BBC HomeExplore the BBC
This page has been archived and is no longer updated. Find out more about page archiving.

Accessibility help
Text only
BBC Homepage
BBC Radio
BBC Radio 4 - 92 to 94 FM and 198 Long WaveListen to Digital Radio, Digital TV and OnlineListen on Digital Radio, Digital TV and Online

Radio 4 Tickets
Radio 4 Help

Contact Us

Like this page?
Send it to a friend!


Go to the Listen Again page
Tuesday 15th February 2005, 9.00-9.30pm
 Print this page


CASE NOTES 10. - Moorfields Eye Hospital


TUESDAY 15/02/05 2100-2130














Hello, I'm standing in the City Road outside the A&E department of probably the best known eye hospital in the world. It was certainly the first. Moorfields Eye Hospital opened its doors 200 years ago to deal with eye infections in troops returning from the Napoleonic wars. Today it's home to some of the most eminent eye specialists in the country.

I'll be discovering the latest on laser eye surgery for short and long sightedness. In the light of recent long term safety concerns raised by the National Institute of Clinical Excellence, NICE, what do the country's top specialists think of the procedure and would they have it done?

I'll also be finding out why annual eye checks are so important for people with diabetes and how cutting corners with your contact lenses could endanger your sight.

But first, let's meet some of the patients and staff here in the A&E.

Now you look like - your eyes look a bit sore.

One of them is yes.

What happened?

It's apparently a recurring conjunctivitis and this is the fourth time in six weeks that I've had it. So the doctor suggested I go to eye casualty.

And I suppose the added advantage is that you come in, you wait, you get it sorted out, you get to see the specialist, you don't have to wait for an appointment.

And you know that Moorfields is the best eye hospital, I'm glad I'm here.

What brings you in?

I've got a problem with my right eye. I had a corneal graft in '87 and it's getting a bit sore now, I'm getting pain in my right eye.

And why did you have a corneal graft - that's a patch to repair the cornea - did you have an ulcer or some problem?

No, I've got atopic eczema and some people with rare conditions they get it, so the eye sort of became lazy and sort of blurred so I had to have a corneal graft on it.

So that was repaired, you've had no problems since then but obviously you're very wary of that eye now you've had it operated on.

Yeah, it's very sore again and like I'm getting headaches and what ever. Last week I had like a headache for about four days.

Good morning.

I'm under Professor Lightman.

How does your eye feel, what is ...?

It's not the uveitis that's the problem. It's been the quieter eye, it's had a torn retina lasered and it's got a cataract growing but suddenly the vision's gone funny. In the last couple of days it's sort of messy vision.

Okay is it the whole field ...?

No pain, more the right side of the left eye.

So Helen you're the triage nurse here at the accident and emergency department. What's your role?

I meet each patient that arrives, I have to talk to them and get their history, why they've come today and find out if they've been to Moorfields before.

Because I mean basically they can come in with anything to do with the eye can't they?

All sorts, yeah.

Someone's just come in the conjunctivitis, now that's the sort of thing that in my area we would be dealing with in the general practice.

Yeah but she's on treatment already from her GP but it hasn't worked so she's come here for - to see us, maybe to have some swabs taken or see why it's not getting better.

At the other end of the spectrum what sort of things might you see, more serious cases?

We see other people maybe come in with a retinal detachment - who might have flashing lights or seeing floaters or shadow in their vision.

Do you deal with eye injuries here?

Eye injuries - we get people with trauma and they get foreign bodies in their eye or more serious trauma, a lot of building sites in London so you get patients coming in with problems.

Up to 200 patients are seen in A&E every day. Seema Varma is the consultant in charge.

We see things what we regard as relatively minor to people who are basically - have been involved in accidents and have lost their vision.

And what sort of catchment area does the hospital have because it's got an enormous reputation and I can imagine people trekking here from miles around?

Sure. And if I said the world it would sound as if we were sort of the only eye hospital in the world but it's true. We will get people from all over London, from the rest of the country, I mean we do get people coming off the plane and coming here straightaway.

But that must put you under an awful lot of pressure. Do you turn patients away or do you see everybody that comes here?

