The influence of long-term corneal contact lens wearing on the stability and quality of tear film in Qinghai

This study was designed to explore the influence of long-term corneal contact lens (CL) wearing on the stability and quality of tear film in Qinghai. Thirty subjects with CL over five years and thirty myopia subjects without CL as control were recruited in our study. Basic tear secretion test, tear film break-up time (TBUT), and corneal fluorescein staining were determined. For further evaluating the quality of tear film of two groups, the mucin levels including mucin 1 (MUC1) and mucin 5AC (MUC5AC) were measured by enzyme-linked immunosorbent assay (ELISA), meanwhile MUC1 and MUC5AC mRNA expression were processed by real-time polymerase chain reaction (RT-PCR) after samples were collected. Compared with control group, basic tear secretion and TBUT decreased, obvious corneal fluorescein staining presented in CL group. The mean protein quantity of MUC1 and MUC5AC in CL group (1.1612±0.2119 ng/ml, 1.6731±0.2457 ng/ml respectively) was less than that of control group (1.2369±0.1825 ng/ml and 1.7892±0.2461 ng/ml respectively), there were significant differences between the two groups (t=2.098, P=0.038; t=2.586, P=0.011 respectively). Both the mRNA expression of MUC1 and MUC5AC in the CL group (1.3944±0.1212 and 1.622±0.1988 respectively) decreased in comparison with control group (1.4630±0.1028 and 1.7056±0.1638 respectively), significant differences was observed between the two groups (t=3.343, P=0.001; t=2.514, P=0.013 respectively). These results suggest that long-term CL wearing in Qinghai might pose an impact on the stability and quality of tear film.