The NaviSight Study: An investigation into the peripheral retina and navigating the built environment

Purpose: To investigate whether peripheral retinal pathology and other clinical parameters impact people navigating the built environment independently
Methods: Participants with varying levels of diabetic retinopathy and retinitis pigmentosa were recruited. Participants completed a short walk of around 1 mile where they discussed confidence, anxiety and difficulty and were asked to describe any issues they encountered. In addition, each participant attended a clinical visit where they underwent widefield retinal imaging, OCT, OCTA, visual field, visual function and dark adaptation tests. Diabetes distress scales (DDS17), quality of life (RetDQol) questionnaires and a medical/study questionnaire were also completed.
Optos widefield retinal images were graded using the Boston Grid overlay on MATLAB software and converted into heatmaps using a pre-existing code. Visual function results, questionnaires and grading results were analysed using Spearmans correlation and compared against confidence, difficulty and anxiety levels during the walkaround.
Results: In total, there were 33 participants - 22 (66.7%) with diabetes and 11 (33.3%) with retinitis pigmentosa. Most (69.7%) were male, and the mean age was 49 (range 18-76). A majority (72.7%) had type 1 diabetes and 22.7% had type 2 diabetes, 1 was in diabetes remission. Diabetes duration ranged from 2-67 years, with a mean of 25. Fifteen eyes had no DR, 25 had mild-severe DR and 3 had proliferative DR. Fifteen eyes had been treated with laser.
Results showed that a majority (80%) of people with RP had problems navigating the built environment, while only 5 (22.7%) stated they faced problems navigating. Despite this, more than 5 people with DR described issues with shared space and lighting. Spearman’s correlation showed that average difficulty during the walkaround was associated with issues such as visual acuity, RetDQol, rod intercept (dark adaptation), visual field loss and percentage of the retina affected. Similarly, confidence was also affected by visual acuity, RetDQOL and visual field loss. Anxiety was not seen to be significantly associated. It was also found that those without an intact ellipsoid zone (EZ) on average had more difficulty navigating the built environment.
Some of the most common barriers to navigating the built environment were pavement issues, bollards, parked cars on pavements, uneven pavements, alfresco dining, light levels and street furniture.
Conclusions: From the results it is clear that visual functionality, quality of life and percentage of pathology in the retina (especially in the periphery) causes dificulty navigating the built environment and can cause confidence issues. Some of the most common problems such as shared space, parked cars on pavements and alfresco dining mirror the literature. In the future, more needs to be done to ensure people with visual pathology/impairments can navigate freely and independently.