Quantitative Measurements of Autofluorescence with the Scanning Laser Ophthalmoscope
Quantitative Measurements of Autofluorescence with the Scanning Laser Ophthalmoscope
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DOI：
10.1167/iovs.11-8319
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发表时间：
2011-12-01
影响因子：
4.4
通讯作者：
Smith, R. Theodore
中科院分区：
文献类型：
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作者：
Delori, Francois;Greenberg, Jonathan P.;Smith, R. Theodore
目的。为评价激光共聚焦扫描检眼镜(CSLO)定量测量眼底自发荧光(AF)图像的可行性和可靠性，对34例正常受试者(年龄范围20~55岁)采用两种不同的cSLO(488 nm激发)采集了30度的AF图像，并配备了内部荧光参照物以考虑不同的激光功率和探测器灵敏度。每个图像的灰度级(GLS)被校准到参考、零GL和放大倍数，以得到定量的自体荧光(QAF)。来自受试者和固定图案的图像被用来测试探测器相对于荧光强度的线性、QAF随探测器增益、场均匀度、折射误差的影响以及重复性的变化的稳定性。结果：QAF在临床相关范围内与探测器增益和激光功率无关，前提是探测器增益被调整以将曝光维持在线性探测范围内(GL<；175)。在中心直径为20度的圆圈内，磁场均匀度优于5%，但在更外围的圆圈内，场强均匀度降低。对理论上的平方反比校正进行了实验验证。光感受器漂白至少20秒。QAF同一天和不同天重测的重复性(95%可信区间)为+/-6%至+/-14%。两个工具之间的一致性(95%可信区间)为
PURPOSE. To evaluate the feasibility and reliability of a standardized approach for quantitative measurements of fundus autofluorescence (AF) in images obtained with a confocal scanning laser ophthalmoscope (cSLO).METHODS. AF images (30 degrees) were acquired in 34 normal subjects (age range, 20-55 years) with two different cSLOs (488-nm excitation) equipped with an internal fluorescent reference to account for variable laser power and detector sensitivity. The gray levels (GLs) of each image were calibrated to the reference, the zero GL, and the magnification, to give quantified autofluorescence (qAF). Images from subjects and fixed patterns were used to test detector linearity with respect to fluorescence intensity, the stability of qAF with change in detector gain, field uniformity, effect of refractive error, and repeatability.RESULTS. qAF was independent of detector gain and laser power over clinically relevant ranges, provided that detector gain was adjusted to maintain exposures within the linear detection range (GL < 175). Field uniformity was better than 5% in a central 20 degrees-diameter circle but decreased more peripherally. The theoretical inverse square magnification correction was experimentally verified. Photoreceptor bleaching for at least 20 seconds was performed. Repeatability (95% confidence interval) for same day and different-day retests of qAF was +/- 6% to +/- 14%. Agreement (95% confidence interval) between the two instruments was