Evaluation of corneal layers and anterior sclera in patients with primary Sjögren's syndrome

ABSTRACT Purpose: We aimed to compare the thickness of anterior sclera, corneal layers, and pre-ocular tear film between patients with primary Sjögren's syndrome and healthy individuals. Methods: Fifty-one patients with primary Sjögren's syndrome and 41 healthy control participants were recruited in this cross-sectional and comparative study. The thickness of the pre-ocular tear film, corneal epithelium, Bowman's layer, stroma, Descemet's membrane, and endothelium were measured on the corneal apex. Anterior scleral thickness was measured at distances of 1 mm and 3 mm from the limbus. The anterior segment module of spectral-domain optical coherence tomography was used to measure thicknesses of pre-ocular tear film, corneal layers, and anterior sclera. Results: Tear film thickness, Schirmer's test, and tear break up time values were significantly lower in the Sjögren's disease group than in the healthy controls (p<0.05). The thickness measurements of corneal layers and sclera were similar between the groups. Tear film thickness was moderately correlated with the Schirmer's test results (r=0.34, p=0.001), but there was no correlation between the Schirmer's test results and tear break up time (r=0.18, p=0.09). Conclusions: Pre-ocular tear film, as measured by anterior segment optical coherence tomography, was thinner in patients with primary Sjögren's syndrome than in the healthy controls. The thicknesses of corneal layers and anterior sclera were similar between the groups.

摘要
研究目的：本研究旨在比较原发性干燥综合征（primary Sjögren's syndrome）患者与健康个体的前巩膜、角膜各层及眼前泪膜的厚度差异。
研究方法：本项横断面对照研究共招募51名原发性干燥综合征患者与41名健康对照受试者。在角膜顶点处测量眼前泪膜、角膜上皮、鲍曼层（Bowman's layer）、基质层、后弹力层（Descemet's membrane）及内皮细胞层的厚度；于距角膜缘1mm与3mm处测量前巩膜厚度。采用光谱域光学相干断层扫描（spectral-domain optical coherence tomography, SD-OCT）的眼前节模块，完成眼前泪膜、角膜各层及前巩膜厚度的测量。
研究结果：干燥综合征组的泪膜厚度、希默试验（Schirmer's test）结果与泪膜破裂时间（tear break up time, BUT）均显著低于健康对照组（p<0.05）。两组间角膜各层与巩膜厚度的测量结果无显著差异。泪膜厚度与希默试验结果呈中度相关（r=0.34，p=0.001），但希默试验结果与泪膜破裂时间无相关性（r=0.18，p=0.09）。
研究结论：通过眼前节光学相干断层扫描测量的眼前泪膜厚度，在原发性干燥综合征患者中显著低于健康对照组；两组间角膜各层与前巩膜厚度无显著差异。