School of Optometry, College of Health and Life Sciences, Aston University, Birmingham, UK.
School of Optometry and Vision Science, Faculty of Medicine and Health, University of New South Wales, Sydney, New South Wales, Australia.
Ophthalmic Physiol Opt. 2023 Sep;43(5):1079-1091. doi: 10.1111/opo.13186. Epub 2023 Jun 25.
Dry eye disease (DED) is a growing global health problem with a significant impact on the quality of life of patients. While neurosensory abnormalities have been recognised as a contributor to DED pathophysiology, the potential role of in vivo corneal confocal microscopy in detecting nerve loss or damage remains unclear. This systematic review with meta-analysis (PROSPERO registered CRD42022381861) investigated whether DED has an impact on sub-basal corneal nerve parameters.
PubMed, Embase and Web of Science Core Collection databases were searched from inception to 9 December 2022. Studies using laser scanning confocal microscopy to compare corneal nerve parameters of DED with healthy eyes were included. Study selection process and data extraction were performed by two independent members of the review team.
Twenty-two studies with 916 participants with DED and 491 healthy controls were included, with 21 of these studies included in subsequent meta-analyses. There was a decrease in total corneal nerve length (-3.85 mm/mm ; 95% CI -5.16, -2.55), corneal main nerve trunk density (-4.81 number/mm ; 95% CI -7.94, -1.68) and corneal nerve branch density (-15.52 number/mm ; 95% CI -27.20, -3.84) in DED eyes compared with healthy eyes, with subgroup analysis demonstrating that these differences were more evident in studies using NeuronJ software, a semi-automated procedure. While this review found evidence of loss of corneal nerve parameters in eyes with DED compared with healthy controls, particularly with the use of a semi-automated image analysis method, it is evident that there is substantial heterogeneity between studies in terms of corneal nerve imaging methodology.
Standardisation is required in terms of terminology and analysis, with more research needed to potentially improve the clinical applicability and practicality of corneal nerve imaging. Further investigation is also required to confirm the diagnostic accuracy of this imaging modality and its potential for monitoring DED treatment efficacy.
干眼症（DED）是一个日益严重的全球性健康问题，对患者的生活质量有重大影响。虽然神经感觉异常已被认为是 DED 病理生理学的一个促成因素，但活体角膜共焦显微镜在检测神经损失或损伤方面的潜在作用尚不清楚。本系统评价（PROSPERO 注册 CRD42022381861）结合荟萃分析调查了 DED 是否对角膜基底神经参数有影响。
从建立至 2022 年 12 月 9 日，我们检索了 PubMed、Embase 和 Web of Science 核心合集数据库。纳入了使用激光扫描共焦显微镜比较 DED 与健康眼角膜神经参数的研究。研究选择过程和数据提取由两名独立的综述小组成员完成。
共纳入 22 项研究，涉及 916 名 DED 患者和 491 名健康对照者，其中 21 项研究纳入了后续的荟萃分析。与健康对照组相比，DED 组的总角膜神经长度减少（-3.85mm/mm；95%CI-5.16，-2.55）、角膜主神经干密度减少（-4.81 个/毫米；95%CI-7.94，-1.68）和角膜神经分支密度减少（-15.52 个/毫米；95%CI-27.20，-3.84），亚组分析表明，使用 NeuronJ 软件（一种半自动程序）的研究中，这些差异更为明显。尽管本综述发现与健康对照组相比，DED 眼中角膜神经参数存在丢失的证据，但特别是使用半自动图像分析方法时，各研究之间在角膜神经成像方法学方面存在明显的异质性。
在术语和分析方面需要标准化，需要进一步研究以提高角膜神经成像的临床适用性和实用性。还需要进一步研究以确认这种成像方式的诊断准确性及其监测 DED 治疗效果的潜力。
