AIM:To observe the change of contrast sensitivity in the middle and the old with dry eyes caused by Meibomian gland dysfunction(MGD)before and after using the artificial tears in the comprehensive therapy and to evaluate the influence of artificial tears on visual function in these patients.

METHODS:One hundred and twenty middle aged and old patients(240 eyes)who were diagnosed with dry eyes caused by MGD for the first time in our department from June 1^st 2014 to January 30^st 2015 were screened. Sixty(120 eyes)normal people were chosen as normal group. The 120 patients enrolled through inclusion criteria were divided into observation group and control group by random digits table. The patients in observation group were treated with artificial tears regularly combined with local massage and systemic treatment. Patients in control group were treated the same as those in the observation group except artificial tears. Normal group did not receive any treatment. The treatments for both observation group and control group lasted for 16wk. The follow-up period after treatment was 8wk. Observe and compare the contrast sensitivity.

RESULTS:Effective rate of observation group was 83.3%, which was obviously higher than that of control group 95.8%,the difference was statistically significant(χ²=10.05,P=0.002). BUT of observation group, control group and normal group were 3.14±2.01s, 2.54±1.01s and 12.85±2.34s respectively. SⅠt of observation group, control group and normal group were 4.56±1.86mm, 3.48±1.23mm and 15.36±2.48mm respectively. There was statistic significance on the two terms among the three groups. But the difference between observation group and control group was not significant. Before treatments, contrast sensitivity at low, middle and high frequency of both observation group and control group was lower than those of normal group(P<0.05),but there was no statistic significance between observation group and control group(P>0.05). After treated by artificial tears, contrast sensitivity of observation group at different frequency(1.8c/d,3.0c/d,6.0c/d,12c/d,18c/d,24c/d)was obviously higher than those of control group, and the difference was statistically significant(P<0.05).

CONCLUSION: After comprehensive therapy combined with artificial tears, the patients with dry eyes caused by MGD have better contrast sensitivity. The subjective symptoms are relieved. The visual acuity is improved. Besides, contrast sensitivity as a non-contact objective examination, can proved evidence to diagnosis and effect evaluation for the patients after treatments.