ABSTRACT
Purpose:
To evaluate the relationship between subfoveal choroidal thickness and plasma asymmetrical dimethylarginine level and the severity of diabetic retinopathy in patients with type 2 diabetes mellitus.
Methods:
A total of 68 cases, including 15 patients without diabetic retinopathy, 17 patients with nonproliferative diabetic retinopathy, 16 patients with type 2 diabetes mellitus and proliferative diabetic retinopathy, and 20 healthy patients (control group), were enrolled in this study. Subfoveal choroidal thickness was measured manually using the enhanced depth imaging optical coherence tomography scanning program, and plasma asymmetrical dimethylarginine level was measured using a commercial micro enzyme-linked immunosorbent assay kit.
Results:
The subfoveal choroidal thickness values and plasma asymmetrical dimethylarginine levels were significantly different between the four groups (p<0.001 and p<0.001). The subfoveal choroidal thickness values were significantly lower in the proliferative diabetic retinopathy group than in the other three groups (no diabetic retinopathy, nonproliferative diabetic retinopathy, and control groups; p<0.001, p=0.045, and p<0.001, respectively). The plasma asymmetrical dimethylarginine levels were significantly higher in the proliferative diabetic retinopathy group than in the other three groups (p<0.001, p<0.04, and p<0.001, respectively). In addition, a significant negative correlation was also found between plasma asymmetrical dimethylarginine level and subfoveal choroidal thickness (p<0.001, r=-0.479).
Conclusion:
Asymmetrical dimethylarginine is an important marker of endothelial dysfunction and endogenous endothelial nitric oxide synthase inhibitor. The severity of diabetic retinopathy was related to increased plasma asymmetrical dimethylarginine level and reduced subfoveal choroidal thickness in type 2 diabetic patients with diabetic retinopathy.
Keywords:
Diabetes Mellitus, Type 2; Diabetic Retinopathy; Choroid; Fovea Centralis; Nitric Oxide; Arginine; Tomography, Optical Coherence