角膜地形图对干眼症患者泪膜稳定性的评价分析

Corneal topography for evaluation of tear film stability in dry eye patients

目的:探讨利用角膜地形图检测并分析角膜表面规则指数(surface regularity index, SRI)、表面不规则指数(surface asymmetry index, SAI)、模拟角膜表面散光值(cylinder, CYL)和角膜预测视力(potential visual acuity, PVA)等参数与泪膜稳定性的关系。方法:采用横断面观察性研究,选择复旦大学附属中山医院青浦分院门诊就诊已确诊为干眼症的患者60例(113眼)为干眼症组,选择干眼症问卷调查中无干眼症状及干眼症相关病史的健康人33名(60眼)为对照组,进行泪膜破裂时间(break-up time, BUT)检查、泪液分泌试验(Schirmer’s test, ST)及角膜地形图SRI、SAI、CYL和PVA分析。结果:干眼症组患者泪膜BUT和ST值均小于对照组(均P<0.05),差异有统计学意义;干眼症组角膜地形图SRI、SAI、CYL值较对照组显著升高(P<0.05),而PVA值较对照组降低(P<0.05),随着SRI、SAI、CYL值升高,PVA值则降低;干眼症组CYL值较对照组升高(P<0.05),但两组角膜地形图屈光力K值无明显相关性。结论:角膜地形图数据可反映泪膜的稳定性,便于干眼症患者重建泪膜的临床疗效判断,同时角膜地形图具有客观、无创、重复性良好的优点,有利于在干眼症患者的泪膜稳定性评价中发挥重要作用。

Objective:To explore the surface regularity index (SRI), surface asymmetry index (SAI), cyclinder (CYL), potential visual acuity (PVA) using corneal topography and analyze their correlations with the stability of tear film. Methods:Cross-sectional and observational study was performed. Sixty dry eye outpatients (113 eyes) diagnosed with dry eye disease at the Qingpu Branch, Zhongshan Hospital, Fudan University were enrolled as dry eye group, and 33(60eyes) healthy volunteers were selected as control group. Tear film break-up time (BUT) examination, Schirmer’s test (ST), and the SRI, SAI, CYL,PVA tests of corneal topography were performed in both groups. Results:BUT and ST values in the dry eye group were significantly smaller than those in the control group (both P<0.05). The values of SRI, SAI, CYL in the dry eye group were significantly higher than those in the control group (all P<0.05), whereas the PVA value was smaller than that in the control group ( P<0.05), with the increase of SRI, SAI and CYL values, PVA values decreased. The CYL value in the dry eye group was higher than that in the control group ( P<0.05), whereas the K values of corneal topography were not significantly correlated between the two groups. Conclusions:The corneal topography parameters could reflect the stability of tear film, and be helpful for the clinical evaluation of tear film reconstruction in dry eye patients. Meanwhile, corneal topography has the advantages of objectivity, non-invasiveness and good repeatability, therefore it might play an important role in the evaluation of tear film stability in dry eye patients.