Purpose <p>Diagnosing pseudo-papilloedema (PPO) in children presents challenges and may lead to invasive investigations, with optic disc drusen (ODD) being the most common etiology. Other specific causes include tilted disc, optic neuritis, tumoral infiltration, vitreo-papillary traction, and Leber hereditary optic neuropathy. Peripapillary hyperreflective ovoid mass-like structures (PHOMS) are frequently observed in these cases, yet their pathophysiology remains unexplained, particularly their relation to ODD, which is still debated. Here, we explored whether patients with PPO associated with ODD, or seemingly isolated cases, could exhibit PHOMS without ODD or ODD without PHOMS, and how this might affect retinal nerve fiber layer (RNFL) thickness.</p> Methods <p>In this two-centre retrospective observational study, we included patients under 20&#xa0;years old presenting with PPO without specific causes, with a subgroup followed for at least one year. Enhanced depth imaging optical coherence tomography was used to assess the presence and evolution of PHOMS and ODD, as well as RNFL thickness.</p> Results <p>We included twenty-seven patients, with thirteen followed for at least one year. In all eyes, we observed concomitant PHOMS and either deep or superficial ODD. RNFL thickness was increased in patients with deep ODD and decreased in those with superficial ODD, which was observed during follow-up.</p> Conclusions <p>ODD and PHOMS are concomitant features present in patients with PPO. PHOMS sometimes serve as indicators, as buried ODD are challenging to identify in young children. However, ODD tend to become more superficial over time, while RNFL thickness decreases.</p> Key Messages <Emphasis Type="BoldItalic">What is known</Emphasis> <p><UnorderedList Mark="Bullet"> <ItemContent> <p>Diagnosing the cause of pseudo-papilledema (PPO) in children is challenging and often requires invasive investigations.</p> </ItemContent> <ItemContent> <p>The relationship between optic disc drusen (ODD) and peripapillary hyperreflective ovoid mass-like structures (PHOMS) in the context of PPO remains poorly understood.</p> </ItemContent> </UnorderedList></p> <Emphasis Type="BoldItalic">What is new</Emphasis> <p><UnorderedList Mark="Bullet"> <ItemContent> <p>PHOMS and ODD seem to consistently co-occur in pediatric PPO cases where no other specific causes are identified.</p> </ItemContent> <ItemContent> <p>Retinal nerve fiber layer (RNFL) thickness increases in the presence of deep ODD and decreases as ODD become more superficial with age.</p> </ItemContent> <ItemContent> <p>RNFL thinning progresses in correlation with the patient’s age.</p> </ItemContent> </UnorderedList></p>