Background: Optic nerve head drusen (ONHD) are considered the most common cause for pseudopapilloedema in children. We aimed to investigate and further characterize a new type of optic nerve head lesion on enhanced depth imaging optical coherence tomography (EDI-OCT) named peripapillary hyperreflective ovoid mass-like structures (PHOMS), and ONHD in asymptomatic children with pseudopapilloedema.
Methods: Retrospective cohort study including 64 eyes from 32 patients with pseudopapilloedema due to PHOMS and/or ONHD. Mean age was 9.0 ± 3.1 years. PHOMS and ONHD were identified and classified on EDI-OCT and infrared images. Ultrasound images were classified for the presence of hyperechogenic structures of the optic nerve head.
Results: On EDI-OCT, PHOMS were detected in 63 out of 64 eyes (98.4%). In 60 eyes (93.8%), small hyperreflective foci inside the PHOMS were present. In all cases, we identified a new ring sign visible on infrared images, corresponding clearly to the edge of the PHOMS as seen on EDI-OCT. On ultrasound, we describe a new feature of PHOMS appearing as small hyperechogenic structures without posterior shadowing. In 13 eyes (20.3%), ONHD were present on EDI-OCT and ultrasound.
Conclusion: This is the first study showing that PHOMS are the most common cause for pseudopapilloedema in children. PHOMS is a new entity of optic nerve head lesions. It might be a precursor of buried optic nerve head drusen, which can lead to visual field defects, haemorrhages and CNV. This study offers new tools to identify and follow-up these lesions early in childhood using EDI-OCT.