# Peripapillary hyperreflective ovoid mass-like structure in arteritic versus nonarteritic anterior ischemic optic neuropathy

## TL;DR

A specific eye imaging feature called PHOMS was found in both types of ischemic optic neuropathy, suggesting it may be linked to the ischemic injury itself rather than the cause of the disease.

## Contribution

This study is the first to describe the occurrence of PHOMS in arteritic anterior ischemic optic neuropathy and compare its prevalence between AION subtypes.

## Key findings

- PHOMS was observed in 36.4% of A-AION cases and 18.2% of NA-AION cases.
- No significant differences in visual acuity or most retinal layer volumes were found between A-AION and NA-AION.
- Mean peripapillary retinal nerve fiber layer thickness was larger in A-AION compared to NA-AION.

## Abstract

A peripapillary hyperreflective ovoid mass-like structure (PHOMS) is an optical coherence tomography (OCT) specific finding associated with axoplasmic stasis in various optic neuropathies. Its occurrence in arteritic anterior ischemic optic neuropathy (A-AION) has not previously been described, and its prevalence and structural implications across AION subtypes remain incompletely understood.

In this exploratory retrospective, age-matched study, patients with A-AION and nonarteritic AION (NA-AION) enrolled in two prior prospective studies between March 2021 and August 2024 were included. All eyes had undergone high-resolution spectral-domain OCT imaging of the optic nerve head as well as visual acuity assessment on first visit of diagnosis. PHOMS was identified according to Optic Disc Drusen Studies (ODDS) Consortium criteria.

Twenty-two patients (22 eyes) were included, with 11 eyes in each AION subtype. PHOMS was observed in both A-AION and NA-AION. PHOMS was identified in 4 of 11 eyes (36.4%) with A-AION compared with 2 of 11 eyes (18.2%) with NA-AION. The estimated odds ratio for PHOMS presence in A-AION compared with NA-AION was 2.57 (95% CI, 0.36–18.33; p = 0.635). Bruch’s membrane opening diameter was similar between groups (A-AION: 1546.78 ± 134.14 μm; NA-AION: 1507.27 ± 133.95 μm), while mean peripapillary retinal nerve fiber layer thickness was larger in A-AION than in NA-AION. No differences were observed in macular ganglion cell layer volume, other retinal layer volumes, total retinal volume, or visual acuity between subtypes.

The observation of PHOMS across ischemic optic neuropathy subtypes suggests that PHOMS in AION may reflect axoplasmic disturbance related to the ischemic insult itself rather than the underlying disease etiology, although confirmation in larger, prospective studies is warranted.