Deinema Laura Adelaide, Vingrys Algis Jonas, Chinnery Holly Rose, Downie Laura Elizabeth
Department of Optometry and Vision Sciences, Faculty of Medicine, Dentistry & Health Sciences, The University of Melbourne, Parkville, Victoria, Australia 3010.
Transl Vis Sci Technol. 2017 May 22;6(3):6. doi: 10.1167/tvst.6.3.6. eCollection 2017 May.
To investigate whether tear hyperosmolarity, a feature of dry eye disease (DED), affects central corneal thickness (CCT), corneal light reflectivity, and/or tear film reflectivity.
This prospective, cross-sectional study involved 48 participants (38 with hyperosmolar tears and 10 controls with normo-osmolar tears). Symptoms and signs of DED (tear osmolarity, sodium fluorescein tear break-up time, ocular surface staining, Schirmer test) were assessed. CCT, and the reflectivity of the cornea and the tear-epithelial interface were quantified relative to background noise using Fourier-domain optical coherence tomography (FD-OCT).
CCT of eyes with severe tear hyperosmolarity, defined as eyes in the upper quartile of the hyperosmolar group, was less than control eyes (539.1 ± 7.4 vs. 583.1 ± 15.0 μm, = 0.02) and eyes with less severe tear hyperosmolarity, defined as hyperosmolar eyes in the lower quartile (622.7 ± 5.8 μm, < 0.0001). CCT showed a negative linear relationship with tear osmolarity for values above 316 mOsmol/L ( = 0.17, = 0.01). Central corneal reflectivity was lower in hyperosmolar eyes than normo-osmolar eyes (45.1 ± 0.3 vs. 48.1 ± 0.6 pixels, = 0.02); the greatest relative difference was in the anterior stroma, where corneal reflectivity was 4.7 ± 1.9% less in hyperosmolar eyes ( < 0.01). Peak reflectivity of the tear-epithelial interface was 4.8% ± 3.5% higher in the hyperosmolar group than the normo-osmolar tear group ( = 0.04).
Individuals with significant tear hyperosmolarity and clinical signs of symptoms of DED show reduced CCT and altered corneal reflectivity.
Anterior segment FD-OCT provides novel insight into corneal microstructural differences in individuals with DED.
研究干眼疾病（DED）的一个特征——泪液高渗是否会影响中央角膜厚度（CCT）、角膜光反射率和/或泪膜反射率。
这项前瞻性横断面研究纳入了48名参与者（38名泪液高渗者和10名泪液渗透压正常的对照者）。评估了干眼的症状和体征（泪液渗透压、荧光素钠泪膜破裂时间、眼表染色、Schirmer试验）。使用傅里叶域光学相干断层扫描（FD-OCT）相对于背景噪声对CCT以及角膜和泪膜-上皮界面的反射率进行了量化。
重度泪液高渗的眼睛（定义为高渗组上四分位数的眼睛）的CCT低于对照眼睛（539.1±7.4 vs. 583.1±15.0μm，P = 0.02）以及泪液高渗程度较轻的眼睛（定义为高渗组下四分位数的高渗眼睛，622.7±5.8μm，P<0.0001）。对于高于316 mOsmol/L的值，CCT与泪液渗透压呈负线性关系（r = 0.17，P = 0.01）。高渗眼睛的中央角膜反射率低于等渗眼睛（45.1±0.3 vs. 48.1±0.6像素，P = 0.02）；最大相对差异在前基质层，高渗眼睛的角膜反射率在此处低4.7±1.9%（P<0.01）。高渗组泪膜-上皮界面的峰值反射率比等渗泪液组高4.8%±3.5%（P = 0.04）。
有明显泪液高渗和干眼症状体征的个体显示CCT降低且角膜反射率改变。
眼前节FD-OCT为干眼个体的角膜微观结构差异提供了新的见解。
