Researchers at University College London and the University of Oxford developed a set of magnetic implants to treat nystagmus in a patient who developed the condition in his late 40s.
The treatment involved implanting magnets in the orbital floor of each eye socket, and stitching another magnet to the extraocular muscles that control eye movement.
The magnets are able to control the involuntary eye movements that characterise nystagmus without being overly restrictive because the force of the flickering movements is weaker than voluntary eye movements.
Nystagmus’ last dance
Testing after the magnets were implanted revealed that the patient’s visual acuity had improved and there was no negative impact on his functional range of movement.
More than four years later, the patient reports a significant improvement in daily activities and has managed to return to paid employment. He has a degree of double vision, but this was present before the magnets were implanted.
Lead author Dr Parashkev Nachev explained to OT that the impact on day-to-day life of nystagmus could be as disruptive as conditions like macular degeneration.
“One of the things that is often neglected with nystagmus is how profoundly disturbing the effect on visual function is,” he added.
Researchers are now recruiting patients for a larger clinical trial involving between six and 12 people.
Before implanting the magnets in the patient, researchers tested the implants externally using a custom-made contact lens.
“We could see that it stopped, or greatly attenuated the oscillation of the eye, but the patient could still shift his gaze,” Dr Nachev shared.
The magnetic prostheses were implanted in two separate sessions by Professor Geoff Rose and David Verity at Moorfields Eye Hospital.
The magnets were encased in titanium – a material that has been used in patients for decades and has no adverse reactions with tissue.
Limited treatment solutions
Dr Nachev highlighted that a diverse variety of neurological problems could give a patient nystagmus, which posed difficulties for treating the condition.
The effectiveness of available drug treatments was variable, he emphasised.
“The problem with those is that they often don’t work very well, but also, whether or not they work in one patient or another tends to be erratic,” Dr Nachev shared.
“What we end up having to do is try one tablet, wait for three months to see if it works and then try another, and so on,” he explained.
There are also unpleasant side effects associated with drug treatments, with drowsiness and dizziness reported in some cases.
Dr Nachev outlined that a surgical solution to nystagmus came with its own pitfalls.
“The major problem with a surgical solution here is that you can’t immobilise the eye, for example with a stitch, without stopping normal eye movements,” he elaborated.
“If you put a partial stitch in then the whole thing will fibrose, even if it’s not fixed at the beginning, it will be fixed within months,” Dr Nachev added.
A new approach
The research is the first time that an implant has been used to alter the normal movement of the eye and opens up new treatment avenues for a broad range of conditions.
Dr Nachev outlined that the case study was an illustration of a more general concept – that neural problems did not always have to have neural solutions.
“Because neurology is so complex and the mechanisms are often so diverse sometimes we have to be innovative and think further down the line, considering other points in the pathway,” he explained.
“The most important thing with any potential treatment is that it helps someone who cannot currently be helped,” Dr Nachev concluded.