Veronica Pisu¹, Aleksandrs Koselevs¹, Sarah Cutler², Maria Patsiamanidi², Sam Khandhadia², Isabel Escofet³, Jay Self^1,2, Andrew Lotery^1,2, Guido Maiello¹; ¹University of Southampton, UK, ²University Hospital Southampton, UK, ³Salisbury District Hospital, UK

Standard clinical vision tests (e.g., acuity charts, perimetry) trade off ease of administration against informativeness: some are quick but narrow, others richer but slow and effortful, especially in challenging clinical populations. Continuous psychophysics offers a promising alternative: a fast and intuitive target-tracking task that yields reliable estimates of visual and motor function (Bonnen et al., 2015; Straub & Rothkopf, 2022). In a pilot study, we evaluated the feasibility, acceptability, and reliability of continuous psychophysics in the clinic, and explored the association of tracking performance with visual acuity (VA). Twelve adults with retinal disease (age range: 54–86 years) attending an intravitreal injection clinic completed two same-day target-tracking sessions and rated the task using the System Usability Scale (SUS). In the tracking task, participants used a mouse to track a randomly moving concentric Gabor target (10 trials/session); testing was binocular and unaided. The task was feasible within the clinic workflow, with short per-session runtime (M 4.03 minutes, SD 0.45; including self-paced inter-trial breaks; 11/12 completed both sessions). Tracking performance indices showed excellent test-retest reliability (rs ≥ .84, ps < .05, N = 6). Performance improved markedly between first and second tracking sessions in post-injection assessments (N = 5), consistent with short-term recovery, and in one participant who wore corrective lenses in the second session. SUS scores (0–100 scale, higher = better) indicated excellent acceptability (M 87.1, SD 11.0). Surprisingly, associations with VA were non-significant. While this may partly be due to our limited sample, the high test-retest reliability we observed suggests that the method is capturing much more than simple visual acuity. These findings support the feasibility of continuous psychophysics in clinical practice and motivate larger studies, including the development of methods to disentangle visual and motor contributions to target-tracking performance.

Acknowledgements: This research was funded by Fight for Sight (Grant Reference: RESSGA2302, awarded to GM) and Wessex Medical Research (Grant Reference: AF04, awarded to GM).