Herbort C P, LeHoang P, Guex-Crosier Y
Department of Ophthalmology, Hôpital Jules Gonin, University of Lausanne, Switzerland.
Ophthalmology. 1998 Mar;105(3):432-40. doi: 10.1016/S0161-6420(98)93024-X.
Indocyanine green angiography (ICGA) detects fluorescence produced by the ICG molecule in the near infrared wave lengths showing choroidal vascular structures. Indocyanine green angiography may prove useful in the workup of uveitis with choroidal involvement. The authors' purpose was to test a standardized ICGA protocol for posterior uveitis to gather systematic and comparable data and to design a schematic approach for the interpretation of angiographic signs.
The proposed ICGA procedure included the search for preinjection fluorescence. In the early phase of ICGA (until +/- 2-3 minutes postinjection), posterior pole frames were taken to detect abnormalities in the retinal and choroidal arteriovenous circulation patterns. During the intermediate phase (12 +/- 3 minutes), posterior pole frames and eight 360 degrees panorama frames were taken to detect fluorescence abnormalities in the background impregnation of the choroid, the same sequence being repeated in the late phase (40 +/- 10 minutes). A cohort of more than 300 patients was analyzed in this standard fashion in 2 centers. PARTICIPANTS AND MAIN OUTCOME MEASURE: Determination of ICGA features and the proposed schematic approach for ICGA interpretation were based on the analysis of 109 cases of posterior uveitis with a well-determined diagnosis.
For uveitis, the intermediate and late phases of ICGA were found to yield the most valuable information showing either ICG hyperfluorescence or hypofluorescence or both. The ICG hyperfluorescence, always reflecting increased leakage or staining but not window defects because there is no pigment epithelium screen in ICGA, could originate either from increased leakage of the choriocapillaris, the large choroidal, or the retinal vessels. The characteristic ICG hypofluorescent dark dots indicating impairment of physiologic impregnation of the choroid could take at least five different patterns.
To date, ICGA features still are difficult to interpret. The proposed standardized ICGA protocol and schematized interpretation for posterior uveitis will help determine ICGA semiology for these disorders and might give new insights into their pathophysiology.
吲哚菁绿血管造影（ICGA）可检测吲哚菁绿（ICG）分子在近红外波长下产生的荧光，显示脉络膜血管结构。吲哚菁绿血管造影可能对伴有脉络膜受累的葡萄膜炎检查有用。作者的目的是测试一种用于后葡萄膜炎的标准化ICGA方案，以收集系统且可比的数据，并设计一种用于解释血管造影征象的示意性方法。
拟议的ICGA程序包括寻找注射前荧光。在ICGA的早期阶段（注射后至正负2 - 3分钟），拍摄后极部图像以检测视网膜和脉络膜动静脉循环模式的异常。在中间阶段（12正负3分钟），拍摄后极部图像和八个360度全景图像，以检测脉络膜背景灌注中的荧光异常，在后期阶段（40正负10分钟）重复相同序列。两个中心以这种标准方式分析了300多名患者。参与者和主要观察指标：ICGA特征的确定以及拟议的ICGA解释示意性方法基于对109例诊断明确的后葡萄膜炎病例的分析。
对于葡萄膜炎，发现ICGA的中间和后期阶段产生的最有价值信息显示为ICG高荧光或低荧光或两者皆有。ICG高荧光总是反映渗漏或染色增加，但不是窗样缺损，因为ICGA中没有色素上皮屏障，其可能源于脉络膜毛细血管、大脉络膜或视网膜血管渗漏增加。指示脉络膜生理灌注受损的特征性ICG低荧光暗点至少有五种不同模式。
迄今为止，ICGA特征仍难以解释。拟议的用于后葡萄膜炎的标准化ICGA方案和示意性解释将有助于确定这些疾病的ICGA症状学，并可能为其病理生理学提供新的见解。
