Prevalence of peripapillary hyperreflective ovoid mass-like structures (PHOMS) in suspected papilloedema in children

Suspected papilloedema is a frequent cause of referral to paediatric ophthalmology clinics. Recent publications have described a new finding called peripapillary hyperreflective ovoid mass-like structures (PHOMS) that may cause pseudopapilloedema. We evaluated the optical coherence tomography (OCT) scans of the optic nerve in all children referred with suspected papilloedema for the presence of PHOMS and report their frequency.

The optic nerve OCT scans from children seen in our suspected papilloedema virtual clinic between August 2016 and March 2021 were evaluated for the presence of PHOMS by three assessors. A Fleiss' kappa statistic was calculated to test the agreement between the assessors for the presence of PHOMS.

A total of 220 scans from 110 patients were evaluated during the study period. The mean patient age was 11.2 SD ± 3.4, (range 4.1-16.8). PHOMS were identified in at least one eye in 74 (67.3%) patients. Of these, 42 (56.8%) patients had bilateral and 32 (43.2%) had unilateral PHOMS. Excellent agreement between assessors for the presence of PHOMS (Fleiss' kappa 0.9865) was observed. PHOMS were common in association with other identified causes of pseudopapilloedema (81.25%) but were also common in papilloedema (66.67%) and otherwise normal discs (55.36%).

Misdiagnosis of papilloedema can lead to unnecessary and invasive tests. PHOMS are found frequently within the paediatric population referred for suspected disc swelling. They appear to be an independent cause of pseudopapilloedema but are often seen in conjunction with true papilloedema and other causes of pseudopapilloedema.