AIM: To investigate the relationship between the severity of diabetic retinopathy(DR)in middle-aged and elderly diabetic patients with serum HbA1c and TNF-α.

METHODS: Totally 200 patients with diabetes mellitus was selected, 60 patients with diabetes mellitus(DM group), 80 patients with non-proliferative diabetic retinopathy(NPDR)and 60 patients with diabetic retinopathy(PDR), and 80 healthy subjects were selected as normal control group(NC group). Patient's physical examination index was observed, the levels of fasting plasma glucose(FPG), 2h postprandial blood glucose(2hPG), serum lipids, serum HbA1c, serum tumor necrosis factor-α(TNF-α)and tear TNF-α of patients were measured.

RESULTS:There were significant differences in body mass index(BMI), FPG, 2hPG, total cholesterol(TC), trilycerides(TG), high density lipoprotein(HDL-C)and low-density lipoprotein(LDL-C)among the four groups(F=37.211, 395.421, 42.515, 7.385, 121.764, 121.568, 34.567, P<0.05). The levels of BMI, FPG, 2hPG, TC, TG, HDL-C and LDL-C of DM, NPDR and PDR groups were significantly higher than those in the NC group(P<0.05). The levels of BMI, FPG, 2hPG, TC, TG, HDL-C and LDL-C of PDR group were significantly higher than those in the NPDR group(P<0.05). The differences of serum TNF-α, tear TNF-α and serum HbA1c in four groups were statistically significant(F=337.256, 215.471, 40.522, P<0.05). The levels of serum TNF-α, tear TNF-α and serum HbA1c in the DM, NPDR and PDR groups were significantly higher than those in the NC group; the serum levels of serum TNF-α, tear TNF-α and serum HbA1c of the NPDR and PDR groups were significantly higher than those in the DM group(P<0.05), the serum levels of serum TNF-α, tear TNF-α and serum HbA1c of PDR group were significantly higher than those in the NPDR group(P<0.05). There was a positive correlation between tear TNF - α and serum TNF–α(r=0.289, P<0.01), and a positive correlation between serum TNF-α and serum HbA1c(r=0.375, P<0.01).

CONCLUSION: The tear TNF-α levels in middle-aged patients with diabetic retinopathy is higher than normal, and with the increase of retinopathy severity, tear TNF-α levels increases. There is a positive correlation between TNF-α in tear fluid and serum TNF-α and HbA1c.