Half a million Britons have glaucoma, which can cause blindness if left untreated.
Last month, Asteroulla Antoniou, 76, a retired dressmaker from London, underwent a new operation to treat it, as she tells LUCY HOLDEN.
THE PATIENT
My eye problems started in 1990.
I’ve always needed reading glasses and at an eye test, my optician strongly advised me to see my doctor because she said she’d spotted something that could be a sign of glaucoma.
I knew about glaucoma because my father had it. It meant there was a blockage stopping fluid draining out of my eye, increasing the pressure in it, which can damage the optic nerve.
Asteroulla Antoniou, 76, is a retired dressmaker from London who has experienced problems with her eyes since 1990
My father went blind from it and I remember him having to be helped around by his grandchildren. I was worried that might happen to me, too.
My GP referred me to an eye specialist at St Thomas’ Hospital in London.
A few weeks later they did more tests and confirmed I had glaucoma in both eyes and prescribed eye drops to relieve the pressure.
That was more than 25 years ago and I couldn’t count how many different types of drops I’ve tried since: you have to swap drops because your eyes get used to them.
I was allergic to several and once spent New Year’s Day in AE because I’d had such a bad reaction to one.
Over the years, both eyes got worse and I started to need to take three different kinds of drops, twice a day.
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In 2013, I tried a laser treatment that works by unblocking the ‘drain’ in the eye. But that didn’t reduce the pressure enough, so I went back to the drops.
I could see fine, but my doctors said my sight was at risk and the damage could happen quite quickly if you didn’t treat it.
I had check-ups with my doctor, Saurabh Goyal, every three months.
Last November he told me about a trial of a new treatment that involved a device called a Kahook Dual Blade, which they use to scrape away the tissue blocking the eye’s drainage system (called the trabecular meshwork).
I liked the sound of it because it meant I might not have to take eye drops any more, or could take them less frequently.
I had the operation on my left eye first (because the glaucoma was worse in that eye) on January 17. I had a local anaesthetic injected right into my eye — can you imagine!
Asteroulla (pictured) became one of the first patients to try the new treatment, and the amount of pressure in her eye had halved in just one day
It was uncomfortable, but I couldn’t see the knife or what was going on (my right eye was covered) and I didn’t know I’d had a few stitches in my eye until after the operation.
It took about half an hour.
I felt a bit dizzy afterwards, but an hour later I was fine and went home. My left eye was covered with a patch for a week (to reduce the chance of infection).
The next day my eye was checked and the pressure in it had halved. I thought, how long will it last? But so far it has.
A week later, I had the stitches taken out. I now need half the amount of drops to control it.
I’m desperate to have the operation in my right eye: life without drops would be brilliant!
THE SURGEON
Saurabh Goyal is a consultant ophthalmic surgeon at Guy’s and St Thomas’ NHS Foundation Trust.
Glaucoma is the leading cause of preventable blindness in the UK.
Pressure rises in the eye when the natural aqueous fluid it produces (which provides nutrients to the eye and helps keep its shape) can’t drain out from an area of tissue known as the trabecular meshwork at the base of the cornea (at the front of the eyeball).
This meshwork is made up of cells that drain into a channel known as Schlemm’s canal. The meshwork can become blocked in the same way a sink can.
Patients with severe glaucoma may be offered an external trabeculectomy, where a hole is cut in the top of the eyeball for the fluid to drain out
It can be spotted in normal eye tests (because the optical nerve becomes cupped when it’s damaged) and it can be diagnosed with a machine called a tonometer, which measures the pressure in the eye.
High pressure damages the optic nerve, which means your brain can’t process what you’re looking at.
When glaucoma starts, peripheral vision is lost (there are fewer optical nerves here so it is susceptible to deterioration).
You might be able to see a road, but not a child crossing it from the side. Or you might bump into things because you can’t gauge how close they are.
As the condition spreads through the eye, patients lose central vision — everything begins to look foggy and they can’t see shapes. Then your sight could disappear.
There are one million retinal nerve fibres and some are naturally lost as we age.
When you have glaucoma, the process is accelerated — how quickly nerve fibres die depends on the level of pressure.
When glaucoma starts, peripheral vision is lost. You might be able to see a road, but not a child crossing it from the side
It can be quick: I’ve seen people lose their sight in months without any symptoms beforehand.
A few factors affect your risk of glaucoma: age, family history, race — African Caribbean patients are more likely to get it, we think for genetic reasons.
It can also be caused by injury, such as a squash or tennis ball hitting the eye, which tears the meshwork and scars it.
No treatment can restore sight once it’s lost, which is why it’s important to control pressure in the eye early on. Treatment aims to reduce the pressure, which patients can’t usually feel.
The eye drops open the uveoscleral pathway, another channel at the back of the eye, as an alternative way for the fluid to drain out.
Another kind of eye drop works by blocking receptors that produce the fluid.
The problem with drops is that many people apply them wrongly, gaining no benefit.
They cost up to £15 a bottle and can have side-effects, as Asteroulla experienced.
Some eye drops open the uveoscleral pathway as an alternative way for the fluid to drain out.
Patients often need to use several different drops at the same time to reduce the pressure. The drops can also make your eyes sore and itchy.
Patients with severe glaucoma may be offered an external trabeculectomy, where a permanent hole is cut in the top of the eyeball for the fluid to drain out.
But it’s hard to predict how it will heal and that can affect whether the pressure in the eye is reduced too much or not enough. Laser treatment is an option, but only short-term.
This new procedure, known as a KDB internal trabeculectomy, involves scraping away the damaged part of the meshwork so fluid drains properly.
We hold the eye open with a clip and use a microscope with a special lens (a gonioscope, which helps you see inside the eye).
We then use a Kahook Dual Blade, which resembles a potato peeler and allows us to cut away the meshwork of cells in the eyeball. It clears the damage in a way a normal knife can’t.
Because we’re removing the damaged area, it is less likely to become blocked again.
The patient can leave hospital the same day and shouldn’t be in any pain. I have operated on a handful of patients and we’ve had great results, reducing eye pressure immediately.
When I am more used to the procedure it should take only ten minutes.
St Thomas’ has one of the only machines in the world that can measure fluid in the eyes and we do this before and after the op, so we know it works. It’s early days, but very exciting.
The treatment is being trialled. You can call 020 7188 4885 for more information.