Paracentral Acute Middle Maculopathy in IRVAN Syndrome: A Case Report Highlighting Vascular Mechanisms

To describe a rare case of paracentral acute middle maculopathy (PAMM) in a patient with idiopathic retinal vasculitis, aneurysms, and neuroretinitis (IRVAN) syndrome, highlighting potential vascular mechanisms underlying this association.

Observational Case report.

An 18-year-old male previously diagnosed with bilateral IRVAN syndrome presented with a sudden paracentral scotoma in the left eye. Multimodal imaging showed multiple macroaneurysms, retinal hemorrhages, focal arteriolar vasculitis, and lipid exudation in both eyes. Swept-source optical coherence tomography (SS-OCT) of the left eye revealed a hyperreflective band in the inner nuclear layer in the paracentral temporal superior macular area, consistent with PAMM, without clear evidence of arterial compression. A conservative approach was chosen, and after three years of follow-up, retinal features and visual acuity remained stable.

PAMM may manifest in IRVAN independent of detectable localized aneurysm compression of the deep capillary plexus. The findings underscore the importance of multimodal imaging and long-term monitoring to assess ischemic complications. Further investigations are warranted to clarify the pathophysiological relationship between these conditions.