Choroidal thickness and choroidal vascularity index changes in children with type 1 diabetes mellitus without retinopathy

Background: Diabetic retinopathy is one of the most important causes of low vision in the working age group. Retinopathy findings start earlier and have a worse prognosis in type 1 DM. The aim of the this study was to compare the choroidal thickness (CT) and choroidal vascular index (CVI) values of type 1 diabetes mellitus (DM) patients without retinopathy findings in pediatric patients and healthy children.

Methods: The study included 89 children, including 43 type 1 DM patients and 46 healthy controls. The age, gender, duration of DM, hemoglobin A1c (HbA1c), refractive error, intraocular pressure (IOP) and axial length (AL) of the participants were noted. CT measurements were performed subfoveally, 1000 µm from the fovea in the nasal and temporal quadrants. The total choroidal area (TCA), luminal area (LA) and stromal area (SA) were calculated using the binarization method using the image J program. The CVI was determined by dividing the luminal area by the total choroidal area.

Results: There were no significant differences between the participants in terms of age, gender, spherical equivalent, IOP, and AL. There was no significant difference between the groups in terms of CT. TCA, LA and SA values were significantly higher in the Type 1 DM group (p=0.034, p=0.036, p=0.037, respectively). There was no significant difference between the groups in terms of the CVI.

Conclusions: The TCA, LA, and SA values were significantly higher in the type 1 DM group. LA/SA and CVI values were lower in the type 1 DM group, although not significantly. There was a negative correlation between the duration of DM and LA/SA as well as CVI. This suggests that vascular reduction starts in the early stages.