The effect of latency on surgical performance and usability in a three-dimensional heads-up display visualization system for vitreoretinal surgery

Purpose Although latency has been cited as a disadvantage of the three-dimensional heads-up display (3D HUD) visualization system for vitreoretinal surgery, there have been no publications evaluating the effect of latency on surgical performance. Methods Thirty participants conducted two tasks (external suturing and inner limiting membrane peeling) on a 3D HUD at 4 levels of latency: 50 ms (ms), 68 ms, 92 ms, and 122 ms. The task completion time was measured and patients answered a subjective questionnaire on usability. Results No difference in completion times was found between different levels of latencies in either task. Regarding usability, significant decreases were found at 122 ms for both the suturing and peeling task overall, but for experienced HUD users, there was less of a decrease. Conclusion This study is the first to evaluate the effect of latency on 3D HUD for vitreoretinal surgery. The levels of latency in the current models of 3D HUD are unlikely to contribute to a decrease in surgical performance and usability with current technologies which have a latency of 70 ms.