Peripapillary Hyperreflective Ovoid Mass-like Structures (PHOMS) in Patients with Acute Leber’s Hereditary Optic Neuropathy

Abstract

Purpose : Peripapillary hyperreflective ovoid mass-like structures (PHOMS) represent an optical coherence tomography (OCT) finding that has been characterized in different disorders, including papilledema, tilted disc syndrome, optic disc drusen, and other forms of pseudopapilledema. Leber’s Hereditary Optic Neuropathy (LHON) is a mitochondrial disorder typically characterized by pseudopapilledema in the acute stage of the disease that eventually evolve to optic nerve atrophy in the chronic stage. The aim of this study was to investigate the prevalence of PHOMS in patients affected by LHON in the acute stage.

Methods : In this IRB-approved retrospective analysis, we collected data from 20 eyes with acute LHON from 14 patients who had structural OCT obtained using a DRI OCT Triton (Topcon Corporation, Tokyo, Japan) device. To be included, patients were required to be in the acute stage of LHON, with visual loss having occurred less than 6 months prior to enrollment, as determined by the neuro-ophthalmologist. Exclusion criteria were the presence of any retinal pathology and/or optic nerve disease other than LHON. The structural OCT image of each included eye was reviewed by two graders, to identify subretinal hyperreflective lesions in the peripapillary region. Each reader performed this grading separately. Graders later met to compare level of agreement, and disagreements were resolved by further discussion and open adjudication to yield a single assessment for each case.

Results : Our analysis included 14 patients (20 eyes; mean±SD age was 24.5±12.9 years) with acute LHON. Among these included eyes, OCT displayed PHOMS in 12 eyes from 9 patients with a prevalence rate of 60.0%. At baseline, the average peripapillary retinal nerve fiber layer (RNFL) thickness was 98.7±31.2 μm. The average peripapillary RNFL thickness was significantly higher in eyes with vs. eyes without PHOMS (p=0.031). In all cases with PHOMS, these alterations resolved during the chronic stage of the disease.

Conclusions : In the present study we observed that LHON eyes may be characterized by presence of PHOMS and that these alterations mainly characterize the acute stage of the disease. Notably, results of the present study demonstrated a significant relationship between amount of peripapillary RNFL swelling and presence of PHOMS in acute LHON.

This abstract was presented at the 2023 ARVO Annual Meeting, held in New Orleans, LA, April 23-27, 2023.