It's very hard I think to expect every GP to know about every sub-speciality, especially when they don't have the equipment that we have to look at some of those conditions. And so in a sense I feel that eye casualty departments also act not just as casualty departments but as primary care centres. Obviously all patients come here not because they want to because they're worried. And so you have to cater for their anxieties but at the same time the government's given us these enormous targets - we have to see all patients within four hours and if you've got a casualty department which is actually acting outside the emergency framework it becomes an impossible task for us.

Obviously if somebody has an injury to the eye they know that they're in trouble and they need to go straight to hospital but there are other warning signs of problems that need to be urgently managed aren't there.

There are indeed and I think that the eye is an organ that has very few ways of telling you something is wrong. I mean either you get pain or you get blurred vision or loss of vision or it just doesn't feel right. And I think that what patients need to be aware of is that if there is a sudden change in their vision or there is sudden onset of pain in conjunction with reduced vision then I think something is going on for which they need to get to a hospital or their GP.

Say somebody comes in here, they've noticed lots of black blobs floating around in their vision - what we call floaters - and some bright flashing lights and they arrive here at the casualty what's the process that someone's going to go through?

Something happened yesterday or today or a few days ago and it's associated with flashes of light then yes there is a concern that they may have detached their retina.

That's the film that's at the back of the eye effectively, that's peeled away from the eye. And that's important to make that diagnosis because?

Usually what happens is it starts with a small tear and then with time fluid gets behind the photographic plate of the eye and just peels it all off. And so from a relatively small contained problem you now have the potential for the whole of the photographic plate of the eye to come out and you can go blind.

An all too familiar story to Tomas Ganga, who is waiting for surgery to repair a detached retina.

Well it happened at about four weeks ago. I felt in my eye - this one - like a black fly and I been thinking that it was nothing and sometimes I've been thinking that it was a fly, I went to catch that but I find it's too busy, it's not a fly.

So every time you moved to go and catch the - the fly moved with you.

Three or four days later after two or three weeks I start to see out my eyes and something black like ring - I go to see my doctor who check in my eyes and he made me go to [name] hospital. They check them - all my eyes and they make a letter to come here.

Have you noticed any flashing lights at all?


So how bad is the vision in your eye now - you can't see - with that eye - with your bad eye you can only just see that the lights are on?

No, just a little light.

So you've lost - almost lost the vision completely in that eye?

Not completely but nearly.

And that's happened over just the last few days?

Yes. But it happened about between three and four days.

Later that afternoon Tomas had his retina repaired under local anaesthetic. The surgeon was Mr James Bainbridge.

So I've just prepared Mr Ganga's eye with some iodine and put a drape over his face to protect the area and keep it clean. I've put a speculum between his eyelids to keep his eye open while we do the operation. So Mr Ganga's eye is anaesthetised because he'll be awake for the operation which involves taking the vitreous jelly out of the eye, in order to reach the retina and then fixing the retinal tears that he has by gluing them in a sense with some freezing treatment and supporting the retina in the right position while it heals using a bubble of gas. So the first part of the procedure is to put three small holes in the eye around the iris on the white of the eye. One hole is for an infusion cannula that keeps the eye filled up with water in order to maintain control and keep it inflated. The second hole is to allow access to the light pipe, to illuminate the eye from the inside of the eyeball. And the third is for the vitreous cutter, which is a little mechanical cutter that sucks and cuts the vitreous jelly out. So you can see on the screen that some of the retina there is flapping about at the bottom, like a sail blowing in the wind.

Now we've removed the vitreous we have access to the retina and I'm going to seal the tears in the retina using cryotherapy, which is a freezing treatment. But because the freezing treatment does take some days to work, bit like a slow setting glue, we use a gas bubble inside the eye to support the retina in the right position while it heals. The gas bubble is normally absorbed over the period of a few weeks, by which time the glue's set and the retina remains in position.

Are you comfortable there Mr Ganga?

It's okay yes, a little pain now by the way.

I'm sorry?

A little pain.

Little pain, alright, we'll give you some more anaesthetic. We're almost finished now, you're doing very well. Can I have some lignocaine on the table please?

The op all went very smoothly and Mr Ganga was discharged home later that day.

Surgeon Bruce Allan concentrates on a very different part of the eye - the cornea - the clear part at the front.

Moorfields offer private laser surgery - known as LASIK - for people who don't want to wear corrective lenses. It costs £1500 per eye and can be used to reshape the cornea to treat three different types of visual impairment.

