Polarised glasses, long used to bring depth to cinema screens, have found a new calling in medical science, and the polarised glasses medical use now being developed in India treats lazy eye in children. The system is called Occlu-pad, and it pairs a pair of spectacles with a polarising filter on one lens and a light-reduction filter on the other, with a touchscreen tablet that has had its polarising film layer removed. Children wearing the glasses can only see the images from the tablet through the eye with the polarised lens, which trains the weaker eye while they play games on the screen.
The polarised glasses medical system was developed by Yo Ishigaki, a specially appointed associate professor at the University of Electro-Communications in Tokyo, with colleagues at the School of Medicine of Kitasato University in Sagamihara, Japan. In the standard treatment for amblyopia, or lazy eye, the stronger eye is covered with a patch so the weaker eye is forced to work. The Occlu-pad system takes a different route: it shows images only to the impaired eye, while the healthy eye sees a blank screen, so the child trains the weak eye without wearing a patch.
Clinical trials carried out by doctors at Kitasato University showed that the polarised glasses medical training was significantly more effective than eye patches for treating the disorder. The results were published by Yo Iwata and colleagues in Current Eye Research in 2018, in a paper on the effects of the Occlu-pad for the management of anisometropic amblyopia in children. Amblyopia is an eye disorder that results in poor vision in one eye, and it is usually treated in childhood, when the visual system is still developing.
Polarised glasses medical use and the India link
The polarised glasses medical work has a direct link to India. Japan has about 30,000 amblyopia patients a year, against 118,000 in the United States, 153,900 in the European Union, 506,000 in China and 830,000 in India. Ishigaki is focusing on supporting treatment of amblyopia in India by working with healthcare institutes in cities including Ahmedabad, Jaipur, Delhi, Mumbai and Kolkata. The main issue for spreading the system in India is cost, since the price of a tablet is too high for most families in India, and Ishigaki is working with colleagues in Japan to develop an Occlu-Smartphone system, which should be much more accessible to people in India and other parts of Asia.
Indian eye care has already worked with the system. Sanjeevan, an eye care facility led by Dr K. K. Goyal, collaborated with Yaguchi Electric Corporation, a certified medical device maker in Japan, and with Dr Tomoya Handa of Kitasato University, on research and development of Occlupad, the device used for treating amblyopia. The Japan International Cooperation Agency decided to support the collaborative project between Japan and India, which ran from October 2017 to March 2018. Occlupad is expected to be more than three times more effective than conventional treatment for treating amblyopia.
Polarised glasses medical use and how the device works
The polarised glasses medical device works because of how the tablet screen is built. The polarising film layer is removed from the liquid crystal display screen of the tablet, so the screen shows only a white backlight to the naked eye. Only after wearing the polarising glasses can the patient see the images on the screen, and only through the eye with the polarised lens. The child then plays games that help in treating the amblyopic eye, turning a daily exercise into play rather than a chore.
For families in India, the promise of the polarised glasses medical system is a treatment that children will actually use. Eye patches are simple but unpopular with children, and many stop wearing them. The polarised glasses medical approach replaces the patch with a game on a screen, and the trials so far show it works better. The remaining step is cost, and the Occlu-Smartphone version now in development is the answer the researchers are working on for India.