Augmented Reality: New tool in ophthalmology

What is augmented reality? Is it the same as virtual reality? “No,” said Dr Linda A Lam MD, MBA, Associate Professor at the University of Southern California Keck School of Medicine, Los Angeles, California, USA, during her presentation at EURETINA 2020 Virtual. “Whereas virtual reality replaces the real world by shutting out the physical world and providing a completely immersive experience, augmented reality enhances the real world, providing a digital overlay over real-world surroundings. Dr Lam said that augmented reality (AR) might be an ideal modality to help patients with age-related macular degeneration (AMD), and explained how a new glasses-like device, the Oculenz, helps reduce central scotomas’ negative effects on patients’ vision. “The Oculenz is revolutionary in that it allows for pixel mapping around the blind spot,” she said. “Currently available devices for patients with AMD use VR systems, which are generally heavy, tethered and intended for indoor use only. They do not provide peripheral vision and thus do not allow users to walk around with the device,” she explained. On the other hand, Oculenz, developed by Ocutrx, uses AR technology for patients with central vision loss. How does this work? “The patient first takes a visual field test while wearing the headset,” she explained. “Based on the results of this test, the device maps the areas that the patient cannot see, creating a scotoma marker.” This scotoma marker shows remarkable correspondence when overlaid by fundus autofluorescence; the scotoma marker fits nearly perfectly on the zones of retinal damage. Step 2 is called pixel mapping. “The scotoma marker data is stored in the processing unit. 4K cameras produce videos from the real world, which are processed to move the images outside of the scotoma,” said Dr Lam. These images are then projected on to the inside of the glasses, to be seen by the healthy retina. In Step 3, infrared lights illuminate eye gaze, allowing eye-tracking cameras to follow eye movement. “This eye-tracking keeps the scotoma marker in line with the augmented image on the glasses lens. This allows Step 4 to occur, in which the image is moved away from the scotoma to areas of healthy retina. Additionally, the device sends visual field test results to the patient’s physician, alerting the physician if the scotoma changes, indicating possible disease progression. “The initial pilot trial of five patients showed a mean improvement from 20/200 to 20/63, with an average improvement of 17 to 19 letters. This new device is anticipated to be available in mid-2021. Linda A Lam: linda.lam@med.usc.edu

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