目的：探讨49例后部多形性角膜营养不良(PPCD)患者在共聚焦显微镜(IVCM)下的影像学特征。

方法：回顾性病例研究。收集我院2013-01/2021-01诊断为PPCD患者49例86眼，包括男32例，女17例，平均年龄42.5±22.9岁。所有患者均进行IVCM检查，分析角膜内皮细胞密度及不同类型病变的镜下特点。

结果：所有患者病灶区内皮细胞数量均较外周细胞数量低。IVCM下病变呈1型囊泡型的有44眼(51%)，表现为角膜内皮层的圆形或不规则弹坑样病灶，单个或多个出现； 2型条带型16眼(19%)，表现为边缘弧形凸起，部分可见似赘疣样影像散在或条索状分布； 3型弥漫型26眼(30%)，表现为内皮细胞大面积缺失，大部分区域内皮成像不清，呈匍匐样、条索样延展的凸起，成像较清晰处部分同条带型病灶。观察病例中有2例患者随访4～5a，IVCM下病灶均较前有变化，包括中央角膜内皮数量的减少和上皮层铁质沉着等。

结论：IVCM能够显示PPCD患者各期内皮细胞和Descemet膜水平的特征性显微结构改变，通过观察其影像学特点可以为疾病提供有效的诊断价值。

METHODS: Retrospective case series study. A total of 49 patients(86 eyes), including 32 males and 17 females diagnosed with PPCD between January 2013 and January 2021 were collected. The mean age was 42.5±22.9 years. All patients were scanned by IVCM to analyze the density of corneal endothelial cells and described IVCM characteristics of different types of PPCD.

RESULTS: The number of endothelial cells in the lesion area of all patients was lower than that in the peripheral area. Under IVCM, 44 eyes(51%)were categorized into type 1 PPCD(vesicular lesions), characterized by single or multiple, central round or irregular crater-like lesion on paracentral corneal endothelial layer; 16 eyes(19%)were categorized into type 2 PPCD(band lesions), which displayed curved and raised edge with scattered or banded-distributed gutta-like lesion between edges. Type 3 PPCD(diffuse lesion)were in 26 eyes(30%), which showed that endothelial cells were missing in many areas. The blurred images of endothelium in most areas featured with spikes lined in a streak, and the clear images in some areas featured with a band lesions. Two patients were followed up for 4-5a. The IVCM images showed different lesions, including the decrease of central corneal endothelial cell density and the iron deposit in the corneal epithelium, etc.

CONCLUSION: IVCM is able to scan the characteristic microstructural alterations at the level of endothelium and Descemet membrane in patients with PPCD, and provide an effective image diagnosis for PPCD.