Ultrasonography, OCT and OCT-angiography in the diagnostic workup of children with suspected papilledema

Abstract

Purpose : Optic nerve sheath dilatation (ONSD) on ocular ultrasound (US) is considered a sensitive and specific indicator of raised intracranial pressure (ICP). Anterior bowing of Bruch membrane (AB-BM) and increase in retinal nerve fibre layer thickness (RNFLT) in superonasal, nasal or temporal sector (SN, N, T) on optical coherence tomography (OCT) may be of similar diagnostic value. OCT-angiography (OCT-A) has not been evaluated in this context. This retrospective observational study explores diagnostic accuracy of US, OCT and OCT-A in children referred for suspected optic nerve head swelling.

Methods : 61 cases assessed over a seven-month period in 2016 at a single centre in London, UK; 26 girls (43%); median age 10.9 years (interquartile range 7.9 to 13). A masked observer collated imaging and clinical data. We calculated specificity and sensitivity for each test; for RNFLT we used published cutoffs as indicators for true optic disc edema: SN: 124, N: 78/74.5, T: 101.5um.

Results : Of 61 cases, three had intracranial pathology: intraventricular tumour (IVT), hypophosphataemic rickets with neuro-imaging signs of chronic raised ICP, and relapse of acute lymphoblastic leukaemia (ALL). All three had symptoms or significant history.
At initial presentation, only one of these three cases had ONSD on ultrasound (sensitivity 33%, specificity 100%). AB-BM had similar accuracy (sensitivity 33%, specificity 96.6%). Increased RNFLT (Fig 1) had higher sensitivity (66.7%), but lower specificity (42.1 to 86%). In all three cases, OCT-A delivered unclear images and could not perform automated measurements of peripapillary vessel density.

Conclusions : In children, ocular ultrasound and OCT alone are not sufficiently accurate to discard the possibility of intracranial pathology. Previous studies have reported that 36.4 to 48% of children with brain tumors or idiopathic intracranial hypertension may not develop papilledema. History and basic neurological assessment remain critical in the diagnostic workup of children with suspected intracranial pathology.

This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.

 

Fig 1. RNFLT (um) superonasal, nasal and temporal sector (right eyes). Case 23 (ALL) had markedly increased RNFLT in the superonasal and nasal sectors. Case 31 (IVT) had marked increase in RFNLT in the temporal sector only. Case 29 (rickets) had no RNFLT increase. Green lines: previously published thresholds for “true papilledema”.