光学相干断层成像(optical coherence tomography，OCT)自1991年发明以来，在生物成像尤其在眼科和心血流成像中起越来越重要的作用。OCT的发展经历了早期的时域系统及最新的频域系统。其中频域系统又分为谱域OCT(spectral domain OCT，SD-OCT)系统和扫频OCT(swept source OCT，SS-OCT)系统。随着眼科临床应用对系统速度、灵敏度及功能化要求的不断提升，眼科扫频OCT已经走向成熟并逐步商用化。本文将简介扫频OCT的原理，并归纳扫频OCT相对于时域和谱域OCT系统的优势，并展示其在眼科临床的应用。
Optical coherence tomography (OCT) has played an important role in biomedical imaging, especially in ocular and cardiovascular imaging. OCT technology has evolved to frequency domain technology from early time-domain technology due to the advantages of high sensitivity and high speed of frequency domain techniques. The swept source OCT is a type of frequency domain OCT. With the increasing requirements for system speed, sensitivity, and functionality in clinical application, swept source OCT is gradually becoming commercially available and widespread in clinical application. In this paper, the principle of swept source OCT was introduced, the advantages of swept source OCT over time domain and spectral domain OCT systems were summarized, and its clinical application in ophthalmology was demonstrated.
帕金森病(Parkinson’s disease，PD)是老年人常见的神经系统退行性疾病，眼部及视觉功能障碍是PD常见的非运动症状之一，进一步影响其生活质量。已有研究表明PD患者视网膜内存在多巴胺浓度的减少以及α突触核蛋白的沉积。目前，PD仍缺乏有效的早期诊断及病情评估工具，光学相干断层扫描及光学相干断层扫描血管成像技术可以显示视网膜各层微细结构及微血管的异常，应用该技术研究者发现PD患者视乳头旁视网膜神经纤维层及黄斑区视网膜的厚度均存在不同程度的变薄，视网膜浅层及深层毛细血管丛的毛细血管密度和复杂性下降。进一步研究者应用该技术在PD临床应用中进行了探索，并发现其可用于检测早期PD中发生的病理变化，反映疾病的病程及严重程度，并且在鉴别诊断中起到一定的作用。总而言之，视网膜相关检测可能成为评估PD患者脑病理严重程度的指标，并且帮助疾病诊断和监测疾病的进展，不过这仍需要大样本、多中心的重复研究以提供更多理论依据。
Parkinson’s disease is a common neurodegenerative disease in the elderly, and ocular and visual dysfunction is one of the common non-motor symptoms of PD, further affecting PD patients’quality of life. Reduced dopamine concentrations and deposition of α-synuclein in the retina of PD patients have been shown in studies. At present, there is still a lack of effective tools for early diagnosis and assessment of PD. Optical coherence tomography and optical coherence tomography angiography can reveal abnormalities in the microstructure and microvasculature of the retinal layers, and researchers applying these techniques have found that the thickness of the parapapillary retinal nerve fiber layer and the retina in the macula in PD patients have had varying degrees of thinning, and the density and complexity of capillaries in the superficial and deep capillary plexus of the retina have been reduced. Further, investigators have explored the clinical application of these techniques in PD and have found that they can be used to detect pathological changes occurring in early PD, reflect the course and severity of the disease, and play a role in differential diagnosis. In conclusion, retinal-correlated testing may be an indicator to assess the severity of brain pathology in PD patients and to aid in disease diagnosis and monitoring the progression of PD, although large sample, multicenter replication studies are still needed to provide more reliable results.
剥脱综合征(exfoliation syndrome,XFS)以眼内异常纤维样物质沉积为特征，临床典型表现为裂隙灯下瞳孔缘和(或)晶状体前囊膜存在灰白色粉末状的剥脱物(exfoliation material,XFM)。XFM可阻塞小梁网引起剥脱性青光眼(exfoliaiton glaucoma,XFG)，并可通过房水循环进入血液，引起血管性损害。眼底病变视力损伤通常不可逆，XFM可进入眼底微血管及毛细血管，引起眼底结构和血管异常。基于光学相干断层成像技术的光学相干断层扫描(optical coherence tomography,OCT)及光学相干断层扫描血管成像(optical coherence tomography angiography,OCTA)以实时、非侵入性、高分辨率等优势，已广泛应用于眼底组织结构及血管病变检查。文章对XFS眼底病变在OCT和OCTA上的表现进行综述。
Exfoliation syndrome (XFS) was characterized by the abnormal deposition of the fber-like material intraocularly, and manifested as white or gray, powdery exfoliation material (XFM) on the pupillary border and (or) anterior lens capsule under slit lamp microscopy. XFM could obstruct the trabecular meshwork and cause exfoliation glaucoma (XFG). In addition, XFM that entered aqueous humor circulation could enter bloodstream and result in vascular damage. XFM could enter ocular fundus microvascular and capillary vessels, causing abnormalities of fundus structures and vessels. Optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA), which were based on optical coherence tomography technology, had the advantages of real-time, non-intrusive and high resolution, et al. OCT and OCTA were widely used in detection of fundus structural and vascular abnormalities. Tis study was to review the fundus lesion of XFS on OCT and OCTA.
