Choroidal Changes of Long-Term Type 1 Diabetic Patients without Retinopathy

The aim of the study is to assess choroidal thickness (CT) and choroidal volume (CV) in 90 type 1 diabetes mellitus (DM1) patients with no diabetic retinopathy (DR) and 60 control eyes using spectral domain optical coherence tomography (SD-OCT) and swept source (SS)-OCT in the areas of the Early Treatment Diabetic Retinopathy Study (ETDRS). Mean ages were 42.93 ± 13.62 and 41.52 ± 13.05 years in the diabetic and control groups, respectively. Significant differences were obtained between both groups with Spectralis SD-OCT in all ETDRS areas and in the total CV, excluding the temporal perifoveal one. With Triton SS-OCT, statistically significant differences were obtained in the subfoveal CT and in the vertical areas. CT showed the same tendency with both OCTs, with greater CT and CV in the DM1 group than the mean values of the control group. To assess the influence of DM1 evolution in the CT modifications, DM1 patients were divided into Group 1, with less than 24 years of diagnosis, and Group 2, with ≥24 years of DM1 evolution. Using both OCTs, seven of the nine ETDRS areas and the CV had lower values in Group 2. CT and CV measured by OCT were higher in DM1 without DR. There is a choroidal thinning related to disease evolution in DM1. In patients with DM evolution greater than 24 years, the CT is statistically lower than in patients with less evolution of the disease.