Hammer H, Schweitzer D, Thamm E, Kolb A, Strobel J
University of Jena, Department of Ophthalmology, Germany.
Int Ophthalmol. 2001;23(4-6):291-5. doi: 10.1023/a:1014430009122.
To determine the coefficient and the anisotropy of scattering as well as the refractive indices in the retina and in the choroid noninvasively in vivo.
The power of coherent reflected light versus fundus depth is recorded in OCT-A-scans. The ratio of refractive indices is derived from the height of the reflection peaks. Provided that the absorption coefficient is known from fundus reflectometry, the scattering coefficient and anisotropy are calculated from the offset and the slope of the signal behind the reflection peaks on the basis of a single backscattering model.
We found scattering coefficients of 12/mm (retina) and 27.5/mm (choroid) as well as anisotropy values of 0.97 (retina) and 0.90 (choroid).
The OCT is usually employed for the measurement of intraocular distances. The new technique described here gives the unique opportunity to determine further interesting parameters of single ocular layers. The values given above are in good agreement with in vitro results.
在体无创地确定视网膜和脉络膜的散射系数、各向异性以及折射率。
在光学相干断层扫描（OCT）A扫描中记录相干反射光功率与眼底深度的关系。折射率之比由反射峰的高度得出。若已知眼底反射测量法中的吸收系数，则基于单一后向散射模型，根据反射峰后信号的偏移和斜率计算散射系数和各向异性。
我们发现视网膜的散射系数为12/mm，脉络膜的散射系数为27.5/mm，视网膜的各向异性值为0.97，脉络膜的各向异性值为0.90。
OCT通常用于测量眼内距离。这里描述的新技术提供了确定单个眼层其他有趣参数的独特机会。上述值与体外结果高度一致。
