Abstract
Purpose: :
To compare the Nerve growth factor (NGF) level in serum and ocular surface between control and diabetic retinopathy patients. We also tried to determine the role of neurotrophic factors in progression of diabetic retinopathy.
Methods: :
Twenty–three age and sex matched control, 40 non proliferative diabetic retinopathy (NPDR), and 29 proliferative diabetic retinopathy (PDR) patients were included. General physical examination was performed and blood sugar, HbA1C, renal and lipid profile of serum were determined. Serum and tear concentration of NGF were also determined with ELISA. Also, the correlations between the severity of the diabetes and concentration of NGF were evaluated.
Results: :
The serum concentration of NGF was 39.1±12.0 ng/ml in control, 45.2±11.2 ng/ml in NPDR patients and 95.1±18.6 ng/ml in PDR patients (p<0.001, ANOVA). The tear concentration of NGF was 1.2±1.1 ng/ml in control, 1.7±0.1 ng/ml in NPDR and 17.3±5.2 ng/ml in PDR (p<0.001, ANOVA). Serum and tear NGF level had statistically significant correlation with each other (r=0.713, p=0.002; pearson correlation coefficient). And the tear and serum concentration of NGF correlated well with severity of diabetic retinopathy, uncorrected visual acuity, insulin dose, HbA1C, and fasting blood sugar level in diabetic retinopathy patients.
Conclusions: :
Tear and serum NGF concentration was significantly elevated in PDR patients. Considering the significant correlation of the tear and serum NGF level with the progression of diabetic retinopathy, the tear and serum NGF would be considered as a candidate for a new marker of diabetic retinopathy progression.
Keywords: diabetes • cytokines/chemokines • cornea: tears/tear film/dry eye