Background Tear hyperosmosis is considered to be one of the core mechanisms of dry eye.The measurement of tear osmolarity is important in the clinical diagnosis of dry eye.However,relevant study is lack in Chinese population.Objective The aim was to investigate the relation of tear osmolarity and pathogenesis of dry eye and evaluate the diagnosis value of tear hyperosmosis in dry eye.Methods Sixty-one consecutive dry eye patients were enrolled in Affiliated Eye Hospital of Wenzhou Medical University from May to August in 2011,including 30 mild and moderate dry eyes and 31 severe dry eyes,and 30 normal volunteers with matched age and gender were collected simultaneously under the informed consent.The visual acuity,Ocular Surface Disease Index (OSDI) questionnaire,osmotic pressure of tear,tear film breakup time (TFBUT),corneal fluorescein staining,conjunctival lissamine green staining,Shirmer Ⅰ test (S Ⅰ t) without anesthesia and meibomian function were examined in turn in the subjects,and lateral eyes with higher tear osmotic pressure were analyzed.The differences in above indexes among the different groups were statistically compared,and the correlations between the osmotic pressure of tear and clinical parameters were assessed.Results The osmotic pressure of tear was (326.46 ±22.66) mOsm/L in the dry eye group,which was significantly higher than (296.60± 10.81) mOsm/L in the normal control group (P＜0.05),and the OSDI scores,TFBUT,corneal fluorescine scores,conjunctival staining scores and S Ⅰ t values in the dry eye group were remarkably elevated in comparison with the normal control group (all at P＜0.05).The osmotic pressure of tear was (341.90 ± 21.15) mOsm/L in the severe dry eye group,which was significantly higher than (310.50±8.99) mOsm/L in the mild and moderate group (P＜0.017).The area under the curve for tear osmolarity in the dry eye group was 0.916,and cutoff value of sensitivity and specificity in dry eye diagnosis was 308 mOsm/L,with the sensitivity value 0.79 and specificity 1.00.The significant correlations were found between the osmotic pressure of tear and OSDI scores,corneal fluorescine scores,conjunctival staining scores and S Ⅰ t outcomes (r=0.338,0.407,0.246,-0.461,all at P＜0.05).However,the osmotic pressure of tear was not correlated with TFBUT (r=-0.113,P＞0.05).Conclusions Tears osmotic pressure might be a useful indicator for the diagnosis of dry eye and assessment of severity.A combined application of tear osmolarity measurement with other relevant indexes can improve the diagnostic value.%背景 泪液高渗透压被认为是引起干眼的核心机制之一,泪液渗透压的测量在干眼临床诊断中具有重要的临床意义,但目前中国关于泪液渗透压与干跟发病的关系的研究资料少见. 目的 研究泪液渗透压改变与干眼发病的关系,探讨泪液渗透压检查在干眼诊断及病情评估中的价值.方法连续收集2011年5-8月在温州医科大学附属眼视光医院确诊的61例干眼患者,包括轻中度干眼30例和重度干眼31例,并纳入同期正常志愿者30人,各组受检者的基线特征匹配.所有受检者在知情同意的情况下双眼依次进行视力检查、眼表疾病指数(OSDI)问卷调查评分、泪液渗透压检测、眼前节裂隙灯显微镜检查、泪膜破裂时间(TFBUT)检测、角膜荧光素钠染色评分、结膜丽丝胺绿染色评分、Shirmer试验Ⅰ(SⅠt)和睑板腺功能评估,选取泪液渗透压值较高一侧眼的结果进行分析,比较各组间受检者各检测指标的差异,并对干眼组受检者的泪液渗透压与临床检测结果的相关性进行分析. 结果 正常对照组和干眼组受检者泪液渗透压值分别为(296.60±10.81)mOsm/L和(326.46±22.66) mOsm/L,干眼组患者泪液渗透压值高于正常对照者,差异有统计学意义(P＜0.05),此外干眼组患者OSDI评分、TFBUT值、角膜荧光素染色评分、结膜丽丝胺绿染色评分和SⅠt检测值均明显高于正常对照组,差异均有统计学意义(均P＜0.05).重度干眼组泪液渗透压为(341.90±21.15) mOsm/L,明显高于轻中度干眼组患者的(310.50±8.99)mOsm/L,差异有统计学意义(P＜0.017).根据ROC曲线分析,干眼组的泪液渗透压受试者工作特征(ROC)曲线下面积为0.916,干眼诊断泪液渗透压临界点为308 mOsm/L,干眼诊断敏感性为0.79,特异性为1.00.泪液渗透压与OSDI评分、角膜染色评分、结膜染色评分和SⅠt结果均相关(r=0.338、0.407、0.246、-0.461,均P＜0.05),但与TFBUT无明显相关性(r=-0.113,P＞0.05).结论 泪液渗透压可能是诊断干眼和评估干眼严重程度的重要指标,泪液渗透压与其他指标的联合应用可提高干眼的诊断价值.
展开▼
