Wednesday 1 May 2019
My Amazing Body is a podcast where we explore interesting, unknown and misunderstood parts of your body with help from medical experts and stories from real Queenslanders.
This episode is all about the eye. With Professor Glen Gole, senior ophthalmologist and professor or ophthalmology at Queensland Children’s Hospital, we discover how your sight developed from the time you were born, and how it might deteriorate as you age. Professor Gole explains some of the different conditions that can affect eyesight and the techniques he uses to restore peoples’ sight. We also hear from two Queenslanders, Jim and Tina, who have dealt with the possibility of losing their vision.
Meet our guests
Audio is great, but some things are best seen as well as heard. These materials provide more information about topics we touch on in the show.
A diagram of the eye
At 01:18, Professor Gole describes what the eyeball looks like. Here’s a diagram to help you understand the different parts of the eye as Professor Gole explains what they do.
Cataracts, pterygium and retinoblastoma
Throughout the episode, Professor Gole mentions different conditions that can affect eye health and eyesight.
When talking about the importance of wearing sunglasses in childhood, at 05:10 Professor Gole talks about fleshy growths that can develop on the eye called pterygium. Pterygium grow across the surface of the eye and can cause vision loss if they reach the cornea. Pterygium are caused by exposure to sunlight and wind.
Cataracts occur when the lens of the eye clouds over. At 08:50 we hear from Jim about discovering he had cataracts in both eyes.
Cataract surgery is the most common elective surgery in Australia. At 10:00 Jim describes what happened during his cataract surgery, followed by Professor Gole at 10:30 who takes us through the process of removing cataracts in adults and babies.
Retinoblastoma is a form of eye cancer that effects about 1 in 18,000 children. Professor Gole speaks about how often the first symptom of retinoblastoma that parents see is a white reflection in their child's eye in photographs.
Thank you to World Eye Cancer Hope for providing these images of retinoblastoma visible in photographs.
Host: Take a moment to look around you. Really look. What can you see? How many colours? How many shapes? How many patterns? For people with sight, 80% of learning is done visually. We engage with the world first and foremost through what we see. But for most of us, sight is a sense we take for granted.
Hi! I’m Elise, and welcome to the latest episode of the My Amazing Body podcast, where we explore interesting, unknown and misunderstood parts of your body. Today, we're learning about the eye.
Do you know what your eyeball actually looks like? Sure, you know the colour, but what happens behind the iris? Like most parts of your body, your eye is more complex than it appears on the surface. We asked eye expert Professor Glen Gole to explain the eye and how it works.
Professor Gole: I'm Glen Gole, I'm a senior ophthalmologist and professor ophthalmology at Queensland Children's Hospital in Brisbane.
Host: Ironically, the best way to understand the parts of the eye are to see it. As Professor Gole describes the eye, you might find it helpful to look at a diagram. We've included one in the show notes. For starters, Professor Gole says that a common misconception about the eyeball is its shape.
Professor Gole: It's slightly oval, so it's not a perfect sphere.
The outer layer is made up of a structural protein called collagen, which makes up the sort of cartilage in your bones and things like that. The inner layer is mostly blood vessels and the purpose of the layer at the back of the eye – the blood vessel layer at the back of the eye – which is the middle layer, the choroid, is to nourish the retina on the inside of it. So, the retina is the inner most layer of the eye.
The cornea is the clear front window in the front of the eye. And that's kept clear by some cells that sit on the back, it's kept to a certain amount of water in it. And it changes shape a lot in the first year of life. The eye sort of adjusts its growth rate to get a sharper focus by the end of the first year of life.
When the cornea's damaged, it'll go cloudy. And it may go cloudy temporarily like if you've got a scratch or something on the front of the eye. Or it may form scar tissue that may be permanent, or the child can be born with various diseases of the cornea, which produce a cloudy or a white cornea, and they're very bad for your vision.
