Retinal Nerve Fiber Layer and Ganglion Cell Complex Thicknesses Are Reduced in Children With Type 1 Diabetes With No Evidence of Vascular Retinopathy

Purpose: To determine whether type 1 diabetes (T1DM) in children with a mean age of 12.21 ± 3.04 years affects the retinal nerve fiber layer (RNFL) and ganglion cell complex (GCC) when compared to age- and sex-matched healthy children. Methods: Forty-six children with T1DM with no diabetic retinopathy (DR) and 50 normal age- and sex-matched controls underwent full clinical ophthalmic and spectral-domain optical coherence tomography (SD-OCT) examination. Using RTVue Fourier-Domain OCT (version 6.11.0.12) average, superior, and inferior RNFL and GCC thicknesses (in μm) were measured. Mean values of patients and the control group were compared. Results: In children with T1DM with no DR, the mean average RNFL thickness was 110.9 μm ± 10.46, and the mean GCC thickness was 95.59 μm ± 5.13; both were significantly thinner than the control group (115.62 μm and 99.30 μm, respectively). The retinal nerve fiber layer and GCC thickness showed no correlation to either age of onset, duration of the disease, or glycosylated hemoglobin (HbA1c). A positive correlation was found between the daily insulin dose and the average RNFL thickness (r = 0.378, P = 0.01). The average GCC in children with dyslipidemia was thinner than those with normal lipid profile (91.29 ± 6.46 μm, 97.11 ± 3.59 μm, respectively) with a P value of 0.011. Conclusions: Thinning of the RNFL and GCC in children with T1DM with no DR compared to healthy controls suggests that neurodegenerative changes occur in the absence of vascular changes. It also shows that neurodegeneration is not related to either disease duration, onset, or control.