that will get rid of that yes.

Louise King

Okay, thank you. I'm just going to get a couple more questions so I'm just going to go through one or two more and then if we don't get through all of yours, we will answer afterwards, just so you know. A quick question, can you do both eyes the same time or do you do one at a time?

Mr Jonathan Aboshiha

Yes, very topical question. Yes, you can, so obviously it was my old mentor was the president of the bilateral same-day cataract society so the reason we didn't do it historically is there was a risk of a blinding infection which is probably about one in two thousand in cataract surgery, so it's very very rare. The argument was you know back in the day when it wasn't that safe that you know if you had a blinding infection which you probably won't know for the first week afterwards you don't want that in both eyes, they've done quite a lot of studies. I mean for example it's been standard practice in Sweden for a long time over the pandemic the NHS changed its mind and now does do same day it's called immediate eventual bilateral cataract surgery but it's basically the same day cataract surgery. Now here at Benenden that's only for people who are having special lenses it's still for the standard lenses, for logistic reasons you have to have one at a time because the standard lenses people are pulled to different surgeons but for the special lenses the surgeon you see in the in the clinic is the surgeon and you will have a discussion about whether you want it on the same day and just to give you an idea of the risk of a blinding infection both eyes is estimated at about one in a million and that is about three times higher there's a bit more cover to say this but three times higher than the risk of you being killed in a car crash on the way to your secondary operation, so it exists but it is very very small and and everything in life has a risk doing nothing has a risk doing two operations has a risk from driving to the second operation so it's something that we do here it's increasingly being done in the NHS and it's certainly something that the mindset has changed over the last 10 years but particularly over the pandemic it's now something that's sort of the universally accepted as safe.

Louise King

Just the final question now, this person says they can't drive at night anymore as it's got so bad, but they have manières diseases and they can't lay flat would they be able to be put to sleep for this?

Mr Jonathan Aboshiha 

Yes so my commiseration because my dad has manières as well, it's a horrible condition yeah especially when you get the attacks yeah if you if you really can't lie flat at all then I think the best thing for you would be to have it done under a general anaesthetic, however that isn't something that Benenden does for Ophthalmology for eye cataract surgery. So yeah by all means general anaesthetic which is probably still about five percent of all cataracts done on the NHS and general anaesthetic much less than it used to be but there are people with dementia, people with certain conditions and if you are unable to lie flat without being in discomfort it may be better to have that done at the NHS hospitals with a general anaesthetic where you're asleep, just go to sleep and you don’t wake up until it's done.

Louise King

Thank you. Sorry if we didn't answer all of your questions, I believe you've all provided your name so we can answer yours via email afterwards. If you haven't, if you want to quickly provide your name. If you'd like to discuss or book your consultation, our Private Patients team is available between 8am and 6pm, Monday to Friday. We're offering a discount for joining this session for the next seven days, with the terms on the screen. You're going to see you'll receive a short survey after this presentation and the next couple of days by email and be grateful if you could spare a few minutes to let us have your feedback. It really helps improve the sessions. Our next webinars include shoulder surgery and podiatry, you can visit our website to sign up and see the dates for those.

So, just to finish really. So, on behalf of myself, Mr Aboshiha, and the expert team at Benenden Hospital, I'd like to say thank you for joining us today and we hope to hear from you very soon. So, thank you very much and goodbye.