Host: While we think of deteriorating eyesight as a problem for the elderly, newborn babies don't have 20/20 vision either. In fact, the world is pretty blurry for new bubs, with their vision about eight times worse than the level set for legal blindness.
Professor Gole: You'll get to your adult level of vision between about age six and eight.
So, in the first few months of life, vision is very poor when you're born, your vision is about eight times worse than blind pension the day you're born. You can still see, because all you'll need to find is the edge of mum's face and look in the right direction and find your food supply.
At about six months of age it's about twice as good as the blind pension, when you're three it's about a line or two off normal and when you get to six to eight you'll get your final vision. But the first few months are really critical.
What all this visual development is about in the first year of life, the eye grows a bit; the front of the eye adopts a more rounded shape, so it focuses better. And the eye makes connections into the brain. So, during the first few years of life it's a lot of active connections being made between the eye and the brain. Because the eye just works like a camera, it receives light and it puts out an electrical signal goes down the optic nerve at the back of the eye into the back part of the brain – which is what you actually see with – so all those connections inside of the eye have to be made and connections along the pathway to the visual part of the brain have to be made, and the visual part of the brain has to organise itself and make connections to the eye.
Host: As a paediatric ophthalmologist, which means he specialises in children's eye health, Professor Gole is passionate about educating Queensland parents on what they can do to promote good eye health and vision for their kids.
Professor Gole: Vision is a developed sense. And you actually have to learn to see.
How can you help your child's visual development? Give the kid lots of visual stimulation. And it's said that the single most important toy you can give to a child is a set of coloured blocks. So, it gives a child size, shape, texture and as well as some different colours. So, it gives the child something tactile and something visual as well.
The big thing that damages eye sight in the state of Queensland is sunlight. So, it's important that when you go outside you should wear sunglasses. And it turns out the first decade of life is very important to wear sunglasses as well because a lot of the fleshy growths we get on the inner part of the eye, in middle age, and you see them out in stockmen and things like that called a pterygium, is related to how much sunlight you got in the first decade of life. And it turns out, and this was an Australian discovery, that the sunlight that produces that actually comes from the side, and gets reflected inside your cornea and focussed on the inner side of the eye. So, it's very important to have wrap-around sunglasses to stop the light coming in from the side as well.
Host: As well as treating children for minor eye injuries and vision issues, at Queensland Children's Hospital, Professor Gole also looks after children with serious diseases.
Professor Gole: About 1 in 2,500 babies are born with cataracts. And these are usually detected at the birth exam in the newborn or at the six-week-old baby check, and every time these checks take place, someone should be looking to check whether or not the baby has had cataracts.
The common causes of cataracts in babies are often hereditary, they run in families. Then there's a whole lot of genetic disorders that cause cataracts. Just for instance 1% of children with Down syndrome have cataracts. So what cataract is, it's a clouding over the proteins in the lens of the eyes, so it's just like the lens is a clear structure at the front of the eye that does most of the focusing, and when you get cataracts it's just like cooking an egg, it just goes white like an egg being cooked, and then that interferes with visual development. The reason it’s so important in babies to find these early, is that vision is a developed sense, you actually have to learn to see. And it's very important to do this in the first few months of life, the visual development goes up until about age eight.
So, a lot of our work involves oncology, dealing with patients with brain cancer et cetera. And we're also the Queensland treatment centre an eye cancer in children called retinoblastoma, and this is a tumour that effects about 1 in 18,000 children so we'd see between four and six a year here at the Children's Hospital.
I think the take home message from this is this tumour grows inside the eye and in its common form it produces a white lump inside the eye, so when you look at the eye it'll have a cat's eye reflex; instead of having a dark pupil there'll be a reflection from inside the eye. This is often seen on photographs. So, if there's a child who has got a white pupil, they need to be seen right away because the worst thing it could be is an eye cancer, there's some other causes as well, there's quite a few, but they're all collectively quite rare.
