Magnetic fluids offer hope for damaged retinas

Researchers at Virginia Tech are developing injectable magnetic fluids to repair torn or detached retinas; a technique they believe could help prevent blindness in thousands of people.

Silicone fluid is currently used to push damaged retinas back in place. A magnetised version of the fluid would make repairs easier and more precise by allowing the fluid to be moved to areas of the eye that are hard to reach, according to the researchers.

The treatment appears promising in laboratory studies, said Judy Riffle, Ph.D., head of the research team and a chemistry professor at the university. Animal studies could take place within a year and human studies could soon follow, she said.

‘We are the first to develop controlled magnetic nanoparticles that are appropriate to use in the eye,’ said Riffle. Her lab has been developing the material for the past ten years.

Tiny particles of cobalt or magnetite are enmeshed in polydimethylsiloxane, a silicone-based fluid. When exposed to an external magnetic field, the fluid can be manoeuvred in much the same way that magnetic pieces are moved around in certain toys, Riffle explained.

The retina is the thin, light-sensitive layer of tissue located at the back of the eye. When it becomes detached or torn, either due to disease or injury, impaired vision results. Blindness occurs if it is not repaired.

The conventional way to repair this disorder is to inject silicone fluid or a special gas directly into the eye to push the retina back into place. In people with more severe damage, this treatment often fails because the material cannot reach certain areas of the eye, particularly the lower parts, said J. P. Dailey, M.D., an ophthalmologist with Erie Retinal Surgery, and a major collaborator in the study.

In searching for a way to distribute the material more evenly inside the eye, Dailey came up with the concept of using magnetic fluids, which are known for their manoeuvrability. Riffle then designed the biocompatible, silicone magnetic nanofluids.

‘If it works, it will be wonderful,’ said Dailey, who cautions that the technology still needs further safety testing. ‘This could be a major innovation in how retinal detachment repair is done.’

‘Our lab’s work may open the door for a whole host of new medical applications for magnetic nanoparticles,’ added Riffle. Similar fluids are being developed by her lab for use in targeted drug delivery.

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