Laboratory Investigation of 3-D versus 2-D Visualization in Endoscopic Skull Base Surgery

Introduction: This study compares subject performance of visuospatial tasks and subjective experience between a standard 2-D endoscope versus a prototype 3-D endoscope. The prototype 3-D neuroendoscope performs real-time light field processing to generate a 3-D image using a single lens and camera system. By eliminating possible image alignment errors, a putative advantage is the reduction of asthenopia and fatigue often associated with image misalignment during 3-D viewing, as the paired images generated by this technology are always aligned. In addition, with a single lens there is no post-image capture processing required and therefore the endoscope is fully compatible with all existing high-definition (HD) 1920 × 1080 pixel resolution cameras.

Methods: Fourteen neurosurgical and otolaryngology residents were assessed using a peg transfer, a circle cutting, and a constrained object removal task under both 2-D and 3-D endoscopic HD visualization. The time required to complete the task and the total of number of errors committed were recorded. Subjects were randomly assigned to performed tasks in either 2-D or 3-D initially.

Results: In the constrained object removal task only, 3-D visualization resulted in significantly fewer errors compared with 2-D (P < 0.01), and subjects that performed the task in 2-D first subsequently completed the task faster with 3-D visualization (P < 0.05) and with fewer errors (P < 0.05). For all three tasks without regard to order, no significant difference was found when comparing the time required to complete the task in 2-D versus that required in 3-D. The majority of subjects (12/14, 86%) stated that 3-D visualization either somewhat or greatly subjectively helped their overall performance. A minority (6/14, 43%) reported mild visual side effects associated with viewing in 3-D.

Conclusions: 3-D endoscopic visualization shows promise in improving the performance of complex visuospatial tasks by both novice and experienced users. The greatest benefit appears to occur when a previously performed task is repeated with the 3-D modality. Further detailed evaluation within the operating room is necessary to better compare 3-D endoscopic visualization with the traditional 2-D view.