Neutrophil-to-Lymphocyte Ratio as a Quick and Reliable Predictive Marker to Diagnose the Severity of Diabetic Retinopathy

Introduction: Diabetic retinopathy (DR) is the most common complication and cause of visual impairment in diabetes patients. The pathogenesis is not fully understood, but several studies have suggested that inflammation plays an important role. The neutrophil-to-lymphocyte ratio (NLR) was defined as a novel potential marker to determine inflammation. We aimed to evaluate the relationship between DR and inflammation by using NLR. Patients and Methods: The study was included 58 patients diagnosed with type 2 diabetes mellitus. Twenty-four of them had DR. The control group was composed of 52 age- and sex-matched healthy subjects. Retinopathy was graded using the International Clinical Diabetic Retinopathy Disease Severity Scale. Results: NLR values of the diabetes patients were significantly higher than those of the healthy control group (P<0.001), and NLR levels of the patients with DR were higher than those of the patients without DR (P<0.001). In addition, NLR values were correlated with the presence of DR and DR grades (r=0.466, P<0.001; and r=0.630, P<0.001, respectively). Conclusions: According to our knowledge, this is the first study investigating the relationship between NLR, which is an inflammatory marker, and DR and its severity. Our results suggest that while evaluating diabetes patients in terms of DR, higher NLR values may be a remarkable marker.