Acute macular neuroretinopathy secondary to central retinal artery occlusion

Purpose: Acute Macular Neuroretinopathy (AMN) may be the result of deep retinal capillary plexus (DCP) impairment, but its mechanism remains elusive. A recent study has described simultaneous onset of Paracentral Acute Middle Maculopathy (PAMM) and AMN, suggesting a related pathogenic pathway. In this report, we analyze and describe the imaging characteristics of patients with concomitant Central Retinal Artery Occlusion (CRAO) and AMN and suggest a mechanistic pathway to explain this relationship.

Observations: A total of 2 cases of CRAO, arteritic and non arteritic, were included in this report. At initial presentation, outer retinal layers were intact. At the two-week follow-up visit, both cases displayed Henle fiber layer hyperreflectivity and ellipsoid zone disruption consistent with AMN.

Conclusions: Secondary development of AMN in CRAO is a new finding. DCP ischemia secondary to CRAO may lead to Henle fiber layer disruption, leading to the characteristic findings of AMN.

Keywords: AMN; AMN secondary to CRAO; AMN, Acute Macular Neuroretinopathy; APMPPE, Acute Posterior Multifocal Placoid Pigment Epitheliopathy; ASHH; ASHH, Angular Sign of HFL Hyperreflectivity; CRAO; CRAO, Central Retinal Artery Occlusion; CRVO, Central Retinal Vein Occlusion; DCP, Deep Capillary Plexus; EZ, Ellipsoid Zone; FA, Fluorescein Angiogram; HFL, Henle Fiber Layer; INL, Inner Nuclear Layer; IZ, Interdigitation Zone; OCT, Optical Coherence Tomography; OD, Oculus Dexter; ONL, Outer Nuclear Layer; OPL, Outer Plexiform Layer; OS, Oculus Sinister; PAMM; PAMM, Paracentral Acute Middle Maculopathy; SD, Spectral Domain.