Evaluation of the coroidal vascular index and ocular parameters in patients diagnosed with TYPE 1 diabetes and comparison with healthy volunteers

Aim: To compare choroidal vascular index (Cvi) and ocular parameters between patients with Type 1 Diabetes Mellitus (T1DM) and healthy control group and evaluation of the relationship between these parameters and laboratory results. Materials and Methods: A total of 104 children, including 50 patients with T1DM diagnosis and 54 healthy controls, who were admitted to Van Yüzüncü Yıl University ophthalmology and pediatric endocrinology and metabolism diseases clinics between July and October 2020, were included in our study. Demographic findings (age, gender, duration of diabetes, laboratory parameters) of the patients were recorded. Ocular anterior segment of the patients was evaluated by specular microscopy (SM) and anterior segment spectral-domain optical coherence tomography (SD-OCT). The posterior segment was evaluated by EDI-OCT and retinal layers were measured by segmentation analysis. Choroidal vascular index (Cvi) was calculated from the pictures obtained by EDI-OCT. Results: The age and gender distribution of the T1DM patient and the healthy control group were similar (13.8 ± 2.48 years versus 13.66 ± 2.22 years)(p=0.738). There was no significant difference between T1DM and control group in terms of total length (TL), endothelial cell density (ECD), central corneal thickness findings (p> 0.05). It was found that corneal endothelial hexagonality value of patients with T1DM diagnosis decreased compared to the control group (%55.38 ± 9.09 versus %51.04 ± 7.50) (p=0.011). The mean ganglion volume of T1DM patients was higher than the control group (p = 0.04). In addition, the Kvi value of the patients with a diagnosis of T1DM was found to be lower than the control group (p=0.013). There was a negative correlation between glycated hemoglobin (HbA1c) and ECD (r=-0.284, p=0.050). Positive correlation was found between HbA1c and average cell size (AVG) (r=0.285, p=0.050). It was found that there was a positive correlation between retinal nerve fiber layer (RNFL) and duration of DM disease, and negative correlations with HbA1c, C-reactive protein (CRP) and microalbuminuria levels (p<0.05). In linear regression analysis performed between specular microscopy and OCT findings, which showed a significant correlation with T1DM duration and HbA1c levels, no significant and explanatory findings were found. Conclusion: While the hexagonality ratio and Kvi value decreased in patients with T1DM compared to the control group, it was observed that there was a negative correlation between HbA1C and RNFL in T1DM patients. Therefore, it may be recommended to use SM and OCT in the detection of early ocular changes in children with T1DM who do not have DR on routine ophthalmologic examinations.