University of Southern California, Doheny Eye Institute, Keck School of Medicine, Department of Ophthalmology, 1450 San Pablo Ave, Suite 3614, Los Angeles, California 90033, USA.
J Biomed Opt. 2011 Oct;16(10):106008. doi: 10.1117/1.3640813.
We investigated the feasibility of a novel method for hyperspectral mapping of macular pigment (MP) in vivo. Six healthy subjects were recruited for noninvasive imaging using a snapshot hyperspectral system. The three-dimensional full spatial-spectral data cube was analyzed using non-negative matrix factorization (NMF), wherein the data was decomposed to give spectral signatures and spatial distribution, in search for the MP absorbance spectrum. The NMF was initialized with the in vitro MP spectrum and rank 4 spectral signature decomposition was used to recover the MP spectrum and optical density in vivo. The recovered MP spectra showed two peaks in the blue spectrum, characteristic of MP, giving a detailed in vivo demonstration of these absorbance peaks. The peak MP optical densities ranged from 0.08 to 0.22 (mean 0.15+∕-0.05) and became spatially negligible at diameters 1100 to 1760 μm (4 to 6 deg) in the normal subjects. This objective method was able to exploit prior knowledge (the in vitro MP spectrum) in order to extract an accurate in vivo spectral analysis and full MP spatial profile, while separating the MP spectra from other ocular absorbers. Snapshot hyperspectral imaging in combination with advanced mathematical analysis provides a simple cost-effective approach for MP mapping in vivo.
我们研究了一种新型方法用于活体黄斑色素（MP）的高光谱映射的可行性。使用快照高光谱系统招募了六名健康受试者进行非侵入性成像。使用非负矩阵分解（NMF）分析三维全空间-光谱数据立方体，其中数据被分解以给出光谱特征和空间分布，以寻找 MP 吸收光谱。NMF 用体外 MP 光谱初始化，并使用 4 阶光谱特征分解来恢复体内 MP 光谱和光密度。恢复的 MP 光谱在蓝色光谱中显示出两个峰值，这是 MP 的特征，在体内详细展示了这些吸收峰。MP 光密度峰值范围为 0.08 至 0.22（平均值 0.15+∕-0.05），在正常受试者中直径为 1100 至 1760μm（4 至 6 度）时变得在空间上可以忽略不计。这种客观方法能够利用先验知识（体外 MP 光谱）来提取准确的体内光谱分析和完整的 MP 空间分布，同时将 MP 光谱与其他眼部吸收剂分离。快照高光谱成像与先进的数学分析相结合，为体内 MP 映射提供了一种简单、具有成本效益的方法。
