Peripapillary Hyperreflective Ovoid Mass-like Structures (PHOMS)
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Peripapillary Hyperreflective Ovoid Mass-like Structures (PHOMS)

  • Definition: PHOMS are oval, hyperreflective structures visualized on OCT B-scans around the optic nerve head, considered a marker of axoplasmic stasis.

  • Prevalence: Found in 7% of eyes across a broad spectrum of neurologic disorders; higher prevalence (up to 44% in intracranial hypertension [IH]) compared to 3-4% in healthy controls.

  • Associated Conditions:

    • Neuroimmunologic diseases (NID) (e.g., multiple sclerosis, neuromyelitis optica spectrum disorders): 4% prevalence.

    • Epilepsy: 7% prevalence.

    • Movement disorders (MD): 6% prevalence.

    • Intracranial hypertension (IH): 44% prevalence, strongly associated with increased intracranial pressure (ICP).

    • Inborn errors of metabolism (IEM): 9% prevalence.

  • Localization: Predominantly nasal (>65%), with minimal temporal involvement (5-10%); exclusively temporal PHOMS reported in Leber’s hereditary optic neuropathy.

  • Volume:

    • Median PHOMS volume: 0.06 mm³.

    • Significantly larger in IH (median 0.23 mm³) compared to NID (0.03 mm³), epilepsy (0.05 mm³), and MD (0.02 mm³).

    • Larger volumes in IH suggest a link to elevated ICP.

  • Intensity: Comparable to optic nerve intensity (0.99 ± 0.19), lower than retinal layers, higher than outer nuclear layer; no significant intensity differences across cohorts.

  • Correlations:

    • Positive correlation with peripapillary retinal nerve fiber layer (pRNFL) thickness (global, nasal-inferior, temporal-inferior, temporal segments).

    • Positive correlation with Bruch membrane opening minimum rim width (BMO MRW), likely due to peripapillary retinal layer deflection.

    • Negative correlation with age (excluding IH patients), suggesting larger PHOMS in younger patients.

    • No correlation with body mass index (BMI) or BMO surface area.

  • Pathophysiology Hypotheses:

    • Axoplasmic stasis (supported by histopathologic findings in papilledema).

    • Impairment of glymphatic drainage or translaminar pressure gradient.

  • Diagnostic Importance: PHOMS are a non-specific marker but more frequent in neurologic disorders; must differentiate from optic disc drusen or papilledema.

  • Clinical Pearl: Larger PHOMS volumes in IH are a key exam question; consider PHOMS in OCT interpretation for neurologic patients to avoid misdiagnosis.

  • Research Implications: PHOMS presence impacts OCT parameters (e.g., pRNFL, BMO MRW), requiring consideration in non-ophthalmic neurologic studies.

  • Limitations: Cross-sectional study design and cohort heterogeneity (age, disease duration) limit conclusions on causality or disease-specific mechanisms.

Citation

Gemert JA, Christmann T, Kaufmann E, et al. Characterization of Peripapillary Hyperreflective Ovoid Mass-like Structures in a Broad Spectrum of Neurologic Disorders. Ophthalmology. 2025;132(5):590-597. https://doi.org/10.1016/j.ophtha.2024.12.013