Investigators plan to conduct a prospective study including children aged 7-18 years that present to the Children's Endocrinology Clinic and Children's Emergency Department. The objective of this study is to assess the utility of sonographic measurements of the ONSD as a tool for identification of DKA-related CE. Specifically, the primary aim of this study is to measure and compare the mean ONSD in children with well-controlled T1DM to those presenting to the Emergency Department (ED) with DKA and to those presenting to the ED with T1DM and hyperglycemia without criteria for DKA. Investigators hypothesize that the mean ONSD measurement is smaller in children with well-controlled T1DM compared to children presenting to the ED with DKA and compared to children with T1DM and hyperglycemia without criteria for DKA. Secondarily, investigators aim to compare the mean ONSD in children presenting to the ED with DKA to those presenting to the ED with T1DM and hyperglycemia without criteria for DKA. The study team hypothesizes that the mean ONSD measurement is larger in children presenting to the ED with DKA compared children presenting with T1DM and hyperglycemia without criteria for DKA.