Peripapillary hyperreflective ovoid mass-like structures (PHOMS) have been recently described on optical coherence tomography (OCT) scans of the optic nerve. We aim to determine if there is a causal relationship between OCT measurements of the optic disc area (DA), scleral canal diameter (SCD) and refractive error (spherical equivalent, SE) on the presence of PHOMS. Retrospective analysis of OCT scans which were graded for the presence or absence of PHOMS in children with suspected papilledema was undertaken. Data on disc area, DA (mm2) and scleral canal diameter, SCD (µm) were obtained from OCT scans. Statistical analysis was performed on two subgroups: unilateral PHOMS vs contralateral control; all eyes with PHOMS vs all eyes without PHOMS (controls). Logistic regression analysis was performed. In unilateral PHOMS (n = 32), there was a non-significant tendency towards a larger DA and SCD in the eye with PHOMS (3.33mm2, 1701 µm) compared to the contralateral eye in the same patient (2.83mm2, 1556 µm). Wider analysis of all eyes with PHOMS (n = 116) versus all eyes without (n = 104) showed there was a significant difference between the DA (3.38mm2 versus 2.65mm2 p = <.0001) and SCD (1763 µm versus 1571 µm, p = <.0001). Logistic regression showed that SCD made a significant contribution to predicting the presence of PHOMS (OR 1.0042, p = 0.0017). PHOMS are frequently seen in pseudopapilledema. It would be useful to understand their pathophysiology as an accurate diagnosis in the context of the asymptomatic paediatric population is crucial. We report that a wider scleral canal diameter was significantly associated with the presence of PHOMS.