Arnab Mazumder, Bachelor’s in Engineering

Undergraduate student, Ramaiah Institute of Technology, Bangalore, India

 

Technology has brought about a massive change to the eye-care industry. The availability of technology has led to better outcomes which have enhanced the quality of life of the patients. The automated visual field instrument was one such computer-driven tool. Various adaptations followed along in subsequent years and the upgradation in existing technology is a recurring process. Initially, instruments were primarily used to diagnose glaucoma. As the technology matured, the ability to manage and rehabilitate patients moved beyond.(1)

Augmented reality (AR) is a technology that adds digitally generated visual cues like 3D models, static images, or textual-based information onto a view of the physical world. The following section explores the use of AR as a visual aid.

Augmented Reality aiding mobility in RP patients

Innumerable individuals exceeding the age of 40 encounters a condition known as low vision and the rationale for it can be Retinitis Pigmentosa (RP), albinism, glaucoma, diabetic retinopathy, and others. This can lead to significant visual disability and cannot be easily corrected with glasses, contact lenses, medication, or surgery. (2)

RP is a blinding disease that affects the peripheral vision and trouble seeing in low light making it difficult to grasp objects while in motion. A new study on RP found that the patients with RP can be rehabilitated with AR to improve their mobility and grasp performance. The AR glasses offer visual colour cues to help people with constricted peripheral vision to interpret complex environments and avoid obstacles in low-light environments. The glass highlights potential obstacles with bright colours that improve spatial understanding and depth perception (refer to figure 1). It was reported that subjects made significantly fewer grasp errors with the AR, with an overall 70% increase in grasp performance.(3)

 

Figure 1: (A) Schematic (top-down view) of Glass hardware configuration: 2D translation of the displayed image is required depending on distance to the object of interest. (B) Schematic (side view) of Glass hardware configuration with the eye in primary position of gaze and the head upright: 10° angular compensations between the virtual display orientation and the camera aiming direction are needed for visual alignment. (C) The camera lens’ distortion presented by photographing a grid (top), and the distortion corrected grid (bottom). Dashed line rectangle is the image portion to be displayed on the virtual display. (4)

Age-related Macular Degeneration and AR

 

Figure 2: Schematic illustration of visual perception of a healthy eye (top panel) compared with a person with Age-related Macular Degeneration (bottom panel) with a central visual field defect.

Age-related macular degeneration (AMD) and retinal disorders (Fig 2) are on the rise with an impact on over 170 million people worldwide, signifying the need for a reliable, cost-effective solution. A case series of three individuals with AMD used the AR device to improve reading speed and accuracy. (5)

They were engaged in a 20-minute training and were subsequently urged to read several paragraphs using their habitual spectacles and later with the AR device. The number of errors made and reading speeds were accounted for. Overall, the case series reported promising improvement of the reading speed with lower font size using AR device. AR device could be used in elderly patients with the macular disease to access extremely small print with only a short training period.

The AR device enables viewing of the entire image beyond the magnification. It has an Auto Zoom Mode that automatically magnifies to bring the text to the user’s most favoured text size, allowing easier and more efficient use. Additionally, the edges of text are sharpened for easier viewing. (6)

Conclusion

With every stride in technology, the goal post keeps shifting. AR is aiding patients with low vision to navigate better in their environments. By combining this capability with computer vision-powered text recognition a new dimension of assistance can be introduced which will aid blind users with a new level of independence in unfamiliar spaces. This technology will improve the management of eye diseases with much broader implications.

 

References

  1. Jones M. HealthCare: How technology impacts the healthcare industry [Internet]. Healthcare in America. 2018 [cited 2021 Apr 15]. Available from: https://healthcareinamerica.us/healthcare-how-technology-impacts-the-healthcare-industry-b2ba6271c4b4
  2. Vargas-Martin F, Peli E. Augmented-view for restricted visual field: multiple device implementations. Optometry and Vision Science. 2002 Nov 1;79(11):715-23.
  3. Angelopoulos AN, Ameri H, Mitra D, Humayun M. Enhanced depth navigation through augmented reality depth mapping in patients with low vision. Scientific reports. 2019 Aug 2;9 (1):1-0.
  4. Hwang AD, Peli E. An augmented-reality edge enhancement application for Google Glass. Optometry and vision science: official publication of the American Academy of Optometry. 2014 Aug;91 (8):1021.
  5. Mehta MC, Kim BT, Kammer R, Watola D. Eyedaptic Augmented Reality Visual Aid Leads to Improved Reading Speed and Accuracy in Individuals with AMD. Investigative Ophthalmology & Visual Science. 2018 Jul 13;59 (9):633-.
  6. Gonçalves P, Orlosky J, Machulla TK. An augmented reality assistant to support button selection for patients with age-related macular degeneration. In2020 IEEE Conference on Virtual Reality and 3D User Interfaces Abstracts and Workshops (VRW) 2020 Mar 22 (pp. 731-732). IEEE.