>Background: With the advent of confocal scanning laser ophthalmoscopes (cSLO), fundus autofluorescence (FAF) resulting mainly from lipofuscin accumulation on the level of the retinal pigment epithelium can be visualised in vivo. Various cSLOs are available to document FAF. The authors analysed and compared results of FAF using three different instruments.>Methods: Eight eyes of eight normal volunteers and 18 eyes of 12 patients with different retinal diseases (age related macular degeneration, macular dystrophy, central serous retinopathy) were examined. FAF images were recorded from each subject with the Heidelberg retina angiograph (HRA), the Rodenstock cSLO (RcSLO) and the Zeiss Prototype SM 30-4024 (ZcSLO). For excitation an argon laser (488 nm) was used (barrier filter: HRA 500 nm; RcSLO 515 nm; ZcSLO 521 nm). 32 FAF images were aligned and averaged using the same software for all cSLOs. FAF distribution was measured and grey scale values as well as root mean square (RMS) contrast were compared.>Results: Mean age of all subjects was 55.5 (SD 21.4) years. The maximum grey scale value averaged across all eyes was 76.19 (39.34) for the HRA, 61.44 (22.12) for the ZcSLO and 37.0 (9.97) for the RcSLO. The RMS contrast was 0.46 (0.20) for the ZcSLO, 0.40 (0.12) for the HRA, and 0.13 (0.05) for the RcSLO. The differences between the cSLOs were statistically significant with higher grey scale levels and more contrast for the HRA and ZcSLO than the RcSLO (repeated measures ANOVA; p<0.0001). The differences between the HRA and the ZcSLO were not significant (post hoc comparisons; p<0.05).>Conclusions: All cSLOs allow clinically useful FAF imaging in retinal diseases. However, grey scale levels and contrast were much lower on the RcSLO. Therefore, RcSLO images appear much darker than HRA or ZcSLO images. Furthermore, not all cSLOs have a fixed photodetector gain and a standardised value for the argon laser amplification, which is mandatory for an absolute comparison of FAF imaging results.
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机译：>背景：随着共聚焦扫描激光检眼镜的出现，可以在体内观察到主要由脂褐素在视网膜色素上皮水平上积累引起的眼底自发荧光（FAF）。各种cSLO可用于记录FAF。作者使用三种不同的仪器分析并比较了FAF的结果。>方法：八名正常志愿者的八只眼和十二种患有不同视网膜疾病（年龄相关性黄斑变性，黄斑营养不良，中心性浆液性视网膜病变）的18眼）进行了检查。使用Heidelberg视网膜血管造影仪（HRA），Rodenstock cSLO（RcSLO）和Zeiss原型SM 30-4024（ZcSLO）记录每个受试者的FAF图像。为了激发，使用氩激光（488nm）（阻挡滤光片：HRA 500nm； RcSLO 515nm； ZcSLO 521nm）。使用相同的软件对所有cSLO对齐和平均32张FAF图像。测量FAF分布，比较灰度值和均方根（RMS）对比度。>结果：所有受试者的平均年龄为55.5（SD 21.4）岁。对于HRA，所有眼睛平均的最大灰度值是76.19（39.34），对于ZcSLO是61.44（22.12），对于RcSLO是37.0（9.97）。 ZcSLO的RMS对比度为0.46（0.20），HRA的RMS对比度为0.40（0.12），RcSLO的为0.13（0.05）。 cSLO之间的差异具有统计学意义，与RcSLO相比，HRA和ZcSLO具有更高的灰度级和更大的对比度（重复测量ANOVA； p <0.0001）。 HRA和ZcSLO之间的差异不显着（事后比较； p <0.05）。>结论：所有cSLO均允许在视网膜疾病中进行临床上有用的FAF成像。但是，RcSLO的灰度等级和对比度要低得多。因此，RcSLO图像看起来比HRA或ZcSLO图像暗得多。此外，并非所有cSLO都具有固定的光电探测器增益和用于氩激光放大的标准化值，这对于FAF成像结果的绝对比较是必需的。
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