Abstract
Purpose :
To investigate structural and microvascular retinal changes in children with new-onset type 1 diabetes mellitus (T1D)
Methods :
Hospitalized Children with no longer than five-day new-onset T1D were consecutively enrolled in an observational study. All patients had been treated with intravenous fluids and insulin infusion at the time of the hospitalization. Healthy age-matched subjects served as controls. Mean peripapillary retinal nerve fibers layer (pRNFL) and single macular layers thicknesses were measured at optical coherence tomography (OCT). Peripapillary and macular perfusion were analyzed in the radial peripapillary capillary plexus (RPCP) and in the macular superficial vascular (SVP), intermediate (ICP) and deep retinal capillary (DCP) plexuses by means of OCT angiography (OCTA). The following OCTA parameters were measured: Vessel Area Density (VAD), Vessel Length Fraction (VLF) and Vessel Diameter Index (VDI). All analyzed parameters were correlated to the following metabolic parameters: blood pH, C-Peptide and HbA1c serum levels at the time of the hospital admission.
Results :
Fifty-two eyes of 26 T1D children and 64 eyes of 32 controls were studied. Mean age did not differ between T1D and healthy children (11.15 ± 2.9 years vs 12.19 ± 4.3 years, respectively, p =0.2771). Mean pRNFL and all single macular layers’ thicknesses were not significantly different, except for the outer retinal layer, that was thinner in the T1D group (p= 0.0018). Some OCTA parameters of the RPCP (VAD and VLF) and of the SVP (VAD and VDI) were significantly increased in T1D children compared to controls (p<0.005 for all). At the ICP and DCP level, all OCTA vascular parameters were significantly reduced in TD1 eyes versus controls (p<0.005 for all). OCTA macular parameters were mostly negatively correlated to C-Peptide level. Only VAD of the RPCP was positively correlated to blood pH and negatively to Hb1Ac level.
Conclusions :
Early retinal microvascular changes are detectable in children acutely treated for new-onset T1D as a consequence of insulin, as a vascular hormone, and fluid acute infusion. The retinal capillary flow redistribution we detected, with dilatation of the superficial plexuses and constriction of the deeper ones, may be the neurovascular coupling response to treatment. This "steal phenomenon" may be compromised in children with lower residual C-Peptide secretion level, a marker of residual pancreas beta cells function.
This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.