Peripapillary intrachoroidal cavitation (PICC) is a common pathological change observed in high myopia. The exact pathogenesis of PICC is still unclear. Expansion and mechanical stretching of the peripapillary sclera, breakage and defect in the retina near the border of the myopic conus and communication between intrachoroidal cavity and the vitreous space may be important segments during the development of PICC. Color fundus photography shows a localized and well-circumscribed peripapillary lesion with yellow-orange colour, often accompanied by fundus changes, such as myopic conus excavation, optic disc tilting and inferotemporal retinal vein bending at the transition from the PICC to the myopic conus. However, the PICC lesion is not easy to be recognized in the fundus photography. Fluorescein angiography shows early hypofluorescence and later progressively staining in the lesion. Indocyanine green angiography shows hypofluorescence throughout the examination. Optical coherence tomography (OCT) is vital in diagnosing PICC. Hyporeflective cavities inside the choroid, sometimes communicating with the vitreous chamber, can be observed in OCT images. OCT angiography indicates lower vessel density or even absence of choriocapillary network inside or around PICC lesions.%视盘旁脉络膜空腔(PICC)是高度近视常见病变之一,其具体发病机制尚不完全明确.视盘周围巩膜扩张与机械牵拉、近视弧周围视网膜组织断裂和缺损、玻璃体腔与脉络膜相通均可能是PICC形成过程中的重要环节.眼底彩色照相检查对PICC的识别率较低.眼底彩色像典型PICC表现为视盘周围边界清晰、橘黄色局限性病灶,常伴有近视弧深凹、视盘倾斜、颞下静脉分支在PICC与近视弧移行处屈曲等.荧光素眼底血管造影检查PICC早期表现为弱荧光,晚期病灶周围荧光着染.吲哚青绿血管造影检查PICC始终表现为弱荧光.光相干断层扫描(OCT)是诊断PICC的重要手段.OCT检查PICC表现为脉络膜内弱反射空腔样结构,部分可见PICC病灶与玻璃体腔相通;OCT血管成像检查可见PICC病灶及周围无血管网或伴有血流密度降低.
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