So, that's the common presenting sign of eye cancer in children is to have a white pupil and it's commonly picked up at photographs. And curiously we see a lot of these children around Christmas time. And we could never figure this out. But now what it is, is families get together Uncle Harry says, “What's wrong with your little child's eye?” Or people will take the photograph at Christmas and someone sees the white pupil in one or both eyes, and they come in and get looked at.
Host: As we age, our eyes age with us, and with that comes other concerns for our vision.
Professor Gole: The common things that can happen to your eye as you age is you may develop cataracts as you get older. The other thing that happens to all of us, is around at age 43 you lose the ability to focus close up, and all of us, sooner or later, need reading glasses, unless we're very short-sighted. It's to do with the muscle that changes the shape of the lens gets a bit stiff and also the lens gets a bit stiff as you get older. So, all of us get that and basically all of us need reading glasses at some stage.
Host: We spoke to two Queenslanders, Jim and Tina, who both noticed that something had changed in their eyesight as they got older.
Jim: Well my vision started changing; even with glasses wasn't quite as sharp as it had been before. I couldn't see television quite as clearly, and I was starting to get little floating embers in the eyes. Which is a classic sign of cataracts apparently.
Host: That's Jim. About a week ago, Jim had two surgeries to remove cataracts from both of his eyes.
Jim: Well I’ve noticed my eyes have been changing quite a bit over the last year or two. And I've been to optometrists in the past and they've said to me I've got the beginnings of a cataract problem in both eyes and that's steadily got worse up to the end of last year when I went and saw a specialist and he said, “Yep you've got cataracts there, and you're going need and operation at some point.” He said, “Come and see me next year when you feel you're ready for it”, and that was this year. So, I went and saw him and I had operations done on both eyes. About a week apart.
For me it basically entailed lying on a bed and then getting up afterwards (laughs). The doctors did all the work. Effectively they put me into a mild anaesthesia sort of sedated me rather that put me out totally. And then they took out the lenses in my eyes and replaced them with intraocular lenses.
Host: Cataract surgery is one of the most common elective adult surgeries in the country. Professor Gole explains that the process for adults, like Jim, is different to the surgery he performs on babies born with cataracts.
Jim: In adults you cut the front of the lens open, you shatter the cataracts with ultrasound, suck the bits out, put a little fold-in plastic lens into the bag that holds the lens. It’s a very safe operation, fantastic outcomes, it's revolutionised the lives of older people.
In babies we cut the front of the lens open, but we generally just suck the cataract out or chew it out with a little cutter, it's like a blood needle with a little guillotine on the end. The back of the lens bag can cloud over, so we have to cut the back of the lens bag open as well and take out about a third of the jelly inside the eye, so we clear the visual pathway once and for all. After that of course the eye is out of focus, so what we do in babies is fit then with contact lenses three or four days after surgery and the reason that contact lenses are so good is as the eye grows and the power of the eye changes, we can just change the contact lenses. Whereas with an intraocular lens like in adults, the adult’s eye growth finished so they need one lens power and that's all they need.
Host: While he's still recovering from his surgery, Jim's been pretty pleased with the results so far.
Jim: Well, the first day, you don't see very much, because you're taking a lot of eyedrops and your eye's a bit foggy and bleary. But I noticed after the second day actually, I noticed significant difference in my first eye, which was really, really bad. And it will never ever be 100%, even with the operation, but just having that operation made such a difference.
I woke up the morning after that operation and I had a book on my bedside table, and normally with that eye, I close my good eye, my right eye, and just look at it with my left eye. Normally, even with glasses, I wouldn't have been able to see the title clearly. But I had no glasses on, and I could see the title of the book, which is pretty incredible for that eye.
Host: For Tina, a Queenslander in her 40s with young children, hearing she had a cataract in her left eye was scary news.
