In Situ Tremor in Vitreoretinal Surgery

OBJECTIVE: Surgeon tremor was measured during vitreoretinal microscopic surgeries under different hand support conditions. BACKGROUND: While the ophthalmic surgeon’s forearm is supported using a standard symmetric wrist rest when operating on the patient’s same side as the dominant hand (SSD), the surgeon’s hand is placed directly on the patient’s forehead when operating on the contralateral side of the dominant hand (CSD). It was hypothesized that more tremor is associated with CSD surgeries than SSD surgeries and that, using an experimental asymmetric wrist rest where the contralateral wrist bar gradually rises and curves toward the patient’s operative eye, there is no difference in tremor associated with CSD and SSD surgeries. METHODS: Seventy-six microscope videos, recorded from three surgeons performing macular membrane peeling operations, were analyzed using marker-less motion tracking, and movement data (instrument path length and acceleration) were recorded. Tremor acceleration frequency and magnitude were measured using spectral analysis. Following 47 surgeries using a conventional symmetric wrist support, surgeons incorporated the experimental asymmetric wrist rest into their surgical routine. RESULTS: There was 0.11 mm/s(2) (22%) greater (p = .05) average tremor acceleration magnitude for CSD surgeries (0.62 mm/s(2), SD = 0.08) than SSD surgeries (0.51 mm/s(2), SD = 0.09) for the symmetric wrist rest, while no significant (p > .05) differences were observed (0.57 mm, SD = 0.13 for SSD and 0.58 mm, SD = 0.11 for CSD surgeries) for the experimental asymmetric wrist rest. CONCLUSION: The asymmetric wrist support reduced the difference in tremor acceleration between CSD and SSD surgeries.