Short sightedness - that's difficulty seeing anything clearly unless it very close. Long sightedness - where the person has good middle and distance vision, but can't focus on things close up and astigmatism - where a slightly misshapen eyeball leads to blurring.

But it's not suitable for everyone, as Bruce explained.

The reason we're doing this surgery here at Moorfields at all is not because it's a cosmetic procedure, it's functional, it makes a big difference to patients' lives. But the folk who it's used for are within that band basically, up to about 10 diopters, up to about +4 of long sight, up to about 6 diopters of the stigmatism.

So people would look at their prescription and see those figures - that's 6 for astigmatism, 4 for long sightedness and up to 10 for ...

Exactly, if you look at your ...

... short sightedness.

... spectacle prescription there'll be two figures in it, separated by a forward slash. The first figure is a plus if you're long sighted, a minus if you're short sighted, the second figure after the forward slash is the amount of astigmatism you've got. And all other things being equal and you're safe for surgery then you can go ahead. But folk who require larger corrections then methods based on lens implantation, like cataract surgery for example or implanting a second lens in addition to the natural lens, are the way to go.
So what actually happens to the patient when they're having the procedure?

When they're having the procedure done the first thing that happens is your eye is numbed with drops and that takes all the sensation away from the corneal surface - you can feel things like warm and cold and fluid running over the eye but no pain. Then little sticky plastic drapes are applied to keep the eyelashes out of the way and keep the area clean and a little retainer is put in to prevent any problems with blinking during the operation. After that what you see as the patient is a blinking red light in front of you, which guides you - your gaze in the right direction and a laser tracker is engaged that follows little eye movements around and so many patients worry that what happens if I blink, what happens if I move my head, that kind of thing, it's all taken care of. And after that the laser treatment's delivered, you hear a loud tapping noise from the laser when it's being delivered and typically it would last up to a minute, depending on how much correction needs to be done. And then after that you feel some more touching around the eyes, more fluid on the surface and the operation is done.

So you're walking out of the treatment centre, how long after you went in?

Here we keep patients back for at least half an hour after the initial treatment and check them again and often longer. Really it's a two or three hour round trip. What it's absolutely not like is getting a haircut - this is an operation and it's day case surgery essentially and so not unlike cataract surgery - you'd typically be out of the hospital about three hours after you come in.

And what sort of follow up is required?

Well we normally see patients at some point in the next 24 hours to three days afterwards, to check that everything is healing well and everything is in place. And after that we would see patients again a couple of months later to check they've got a good result and are heading in the right direction. And a percentage of patients after that who haven't got the outcome they were looking for first up, in other words good normal vision, 20/20 vision, we'd invite them back later on and assess them with a view to doing a re-treatment. And one of the nice things about LASIK is the result is adjustable, you can quite easily follow up and put down a few more laser pulses if that's required.

Now the National Institute for Clinical Excellence, NICE, have just done a review of this type of surgery and one of their criticisms was that there isn't enough long term data about its safety, which I suppose is inevitable with a procedure that's relatively new.

Well that's right, I mean although the procedure is relatively new it didn't evolve from nothing, the K in LASIK stands for a procedure called keratomileusis which the boxer Frank Bruno had back in the 1980s and it's been formed since the late 1960s. Now this splits the cornea in exactly the same way and there have been no problems with long term biomechanical stability there.

By biomechanical stability you mean - well the eye becomes misshapen in somebody because it's weakened because you've thinned the front of the eye.

Exactly, I'm referring to the specific concern that NICE raised on this. But I would emphasise that there's absolutely no evidence that the cornea will be unstable afterwards, in fact there's a good body of evidence that treating within safe limits should not affect the strength of the eye wall at all.

And what about other side effects, are there any other long term concerns?

Given that we've been doing operations on the cornea, which split the cornea in this way, for quite a long time now it would be deeply surprising if we find out something about it in 20-30 years time that we don't know now. Any modern operation will not have 50 year, 20 year, 10 year data on it, you know it takes time. But problems emerge really through epidemiological data, in other words people turning up in casualty with complications late into a procedure. Now eight million people have had laser eye surgery done over the last 10 years and it would be a very, very big surprise indeed if there were a problem associated with it that wasn't already apparent.

What are the success rates like and how would you define a success rate?

