The effect of coexisting autoimmune thyroiditis in children with Type 1 diabetes on optical coherence tomography...

To assess the influence of thyroid hormones status and coexistence of autoimmune thyroiditis on optical coherence tomography (OCT) and optical coherence tomography angiography (OCTA) results in children with Type 1 diabetes (T1D).

In the prospective, observational study (n = 175) we analyzed the impact of thyroid hormones on OCT results and the differences between the matched groups of children with T1D (n = 84; age = 13.14 ± 3.6; diabetes duration = 5.99 ± 3.3 years) and the children with T1D and autoimmune thyroiditis (AT) (n = 20; age = 13.94 ± 3.6; diabetes duration = 6.7 ± 4 years). We analyzed the following parameters: fovea avascular zone (FAZ), foveal thickness (FT), parafoveal thickness (PFT), ganglion cell complex (GCC), loss volume (global-GLV, focal-FLV), capillary vessel density: superficial (whole-wsVD, foveal-fsVD, parafoveal-psVD), and deep (whole-wdVD, foveal-fdVD, parafoveal-pdVD. The differences between the groups were tested by the unpaired t-Student test, Mann-Whitney U test as appropriate, whereas p level .05 was recognized as significant.

We detected the significant correlations between thyroid-stimulating hormone (TSH) level and PFT (r = -0.14; p < .05), psVD (r = -0.18; p < .005). The level of free triiodothyronine (FT3) was correlated with psVD (r = -0.14; p < .05). We found significant correlation between free thyroxine (FT4) and fsVD (r = -0.17; p < .01). In the studied T1D and AT groups there were statistical differences in FT (p < .005), PFT (p < .03), GCC (p < .01), and GLV (p < .003). We did not observe any significant differences in the FAZ area between the groups.

In our patients the co-occurrence of T1D and AT worsens the status of retinal parameters. Further studies are necessary to observe these relations and their potential influence on the occurrence of diabetic retinopathy (DR).