AIM: To investigate the effect of long-term wearing rigid gas permeable(RGP)contact lenses on the stability of tear film, and to observe its safety.

METHODS: Totally 60 myopia patients(120 eyes)wearing RGP in our hospital from October 2014 to January 2016 and 30 low myopia patients(60 eyes)without a history of wearing RGP were selected. There were 26 patients(52 eyes)wearing RGP at daytime were included into daytime wearing group; 34 patients(68 eyes)only wearing RGP at night were set as the night wearing group. And patients without wearing RGP were set as control group. Schirmer Ⅰ test(SⅠt), tear film fern experiments, and break-up time(BUT)of tear film were performed before wearing RGP, wearing for 1mo, wearing for 6mo, wearing for 1a, wearing for 2a, respectively.

RESULTS: After wearing RGP, the BUT and SⅠt of daytime wearing group and night wearing group significantly decreased, and were significantly lower than those of the control group at the time points, the difference was statistically significant(P<0.05). After wearing for 6mo, 1a and 2a, the BUT and SⅠt of daytime wearing group was significantly lower than that of the night wearing group, the statistic found significant difference(P<0.05). The three groups had no statistically significant differences in tear fern classification experiment before wearing RGP and wearing for 1 and 6mo(P>0.05). The number of the eyes ≥ Ⅲ in daytime wearing group and night wearing group was significantly higher than that of the control group after wearing for 1 and 2a, the difference was statistically significant(P<0.05), but the difference between daytime wearing group and night wearing group found no significant difference(P>0.05).

CONCLUSION: Wearing RGP can result in reducing tear secretion and decreasing the stability of tear film.