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

Purpose: 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.

Methods: Observational Case report.

Results: 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.

Conclusion: 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.