Center for Biomedical Engineering, University of Texas Medical Branch, Galveston, Texas 77555-1106, USA.
Invest Ophthalmol Vis Sci. 2011 Aug 9;52(9):6300-7. doi: 10.1167/iovs.10-7033.
To demonstrate the usefulness of dual-wavelength fundus autofluorescence (FAF) imaging for noninvasive, quantitative monitoring of dynamic changes associated with healing of retinal photocoagulation lesions in a small animal model.
Brown Norway rats, exhibiting substantial age-dependent lipofuscin autofluorescence, were used to characterize the kinetics of FAF recovery after retinal photocoagulation. An argon laser with a beam diameter of 100 μm, exposure duration of 0.1 seconds, and a range of laser powers (8-22 mW) were used to create subthreshold, threshold, and suprathreshold lesions. A modified retinal angiograph was used to obtain dual-wavelength FAF images at 488 and 514 nm to quantify and monitor changes in retinal fluorescence up to 6 months.
Compared to white light funduscopy, the FAF images exhibited heightened definition and clarity of lesion boundaries immediately after laser exposure. No significant reduction in FAF was measured at or below laser powers of 8 mW. Furthermore, a linear, dose-dependent decrease in FAF (R(2) = 0.9605) was observed immediately after laser exposures of 13 to 22 mW. Complete recovery of baseline FAF was observed for 13.5 and 16 mW exposures at 3 weeks and 4 months, respectively. However, retinal damage was still evident at 6 months after suprathreshold exposure induced using 22 mW laser power.
The accumulation of lipofuscin in the aged Brown Norway rat makes it a suitable small animal model for the characterization of laser-induced injury in the retina based on FAF. Dual-wavelength FAF measurements provide a sensitive, quantitative, noninvasive means of monitoring recovery of laser-induced retinal injury.
展示双波长眼底自发荧光（FAF）成像在非侵入性、定量监测与视网膜光凝损伤愈合相关的动态变化方面的有用性，该模型为小动物模型。
使用具有显著年龄依赖性脂褐素自发荧光的褐家鼠，对视网膜光凝后 FAF 恢复的动力学进行特征描述。采用光束直径为 100μm、曝光时间为 0.1 秒、激光功率范围为 8-22mW 的氩激光，制作亚阈值、阈值和超阈值病变。使用改良视网膜血管造影仪，在 488nm 和 514nm 处获得双波长 FAF 图像，以定量和监测视网膜荧光变化，时间长达 6 个月。
与眼底检眼镜相比，FAF 图像在激光照射后立即显示出更高的病变边界清晰度和清晰度。在激光功率为 8mW 或以下时，FAF 没有明显降低。此外，在 13 至 22mW 的激光照射后，立即观察到 FAF 的线性、剂量依赖性降低（R²=0.9605）。在 3 周和 4 个月时，分别用 13.5mW 和 16mW 的激光照射，FAF 恢复到基线水平。然而，在使用 22mW 激光功率诱导的超阈值暴露后 6 个月，仍可见视网膜损伤。
随着年龄的增长，褐家鼠脂褐素的积累使其成为基于 FAF 对视网膜激光损伤进行特征描述的合适小动物模型。双波长 FAF 测量提供了一种敏感、定量、非侵入性的监测激光诱导视网膜损伤恢复的方法。
