Corneal Neurobiology Laboratory, Department of Ophthalmology and Visual Sciences, University of Illinois at Chicago, College of Medicine, Chicago, Illinois.
Invest Ophthalmol Vis Sci. 2013 Dec 11;54(13):8051-61. doi: 10.1167/iovs.13-12844.
To determine the abundance of extracellular DNA (eDNA) in tear fluid of patients with dry eye disease (DED) and to report clinical outcomes after DNase I eyedrops use to reduce excessive tear fluid eDNA.
Tear fluid was collected from healthy control subjects and patients with DED. The eDNA abundance was determined with the PicoGreen dye assay. The DED symptoms and clinical signs were recorded and correlated with eDNA abundance. Two patients with DED having excessive eDNA in tear fluid were treated with DNase I eyedrops.
The PicoGreen dye assay measures tear fluid eDNA abundance after a 2-minute incubation time. With longer incubations, admixed cells also contribute to eDNA measurements. The mean (SE) eDNA abundance in healthy control subjects' tear fluid was 1.4 (0.2) μg/mL. The mean (SE) eDNA abundance in tear fluid of patients with nonautoimmune DED, autoimmune DED, and graft versus host disease was significantly higher: the values were 2.9 (0.6), 5.2 (1.2), and 9.1 (2.3) μg/mL, respectively (P < 0.05). In most of these patients, the PicoGreen dye kinetic assay of tear fluid showed an increase in fluorescence signal due to the presence of viable cells in tear fluid. Tear fluid eDNA had the best correlation with corneal Rose Bengal staining (r = 0.55). Treatment of patients having DED with DNase I eyedrops reduced eDNA abundance, abrogated signal increase, and improved comfort.
Excessive eDNA is present in tear fluid of patients with dry eyes. A novel therapeutic approach for managing DED may be to measure eDNA abundance in tear fluid with the PicoGreen dye assay and reduce excessive amounts with DNase I eyedrops.
确定干眼症（DED）患者泪液中细胞外 DNA（eDNA）的丰度，并报告使用脱氧核糖核酸酶 I 滴眼剂减少过多泪液 eDNA 后临床结果。
从健康对照者和 DED 患者中收集泪液。用 PicoGreen 染料法测定 eDNA 丰度。记录 DED 症状和临床体征，并与 eDNA 丰度相关联。对 2 例泪液中 eDNA 过多的 DED 患者进行脱氧核糖核酸酶 I 滴眼剂治疗。
PicoGreen 染料法在 2 分钟孵育时间后测量泪液中的 eDNA 丰度。孵育时间较长时，混合细胞也会影响 eDNA 测量值。健康对照者泪液的平均（SE）eDNA 丰度为 1.4（0.2）μg/mL。非自身免疫性 DED、自身免疫性 DED 和移植物抗宿主病患者泪液中的平均（SE）eDNA 丰度显著更高：分别为 2.9（0.6）、5.2（1.2）和 9.1（2.3）μg/mL（P<0.05）。在这些患者中，大多数患者的泪液 PicoGreen 染料动力学分析显示荧光信号增加，这是由于泪液中存在有活力的细胞。泪液 eDNA 与角膜 Rose Bengal 染色的相关性最好（r=0.55）。使用脱氧核糖核酸酶 I 滴眼剂治疗 DED 患者可降低 eDNA 丰度，消除信号增加，并改善舒适度。
干眼症患者的泪液中存在过多的 eDNA。一种新的治疗方法可能是使用 PicoGreen 染料法测量泪液中的 eDNA 丰度，并使用脱氧核糖核酸酶 I 滴眼剂减少过多的 eDNA。
