Implants could help treat eye condition which causes vision loss

Straits Times

5 days ago

The implant has already received approval from the US Food and Drug Administration. ST PHOTO: DESMOND FOO
Implants could help treat eye condition which causes vision loss
SINGAPORE - Instead of receiving uncomfortable eye injections around once a month for a disease that can lead to blindness, patients may soon have an easier alternative.
A new innovation will allow them to be treated twice a year via an implant the size of a rice grain.
Swiss healthcare firm Roche, which developed the treatment, is now conducting a study of the implant involving more than 400 participants in 16 countries, including Singapore – the only country in South-east Asia in the study and one of only three Asian countries.
The study, which ends in December 2026, looks at the efficacy and safety of refilling the implant every nine months, compared with every six months.
The implant has already received approval from the US Food and Drug Administration.
Treating neovascular age-related macular degeneration (nAMD) currently requires injections into the eye as often as once a month.
Studies have noted that patients' discomfort with the treatment can lead to undertreatment of the disease.
The disease affects the part of the eye that provides the sharp vision needed for activities such as reading and driving, and can result in rapid and severe vision loss if left untreated.
It results when new and abnormal blood vessels grow uncontrolled under the macula – the part of the retina responsible for sharp central vision – causing swelling, bleeding and fibrosis.
The condition, also known as 'wet' AMD because these new blood vessels leak fluid into the retina, is one of the leading causes of blindness in Singapore, affecting more than 125,000 people aged 40 or older.
This number is expected to increase to almost 200,000 by 2040, according to a study published in Annals, the official journal of the Academy of Medicine, Singapore in 2018.
Roche's innovation to treat nAMD a refillable eye implant that continuously delivers a customised formulation of ranibizumab – a drug used to treat a number of eye conditions – over a period of several months.
Also known as a port delivery system, the implant is inserted into the eye via a simple procedure and requires just two refills a year.
Roche said in a statement that the implant could result in more reliable improvements in vision for people living with nAMD, reducing the risk of disease recurrence.
Decreasing the need for frequent eye injections and doctor visits can also reduce the treatment burden for patients, the firm said.
Singapore currently has four sites involved with the trial – the National University Hospital (NUH), Singapore General Hospital, Tan Tock Seng Hospital, and Eye & Retina Surgeons @ Camden Medical, a private clinic.
Prof Caroline Chee and Dr Yuen Yew Sen from the department of ophthalmology at National University Hospital who took part in the trial.
ST PHOTO: DESMOND FOO
Dr Yuen Yew Sen, a consultant with NUH's ophthalmology department, is among those involved with the Roche's study here.
He told The Straits Times only those who have recently been diagnosed with nAMD qualify for the trial, and four patients have received the implant at NUH.
Once the treatment becomes commercially available – which he said could happen by 2026 – most patients should qualify for the treatment, except for those who have other eye conditions such as glaucoma.
Beyond some initial minor discomfort following the surgery, patients who receive the implant are unlikely to notice it is even there, Dr Yuen said.
'Once the stitches dissolve, they don't actually feel anything,' said Dr Yuen, noting that similar implants are also used to treat conditions such as glaucoma.
Such implants can also be used to treat other diseases related to the eyes, with trials looking at their use in addressing diabetic retinopathy on the cards, he said.
Professor Gemmy Cheung, head of the retina research group at the Singapore Eye Research Institute, notes that nAMD presents differently in Asian populations due to the higher prevalence of a subtype known as polypoidal choroidal vasculopathy (PCV).
'PCV primarily impacts the blood vessels in the layer beneath the retina, causing serious vision impairment or even vision loss if left untreated,' she said.
This is of concern because PCV has historically been considered more difficult to treat, with less predictable outcomes than typical nAMD, she said.
While conventional treatments are effective in most PCV cases, frequent retreatment is required, said Prof Cheung, who also heads the medical retina department of the Singapore National Eye Centre.
Lapses in treatment can result in reactivation of lesions and new instances of bleeding, she added.
New therapies such as the port delivery system offer a 'promising approach to providing sustained disease control' in PCV, she said, adding they can potentially reduce the burden of frequent injections and improve long-term outcomes for patients.
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