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ADRIAN MONTI: New implant to treat glaucoma – and get your cataracts done at the same time!

Glaucoma, which is caused by a fluid build-up in the eye, can lead to irreversible sight loss. 

Roger Pledge, 76, from Colchester, Essex, was the first in the UK to have a new type of implant fitted in both eyes to combat it, as he tells Adrian Monti.

The patient

Five years ago, I was shocked to discover I had glaucoma. There were no symptoms, but it was picked up during the annual eye screening I have for type 2 diabetes, a condition that was diagnosed 20 years ago.

Glaucoma can make you blind because the fluid build-up puts pressure on the optic nerve. My optician said using daily drops (travoprost) could reduce the pressure, but that if it became too high then I might need surgery.

Over time, the pressure in both eyes gradually rose. Then, late last year, tests showed my eyesight was deteriorating, so my optician referred me to a consultant at Colchester Hospital eye clinic.

By then, I was struggling to identify colours or read the paper, so I wasn’t surprised when he told me I’d need an operation to reduce the pressure.

This involves creating a new drainage channel in the eye, enabling fluid to drain away. But the consultant thought I was suitable for a new type of surgery to insert a tiny silicone implant in the corner of my eye, which allows excess fluid to drain via a different route.

Glaucoma, which is caused by a fluid build-up in the eye, can lead to irreversible sight loss. A stock image is used above

It was very new, but sounded worth trying, and he said he’d also operate on my cataracts [where the lens becomes cloudy].

I had the operation on my right eye — the eye with the most advanced glaucoma — under local anaesthetic in March, and went home later that day with a protective eye shield to wear for the first 24 hours. I had to use antibiotic eye drops for ten days and anti-inflammatory eye drops for eight weeks.

Gradually, the sight in my right eye improved. At a follow-up appointment two weeks later, I could read a few lines lower down the chart with my right eye alone compared with what I’d previously read while wearing my glasses. I could also see colours more clearly again.

In May, I had the same operation on my left eye and now, just seven weeks later, my sight is already better. At my recent check-up, the pressure in both eyes was in an acceptable range. I still need reading glasses for tiny writing but not my varifocals, nor my travoprost eye drops.

I’m looking forward to returning to driving and taking my wife Barbara out shopping and seeing more of our family, including our three great-grandchildren.

The surgeon

Chrys Dimitriou is a consultant ophthalmic surgeon at Colchester eye clinic and glaucoma lead at the East Suffolk and North Essex NHS Foundation Trust.

Glaucoma occurs when the optic nerve, which transfers visual information from the back of the eye to the brain, becomes damaged as the fluid (aqueous humour) that keeps the eye healthy becomes trapped.

Around 680,000 people in the UK have primary open angle glaucoma, the most common type, which becomes more prevalent with age and a family history of the condition.

Normally, this watery fluid drains away through a network of tiny channels, called the trabecular meshwork. But with open angle glaucoma, this network can become clogged with deposits of dead cells and proteins — we don’t completely understand why.

As a result, fluid doesn’t drain away as it should, causing pressure to build inside the eye and squeezing the optic nerve.

The condition is normally picked up during routine optician appointments. Early signs are detected by measuring internal eye pressure and checking peripheral vision.

Many older people develop cataracts and glaucoma around the same time but operating on both isn¿t possible with a trabeculectomy due to the risk of inflammation when removing the cloudy lens

Many older people develop cataracts and glaucoma around the same time but operating on both isn’t possible with a trabeculectomy due to the risk of inflammation when removing the cloudy lens

This type of glaucoma develops very slowly. Initial changes are subtle, and once someone notices problems, it can be far advanced and irreversible. One clue can be changes to colour perception, due to damage to the photosensitive cells at the back of the eye.

Pressure is eased with eye drops that either reduce the production of fluid inside the eye or enhance the outflow of fluid from the eye. But these can stop being effective as the disease progresses.

Another treatment is selective laser trabeculoplasty. This involves firing a low-energy laser beam at specific cells in the trabecular meshwork, causing the meshwork to rebuild so fluid can easily drain again.

In advanced cases, we perform a trabeculectomy — creating a new artificial drainage channel in the white of the eye, with a small trapdoor above it, called a ‘bleb’, to let fluid drain.

But this is a complicated procedure, and if one step goes wrong, it won’t work.

Now there is a new type of surgery, micro-invasive glaucoma surgery, where we insert an implant, called MINIject, to lower eye pressure. 

The implant, 5mm-long and 0.6mm-thick, is made from a flexible medical-grade silicone with thousands of tiny holes that allow the aqueous humour to flow freely.

The implant allows the excess fluid to drain away — there’s no need to create new channels, as with the trabeculectomy; instead the implant redirects the fluid to another existing drainage network in the eye called the supraciliary and suprachoroidal space.

The implant can be put in place under a local anaesthetic.

Roger was the first UK patient to have MINIject in both eyes.

It can be done as a standalone procedure or alongside cataract surgery. Many older people develop cataracts and glaucoma around the same time but operating on both isn’t possible with a trabeculectomy due to the risk of inflammation when removing the cloudy lens.

The surgery takes under 30 minutes. Using a specialised microsurgery knife, I cut through the limbus, where the cornea [the clear outer layer of the eye] meets the sclera [the white of the eye] and insert a thin sheath containing the implant. Once in place, the implant is released and the sheath withdrawn.

We hope the procedure will be effective for around ten years, but only time will tell. This implant works best for patients, like Roger, with early to moderate open angle glaucoma.

This procedure is available at a few other UK hospitals including in London, Edinburgh, Guildford and Manchester.

The cost of a MINIject implant is £1,700 on the NHS.

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