Identification of Optic Nerve Swelling Using Point-of-Care Ocular Ultrasound in Children

The aim of this study was to determine the feasibility and accuracy of point-of-care (POC) ocular ultrasound (US) when performed by a pediatric emergency medicine (PEM) physician to detect optic nerve abnormalities concerning for swelling, as compared with the fundus examination performed by an ophthalmologist.

This was a single-center, prospective cohort pilot study of children aged 12 months to 18 years who required optic disc evaluation by an ophthalmologist. Eligible subjects were enrolled from the emergency department, inpatient wards, and neuro-ophthalmology outpatient clinic of an urban, tertiary care children's hospital. Point-of-care ocular US, specifically assessing optic nerve sheath diameter and optic disc elevation, was performed. Findings on US were compared with findings identified by an ophthalmologist on dilated fundus examination.

Seventy-six subjects were enrolled; 20 (26%) of 76 had findings concerning for optic nerve swelling diagnosed by an ophthalmologist on fundus examination. Using a sonographic definition for optic nerve swelling of optic nerve sheath diameter greater than 4.5 mm or the presence of optic disc elevation, the sensitivity and specificity were 90% and 55%, respectively. The success rate of POC ocular US was 100%, and the mean time to completion was 8 minutes. For emergency department subjects in whom direct fundus examination was attempted, the PEM physician could visualize the optic disc and assess for swelling in only 40% (14/35) of examinations.

The results of our study suggest that POC ocular US performed by PEM physicians was feasible and determined to be sensitive but nonspecific in the detection of optic nerve swelling. Additional larger studies may determine generalizability to other nonophthalmologist physicians performing POC ocular US.