Ophthalmoscopes aren’t the easiest things to use. Practicing for clinical exams, groups of medical students get together and when one exclaims “I SEE IT I SEE IT!”, nobody else seems to be able to verify the findings. I’m a second year medical student myself, and I think I’ve found one optic disc in an undilated pupil in all of my countless attempts. (Maybe.) Wouldn’t it be nice if we could have an easy-to-use solution that also records the image? When I heard about D-EYE, a smartphone lens attachment that turns a variety of smartphones into digital ophthalmoscopes, I was curious to find out what made it a good alternative.
I chatted with Dr. Andrea Russo, an ophthalmologist who’s completing his PhD, about his D-EYE device to learn more.
Ben Ouyang, Medgadget: How does the D-EYE work?
Andrea Russo: Light comes from the smartphone’s LED, off-axis from the camera lens. We create a path of light from this LED to deliver the light exactly coaxial to the camera using a combination of levers and beam splitters. This way you can enter the pupil and eye to see great. Once you see the red reflex from the eye, the D-EYE is correctly focused. You can increase the field of view by moving the phone/D-EYE closer to the eye, without changing the focus. Our suggestion is to go as close as you can to the eye to get the best field of view.
D-EYE uses the principle of direct ophthalmology. It’slike looking through a keyhole – the closer you are to the keyhole, the wider the field of view you have beyond it. We can correct for various refractive errors by using the smartphone’s autofocusing capabilities to compensate between -10D myopia to +10D hyperopia. Even with undilated pupils, it’s possible to scan the retina with a field of view of 5-8º. We can see the optic disc with pupils as small as 2mm, so the D-EYE can offer a rapid screening for glaucoma or hypertensive retinopathy for undilated pupils.
Medgadget: What’s the learning curve like for this device?
Russo: It’s quite straightforward. People can start to scan the eye in 15 minutes. As the inventor, I can scan the retina with the D-EYE in a few seconds. The important part is to fix the focus – once it’s correctly set, it’s really easy.
Babies are often scared by our equipment, either noisy, or really bright using the ordinary ophthalmoscope. The light coming from the D-EYE is not “invasive” – it’s a small light. Babies are naturally attracted by smartphones, and they tend to look at the smartphone, while you look at the retinal details that you need.
Medgadget: How did the D-EYE system come to be?
Russo: A couple of years ago, I finished my residency program in ophthalmology and I had tons of innovations to test patients for hypertensive retinopathy or diabetic retinopathy. I was wondering if there was a way to couple the powerful smartphones in our pocket and their high resolution cameras, with the ability to get retinal images. I bought a 3D printer, and I started to make the first prototypes of the D-EYE and it just worked pretty well, exploiting the principle of direct ophthalmoscopy. This is why the D-EYE is so simple and so portable. I requested the patent, now pending, and I joined the company in Italy and together, we went ahead to build the D-EYE.
We published a paper in the American Journal of Ophthalmology. It was a comparison between the D-EYE system and the slit lamp gold standard, and we showed a 90% agreement. The smallest diameter of pupil that we can assess is 2mm.
Medgadget: What makes D-EYE the best digital ophthalmoscope out there right now?
Russo: The most similar to the D-EYE, I think, is the Eye Examiner from Welch-Allyn. It uses a bracket to mount onto the iPhone 4. The system is portable, like ours, but the main drawback of the system is that the learning curve is longer, it’s bulkier, and the image quality is not as good as the D-EYE, because we provide much better enlargement. It’s also close to $1000 – more than double the price of the D-EYE. Another company, Volk, provides devices that make beautiful images of the retina, but the price is around €8000-9000, so they’re a different segment of the market, in my opinion. What we produce is something in between the field and hospital. We don’t want to replace the excellent and expensive equipment, we want to make something in the middle to screen the population before referring them to onwards.
Medgadget: How useful could this be as an educational tool for medical students?
Russo: Probably one of the best targets for us, are the students of medicine or the paramedical field because it’s a very convenient way to assess the retina. The technique is rapid – seeing the optic disc is just like “1,2,3”. For students, it’s amazing because the ordinary ophthalmoscopes are not easy to use, and you also have to lean in towards the patients, which can be inconvenient for many reasons. With this, you can move just your hands, not your face, towards the patient and obtain images of the retina.
Medgadget: Do you have any tips for innovative healthcare workers?
Russo: My story started with an idea that I could personally test in the field with a few cheap components assembled with glue and tape. Since the first results were encouraging, I decided to buy a 3D printer (Makerbot Replicator 2, NY – USA). This was an affordable tool (1500 – 3000 USD), crucial in my story. The 3D printer made it possible to physically create and test more than 50 versions of the hardware in a few weeks. Enough to deposit my patent request and start the industrial process.
Generally speaking, most of the ideas have an easy principle which is assessable with a limited budget. I encourage everybody to make this very first step, al least. As per the next steps, I was lucky enough to have the minimum 3D graphics, computer, and optical skills needed to go ahead by myself. However, nowadays many open space offices (such as Talent Gardens in Europe) shared by smart people are available worldwide: these are essential to meet the skills needed to pursue the project.
Here’s a video example of the D-EYE in action: