Obata Ryo, Tamaki Yasuhiro, Yanagi Yasuo, Kami Junko
Department of Ophthalmology, University of Tokyo School of Medicine, Tokyo, Japan.
Jpn J Ophthalmol. 2007 Nov-Dec;51(6):462-9. doi: 10.1007/s10384-007-0484-8. Epub 2007 Dec 21.
To develop a new device for measuring reflected light during diode-laser irradiation in transpupillary thermotherapy (TTT) and to assess the correlation between fundus pigmentation, the measured intensity of reflected light, and the increase in fundus temperature.
We developed a device to measure reflected light by modifying a slit-lamp-mounted 810-nm diode-laser delivery system used clinically for TTT. The diode laser was used to irradiate test charts with various degrees of reflectance in in vitro experiments, and the fundus of nonpigmented or pigmented rabbits in in vivo experiments; then, the intensity of the reflected light and the temperature increase at the target were measured. The retinal sections were also examined histologically.
There was a significant negative correlation between the intensity of the reflected light and the temperature increase in the target that depended on the degree of reflectance of the charts or the pigmentation of the rabbit eyes. On histopathologic examination, the extent of the changes in the irradiated retina after TTT was clearly different between pigmented and nonpigmented rabbits.
Correlations between fundus pigmentation, the intensity of reflected light during diode-laser irradiation, and the temperature increase in TTT were demonstrated in vitro and in vivo. Our results suggest that measurement of the intensity of reflected light should be helpful for modulating the laser power in TTT according to the degree of fundus pigmentation.
研发一种用于经瞳孔温热疗法（TTT）中测量二极管激光照射期间反射光的新装置，并评估眼底色素沉着、测量的反射光强度与眼底温度升高之间的相关性。
我们通过改进临床上用于TTT的安装在裂隙灯上的810纳米二极管激光传输系统，开发了一种测量反射光的装置。在体外实验中，用二极管激光照射具有不同反射率的测试图表，在体内实验中，照射无色素或有色素兔子的眼底；然后，测量反射光强度和目标部位的温度升高。还对视网膜切片进行了组织学检查。
反射光强度与目标部位温度升高之间存在显著的负相关，这取决于图表的反射率或兔子眼睛的色素沉着程度。组织病理学检查显示，TTT后色素沉着和无色素兔子的受照射视网膜变化程度明显不同。
在体外和体内均证实了眼底色素沉着、二极管激光照射期间反射光强度与TTT中温度升高之间的相关性。我们的结果表明，测量反射光强度有助于根据眼底色素沉着程度调节TTT中的激光功率。
