Article Text

other Versions

Download PDFPDF
Usability testing of a smartphone-based retinal camera among first-time users in the primary care setting
  1. Patrick Li1,
  2. Yannis Paulus1,
  3. Jose Davila2,
  4. John Gosbee3,
  5. Todd Margolis4,
  6. Daniel Fletcher5,
  7. Tyson Kim1,6
  1. 1Department of Ophthalmology and Visual Sciences, University of Michigan, Ann Arbor, Michigan, USA
  2. 2Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, USA
  3. 3Department of Internal Medicine and Biomedical Engineering, University of Michigan, Ann Arbor, Michigan, USA
  4. 4Department of Ophthalmology and Visual Sciences, Washington University in St. Louis, St. Louis, Missouri, USA
  5. 5Department of Bioengineering and Biophysics, University of California, Berkeley, Berkeley, California, USA
  6. 6Department of Ophthalmology, University of California, San Francisco, California, USA
  1. Correspondence to Dr Tyson Kim, Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA;{at}


Smartphone-based retinal photography is a promising method for increasing accessibility of retinal screening in the primary care and community settings. Recent work has focused on validating its use in detection of diabetic retinopathy. However, retinal imaging can be technically challenging and additional work is needed to improve ease of retinal imaging in the primary care setting. We, therefore, performed usability testing of a smartphone-based retinal camera, RetinaScope, among medical assistants in primary care who had never performed retinal imaging. A total of 24 medical assistants performed first-time imaging in a total of five rounds of testing, and iterative improvements to the device were made between test rounds based on the results. The time to acquire a single ~50° image of the posterior pole of a model eye decreased from 283±60 s to 34±17 s (p<0.01) for first-time users. The time to acquire five overlapping images of the retina decreased from 325±60 s to 118±26 s (p=0.02) for first-time users. Testing in the human eye demonstrated that a single wide-view retinal image could be captured in 65±7 s and five overlapping images in 229±114 s. Users reported high Systems Usability Scores of 86±13 throughout the rounds, reflecting a high level of comfort in first-time operation of the device. Our study demonstrates that smartphone-based retinal photography has the potential to be quickly adopted among medical assistants in the primary care setting.

  • diabetic retinopathy
  • primary care
  • usability testing
  • teleophthalmology

Statistics from

Request Permissions

If you wish to reuse any or all of this article please use the link below which will take you to the Copyright Clearance Center’s RightsLink service. You will be able to get a quick price and instant permission to reuse the content in many different ways.


  • Contributors PL designed the study with significant contribution from TK and YP. PL and JD collected data for the whole trial. PL analysed the data and drafted the manuscript with assistance from YP and TK. All authors participated in manuscript revision and approve the final version of the manuscript.

  • Funding This work was supported by the University of Michigan Translational Research and Commercialization for Life Sciences (TK and YP), the University of Michigan Center for Entrepreneurship Dean’s Engineering Translational Prototype Research Fund (TK and YP), the National Eye Institute grant 4K12EY022299 (YP), National Eye Institute grant 1K08EY027458 (YP), the University of Michigan Department of Ophthalmology and Visual Sciences and unrestricted departmental support from Research to Prevent Blindness (University of Michigan and Washington University).

  • Competing interests TK, DF and TM are inventors of RetinaScope on pending US patent applications.

  • Patient consent for publication Not required.

  • Ethics approval The study was exempt from the University of Michigan Institutional Review Board approval because it did not involve patients or protected health information.

  • Provenance and peer review Not commissioned; externally peer reviewed.

  • Data availability statement Data are available on reasonable request.