Purpose: To determine early ocular changes in children and adolescents with type 1 diabetes mellitus without retinopathy (T1DM-woR) by optical biometry (OB) and optical coherence tomography (OCT).
Methods: Seventy children and adolescents with T1DM-woR (patient group) and 72 healthy children and adolescents (control group) were included. Demographic data, anthropometric measurements and anterior-posterior segment parameters of groups were compared. Correlations between ocular parameters and glycosylated hemoglobin (HbA1c) level, age at diabetes mellitus (DM) onset and DM duration were evaluated.
Results: Patients with T1DM-woR had significantly shallower anterior chambers (3.50 ± 0.12 vs 3.67 ± 0.11 mm, p < 0.001), thicker lenses (3.65 ± 0.15 vs 3.37 ± 0.14 mm, p < 0.001), thinner central retinal nerve fiber layer (RNFL) thicknesses (95.3 ± 6.7 vs 104.8 ± 6.2 µm, p < 0.001) and thinner central choroidal thicknesses (292.8 ± 23.6 vs 325.1 ± 24.7 µm, p < 0.001) than healthy individuals. As the lens thickness (LT) increased, anterior chamber depth (ACD) decreased in patient group (r = - 0.368, p = 0.040). Other anterior (central corneal thickness, axial length, keratometry, spherical equivalent) and posterior (superior temporal, superior nasal, nasal, inferior nasal, inferior temporal, temporal RNFL thicknesses; nasal and temporal choroidal thicknesses; central part's and inner-outer macular segments' thickness and volume measurements) segment parameters of groups were similar (p > 0.05). In patient group, as HbA1c level increased, central RNFL and choroidal thicknesses decreased (r = - 0.639, p < 0.001; r = - 0.486, p = 0.010, respectively).
Conclusions: In patients with T1DM, we found that LT increased, and ACD, central RNFL and choroidal thicknesses decreased by OB and OCT before visible findings appeared in routine ophthalmological examination. Determination of early changes is warning to physician and patient in order to prevent more serious damages occurring later.
Keywords: Children; Optical biometry; Optical coherence tomography; Type 1 diabetes mellitus.