Changes in conjunctival mucin expressions in patients with first diagnosis of dry eye and its clinical significance / 中华实验眼科杂志

ABSTRACT

Objective:To investigate the expressions of MUC1, MUC4, MUC5AC and MUC16 in patients with first diagnosis of dry eye and their correlation with dry eye symptoms and signs.Methods:A cross-sectional study was conducted.Sixty-nine dry eye patients (69 eyes) as dry eye group and 40 normal volunteers (40 eyes) as normal control group were recruited in Xiamen Eye Center of Xiamen University, Beijing Tongren Hospital, West China Hospital of Sichuan University and Shanghai Puotuo District Center Hospital from December 2016 to May 2018.Symptoms were evaluated by Chinese dry eye questionnaire, Ocular Surface Disease Index (OSDI) and Dry Eye-Related Quality-of-Life Score Questionnaire (DEQS). Signs were assessed by tear film breakup time (TBUT), keratoconjunctival fluorescein sodium staining, and Schirmer I test.Conjunctival cells were collected by conjunctival impression cytology.The expression levels of MUC1, MUC4, MUC5AC and MUC16 mRNA in the two groups were determined by real-time fluorescence quantitative PCR.The correlation between the mRNA levels of conjunctival mucins and dry eye symptoms and signs were analyzed by Spearman correlation analysis.This study adhered to the Declaration of Helsinki.The study protocol was approved by the Ethics Committees of Xiamen Eye Center of Xiamen University (No.2017003), Beijing Tongren Hospital, Capital Medical University (No.TREC2016-29), West China Hospital of Sichuan University (No.2016310) and Shanghai Puotuo District Center Hospital (No.PTEC-A-2016-18-1). Written informed consent was obtained from each subject before any medical examination.Results:The expression levels of MUC1 and MUC16 mRNA in dry eye patients were 3.277(0.568, 5.790) and 1.815(1.048, 3.694), which were higher than 1.055(0.550, 2.010) and 1.024(0.541, 1.965) in normal control group (Z=819.00, P=0.008; Z=861.00, P=0.002). According to OSDI scores, MUC1 was mainly increased to 3.277(1.161, 6.226) in mild to moderate (12-32 points) dry eye patients (Z=9.04, P=0.029), and MUC16 was mainly increased to 1.968(1.074, 3.726) in severe (>32 points) dry eye patients (Z=12.24, P=0.007). MUC1 expression was positively correlated with TBUT, and was negatively correlated with corneal staining scoring and keratoconjunctival staining scoring ( r s=0.270, P=0.025; r s=-0.331, P=0.006; r s=-0.325, P=0.007). MUC16 expression was positively correlated with TBUT, and was negatively correlated with blurred vision scoring, symptom exacerbation scoring during reading, impact scoring of driving at night, impact scoring of computer and impact scoring of TV use ( r s=0.249, P=0.039; r s=-0.359, P=0.047; r s=-0.370, P=0.034; r s=-0.558, P=0.016; r s=-0.498, P=0.006; rs=-0.515, P=0.002). Conclusions:The gene expressions of MUC1 and MUC16 are higher in conjunctiva of dry eye patients.MUC1 mRNA expression is related to patients' signs.MUC16 mRNA expression is related to the quality of life of patients.