LED light characteristics for surgical shadowless lamps and surgical loupes

Blue light has more energy than longer wavelength light and can penetrate the eye to reach the retina. Phototoxic retinal damage is expected to occur with wavelengths in the blue-light spectrum, especially below 460 nm.1–4 In medicine, surgeons use magnifying loupes under intensive surgical shadowless lamps or operating room (OR) lights for better view of the surgical field. For general surgeries, the luminance is 100,000–160,000 lx, which is 200 times brighter than typical office lighting. In the past, the light sources for surgical lamps were incandescent or halogen lamps. These lights are being replaced by more energy-efficient light-emitting diodes (LEDs), leading to increased blue light exposure. However, the accumulated knowledge of blue light hazards has accelerated the use of less-blue LEDs (LBLEDs) in surgical lamps. We hypothesized that the eyeglasses to which the surgical loupe is attached can affect the light spectrum and intensity. In this study, we evaluated the light characteristics for the combination of different glass lenses with different LEDs in shadowless lamps.