Author: Özge Yanık Odabaş (Turkey)
Co-authors: Emine Temel, Gökçen Özcan, Sibel Demirel, Figen Şermet, İrem Kar, Emin Özmert
To assess the choroidal alterations in diabetic patients with/without retinopathy and to evaluate the relationship of these alterations with the duration of disease and HbA1c level.
An observational comparative study
This study included 30 eyes of 30 patients with diabetic retinopathy (DR) (group 1), 30 eyes of 30 diabetic patients without DR (group 2), and 30 eyes of 30 healthy subjects (group 3). Patients were also grouped according to the duration of diabetes: long-term group (≥15 years, n=32) and short-term group (˂15 years, n=28). The choroidal thickness was measured at three points; subfoveal, 1500 μm nasal, and 1500 μm temporal to the fovea. The choroidal area, stromal area, luminal area (LA), and choroidal vascularity index (CVI) were measured with the binarization method.
The mean subfoveal, nasal, and temporal choroidal thicknesses were decreased in group 1 in comparison to controls (p˂0.001, p=0.035, and p=0.005, respectively). The mean LA in group 1 and group 2 were both significantly lower compared to group 3 (group 1 vs group 3, p=0.004; group 2 vs group 3, p=0.020). CVI was significantly lower in group 1 and group 2 than in controls (group 1 vs group 3, p=0.019; group 2 vs group 3, p=0.025). CVI was significantly lower in the long-duration group than in the short-duration group (p˂0.001). A moderate negative correlation was found between the duration of diabetes and CVI (r=-0.467, p˂0.001). Additionally, a moderate negative correlation was found between HbA1c level and CVI (r=-0.425, p˂0.000). Partial correlation analysis revealed a significant negative correlation between HbA1c and CVI (r=-0.312, p=0.016) when the effect of duration of diabetes was controlled. Also, there was still a significant negative correlation between the duration of diabetes and CVI (r=-0.352, p=0.006) when the effect of HbA1c was controlled.
Choroidal structure and CVI may alter even in the absence of clinically confirmed retinopathy and these alterations are related to the duration of diabetes and HbA1c level.