What people are looking for is the kind of vision which would allow you to do sport, socialise and work without glasses, that's a realistic aspiration. And a key point to make is that although over 90% of patients get there with one treatment, if you don't get there with one treatment then re-treatment is very effective in sharpening up the result.

So there may be 10% that may need re-treatment?

That's right and that 10% figure is quite important because there were some very misleading newspaper articles about this before Christmas, in relation to the NICE report quoting a 10% failure rate. Now that's not a failure, this is a patient who is going to get a great result from a re-treatment.


So overall a hundred people come to you wearing specs, how many will go away not needing them at all?

After the second treatment almost none. The main reason for carrying on wearing spectacles after this kind of treatment is the loss of near vision that's age related, something we call presbyopia and ...

... in your 40s, it's happening to me.

Well you and I are sitting here at about the same age and ...

And of course laser surgery can't treat that, so you will need glasses, no matter what you have done to help you read.

Not entirely true, you will certainly need a compromise. It's possible to leave one eye slightly near sighted to mitigate the loss of flexibility in the natural lens that is the cause of this loss of near vision in later life. So using that strategy, so-called monovision, you can leave one eye short sighted, one eye focused to distance, and they work quite well together as a working pair.

It seems to be quite a price competitive market, it's an expensive procedure, it's only available privately in the UK. Should they be looking purely on price alone?

I think they absolutely shouldn't be looking on price alone. It's very difficult for the public to choose a surgeon that's going to be safe, just on the basis of what's possible to find out from the internet, purely because no clinic publishes bad results. I think that the strategy of maximum safety is to have it done with a consultant surgeon who has a specialist interest in the cornea and holds an NHS appointment and preferably have it done within a hospital setting. And there's two good reasons for that. One is that you'll be sure then that all the right ethical and governance checks and balances are in place and the second reason for doing it is for a hospital like Moorfields we derive an income stream from the procedure itself, so rather than the money that's made from the procedure going straight into some businessman's back pocket then it's coming here to support patients with other eye problems.

One question I must ask you is that if it is so good why do so many eye surgeons still wear spectacles?

Well in fact one in six of the surgeons who does the surgery has had it done to themselves and bearing in mind that half of those surgeons would have had good sight anyway and therefore wouldn't have needed the operation that's a pretty high uptake in a group who are fundamentally dependent on good vision for their occupation.

Bruce Allan.

Of course surgery isn't the only option for people who want to avoid wearing specs - contact lenses are another popular choice - but they are not problem free either. I caught up with consultant Frank Larkin at his clinic where he sees lens wearers who have developed complications.

There are two principle categories of problems that we see. The most common of them is allergic eye disease caused by contact lenses, that is an allergy usually of the conjunctiva of the eye, that's the lining of the white of the eye, which is an allergy to the lens material or deposits on the contact lens surface. And we see this most in those people who wear lenses but who also have other allergic disorders, for example asthma, allergic eczema.


And do they tend to develop the problem fairly early on in their contact wearing?

On the contrary many of them in fact go for many years without apparent problem and then perhaps 5-10 years after starting lens wear they get very itchy uncomfortable eyes during lens wear and following lens removal. So it can be a very delayed type of allergic response.

And how do you deal with that, does that mean that they can no longer wear those lenses?

Well often simple modifications can be made to the type of lens that the patient is wearing, to modify the cleaning methods that they're using and the disinfecting methods that the patient is using. It may require medication, it may of course in some patients mean that they have to switch out into a different lens material altogether or abandon lens wear entirely. It can be in a small number of patients allergy to the lens, the disinfection solutions. The other type of problem we see actually causes us much more concern because it's usually a fast onset infection in a patient who's a known lens wearer, so in contrast to allergic disease, in which there could be protracted and very long history that a patient will give of several months of discomfit, patient with infection will often come to us with two or three days of severe eye pain in one of the eyes or occasionally both eyes and no previous problems with lens wear whatsoever. These lens infections or lens associated infections can either be infections by bacteria or a different type of organism called an amoeba, so we see both of those categories of infection far, far more frequently in lens wearers than in people who don't wear lenses at all.

Is it anything to do with the way that lenses are looked after?


In many cases it is. The other very significant risk factor, which those who wear lenses need to know about, is overnight lens wear and we've got very good evidence that if a contact lens wearer or soft lens wearer wears lenses on an extended wear basis, that is day and night, they have a very significantly high risk of getting infections than otherwise.

