定量自体荧光眼底视网膜疾病的评价
Summary
The retinal pigment epithelium (RPE) supports the sensory retina through recycling visual cycle byproducts, which accumulate as lipofuscin. These products are autofluorescent and can be qualitatively imaged in vivo. Here, we describe a method to quantitatively image RPE lipofuscin using confocal scanning laser ophthalmoscopy.
Abstract
The retinal pigment epithelium (RPE) is juxtaposed to the overlying sensory retina, and supports the function of the visual system. Among the tasks performed by the RPE are phagocytosis and processing of outer photoreceptor segments through lysosome-derived organelles. These degradation products, stored and referred to as lipofuscin granules, are composed partially of bisretinoids, which have broad fluorescence absorption and emission spectra that can be detected clinically as fundus autofluorescence with confocal scanning laser ophthalmoscopy (cSLO). Lipofuscin accumulation is associated with increasing age, but is also found in various patterns in both acquired and inherited degenerative diseases of the retina. Thus, studying its pattern of accumulation and correlating such patterns with changes in the overlying sensory retina are essential to understanding the pathophysiology and progression of retinal disease. Here, we describe a technique employed by our lab and others that uses cSLO in order to quantify the level of RPE lipofuscin in both healthy and diseased eyes.
Introduction
视网膜色素上皮细胞（RPE）支持感官视网膜通过众多方法1的功能。年龄相关性黄斑变性（AMD）是在工业化国家无法治疗失明的最重要的原因，其特征是在RPE中的变化，包括颜料的损失，功能和萎缩损失。在AMD和在正常的老化中，RPE积聚含有吞噬感光体的片段，称为脂褐素颗粒的荧光，溶酶体衍生的细胞器。 RPE脂褐素的累积已经认为表明氧化功能低下1，但最近的研究表明，视网膜色素上皮形态学老年眼睛保持正常高脂褐素水平2。然而，脂褐质分布异常模式，脂褐素的具体损失，都记录标志物AMD和AMD的进展，无论是组织学和临床3,4
缺陷PROCESRPE脂褐素唱也已显示在某些遗传性视网膜变性发生。患有斯特格病（STGD）遭受聚积在RPE脂褐素在年轻的时候，最终建立类似于AMD 5所示视力丧失。这些结果表明，脂褐质积聚本身可能是有毒的和驱动RPE功能障碍6,7。然而，受试者STGD随着时间的推移了详细的影像学研究并未证实焦点脂褐素的积累导致了随后的RPE损失8。因此，尽管脂褐质的异常是视网膜变性的标记，对于脂褐素的直接毒性作用尚未得到证实。
视网膜色素上皮是视网膜的最后的细胞层，但是产生从眼底的多数荧光信号。可使用共焦扫描激光眼底镜（CSLO），其允许六执行从RPE衍生产生和自体荧光（AF）的检测眼底AF的空间分布sualization。某些视网膜变性表明在这些条件下，诊断和监测眼底房颤独特的模式，和AF成像助剂。虽然标准的自动对焦成像是临床上重要的，定量的AF（QAF）已成为评估RPE健康的一个重要手段。我们和其他人开发了一种标准化的方法，能够可靠地确定在特定的视网膜部位9 QAF水平。 QAF在诊断和潜在的应用的视网膜条件监视，并且还可以具有在预后和风险分层效用。此外，QAF的诊断功能也已为某些视网膜疾病10-12所述。在这里，我们提供了对我们的技术伴随着它在健康和患病的眼睛的评价中的应用的可视化演示逐步细节。
Protocol
Representative Results
Discussion
异常RPE脂褐素分布，是否增加或减少，是视网膜疾病的敏感标记物和一般与感官视网膜功能的丧失相关。在这里，我们描述了RPE脂褐素的评价QAF的应用。内部荧光参考掺入纠正可变激光功率和探测器的灵敏度9与我们的标准化的成像技术使得AF水平的可靠的定量。这是我们的目标，该方法将在诊断和视网膜疾病的监测帮助，并最终在评估治疗性干预，如药物或基因疗法的功效。 QAF也可协助?…
Divulgations
The authors have nothing to disclose.
Acknowledgements
我们要感谢我们的合作者，弗朗索瓦Delori，托马斯·伯克和Tobias Duncker。
研究支持： NIH / NEI R01 EY015520（RTS，JPG），并且从研究经费不受限制防盲（RTB）。
Materials
| Spectralis HRA + OCT | Heidelberg Engineering | n/a | |
| 0.5% tropicamide ophthalmic solution | n/a | n/a | Any brand can be used |
| 2.5% phenylephrine ophthalmic solution | n/a | n/a | Any brand can be used |
| Internal fluorescent reference | Heidelberg Engineering | n/a | |
| IGOR Pro software | WaveMetrics | n/a |
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