Diabetic peripheral neuropathy (DPN) is a serious complication of diabetes, where skin biopsy assessing intraepidermal nerve fiber density (IENFD) plays an important diagnostic role. In vivo confocal microscopy (IVCM) of the corneal subbasal nerve plexus has been proposed as a non-invasive diagnostic modality for DPN. Direct comparisons of skin biopsy and IVCM in controlled cohorts are lacking, while IVCM relies on subjective selection of images depicting only 0.2% of the nerve plexus. We compared these diagnostic modalities in a fixed-age cohort of 41 type 2 diabetes and 36 healthy subjects, using machine algorithms to create wide-field image mosaics and quantify nerves in an area 37 times the size of prior studies to avoid human bias. In the same subjects, and at the same time point, no correlation between IENFD and corneal nerve density was found. Corneal nerve density did not correlate with clinical measures of DPN, including neuropathy symptom and disability scores, nerve conduction studies or quantitative sensory tests. Our findings indicate that corneal and intraepidermal nerves likely mirror different aspects of nerve degeneration, where only intraepidermal nerves appear to reflect the clinical status of DPN, suggesting scrutiny is warranted concerning methodologies of studies using corneal nerves to assess DPN.

中文翻译：

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新型广角体内角膜共聚焦显微镜与皮肤活检评估 2 型糖尿病周围神经病变的比较

糖尿病周围神经病变 (DPN) 是糖尿病的严重并发症，其中评估表皮内神经纤维密度 (IENFD) 的皮肤活检起着重要的诊断作用。角膜基底下神经丛的体内共聚焦显微镜 (IVCM) 已被提议作为 DPN 的非侵入性诊断方式。缺乏对照队列中皮肤活检和 IVCM 的直接比较，而 IVCM 依赖于主观选择的图像，仅描绘了 0.2% 的神经丛。我们在 41 名 2 型糖尿病和 36 名健康受试者的固定年龄队列中比较了这些诊断方式，使用机器算法创建广域图像马赛克并量化先前研究大小 37 倍的区域中的神经，以避免人为偏差。在相同的科目，在相同的时间点，未发现 IENFD 与角膜神经密度之间存在相关性。角膜神经密度与 DPN 的临床指标无关，包括神经病变症状和残疾评分、神经传导研究或定量感觉测试。我们的研究结果表明，角膜和表皮内神经可能反映了神经变性的不同方面，其中只有表皮内神经似乎反映了 DPN 的临床状态，这表明需要对使用角膜神经评估 DPN 的研究方法进行审查。