And how serious are these infections?

Well they can be sight threatening. While it's true to say that if those with infections come in very early and we can identify the infecting organism and institute the right treatment those patients can get a very good result from their treatment. But there are some in whom infection progresses very quickly through the cornea of the eye and can lead to perforation of the cornea with very severe eye disease and long term complications.

Because I can imagine contact lens wearers realising obviously when they get a sore eye that the first thing they would do is try taking the lens out and see how they get on but should they be seeking medical advice?

In some circumstances a severe onset of pain might be due to what we term an abrasion on the surface of the cornea, that means effectively a scratch, but that's usually in those who wear rigid gas permeable lenses and these lens wearers will often be able to discriminate an abrasion from something that just seems to be getting worse and worse irrespective of the removal of the lens.

Patients have a lot of different types of lenses to choose from now, is there one that's medically better for the eye than the others, it might not fit with their lifestyle but medically better?

That's a good question and my answer would be, looking at all of the range of contact lenses currently in use, those with the rigid gas permeable contact lens have a much, much lower risk of severe allergy and of infection.

And these are lenses that are taken at night?

Correct and put back in, in the morning and they're lenses that usually these patients will keep for a year or two or three prior to replacement. So quite different to the soft lenses, many of which on sale today are disposable.

Frank Larkin.

Time now to travel deeper into the eye and return to the retina.

Diabetic retinopathy - a common form of retinal damage seen in people with diabetes - makes up another large slice of Moorfields' workload. High sugar levels damage the delicate blood vessels supplying the retina and can lead to irreversible visual loss.

Surgeon Jonathan Dowler has a special interest in the condition.

Essentially blood is thickened, the walls are not normal and the flow of blood is different. This leads to small blockages of blood vessels in the retina and that results in the changes we see when we look in.

How would somebody with diabetes know that they had a problem or would they?

That's the key, they don't know, unless somebody looks they can't identify the disease at a stage when it can be treated. If you wait until vision is lost treatment is less effective because treatment is only useful at preventing visual loss.

If somebody has diabetes what's the gold standard way of monitoring their eyes to make sure that they don't have a problem?

I think an examination or a photograph taken by somebody with an interest or expertise in doing so. It's still difficult, people say that it's easy to identify and certainly - well described stages of disease but not everybody follows those stages.

A lot of patients will be depending on regular checks with their optometrist, their high street optician, is that adequate?

Yes that can be very adequate. The only concern that some people have expressed about that is the fact that it doesn't allow an audit trail if no photograph is taken. If you've got a photograph you can say it was this bad at that stage and that's very useful.

This here is the head of the optic nerve.

Bright yellow doughnut if you like in the corner.

Yes and that's the nerve that joins the eye to the brain as it were. And along it you see all the blood vessels ...

Kulwant Semi heads the team responsible for taking images of the retina.

Now if you look this is a diabetic patient with very minimal sort of diabetic changes in the back of the eye. I'll just enhance the image a bit. Can you see these little tiny sort of red dots?


Now these are micro-aneurysms.

Little swellings of the blood vessels.

Little dilatation of the finer sort of capillaries. And also you see these little deposits of lipid.

Those are fat basically.


And this patient would be blissfully unaware that there was anything going on?

Well he's aware he's diabetic.

But he wouldn't know he had a visual problem?

No, it doesn't look as though - but what we do is we do a test called the fluorescein angiogram. So fluorescein is a dye that's injected intravenously and then we photograph this dye as it mixes with the blood and then circulates in the back of the eye. So I'll just show you a fluorescein angiogram here. Now you saw the colour picture earlier and it looked quite normal, but when you do a fluorescein angiogram you see these myriad of micro-aneurysms. There are ...

White spots all over the place, looks a bit like an x-ray - it's a black and white picture and all the blood vessels are coming out in white and you can see where they're leaking and the little dots around. It's much easier to see isn't it.

And also much easier to treat when it comes to treating because you know exactly what are the abnormal areas that there are.

Well the earliest changes are tiny little dilatations of the smallest blood vessels in the retina, the capillaries, and these things can only be 10 microns in size, absolutely tiny. But as time goes on there are more obvious changes, the vessels may become irregular in calibre and you may get abnormal growth of vessels into the retina, you may get increasing haemorrhage and leakage.

