Inter-eye osmolarity differences in patients with symptomatic and non-symptomatic dry eyes

ABSTRACT Purpose: To analyze whether inter-eye osmo larity differences were related to dry eye symptomatology. Methods: A total of 135 participants were randomly recruited from those who visited in the Optometry Clinic of the Optometry Faculty (Universidade de Santiago de Compostela). In a single scheduled session after the recruitment, Ocular Surface Disease Index was filled out following the standard instructions and TearLab measurements were made in both the participants’ eyes (10-15 min lapse). Osmolarity values were compared between the right and left eyes and the absolute inter-ocular difference (|OD-OS|) correlated with the Ocular Surface Disease Index score for the whole sample. Based on the Ocular Surface Disease Index score, the sample was divided into four symptomatic subgroups, and differences in the |OD-OS| values were calculated. Results: The whole sample showed a statistically significant inter-eye osmolarity difference (p=0.025; |OD-OS| = 9.2 ± 9.3 mOsm/l) and the correlation between Ocular Surface Disease Index and |OD-OS| (r=0.369; p<0.001). A statistically significant difference was found in the |OD-OS| value between symptomatic subgroups (Kruskal-Wallis, p=0.003). Mann-Whitney U test showed a significant difference between asymptomatic vs. moderate (p=0.006) vs. severe symp tomatic patients (p=0.001) and between mild vs. severe symptomatic patients (p=0.045), whereas no difference on |OD-OS| was found between participants with contiguous symptomatic subgroups (all p³0.174). Conclusion: Tear film inter-eye osmolarity differences are significantly higher in severe dry eye disease symptoms.

摘要
研究目的：分析双眼泪膜渗透压差异是否与干眼症状相关。
研究方法：从圣地亚哥-德孔波斯特拉大学（Universidade de Santiago de Compostela）验光学院验光门诊的就诊人群中随机招募135名受试者。在招募完成后的单次预约就诊中，受试者按照标准指导填写眼表疾病指数（Ocular Surface Disease Index, OSDI）量表，并使用TearLab检测仪对双眼进行渗透压检测（两次检测间隔10~15分钟）。比较双眼的渗透压值，针对全部受试者分析双眼绝对渗透压差值（|OD-OS|）与眼表疾病指数评分的相关性；根据眼表疾病指数评分将受试者分为4个症状亚组，计算各组间|OD-OS|值的差异。
研究结果：全部受试者的双眼渗透压差异具有统计学意义（p=0.025；|OD-OS|=9.2±9.3毫渗透压摩尔每升），且眼表疾病指数评分与|OD-OS|值呈显著相关（r=0.369；p<0.001）。不同症状亚组间的|OD-OS|值差异具有统计学意义（Kruskal-Wallis检验，p=0.003）。曼-惠特尼U检验显示，无症状组与中度症状组（p=0.006）、无症状组与重度症状组（p=0.001），以及轻度症状组与重度症状组（p=0.045）的|OD-OS|值存在显著差异；而相邻症状亚组间的|OD-OS|值无统计学差异（所有p≥0.174）。
研究结论：伴重度干眼症状的受试者，其双眼泪膜渗透压差值显著升高。