Peripapillary hyperreflective ovoid mass-like structures (PHOMS) are now thought to be distinct from optic disc drusen, and the donut-shaped forms have been found in the setting of pseudopapilledema, tilted optic discs, or other disorders. Yet, a large study published in the American Journal of Ophthalmology finds PHOMS is somewhat common in children, even those without optic disc drusen or edema, suggesting that the finding does not necessarily imply pathology.
The Copenhagen Child Cohort 2000 Eye Study included 1314 pediatric patients (all ages11 to 12 years) who met criteria. All patients were examined using visual acuity, axial length, enhanced depth imaging (EDI) with spectral-domain optical coherence tomography (SD-OCT) and other tests. PHOMS was present in 8.9% of patients, in at least 1 eye.
Bilateral incidence accounted for 73 of the 117 case of PHOMS. No significant differences emerged between children with or without PHOMS, including gestational age, birth weight, sex, or maternal smoking. However, the median spherical equivalent (SE) refraction of those with PHOMS was -0.125 D (IQR 0.75), compared with individuals without, 0.00 D (IQR 0.625); a significant difference (P <.001).
Lesion sizes varied widely; from small 30° partial donut-shaped PHOMS, to a large structure of almost 360° — on average, the lesion covered 25% of the circumference. Considering 12 potential peripapillary regions, PHOMS most often appeared in nasosuperior (89%), nasal (74%), and superonasal (57%) sectors. No lesions occurred solely temporally, thus researchers speculate PHOMS only extends to this area as it expands to a fully formed ring.
Of participants with PHOMS, 60 (51.3%) also had an ONH tilt — including 7 with prelaminar hyperreflective lines, as well — but 43 (37.0%) had neither. Only 14.5% of children without PHOMS exhibited ONH tilt (P <.001). In fact, ONH tilt raised PHOMS risk (P <.001), and each 1° increase in tilt augmented risk (P =.002). Risk for prelaminar hyperreflective lines was associated with maternal smoking (P =.02) and greater birth weight per 100 grams (P =.01). Also, of children with PHOMS and prelaminar hyperreflective lines, 71.4% had lowest quartile scleral canal diameter, vs those with PHOMS only, with 30.2% presenting such a small diameter.
PHOMS may be a sign of axoplasmic stasis. Since no PHOMS appeared temporally isolated; nasal and superior peripapillary areas appear susceptible to axon fiber herniation away from the optic disc, over Bruch’s membrane opening. Prior research has revealed that in children with myopia and tilted-disc PHOMS, myopia and optic tilt angle were correlated, as well as that patients with PHOMS were highly myopic compared with control individuals.
“The odds ratios of myopic eyes having PHOMS reveal that not only is myopia a risk factor for having PHOMS, but increasing myopia causes exponentially increasing risk of having PHOMS, likely through the severity of axial elongation and disc tilt,” the study authors explain.
The researchers considered refraction a continuous variable rather than a categorical one, a limitation of this study. A strength involves being the first analysis of PHOMS prevalence in a population-based sample of children.
Behrens CM, Malmqvist L, Jørgensen M, et al. Peripapillary hyperreflective ovoid mass-like structures (phoms) in children: the copenhagen child cohort 2000 eye study. Am J Ophthalmol. Published online on Sept. XX, 2022. doi: 10.1016/j.ajo.2022.09.003