Abstract
Purpose :
There is concern for retinal phototoxicity with xenon-based fiber optic endoillumination light sources found in newer generation vitrectomy machines. Three-dimensional (3-D) heads-up vitreoretinal surgery platforms may reduce risk of photoxicity by digitally amplifying camera image signals, thus minimizing endoillumination requirements. The purpose of this pilot study was to correlate endoillumination levels utilized during heads-up 3-D vitreoretinal surgery to subjective digital image quality and heads-up display (HUD) luminous emittance.
Methods :
Prospective, observational case series. Ten eyes underwent 23-, 25-, or 27-gauge 3 port vitreoretinal surgery using the Constellation Vision System (Alcon Laboratories, Fort Worth, TX) and a commercially available 3-D HUD surgery platform (TrueVision Visualization System, Santa Barbara, CA). All surgeons were positioned approximately 1.5 m from the display and wore polarized 3-D glasses (Figure 1). Following core vitrectomy, the endoillumination probe was positioned in the mid-vitreous cavity, centering the light cone on the optic disc. Endoillumination levels were then set to the standard output at our institution (40% of maximum output) and were decreased at set intervals until the illumination level was 0%. Corresponding luminous emittance (lux) of the HUD was measured 40 cm from the display using a luxmeter (Dr. Meter, Model #LX1010BS) and associated screenshots were captured.
Results :
Endoillumination levels were positively correlated with luminous emittance from the 3-D HUD (p=0.027, two-tailed Pearson’s coefficient). The average coefficient of variation of HUD luminance was 0.297. At 40% and 10% of maximum endoillumination output, 35.4 ± 12.9 and 16.3 ± 5.2 lux were respectively emitted from the HUD. In 9 of 10 experimental cases, the surgeon felt they could operate comfortably at an endoillumination level of 10% of maximum output. In the remaining case, the surgeon felt comfortable at a 3% endoillumination level with corresponding HUD emittance of 15 lux. Below this threshold, subjective image dimness and digital noise limited visibility. There were no intraoperative complications.
Conclusions :
With real-time digital processing and automated brightness control, 3-D HUD platforms may allow for reduced intraoperative endoillumination levels and a theoretically reduced risk of retinal phototoxicity during vitreoretinal surgery.
This is an abstract that was submitted for the 2016 ARVO Annual Meeting, held in Seattle, Wash., May 1-5, 2016.