Quantitative Evaluation of the Supercontinuum Laser Eye Dazzling Effect: in vivo Experimental Research

Background: Laser eye dazzling affects the visual performance through the instant high-intensity light stimulation. The temporary loss or deterioration of the visual function may occur when radiated by lasers. To quantitatively evaluate the dazzling effect of each spectrum band of supercontinuum laser, we conducted an experimental research for exploring the safety and dazzling of animals’ eyes. Methods: Under the condition of dark adaption, the laser with different power densities and spectral bands was output, and the rabbit eyes were radiated by normal incident mode for 0.25 s. The fundus of the rabbit eyes was examined through the inspection mirror, and the upper limit of safe power density was explored. Rabbit eyes were radiated at the upper limit of safe power density, and the microscopic damage model was established for pathomorphological analysis. The eyes were radiated with blinding light for 0.1 s. The visual electrophysiological signals were collected dynamically and the recovery time of ERG-b amplitude was recorded and analyzed after laser radiation. Results: Under dark adaptation, the upper limit of safe power density was 247.00 mW/cm2 in the VS, 194.00 mW/cm2 in the VIS, 1184.00 mW/cm2 in the IS, and 1052.00 mW/cm2 in the FS. The above power densities of laser radiation in rabbit eyes could cause pathological changes of retinal structure, such as local bulge, uneven thickness and disorder of inner and outer nuclear layers, local inflammatory exudation and so on. When the power density was 8.00 mW/cm2, the recovery time of ERG-b wave in rabbit eye was 4.11 ± 0.67 s. When the power density was 12.00 mW/cm2, the recovery time of ERG-b wave in rabbit eye was 4.16 ± 0.55 s. The recovery time of ERG-b wave was 4.50 ± 0.94 s at the power density of 4.60 mW/cm2 in the full spectrum-1, 3.81 ± 0.11 s at the power density of 5.00 mW/cm2 in the full spectrum-2, and 628.00 mW/cm2 in the infrared spectrum. The recovery time of ERG-b wave was only 0.84 ± 0.09 s. Conclusion: The VS, FS, FS-1 and FS-2 of the supercontinuum laser had a good dazzling effect on rabbit eyes, and the dazzling effect was enhanced with the increase of radiation power density, but the infrared spectrum had a little dazzling effect.

The Use of Supercontinuum Laser Sources in Biomedical Diffuse Optics: Unlocking the Power of Multispectral Imaging

Optical techniques based on diffuse optics have been around for decades now and are making their way into the day-to-day medical applications. Even though the physics foundations of these techniques have been known for many years, practical implementation of these technique were hindered by technological limitations, mainly from the light sources and/or detection electronics. In the past 20 years, the developments of supercontinuum laser (SCL) enabled to unlock some of these limitations, enabling the development of system and methodologies relevant for medical use, notably in terms of spectral monitoring. In this review, we focus on the use of SCL in biomedical diffuse optics, from instrumentation and methods developments to their use for medical applications. A total of 95 publications were identified, from 1993 to 2021. We discuss the advantages of the SCL to cover a large spectral bandwidth with a high spectral power and fast switching against the disadvantages of cost, bulkiness, and long warm up times. Finally, we summarize the utility of using such light sources in the development and application of diffuse optics in biomedical sciences and clinical applications.