A Growing Concern
With 70 million people with diabetes, India has a growing problem with diabetic retinopathy. The disease creates lesions in the back of the retina that can lead to total blindness, and 18 percent of diabetic Indians already have the ailment. With 415 million diabetics at risk for blindness worldwide (the United States, China, and India have the most cases), the disease is a global concern.
of the 70 million people with diabetes in India have the ailment.
But the good news is that permanent vision loss is not inevitable. For those who are diagnosed early enough, medications, therapies, exercise and a healthy diet are highly effective treatments for preventing further damage.
Awareness is a huge issue with diabetic retinopathy. Many diabetic patients assume that early signs of the disease are simply minor vision problems, according to Dr. Rajiv Raman, a retina surgeon at Sankara Nethralaya Eye Hospital in Chennai, India. With no word in Hindi for 'retina', just talking about the disease is a challenge. 'For cataracts, we have a word, for glaucoma we have a word in Hindi as well as in Tamil, but diabetic retinopathy is – there is no translational word', Dr. Raman says.
But while an ophthalmologist can explain the disease and how regular exams will monitor its progress, the real difficulty is getting at-risk patients a retinal exam in the first place. For rural communities worldwide, the prevalence of late-stage diabetic retinopathy has more to do with infrastructure than medicine. The journey from home to the nearest specialist can be long, and keeping multiple appointments is often very difficult.
'Many of the rural patients have an advanced stage of diabetic retinopathy, but they don’t know they are diabetics'
It is often impossible for patients in poverty with dependents to also care for themselves. Instead, they will carry on until the effects of diabetic retinopathy become too bad to ignore, which is often too late. 'Many of the rural patients have an advanced stage of diabetic retinopathy, but they don’t know they are diabetics', says Dr. Sheila John, head of teleophthalmology at Sankara Nethralaya. 'They are losing sight. In some cases, they have lost vision in one eye, [and] the other eye we have to save.'
Assembling the Team
The biggest challenge with diagnosing diabetic retinopathy, however, is the sheer number of cases. India alone has 70 million diabetics who must be screened, and there just aren’t enough trained clinicians to review their retinal scans.
But it simply isn’t feasible for specialists to open practices in rural areas where only a few patients may reside, according to Dr. R. Kim, chief medical officer at Aravind Eye Hospital in Madurai, India. 'We need to screen them early on when their vision is still good. So how do we do that?' Dr. Kim asks. 'Because it’s not humanly possible to screen these 70 million.'
If Google’s artificial intelligence could help make diagnosing diabetic retinopathy easier by accurately interpreting retinal scans, perhaps the eyesight of millions could be saved.
The tricky part was creating a data set for the AI model to learn from – a task which involved scoring and labeling all the scans one by one for different grades of severity. Solving that problem would eventually require a large team of ophthalmologists whose scoring of the scans would inform the AI model.
But the team would need more quality data if it was going to teach the AI model the nuances to truly read a retinal scan.
How the AI Works
How the AI Model Works (1/4)
Over 50 ophthalmologists have manually reviewed more than 1 million anonymous retina scans, rating each for the level of diabetic retinopathy present.
How the AI Model Works (2/4)
Each scan is reviewed multiple times and is graded manually on a scale of 1 (no diabetic retinopathy signs present) to 5 (extreme signs present).
How the AI Model Works (3/4)
The graded images are then fed into an image recognition algorithm. By feeding the algorithm thousands of graded images, it can start to understand signs of diabetic retinopathy just like an ophthalmologist would.
How the AI Model Works (4/4)
Once the algorithm has been trained, it can be used to power an application called an Automated Retinal Disease Assessment (ARDA). ARDA allows a user to upload a retina scan for instant analysis of diabetic retinopathy.