Associations between individual retinal layer thicknesses and diabetic peripheral neuropathy using retinal layer segmentation analysis

Abstract

PurposeTo evaluate clinical correlations between the thicknesses of individual retinal layers in the foveal area of diabetic patients and the presence of diabetic peripheral neuropathy (DPN).MethodsThis retrospective, observational cross‐sectional study enrolled a total of 120 eyes from 120 patients. The eyes were divided into three groups: normal controls (n = 42 eyes), patients with diabetes mellitus (DM)(n = 42 eyes) but no DPN, and DM patients with DPN (n = 36 eyes). The primary outcome measures were the thickness of all retinal layers in the central 1 mm zone measured by using the segmentation analysis of spectral domain optical coherence tomography (SD‐OCT). Correlations between the thicknesses of the individual retinal layers and the presence of DPN were also analyzed. Logistic regression analyses were used to determine which change of layer thickness had the most significant association with the presence of DPN.ResultsThe mean thicknesses and the ratios of retinal nerve fiber layers (RNFLs) to total retina thicknesses in the DPN group were 10.77 ± 1.79 μm and 4.10 ± 0.55 percent (%), significantly lower than those in normal controls and the DM with no DPN group (p = 0.014 and p = 0.001, respectively). Logistic regression analyses also showed the decrease in thicknesses of the RNFLs and the INL are significant factors for predicting a higher risk for DPN development (odds ratio = 7.407 and 1.757; p < 0.001 and p = 0.001, respectively).ConclusionsA decrease in the RNFL and the INL thickness was significantly associated with presence of DPN. Using SD‐OCT segmentation method, these structural changes could be used as a potential biomarker for early detection of DPN.