■遗传性视网膜变性(IRD)是指导致感光细胞死亡和随后视力丧失的一组异质性进行性疾病。这些疾病通常会影响周边视网膜,直到最近,客观评估一直很困难。眼底自发荧光(FAF)是一种非侵入性视网膜成像技术,其描绘了内在荧光团在视网膜中的分布。视网膜自发荧光的主要来源是脂褐素,它包含在视网膜色素上皮(RPE)中。脂褐素的过度积累和可归因于感光体色素损失的窗口缺陷导致增加的FAF,而RPE的损失导致减少的FAF。在IRD过程中可以看到这些变化。
■虽然传统模式的视角有限,最近的技术进步,被称为宽视场和超宽视场FAF成像,已经实现了远周边视网膜的可视化。尽管该技术在IRD患者中的临床应用仍处于起步阶段,一些研究已经表明了它的有用性。例如,FAF降低的区域与色素性视网膜炎(RP)或锥杆营养不良的视野缺损密切相关。异常的FAF模式可能有助于IRD和相关疾病的诊断。此外,X连锁RP的女性携带者和女性脉络膜血症表现出特征性外观。相反,尽管存在严重的视网膜变性,但不存在异常FAF有助于区分癌症相关视网膜病变。
■本文回顾了FAF的原理,宽场成像,以及特定疾病的发现。宽视场成像,特别是宽视场FAF,将为特征提供进一步的信息,预后,和IRD的发病机制。
UNASSIGNED: Inherited retinal degeneration (IRD) refers to a heterogenous group of progressive diseases that cause death of photoreceptor cells and subsequent vision loss. These diseases often affect the peripheral retina, objective evaluation of which has been difficult until recently. Fundus autofluorescence (FAF) is a non-invasive retinal imaging technique that depicts the distribution of intrinsic fluorophores in the retina. The primary source of retinal autofluorescence is lipofuscin, which is contained in the retinal pigment epithelium (RPE). Excessive accumulation of lipofuscin and a window defect attributable to loss of photoreceptor pigment result in increased FAF whereas loss of the RPE results in decreased FAF. These changes can be seen during the course of IRD.
UNASSIGNED: While conventional modalities are limited in their angle of view, recent technologic advances, known as wide-field and ultra-widefield FAF imaging, have enabled visualization of the far peripheral retina. Although clinical application of this technique in patients with IRD is still in its infancy, some studies have already indicated its usefulness. For example, an area with decreased FAF correlates well with a visual field defect in an eye with retinitis pigmentosa (RP) or cone-rod dystrophy. An abnormal FAF pattern may help in the diagnosis of IRD and associated diseases. In addition, female carriers of X-linked RP and female choroideremia show characteristic appearance. Conversely, absence of abnormal FAF despite severe retinal degeneration helps differentiation of cancer-associated retinopathy.
UNASSIGNED: This paper reviews the principles of FAF, wide-field imaging, and findings in specific diseases. Wide-field imaging, particularly wide-field FAF, will provide further information for the characteristics, prognosis, and pathogenesis of IRD.