Now we call this diabetic retinopathy but practically why does it matter that the blood vessels are slightly abnormal in the back of the eye, what effect does that have for the patient's vision?

Two principle mechanisms of visual loss, one is by water logging of central retina, which reduces what you can see when you look at visual acuity chart and more sinister is the growth of new blood vessels on the surface of the retina, which if they bleed, as they tend to, you can get abrupt loss of vision.

And that's because presumably the blood is literally occluding the retina - it's covering the photographic plate if you like.

Yeah exactly, like a big red soup.

So the onus is on us as GPs to monitor patients, to make sure that their sugars are tightly under control to try and prevent this happening and if we spot it happening in the early stages to refer to the likes of you. But what can you then do to help assuming that the person's control of their diabetes is good?

Assuming their control is good there are treatments including laser treatment and more recently other treatments, biologically based treatments, which may prove to be effective in slowing down the disease. I don't know of anything at present however that reverses it.

Why biological treatments - what do you mean by that?

Well it is thought that the growth of new blood vessels and the leakage from blood vessels depends on a number of growth factors and agents have been synthesised that block the action of those growth factors.

And you're using a laser presumably to literally sizzle up the extra blood vessels are you?

Indeed, well what we think we do, we don't actually know, all we know is it works, we laser areas of retina, for example, when new blood vessels form, that are not required and that seems to reduce the amount of growth factor produced and that makes the blood vessels shrink.

And if someone's had a part of their retina lasered is that part of the retina useful for vision anymore?

It's less useful than it was, however, the disease itself can take away some of that usefulness.

And of course diabetics don't just get problems with the back of the eye do they?

No indeed, they may develop cataract, if you look at the population generally perhaps 1 in 50 patients has cataract, of the patients undergoing cataract surgery perhaps 1 in 8 or 1 in 9 is a diabetic and certainly it seems that diabetes predisposes towards the formation of cataract.

One particular worry that people have with diabetes is that it's - well they talk about the diabetes epidemic, and we're seeing a dramatic rise in the number of cases of diabetes, Type II diabetes, the one that comes on later in life and presumably you're seeing a similar increase in eye problems as a result.

Indeed and I think the principle issue, and which this programme addresses, is the education of people. They think I can see, I don't have a problem, but that doesn't actually work, you have to have somebody check it.

Mr Jonathan Dowler.

That's it for today's programme, the last in the current series. We will be back in May. Until then, goodbye.

Back to main page
Listen Live
Audio Help
Leading Edge
Emergency Services
Heart Attacks
Cot Death
Antibiotics and Probiotics
Bariatric Surgery
Backs - Slipped Discs
Prostate Cancer
Sun and Skin
Bowel Cancer
Cystic Fibrosis
Side Effects
Metabolic Syndrome
Down's Syndrome
The Voice
Childhood Burns
Sexual Problems
Me and My Op
Lung Cancer and Smoking
Cervical Cancer
Caesarean Sections
The Nose
Multiple Sclerosis
Palliative Care
Blood Pressure
Parkinson's Disease
Head Injuries
Tropical Health
Arts and Health 
Menopause and Osteoporosis
Intensive Care (ICU)
Manic Depression
The Bowel
The Jaw
Keyhole Surgery
Out of Hours
Body Temperature
Face Transplants
Heart Failure
The Royal Marsden Hospital
Cosmetic Surgery
Tired All The Time (TATT)
Coronary Artery Surgery
Choice in the NHS
Back to School
Hearing and Balance
First Aid
Alder Hey Hospital - Children's Health
Moorfields Eye Hospital
Wound Healing
Joint Replacements
Premature Babies
Prison Medicine
Respiratory Medicine
Urinary Incontinence
The Waiting Game
Auto-immune Diseases
Prescribing Drugs
Get Fit and Get Well Food
Oral Health
Heart Attacks
Genetic Screening
A+E & Triage
Screening Tests
Sexual Health

Back to Latest Programme
Health & Wellbeing Programmes
Current Programmes
Archived Programmes

News & Current Affairs | Arts & Drama | Comedy & Quizzes | Science | Religion & Ethics | History | Factual

Back to top

About the BBC | Help | Terms of Use | Privacy & Cookies Policy