Video-endoscope versus endoscope for paranasal sinus surgery: Influence onvisual acuity and color discrimination

Endoscopic and video-endoscopic visual acuity and color discrimination were investigated using a standard disk for testing visual acuity and a color d iscrimination test. A 1-chip-CCD-Camera (CCC) or 3-chip-CCD-Carnera plus di gital image processing (digivideo) on the endoscope and a 15 inch high reso lution video monitor were used. Color discrimination was investigated by co mparing the ability to sort colored disk of low chromatic saturation (desat urated Panel D-15 Test), ranging from yellow to red, under direct vision or via monitor using the same 1-CCC- and 3-CCC-system. Visual acuity deterior ated by 1.58 +/- 0.16 steps (+/-SEM)for the I-CCC and 1.21 +/- 0.16 steps f or the S-CCC plus digivideo compared to vision through the endoscope (p < 0 .001 and p < 0.001). Visual acuity was significantly better for the 3-CCC-v ideo-endoscope compared to the 1-CCC-video-endoscope (p = 0.0045). The diff erence in color discrimination between the naked eye and the I-CCC-monitor system was not significant. More mistakes were made with the 3-CCC-monitor system. The impairment of image quality with the video endoscope, which is experienced by many surgeons, is reflected in a marked loss of visual acuit y in our experiments. Sharpness and contrast of the video-image are signifi cantly enhanced by the 3-CCC plus digital image processing, compared to the I-CCC. Color discrimination, however, was not impaired by the I-CCC, indic ating that color perception with the video-endoscope can be very good and m ay not contribute significantly to the loss of image quality.