Changes in ocular pulse amplitude and posterior ocular structure parameters in type 1 diabetic children without diabetic retinopathy

Background: It is important to determine changes in posterior ocular structures in the early period before retinopathy develops in pediatric patients with type 1 diabetes mellitus (DM). Objective: To evaluate inner plexiform layer (IPL), ganglion cell layer (GCL), and retinal nerve fiber layer (RNFL) thicknesses, as well as the relationship between choroidal thickness (CT) and ocular pulse amplitude (OPA) in type 1 diabetic children without diabetic retinopathy (DR). Design: A prospective observational study. Methods: Group 1 (n = 44) consisted of pediatric patients with type 1 DM without DR, and Group 2 (n = 65) of pediatric control subjects. Both intraocular pressure (IOP) and OPA were measured using a dynamic contour tonometer. CT, IPL, GCL, and RNFL were all measured using spectral domain optical coherence tomography (OCT). Results: The mean IOP and OPA values were 16.67 +/- 2.34 and 1.85 +/- 0.34, respectively, in group 1, and 15.14 +/- 2.17 and 1.65 +/- 0.25 in Group 2 (p = 0.001 for both). The mean subfoveal CT value was 294.30 +/- 67.61 mu m in group 1 and 394.42 +/- 69.65 mu m in Group 2 (p < 0.001). The mean GCL and RNFL values were 1.09 +/- 0.11 and 96.46 +/- 11.69, respectively, in group 1, and 1.14 +/- 0.09 and 101.73 +/- 9.33 in Group 2 (p = 0.005 and p = 0.008, respectively). Conclusions: IOP and OPA values were higher, and CT, GCL, and RNFL values were lower in children with type 1 DM during the early stages than in the healthy control group. These findings suggest that CT may be a marker of retinal involvement in children with type 1 DM without DR.