Tina: I started noticing that my distance vision was not right and when I would sit, and still until it gets corrected still is the case, when I'd sit anything further than a metre away from someone I couldn't see the expression on their face. They could be looking at me, they could not be looking at me, just not sure, so it started feeling out of place and it feels a bit scary.
It is a dramatic change in sight, especially being a mum.
Host: Tina has always had problems with her eyesight. In fact, she was born with one eyeball, her right, significantly larger than the other. Throughout childhood she had eye tests and found out that the eyesight in her right eye was very poor.
Tina: Your average eyeball, let’s say it was like 28ml in diameter, mine’s like 36.
I don't recall ever having sight in my right eye. I remember the first time going to like an eye specialist with my mum and the eye specialist saying to me at the time, or to my mum at the time, that I should never go into a profession where you're sitting looking at a screen – right! – for very long periods of time (laughs).
My job is one that entails constantly looking on, if not a computer, a form of a device. I manage workflow, so like a project manager, so as you can imagine it’s always data reporting, constantly looking at progress of projects and, yeah, I’m also finding that on the computer now I'm increasing the view of the screen.
Host: Without surgery to remove her cataract, Tina's eyesight would be severely impacted. She's looking forward to her surgery in a couple of months.
Tina: I'm listed as a category two. Whereas, you know, category one is life-threatening, so it's at the highest category it can be without it being life-threatening which it's not at the moment. I wish it was tomorrow! (laughs) But yes, I look forward to it.
Looking after your eye health is as important as every other part of your body. So, having the annual check-up is a great preventative method to ensure you don't have any eyesight issues. Because it is a scary place when you feel that your eyesight is not what is was.
Also, just be aware of it with kids, and we don't often tend to put sunglasses on kids, but it is an important thing to do.
Host: Do babies only see in black and white, should you eat carrots to help you see better, and is screen time really making children’s eyesight worse? To finish off the episode, we asked Professor Gole to bust some eyesight myths.
Professor Gole: No babies don't see in black and white, they have the same colour vision that we do.
There's a bit of vitamin A in carrots but mainly in leafy green vegetables. So, it's important to have a balanced diet to, just a normal diet will produce no problems for your eye.
We've seen a couple of children over the years who are on fad diets and particularly children who just eat potato chips. And they contain no vitamin A at all. We've had a couple of children over the years go blind from nutritional optic neuropathy. A mixed diet is very important; if you're child just eats potato chips in the end they'll lose their eyesight. From a treatable condition.
The big emerging thing over the last few decades around the world has been an increase in the number of children who are short-sighted. And there's been a lot of research done on this because it's only been in the last 25 or 30 years this has taken place. It's very common in Asian countries and until recently it wasn't quite as common in Australia as it was elsewhere.
And a lot of work has been done on this, particularly in Singapore. Everyone in Singapore goes into the armed forces at age 18, so they know what's happening to teenagers in the population and probably 80 or 90% of them are now short-sighted. But about 10% of people with short-sightedness become very short-sighted and then they're at risk of macular degeneration in middle and old age, and of getting detached retinas throughout life.
So, it's a big public health problem, because if you look at Singapore, 90% of the population, roughly, being short-sighted, it may be 10% being at risk of vision loss as they get older. It's a big public health problem. So, they've done an enormous amount of research on it; it turns out that the biggest single risk factor is not too much close work, which we've all thought for about 150 years, but not looking in the distance enough and not getting enough bright light, basically.
So, recommendation is to go outside if you're doing a lot of close work. Go outside and look in the distance and get some more distance work every hour or so go out and look outside. So, in Australia we've all been outdoors and kicking footballs et cetera, this hasn't been as common, but it's now becoming more common.
Host: Thanks for joining us. My Amazing Body is brought to you by Queensland Health. With special thanks to our expert guest, Professor Gole, patients Jim and Tina, and my podcast colleagues: Lauren our researcher, writer and producer; Carol our audio technician; Dan our music guru; and the media team at Children’s Health Queensland.