Desmettre T J, Soulie-Begu S, Devoisselle J M, Mordon S R
INSERM, French National Institute of Health and Medical Research, Lille.
Lasers Surg Med. 1999;24(1):61-8. doi: 10.1002/(sici)1096-9101(1999)24:1<61::aid-lsm10>3.0.co;2-g.
The aim of the study was to evaluate the feasibility of retinal thermal damage assessment in a rabbit eye model by using laser-induced release of liposome-encapsulated dye.
STUDY DESIGN/MATERIALS AND METHODS: After anesthesia, thermosensitive liposomes (DiStearoyl Phosphatidyl Choline: DSPC) loaded with 5,6-carboxyfluorescein were injected intravenously to pigmented rabbits. Retinal photocoagulations were performed with a 810nm diode laser (P=100-400 mW, laser spot=500 microm, 1s) (OcuLight, IRIS Medical Instruments, Mountain View, CA). Fluorescence measurements in the area of the laser exposures were then realized with a digitized angiograph (CF-60UVi, Canon-Europe, The Netherlands; OcuLab, Life Science Resources, UK).
Fluorescent spots were observed for power ranging from 100 +/- 5 mW to 400 +/- 5 mW. The fluorescence intensity increased linearly with the power and reached a plateau at 280 +/- 5 mW. The fluorescence intensity was correlated to the maximum temperature at the center of the laser spot with a linear increase from 42 +/- 3 degrees C to 65 +/- 3 degrees C. These results are in agreement with our two previous studies with DSPC liposomes for temperature measurements in a tissue model and then in a vascular model.
This preliminary study demonstrates the possibility of a laser-induced release of liposome-encapsulated dye for a quantification of diode laser induced thermal damage in ophthalmology. Such a method could be useful for a real-time monitoring of laser photocoagulation for conditions such as choroidal neovascular membranes when a precise thermal damage is required near the foveolar area.
本研究旨在通过利用激光诱导脂质体包裹染料的释放，评估兔眼模型中视网膜热损伤评估的可行性。
研究设计/材料与方法：麻醉后，将负载5,6-羧基荧光素的热敏脂质体（二硬脂酰磷脂酰胆碱：DSPC）静脉注射到有色家兔体内。使用810nm二极管激光（功率=100-400mW，激光光斑=500微米，1秒）（OcuLight，IRIS Medical Instruments，山景城，加利福尼亚州）进行视网膜光凝。然后用数字化血管造影仪（CF-60UVi，佳能欧洲公司，荷兰；OcuLab，生命科学资源公司，英国）在激光照射区域进行荧光测量。
在100±5mW至400±5mW的功率范围内观察到荧光斑点。荧光强度随功率线性增加，并在280±5mW时达到平台期。荧光强度与激光光斑中心的最高温度相关，从42±3℃线性增加到65±3℃。这些结果与我们之前两项关于DSPC脂质体在组织模型和血管模型中进行温度测量的研究一致。
这项初步研究证明了激光诱导脂质体包裹染料的释放用于量化眼科二极管激光诱导热损伤的可能性。这种方法对于在黄斑中心凹区域附近需要精确热损伤的情况下实时监测激光光凝治疗脉络膜新生血管膜等病症可能是有用的。
