Around half-a-million Britons have glaucoma, a build-up of pressure in the eye, which can lead to loss of vision. Sandra Day, 64, a medical secretary from Borehamwood, Herts, underwent a new form of procedure for it, as she tells MATTHEW BARBOUR.
THE PATIENT
At a regular check-up at the opticians I was diagnosed with early-stage glaucoma. It was a bit of a shock because I hadn’t had any symptoms.
When I was referred to the Royal Free Hospital in London for tests, the pressure in my left eyeball was 23mmHg [10-21 is normal]. I was prescribed eye drops, latanoprost, to take once a day.
I used these, but at every check-up — every four to six months — my eye pressure was higher, until in May last year, it reached 28mmHg.
I started to lose my field of vision: I couldn’t see objects clearly to the far right or left without turning my head.
Later that month, my consultant, Vik Sharma, told me that with the maximum strength drops not working, I’d need surgery to open up the drainage channel in that eye.
At a regular check-up at the opticians I was diagnosed with early-stage glaucoma. It was a bit of a shock because I hadn’t had any symptoms (stock image)
I started to lose my field of vision: I couldn’t see objects clearly to the far right or left without turning my head (stock image)
The following month, I had a tiny, thin tube [stent] fitted in my left eye to drain the fluid build-up and release some of the pressure. This operation took ten minutes and initially it seemed to work.
But in the following weeks, the tube became uncomfortable, and the eye became red.
Mr Sharma said he would take it out, but that there was another option — which would have the same effect, opening up the channel using a thin tube to widen it, and without leaving a stent in my eye.
This involved another ten-minute procedure: the day after, my vision was very blurred, but by morning it had almost cleared. Within three to five days it was back to normal. I returned to work the following week. The pressure in my eye has dropped to around 10mmHg and my vision is good and stable.
THE SPECIALIST
Vik Sharma is a consultant ophthalmologist at the Royal Free Hospital in London and London Ophthalmology Centre.
Glaucoma is caused when the aqueous humour liquid in your eyeball — the fluid produced by the eye to nourish it and maintain its shape — doesn’t flow out properly, leading to increased pressure, which can damage your optic nerve.
It affects 2-3 per cent of the population over 40, and is known as the ‘silent thief of sight’ because there are no signs until it’s too late and irreversible damage has been done.
This is why having regular eye checks is so important as you get older — from the age of 40, or earlier if you have risk factors, such as a family history of the condition or if you’re diabetic or short-sighted. Left untreated, it can lead to blindness. Patients with moderately high intraocular pressure (pressure in the eyeball) — greater than 21 — can use drops to lower it.
These stop production of fluid and/or increase drainage by making existing drainage channels more efficient but when they stop working, surgery is needed.
The gold standard has been a trabeculectomy, creating a new drainage channel in the top part of the white of the eye under the top eyelid: a small hole is cut in the front of the eye, just under the eyelid, and fluid drains into a new reservoir under the tissue of the eyeball.
It affects 2-3 per cent of the population over 40, and is known as the ‘silent thief of sight’ because there are no signs until it’s too late and irreversible damage has been done (stock image)
While effective, the operation takes around an hour and there are potential complications.
Recovery time can be eight to 12 weeks, during which time vision can be blurred; there’s a risk of lowering the pressure too far; loss of vision from a bleed in the eye; and infection.
Newer surgical options involve using micro tubes and stents — small gel or metal tubes inserted inside the existing drainage channel, which remain in the eye to encourage fluid to drain through this natural drainage channel rather than creating a new one.
The metal 8mm Hydrus stent, available since 2021 and similar to stents used in heart operations, is one option.
The advantage of these over the traditional operation is there are no large cuts or stitches, so fewer complications such as infection, and no risk of the pressure going too low.
However, in some patients — such as Sandra — any foreign object left in the eye can cause discomfort and needs to be removed. The new OMNI device corrects the problem without leaving an implant in the eye.
A special pen is used to insert a catheter — a plastic thread, the width of a human hair — through a 1mm incision on the side of the cornea, the clear dome at the front of the eye.
Once this is in place, where the cornea and iris meet, the surgeon carefully ejects the catheter to reopen the natural drainage canal. Hyaluronic acid, naturally found in the eye, is used to flush the canal if needed. The catheter is then drawn back into the pen and removed from the eye; the 1mm incision naturally closing without the need for any stitches but the drainage channel remains open, as the OMNI device has dilated and flushed the canal.
At every check-up — every four to six months — my eye pressure was higher, until in May last year, it reached 28mmHg (stock image)
In total, it takes around five minutes. Because it only requires a very small amount of local anaesthetic, the patient can leave after an hour or so, returning to work after a day, and driving within a week.
Antibiotic and steroid eye drops can be prescribed to help the eye heal, and a plastic shield is worn at night for a week to cover the eyes, to stop any rubbing or pressing which could cause inflammation. I’ve carried out the OMNI procedure around 50 times, both privately and on the NHS, with no complications and good results.
OMNI was recently approved for use on NHS patients and there’s a wealth of strong clinical data backing its use.
Like all glaucoma patients, Sandra will need regular check-ups, two to three times a year, but won’t need drops or any other interventions unless eye pressure rises to over 16mmHg.
WHAT ARE THE RISKS?
As with other eye procedures, there is a risk of infection.
Dr Sally Ameen, a consultant ophthalmic surgeon at Imperial College Healthcare NHS Trust in London, and at the OCL Vision clinic, says: ‘The OMNI system is one of the latest surgical options for glaucoma, developed in the U.S. and approved by NICE [the National Institute for Health and Care Excellence] in 2022.
As with other eye procedures, there is a risk of infection (stock image)
‘Unlike existing techniques, it doesn’t involve device implantation. A recent research paper showed OMNI treatment delivered a sustained 20 per cent reduction in patients’ eye pressure over three years with ‘minimal side-effects’.
‘The jury is still out on how it compares with more established surgical procedures [such as using stents]. There have been some case studies comparing the OMNI system to these but no robust studies, as it has not been available for long.
‘The OMNI system is in its infancy — it remains to be seen if it will be widely adopted by surgeons, but it does have one clear advantage — it costs significantly less. OMNI costs £850 compared to around £1,300 for a stent [excluding surgeon’s costs].
‘This will appeal to public and private healthcare providers, and could see OMNI become a first-line treatment for glaucoma.’
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