Advances in eye care over the last century have seen technology enabling finer and more precise procedures on the eye itself. From removing a clouded lens in a cataract patient and replacing it with a clear artificial intraocular lens to reshaping the cornea with a laser in LASIK surgery for treating myopia, the aim was to fix the optics for good vision and sight.
While this has helped millions of patients, it ignores the fact that the eye only collects light and it is the brain that interprets it. In cases where the fault lies in the brain, there is a need for a different approach.
Take the case of amblyopia, commonly known as lazy eye, a disorder where the brain favours one eye over the other. The affected eye is usually normal on examination. The problem commonly begins early in childhood when one eye sends a blurred or misaligned image to the developing brain, which resolves the conflict by suppressing that eye’s signal and eventually ignores it altogether. Patching the good eye to force the brain to use the weaker one has been the standard treatment for a century. While this works reasonably well in young children, it is not liked by many of them.
There is now an option – the innovative treatment called dichoptic therapy. Instead of switching the strong eye off, each eye is shown a different part of the same scene, with the image to the strong eye dimmed. This facilitates neuroplasticity or the ability of the brain to change and reorganize its functions. Neither eye can complete the picture alone, so the brain has to accept input from both. The aim is to shift from punishing one eye to giving both eyes a reason to cooperate.
Two therapies give insights into how this concept works. Luminopia One, authorised by the US FDA, is a binocular therapy that uses a VR headset to stream modified television shows through a headset. CureSight adds eye tracking. The system follows the child’s gaze and blurs the centre of what the stronger eye sees, wherever the child happens to look, so the weaker eye has to supply the detail.
Beevee, India’s first AI-powered VR wearable for amblyopia care, is now available across India, enabling patients to undergo treatment from the comfort of their homes.
A new solution for vision therapy based on virtual reality using artificial intelligence has been launched in India to enable easier treatment for amblyopia away from the clinic. Vision therapy with the help of adaptive VR training helps to correct vision, and now this solution becomes available to use for home-based vision therapy. It shows the general trend of applying immersive technologies and digital therapeutics in eye care industry.
The challenge is in getting children to follow the instructions, for example, ensuring they play a dichoptic video game as prescribed. This is where artificial intelligence comes in to provide a solution and promote adherence with games that adjust difficulty in real time, so that a child stays involved and is neither bored nor defeated. AI also helps to tell that a child is actually watching and for exactly how many minutes.
For India, the practical implications are significant. School surveys show that amblyopia is found in around 1-2% of school-going children, which amounts to millions of cases. Many of these children are diagnosed late and many may not have access to treatment. Families in smaller towns especially cannot travel repeatedly to a city hospital for therapy sessions. A treatment that can be taken at home on a tablet, records its own usage and requires a clinic visit every few months can make a big difference in the lives of these children.
The conventional understanding is that the window to correct amblyopia shuts by 7-8 years of age and nothing much can be done after that. However, new studies have found that intensive, repeated visual training produces measurable improvement in the affected eye. Targeted neuro-visual rehabilitation helps to reduce the suppression of the weaker eye by the brain and reinforce the neural pathways associated with visual processing.
This means that even for teenagers and adults, the window to correction is open and they can undergo a trial of binocular therapy. Going beyond reading the conventional eye chart, how well the two eyes work together must be measured. School screening programs must be designed along with plans to offer treatment that will reach the child at home.
Neuro-visual rehabilitation is relevant to a far larger group of patients than children with lazy eye alone. Roughly a third of stroke survivors lose part of their field of vision, and repeated visual training within the blind area including virtual reality programmes can help in modest gains in vision.
Some things need to fall into place. While neuro-visual rehabilitation devices fall under the regulatory oversight of the Central Drugs Standard Control Organization (CDSCO), there is no settled regulatory route for software that is prescribed as treatment. Clarity on this will help drive the shift on what can be treated. Once checking of binocular function and the ability of the two eyes to work as a pair becomes part of routine examination, and once we move from just the eye to considering the brain behind vision and address the neural issues through neuroplasticity, we will be able to help not just school-going children but adults too.