Diabetic ketoacidosis (DKA) is a complication of type 1, or "insulin-dependent," diabetes (T1DM) and is defined by a high blood glucose level (over 200 mg/dL) coupled with severe acidosis. In this state the body breaks down fat tissue for adequate energy production. This results in ketone and acid production, and ultimately DKA. Cerebral edema (CE), or "brain swelling," can also occur with severe DKA. Current evaluation for DKA-related CE necessitates a high index of clinical suspicion and often times such patients receive advanced brain imaging such as computed tomography (CT) scans.Ocular sonography (ultrasound) is an alternative imaging technique that can provide immediate diagnostic capability at the bedside and minimize radiation exposure. This technique has been used to rapidly and accurately detect increased brain swelling through measurement of the optic nerve sheath diameter (ONSD) in a number of clinical situations including pediatric head trauma, hydrocephalus and ventriculoperitoneal shunt malfunctions, and altitude sickness in adults. Investigators plan to conduct a prospective study including children aged 7-18 years. 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.