By Patrick Hutchens
A group of New Zealand-based social entrepreneurs, led by ophthalmologist Dr Hong Sheng Chiong, has designed a 3-D printable retinal imaging tool that is attachable to a smartphone.
The group, OphthalmicDocs, has freely released the patent for the device and made the 3-D printing instructions open source via the web, allowing the technology to be widely and rapidly distributed in parts of the world where ophthalmoscopes are few and far between.
The retinal imaging tool is not the first to take advantage of the in-built light and camera capabilities of smartphones, but its free dissemination and low cost of construction mean that it has enormous potential for assisting the diagnosis of eye diseases, particularly in regions of the world where expensive optometric equipment is unattainable.
Dr Hong, an ophthalmologist registrar at Gisborne Hospital in New Zealand, developed the idea for the adapter after working as a doctor in Malaysia, Nepal and Kenya.
He was troubled to find that doctors in developing nations were making diagnoses for conditions such as retinal pathologies without having properly examined the eye.
‘It was in general practice that I realised that doctors didn’t have the right equipment or tools to examine a patient’s eye properly,’ Dr Hong said.
The OphthalmicDocs retinal imaging tool uses the indirect ophthalmoscope technique to take pictures of the retina.
‘We’ve created a 3-D printable adapter where you can place the lens right in front of the lens mount and then adjust the distance between the lens and the camera. The camera’s torch acts as illumination so you can take a video or a photo of the retina,’ he said.
The tool can be used by any health professional so that images of the eye can be sent instantly for professional diagnosis.
With a 3-D printer, the tool can be assembled within four hours and the accompanying plastic 20 dioptre lens can be bought separately for about $45.
To distribute the tool to locations where it is most needed, OphthalmicDocs has taken advantage of a world-wide network of 3-D printers. An online database lists publicly available 3-D printers around the world.
Once assembled, the tool can be used to diagnose macular degeneration, diabetes and glaucoma, as well as emergency conditions such as retinal detachments.
Those who download the instructions to build the retinal imaging adapter tool are able to modify the design of the device to suit their needs. They can also submit their modifications to a peer review process that will later allow the designs to be accessed by others if the modification is found to be useful.
A presentation to promote and explain the device, which Dr Hong delivered in Auckland earlier this year, was uploaded to the popular video platform TEDx Talk and has been viewed on YouTube more than 7,000 times.
Since the release of the adapter tool in May this year, the printing instructions have been downloaded close to 3,000 times. So far these have been concentrated in Eastern Europe, Russia, the Philippines, Ukraine, Singapore and Hong Kong.
A free supporting app for smartphones has also been designed by OphthalmicDocs to securely store and transfer patient images. It requires registration of health-care providers to protect patient privacy.
The OphthalmicDocs team is also trialling a prototype of a 3-D printable slitlamp tool for a smartphone, which will be released with the same open source principles of the retinal imaging adapter tool.
The slitlamp tool is expected to be ready for release in the next three months and will be useful in diagnosing cataracts, conjunctivitis and other conditions.
Dr Hong said that even in countries like New Zealand, GPs did not have slitlamp microscopes they could use to examine the anterior eye.
‘Of the patients who come in with a red eye, the most common diagnosis I get is conjunctivitis, and obviously that’s not true. There are a lot of conditions like anterior uveitis and corneal diseases that could easily be picked up with a device like this on a smartphone,’ he said.
One of the central aims of the 3-D printable tools and the mobile application is to reduce the delay in diagnosis for patients.
‘Instead of doctors trying to explain something down the phone about something they’ve never seen before, the GP can just send a photo and it explains itself,’ Dr Hong said.
The next stage of development by OphthalmicDocs will see the company fundraising and working with groups such as Rotary International and the Fred Hollows Foundation to distribute assembled versions of the two devices to areas in Africa.
Information on OphthalmicDocs can be found at www.ophthalmicdocs.com.