Objectives:
Despite advancement in new equipment and surgical instruments, it is only recently that three-dimensional (3D) endoscopes have been used in endonasal and anterior skull base surgery. Previous publications have shown the importance, advantages and limitations of three dimensional endoscopy either in endonasal or skull base surgical approaches.(1, 2) The endoscopes used in this study incorporate dual ‘chip-on-the-tip’ technology in which two video chips create two different digital images which are displayed onto a 3D screen. Polarising glasses are worn to project a different image to each eye.(3)
Extended endoscopic endonasal approaches are increasingly applied in the management of various intracranial and cranial base pathologies. On one end of the complexity spectrum, lie lesions such as pituitary adenomas and encephaloceles of the cribriform plate, which can be more easily approached through the endonasal corridor.(4-6)
There are many advantages of endoscope however, it does not achieve the binocular vision. The monocular endoscopes create a 2D image during the operative view which lack the depth of perception, size orientation and hand –eye coordination.(7, 8) Human kinematic studies proved that the longer movement times are required by monocular cues to estimate the distance between variable surgical landmarks.(9)
Many binocular cues are essential to gain the depth of perception like convergence, stereopsis and vertical disparities which are the main features of the three dimensional technology. To achieve stereopsis it requires two meticulously different retinal images obtained from different angles and directions and then the human cortex superimposes these two images to give the stereopsis. Like the majority of stereoscopic systems which give the 3D display of the surgical field by production of minimally different images, then displayed separately to each eye, so the generated two images are the concept of stereopsis which named the dual channel and the shutter mechanism technologies.(7)