New treatments for glaucoma in the works

SINGAPORE — Within a decade or so, glaucoma patients may be able say goodbye to eye drops and have their pick of treatments, making a visit to the clinic akin to a shopping experience.

Singapore is taking part in a 20-country clinical trial for a medicine that has to be applied every four to six months, instead of daily. Among a host of ongoing trials for similar products, this medicine, formulated by global pharmaceutical company Allergan, is at an advanced stage of development and could be sold in the market in three years.

The Singapore National Eye Centre (SNEC) is calling for about 120 volunteers to take part in a two-year trial at National University Hospital, Khoo Teck Puat Hospital and Changi General Hospital.

The procedure involves an injection into the inner eye, in the region between the iris and the cornea called the anterior chamber. A pellet of a slow-release drug is injected via a needle that is less than 1mm in diameter. This drug implant will then sit at the bottom of the chamber for the next four months. The drug is biodegradable and will not leave any residue.

During a preliminary trial a year ago on 100 people worldwide — five of them Singaporeans — it was found that in 91 per cent of the patients, the implant relieved eye pressure for up to four months.

Two other glaucoma treatments making progress in Singapore involves an injection into the tear duct, which is effective for up to two months, and the subconjunctival — the outer, glassy part of the eye — which is effective for up to six months.

Professor Aung Tin, executive director of Singapore Eye Research Institute, said: “The time will come when you go to the doctor and they will give you a menu: Do you want eye drops? Tear duct injection? … In future, maybe all the different technologies could be used (for one patient).”

Glaucoma — where sufferers have high fluid pressure in the eyes — accounts for 40 per cent of blindness in Singapore, and it affects 10 to 12 per cent of those over the age of 70 here.

In total, about 80,000 people here are affected by glaucoma, and about 10 per cent of them turned blind because they did not apply medication as instructed. Two of the Singaporean participants in the preliminary trial, identified only as Madam Sham and Mr Tan by the SNEC, said that the process was painless. The two 60-year-olds also did not have any itchy sensation in the months the drug implant was taking effect.

Adjunct Associate Professor Shamira Perera, senior consultant at SNEC’s glaucoma department, said: “When you apply eye drops, only 5 per cent is being used inside the eye ... But if you are putting the medication directly inside the eye, that’s the best, and you can put less of it (and the medicine will be as effective).”

For Mdm Sham, who also has diabetes, high blood pressure and high cholesterol, the new treatment is a relief. She occasionally forgets to apply her eye drops with the many sets of medication she takes for her other health problems. “When travelling, I need to carry it along … eye drops are troublesome.”

Mr Tan said: “One day, I hope this eye procedure can also be ‘bypassed’ (like a heart bypass surgery), so I won’t even have to go for an injection.” WONG PEI TING