Janknecht P, Funk J
Univ.-Augenklinik Freiburg.
Klin Monbl Augenheilkd. 1994 Aug;205(2):98-102. doi: 10.1055/s-2008-1045499.
We measured the reproducibility and relative error of the Heidelberg Retina Tomograph (HRT) in a model eye with various widths of the pupil.
We put diaphragms of various diameters in front of the lens of a model eye. The volume of an artificial papilla which was inserted into the model eye was measured three times. The coefficient of variation (standard deviation/mean value) was taken as a measure of the reproducibility. The relative error was defined as the absolute value of the quotient of the difference between measured and real value.
The relative error for diaphragms of 1.5 to 5 mm was 7% to 18.4%, for a diaphragm of 1 mm 19.8%, and for a diaphragm of 11 mm 21.3%. The coefficient of variation ranged from 0.49% to 1.95% for diaphragms of 1.5 to 11 mm diameter, and was 8.1 for a diaphragm of 1 mm diameter.
The HRT is capable of measuring volumes with a reasonable accuracy. The accuracy does not depend on the width of the pupil over a wide range of pupil diameters. In cases of very small or very much dilated pupils the accuracy and reproducibility declines.
我们在具有不同瞳孔宽度的模型眼中测量了海德堡视网膜断层扫描仪（HRT）的可重复性和相对误差。
我们在模型眼的晶状体前放置不同直径的光阑。对插入模型眼中的人工视乳头体积进行三次测量。变异系数（标准差/平均值）用作可重复性的度量。相对误差定义为测量值与实际值之差的商的绝对值。
直径为1.5至5毫米的光阑的相对误差为7%至18.4%，直径为1毫米的光阑为19.8%，直径为11毫米的光阑为21.3%。直径为1.5至11毫米的光阑的变异系数范围为0.49%至1.95%，直径为1毫米的光阑的变异系数为8.1。
HRT能够以合理的精度测量体积。在很宽的瞳孔直径范围内，精度不取决于瞳孔宽度。在瞳孔非常小或极度散大的情况下，精度和可重复性会下降。
