The impact of intraoperative optical coherence tomography on cognitive load in virtual reality vitreoretinal surgery training.

Ophthalmic surgeries consist of highly demanding microsurgical tasks that require surgeons to sustain mental focus and extreme manual dexterity for extended periods. To improve surgical precision and decision-making, intraoperative Optical Coherence Tomography (iOCT) has been integrated into surgical microscopes, offering cross-sectional imaging of anatomical tissues and instruments alongside the traditional microscopic view. While the clinical benefits of iOCT have been demonstrated across various ophthalmic procedures, the impact of this auxiliary information on the surgeon's cognitive load has not yet been explored. This work is the first study to investigate physiological and subjective cognitive load during simulated iOCT-guided retinal surgery in 17 novice users. The eye tracking capabilities of a virtual reality eye surgery simulator were used to capture blink rate and pupil diameter. Electrocardiography was used to record heart rate (HR) and heart rate variability (HRV). iOCT-guided surgery resulted in significantly higher cognitive load than traditional microscope-guided surgery, indicated by increased HR (p<0.01), HRV (p<0.05), subjective task load (p<0.001) (NASA-TLX, mental effort), and task time (p<0.001). However, our findings indicate that although iOCT initially imposed a higher cognitive load on novice users, it ultimately enhanced their depth-related targeting precision, which is crucial for improving surgical accuracy and overall outcomes in vitreoretinal surgery.