AIM: To estimate the correlation between diabetic duration, blood glucose levels, plasma C-peptide and dry eye, and the risk factors for dry eye in patients with type 2 diabetes mellitus(T2DM)

METHODS: The clinical data of 51 patients(102 eyes)with type 2 diabetes diagnosed by the Department of Endocrinology, Jiangsu Provincial Hospital of Traditional Chinese Medicine was collected, in that 44 cases(88 eyes)of patients diagnosed with dry eye. Those patients were detected for the levels of glycosylated hemoglobin A1c(HbA1c), fasting blood-glucose(FBG), postprandial 2h blood-glucose(2h PBG), fasting plasma C-peptide and insulin, 1h C-peptide and insulin. Corneal fluorescein staining(FL), tear break-up time(BUT)and Schirmer Ⅰ test(SⅠt)were collected from all subjects. Compared biochemistry index and ocular surface index. The multiple Logistic regression was used to analyze the risk factors for dry eye in patients with T2DM.

RESULTS: There was no significant differences between the patients with different diabetic duration, on BUT, SⅠt, winking frequency, vision, FL and the scores of dry eye symptoms(P>0.05). HbA1c was significantly correlated with FL(P<0.05). There were significant differences in FL among patients with HbA1c in 8.1% to 11.8%(P<0.01). FBG was significantly correlated with FL and winking frequency(P<0.05). The 2h PBG was significantly correlated with tear secretion and vision(P<0.05). Plasma C-peptide was significantly correlated with BUT(P<0.05). There were significant differences in BUT among patients with 1h C-peptide in 3.3-5.5ng/mL(P<0.05). FBG and plasma C-peptide in T2DM patients were risk factors for occurrence of dry eye(P<0.05).

CONCLUSION: Poor function of insulin secretion and poor control of blood glucose in T2DM patients are risk factors for dry eye. Both of them can decline tear film stability. High blood glucose levels easily lead to decrease of tear secretion, vision and corneal epithelial defect.