“Micro-tube” offers hope for glaucoma sufferers

The tube is inserted into the eye. www.snf.ch

An eye specialist in Lausanne has pioneered a new technique which could help millions of people worldwide suffering from glaucoma.

It involves inserting a microscopic tube into the eye to drain away excess fluid and relieve pressure on the optic nerve, preventing loss of sight.

The technique was developed by André Mermoud from the Jules Gonin eye hospital and trials on ten patients have successfully stabilised the pressure inside the eye.

The operation simplifies and removes many of the risks from a procedure invented in Lausanne in 1990.

“There are different types of operation today but unfortunately they are linked to many post-operative complications, and the success rate is not that good,” Mermoud told swissinfo.

“That’s why our group is trying to have new techniques which are more reliable, less traumatic and more successful.”

Millions affected

More than 100,000 people in Switzerland suffer from glaucoma. Worldwide, it’s estimated that there are more than 70 million cases.

The half-hour operation, which is carried out under a local anaesthetic, involves Mermoud’s team cutting into the tough, white outer coat of the eye – the sclera.

They then insert a tube, about three millimetres long and 50 microns in diameter, which lodges in the eye.

The micro-tube allows excess fluid to drain from the front compartment of the eye, known as the anterior chamber, into the pocket created by the slit in the sclera.

The technique devised in 1990 also involved cutting into the sclera, creating a pocket to serve as a reservoir for the excess liquid.

But instead of inserting a tube, surgeons left a small membrane intact for the liquid to flow through.

“With this intervention, there’s a great risk of perforating the membrane,” explained Mermoud. “To simplify the procedure and make it possible for as many surgeons as possible to perform it, we developed the micro-tube technique.”

Another disadvantage of the old method is that in 50 per cent of cases, the membrane clogged up over time and needed correction with laser treatment.

Loss of vision

Glaucoma is a group of diseases that can damage the eye’s optic nerve and lead to patchy loss of vision or blindness.

It results from the watery fluid in the eye failing to drain away as quickly as it is produced.

The resulting build-up of pressure can damage the optic nerve – the part of the eye which carries visual information to the brain.

It is made up of over one million nerve cells which become compressed, damaged and eventually die unless the pressure is relieved. The death of these cells results in permanent visual loss.

There is currently no cure for glaucoma; however, with early detection and treatment, the progress of the condition can be minimised.

“The main problem is that patients don’t show any symptoms, so the disease is very difficult to diagnose,” said Mermoud.

“Regular check-ups after the age of 40 are very important so that the disease can be treated on time.

“If the pressure is too high for too long then the optic nerve gets damaged and atrophied, and the disease leads to blindness.”

Treatment includes eye drops, pills, laser surgery or eye operations.

swissinfo, Vincent Landon

Glaucoma

More than 100,000 people in Switzerland suffer from glaucoma.
Worldwide, it’s estimated that there are more than 70 million cases.
Glaucoma is one of the most common eye disorders amongst older people.
It is much more widespread in people of African-Caribbean origin than Caucasians.