Objective: To investigate the cellular changes and quantitative analysis of basal cell density (BCD) and corneal epithelial thickness (CET) in limbal stem cell deficiency (LSCD) by in vivo confocal microscopy (IVCM). Methods: Prospective case-control study. A total of 35 eyes of 23 patients diagnosed with LSCD and 25 eyes from normal subjects were included in this study. Based on slit-lamp presentation and the global consensus on classification, the LSCD patients were classified into LSCD Ⅰ, LSCD Ⅱ and LSCD Ⅲ. Confocal images of the central cornea, and the superior, inferior, nasal and temporal limbus were inspected by IVCM. Morphologic characteristics of LSCD were summarized. The BCD and CET in all locations were measured. ANVOA or Kruskal-Wallis test was used for analysis when appropriate. A receiver operating characteristic was used to detect the diagnosis efficiency of BCD and CET. Results: The characteristics in the corneal epithelium of LSCD on IVCM included nested corneal epithelial cells, goblet cells with hyper-reflective spots, irregular basal cells and decreasing subbasal nerve density. The mean BCD of the LSCD group was (8 976±1 096) cells/mm2 in the central cornea. Compared to the control group, the BCD in the central cornea, superior, inferior, nasal and temporal limbus decreased by 30.2%, 26.0%, 28.7%, 29.3% and 30.2%, respectively (all P<0.007). The CET in the central cornea was (47.3±8.1) μm. The CET in the central cornea, superior, inferior, nasal and temporal limbus decreased by 27.9%, 23.7%, 20.6%, 26.9% and 23.1%, respectively, compared to the control group (all P<0.007). There was a decline of BCD and CET in more serious LSCD. Additionally, the decline of BCD and CET was shown in the unaffected region. The receiver operating characteristic showed the diagnosis efficiency of BCD in the corneal center and limbus (0.931 and 0.916) was superior to CET (0.853 and 0.817). Conclusions: There was a series of characteristic cellular changes in LSCD on IVCM. Both BCD and CET decreased significantly in LSCD. The BCD had higher diagnostic efficiency for LSCD.(Chin J Ophthalmol, 2020, 56:447-455).
目的： 探讨角膜缘干细胞缺乏（LSCD）患者的角膜在活体共聚焦显微镜（IVCM）下的影像学特征及其诊断意义。 方法： 前瞻性病例对照研究。2019年3至10月连续收集在首都医科大学北京同仁医院角膜病门诊诊断为LSCD的患者23例（35只眼）作为LSCD组，其中男性7例，女性16例，年龄（41.74±15.62）岁。另选取与LSCD组年龄、性别相匹配的健康受试者25人（25只眼）作为对照组，其中男性6人，女性19人，年龄为（41.38±12.72）岁。使用IVCM中的“volume”模式对角膜中央、角膜缘上方、下方、鼻侧、颞侧连续扫描，将获得的图像资料进一步分析，观察不同分期LSCD患者角膜中央及角膜缘区域细胞学变化情况及上述各部位的角膜上皮基底细胞密度（BCD）及角膜上皮厚度（CET）变化趋势；上述参数若符合方差齐性，则采用ANOVA检验，若不符合，则采用Kruskal-Wallis秩和检验进行统计学分析；利用受试者操作特征（ROC）曲线获得这些参数在LSCD诊断中的特异度和灵敏度。 结果： LSCD患者IVCM特征性表现为角膜病灶区结膜上皮细胞移行，角膜上皮细胞巢状分布，并可见胞质颗粒高反光的杯状细胞浸润；角膜基底细胞形态不规则、体积增大，基底膜下神经密度减低。定量分析LSCD患者的BCD和CET发现，角膜中央BCD为（6 261±1 593）个/mm2，较对照组（8 976±1 096）个/mm2减少30.2%，且上方、下方、鼻侧、颞侧角膜缘较对照组分别减少26.0%、28.7%、29.3%、30.2%（均P<0.007）。LSCD患者角膜中央CET为（34.1±6.9）μm，较对照组（47.3±8.1）μm减少27.9%，上方、下方、鼻侧、颞侧角膜缘处CET较对照组分别减少23.7%、20.6%、26.9%、23.1%（均P<0.007）。随着疾病程度的加重，BCD及CET均逐渐减低。此外，角膜上方、下方、鼻侧、颞侧4个象限的非受累区BCD与对照组间差异均有统计学意义（Z=5.146，-5.366，-5.469，-5.224； P <0.001），且鼻侧及颞侧角膜缘的非受累区CET与对照组间差异有统计学意义（Z=4.605，-4.065；P<0.001）。ROC曲线提示角膜中央及角膜缘BCD的诊断效能（0.931和0.916）优于角膜中央CET和角膜缘CET（0.853和0.817）。 结论： LSCD患者角膜在IVCM下具有较为特异的影像学特征，表现为中央、角膜缘BCD和CET较低。BCD下降对LSCD具有较高的诊断价值。（中华眼科杂志，2020，56：447-455）.
Keywords: Cornea; Epithelium, corneal; Microscopy, confocal; Stem cells.